Monday, February 28, 2005

156 comments:
THE SNOW'S THERE, YOU JUST CAN'T SEE IT
New update in progress, check back by 8:45 AM

WHERE WE GO FROM HERE AND WHY
10:30 pm Sunday update, Thank you for being patient. These things take time.

I am working on the FINAL WORD of your snowfall totals and storm track information. Please understand that sometime I am at the mercy of the loading speed of my home network. Sometimes blogger zips it right along, other times it crawls for reasons I do not know. So if it appears to be taking a while, I am not lounging on the coach watching Seinfeld or the Oscars. I am working on the update and will post it in pieces as it becomes available.

We are going to put to rest this business Paul Kocin on the Weather Channel has been saying about the computer models contradicting each other...because sometimes you just have to go out there with your decision, and STICK TO YOUR GUNS. The only uncertainty that exists is in his mind. The public is now certain this will be a major event...I got reports from my friends in suburban Philly that a a large grocery store called "GIANT" (you all know Giant, right)...was OUT of BREAD and MILK. Totally OUT. Then I was walking down a residential parking lot at some condos, and I noticed many cars with their windshield wipers straight up in the air. That was weird to see. Even weirder will be when millions of people in many hundreds of cities are going to wake up Monday morning and say, "WHOA! Where did this come from? Hey honey, there's no school and we have a foot of snow in the forecast."

THE WHY OF THE FORECAST: I am confident of these numbers for a few simple reasons. The New York Times reported earlier today that meteorologists from HPC stated that initialization data for the North American Mesoscale Model (the NAM) was incorrect and thus the reason why the model has been trending so far west. I learned this from a statement made by Elliot Abrams at Accuweather, who reported the news story this evening. So what we have here is many many forecasters hedging their data and their predictions because they are hinging everything on the NAM because it has peformed so well this year. What they (and Paul Kocin) may not know at this late hour is that the DATA FOR THE NAM WAS CORRUPTED, AND HENCE THE CORRUPTED FORECAST FOR A WESTWARD TRACK. So yeah, the GFS may have scored big time with this storm, but the losers are the public as they have been getting bad information all day long. You notice this because someone earlier today in our comments link said "Wow, the forecast went from rain to a foot of snow in 12 hours!"

My other reasons are outlined on the Observation Map posted above. I think this storm is going to surprise, delight and stress us out in more ways than we can know right now. The major cities could still get 1 - 2 feet of snow out of this, and interior sections from Virginia to Maine could also see that much for different reasons. Overnight tonight, some weird things are going to start happening, and some areas might wake up to a Blizzard Watch with 12 -20" in their forecast. I will hunt down and find that article and post it for you here.


TIMING : This will be a heavy wet snow for all locations, so downed power lines and outages are likely along with strong winds blowing and drifting the snow around. Time of arrival will be, as Eric Clapton would say "After Midnight" from Washington to Baltimore, by sunrise in Philadelphia and Pittsburgh, by noontime in New York, by sunset in Boston.

SNOWFALL: These are my "mostly final" ranges, from which I will extract and post the storm grade amounts.

NORTH CAROLINA...1 - 3 INCHES IN THE RESEARCH TRIANGLE, 2 - 3 INCHES FROM DURHAM AND ASHEBORO WEST TO WINSTON SALEM. 4 - 6 HEADING INTO THE MOUNTAIN AREAS WEST OF WINSTON-SALEM.

VIRGINIA....10 - 15 INCHES IN SOUTHWEST TO CENTRAL VA...including Roanoke, Front Royal, Charlottesville. 5 - 8 INCHES FOR THE WASHINGTON AREA. 2 - 4 INCHES FOR RICHMOND, 1 - 3 ALONG TIDEWATER AREA AS STORM MOVES AWAY TO THE NORTH.

MARYLAND/WEST VIRGINIA...8 - 12 INCHES THROUGHOUT CENTRAL MD, including the Baltimore Metro region from Annapolis to Aberdeen, west to Frederick, southeast to Rockville. 12 - 18 INCHES IN NORTHEAST MARYLAND / DELAWARE including Elkton, Wilmington. 10 - 15 INCHES IN MOUNTAINS OF WESTERN MARYLAND, VIRGINIA, WEST VIRGINIA, including the cities of Martinsburg, Cumberland, Hagerstown, Elkins.

PENNSYLVANIA... 12 - 18 INCHES FROM PHILADELPHIA N AND W INTO THE SUBURBS, including the counties of Chester, Delaware, Bucks, Montgomery. 5 - 10 INCHES IN CENTRAL/SOUTH-CENTRAL AND SOUTHWEST PA, from Lancaster County west to Somerset County and northeast to Centre County. This includes the cities of Lancaster, York, Harrisburg, Breezewood, Somerset, Pittsburgh, Altoona, State College. 10 inches PLUS IN THE SW PA MOUNTAINS near the Seven Springs Ski Resort. 10 - 15 INCHES IN EAST CENTRAL PA INTO SE NEW YORK STATE..from Centre County east to Stroudsburg along I-80 and then into the NY/NJ/PA intersect.

NEW YORK CITY...8 - 14 INCHES. INTERIOR NEW ENGLAND...12 INCHES OR MORE.

BOSTON AND SURROUNDING AREAS...6 - 12 INCHES ACCOMPANIED BY STRONG WINDS AND COASTAL FLOODING late Monday into Tuesday. More details on specific city amounts Monday morning.


NORTHERN NEW ENGLAND / DOWNEAST MAINE I am looking at this area more closely for the possibility of either a hurricane-like rainstorm or a major blizzard, depending on track of low and speed of upper level system.

THE HOW OF THE FORECAST

1. Storm Grade Totals for certain locations, but not all, as representative amounts will come out first thing tomorrow morning after I see "Baltimore County Closed" on the bottom of my TV screen. I may revise my final numbers up or down an inch or two before settling on straight line call.

2. THREE SCENARIOS...ONE WILL COME TRUE:

A) DAY AFTER TOMORROW, PART 2. The most crippling snowstorm the Northeast has ever known since the post-WW II era. How? The high over NY State, which was not forecasted to be there AT ALL by now, gets squeezed between the west-southwest retrograding Labrador Low, and the northeastward moving Gulf Low. The result is that cold subpolar air is directed out into the Atlantic, swings back around, runs into the Low. This squeeze effect wrings every last drop of water out of the sky and we have 12 to 36 inches in the major cities, with higher amounts in land. School is shut down an entire week from DC to Boston.

OR

B) WAS NEVER MEANT TO BE. Our catacyclismic storm never happens because the low level dry slot of air working into the storm from Texas as seen on satellite is forceful enough to shunt the storm too far out in the Atlantic. We see a repeat of March 2001, where forecasts for 12-36 inches in major cities never materialized, and instead they got 2-3 inches. Extreme coastal areas get blasted with a blizzard, and students are back in school Tuesday asking, "where did the big storm go?"

OR

C) RAINY NIGHTS AHEAD. Our big snowstorm turns into a big rainstorm and The high pressure being squeezed by the Labrador low has the opposite effect, and directs warm moist air in from the Gulf Stream ahead of the storm. The combined effect of the ESE winds plus the high pressure inflow channels the storm back toward the coast, and snow changes to rain with a total washout in the major cities.

SO WHICH ONE? AND HOW DO YOU KNOW?

Obviously if you've been following this site, you know we've been leaning on Option A for weeks now. My proof is...

1. Negative NAO. Go look for yourself. It is unbelievably low, and argues for a massive crippling storm and super cold 10-20 degrees below normal. Think January temps in March and you've just about got the idea.

2. Negative SOI. When the Southern Oscillation Index of air pressure changes in the South Pacific between Tahiti and Darwin, Austrailia crashes in early winter.. history shows that there is a massive storm on the east coast in February or March. The SOI is usually around -1 to -5. Last month? -30. That is phenomenally low, and argues for a big storm.

3. Constipation. That's right, the atmosphere has major blockage, and is simply constipated. The solution to that problem on a human scale, is... well, you know. Do something about it. On an atmospheric scale, when the Azores High near Africa/Spain noses it's way into Greenland, the Icelandic Low is shifted very far west, this in turn sends the Labrador Low over by the East Coast. All this means the atmosphere is constipated. The normal flow odf air currents is totally off kilter, and the only way to fix it is with a big storm, the equivalent of an enema, right? The combination of these factors directs the Northern jet stream toward the Mid-Atlantic. In contrast, all those hurricanes in Florida stirred up the water off the coast, making it colder than normal. That in turn created a large stable high pressure system, which ends up directing the subtropical jet northward over time. Get these two pixies together, throw in cold Canadian air, and you've got yourself....

A BIG KAHUNA, WHICH WE'VE BEEN TALKING ABOUT FOR WEEKS NOW, AND HERE IT IS.

Previous post from this afternoon is below:

"I HAVE A BAD FEELING ABOUT THIS"
- Han Solo, as he approached enemy ships in Star Wars

WILL THIS PICTURE BELOW REPEAT ITSELF? Or will we be writing a new chapter in storm history as March roars in with the Mother of all Lions and a Big Kahuna strapped to her back.


9:55 PM - I am working on the current update and will post as soon as I can.

This photo was taken Sunday evening February 16, 2003 by the author, around 10 PM at Dundalk High School in Baltimore County, MD during the height of the 2003 Blizzard. While millions more are obviously impacted by storms than just the schools, many customers of this site are members of the school community.

It was the start of an incredible week that will live on the memories of many teachers, students and administrators for the significant ripple effect that storm had on the rest of the school year. Everyone up and down the East Coast had their plans altered in many ways as a result of this storm, spring break plans were canceled or changed, graduations moved, rescheduled, finals were affected, the school year extended. Summer work crews had one LESS week to prepare buildings for the 03-04 school year, it was a mess.

We might be looking at a repeat of that, or worse, a SURPASSING OF IT. I am working on as simplistic of an explanation as I can make it for what might turn out to be either:

A) The most crippling snowstorm the Northeast has ever known since the post-WW II era

OR

B) Scenario A plus the beginning of the worst 2 week period of winter we have seen since the post World War II era, replete with storm after storm to pretty much cancel spring right out of March altogether

OR

C) A big busted storm forecast this time that simply sets the stage for Scenario A to play itself out again in about 7-10 days.

I am very concerned we are going into a weather pattern that is going to make the disruptions of the February 2003 storm look like a holiday. So if you are a teacher, administrator, athletic director reading this... ask yourself: What adjustments to the schedule would need to be made if we (schools from DC to Boston) are out for an entire week starting tomorrow?

If you are a family with children reading this, ask yourself: Based on your experiences of the last blizzard, what small ot medium preparations should you make so this time around it is not so difficult or you are more ready for the storm. Note that I am not talking about buying milk and bread, we are beyond that now and into the realm of safety for your family.

Here's what the Foot Family will be doing if necessary come Monday morning:

- Marking the sump pump drain opening to our street with tall metal stakes in case there is heavy rain following the storm later in the month.

- Clearing gutters of leaves, debris. Our basement steps to the outside are covered so I dont't have to shovel 2 feet of heavy wet snow out of them, it took 2 hours last time.

- The snowblower is outside and covered. We have water frozen in bottles in the freezer in the event of power outages.

- Cell phones are fully charged, we also have a non-electric phone that will still work if there is no power.

- I know by now you think I am a little OCD over this, but believe me, I was too busy being excited about the last blizzard that I did not pay attention to the real needs of the home. Thus the whole week was spent playing catchup and fixup of the problems I could have prevented.

OK, you're not really concerned about work or home preparations, you just want to know how much snow? Well if you've been watching anything relating to weather the past 2 days, you know that every weather media outlet has been either been hedging all day long, or starting to lean towards the unfathomable...a crippling snowstorm in the I-95 major cities as well as most interior sections of all the Northeast states from North Carolina northward to Maine. The concern for this is evidenced by the National Weather Service having posted Winter Storm Watches from NC to Maine.

HOW MUCH SNOW?

I know you're going to scoff at this, but 12 to 36 inches is not impossible in the major cities if you consider how will have I arrived at that figure. It seems totally unrealistic but I have a scientific basis for both how that could occur AND how it could all bust and school is open for business Monday as usual. I will post those two scenarios for you before 5 PM. Then I am out for a few hours and will be able to answer your comments around 9:30 PM. I remind you this is my worst case outline, and NOT my FINAL WORD. That will have to wait until early tomorrow morning or late tonight. My EARLY WORD is at least 5 inches in the I-95 corridor, at least 8 inches north and west of the cities, but those numbers are going to change. Please don't holler and scream asking "HOW DID YOU COME UP WITH THOSE NUMBERS?" because I will explain it to you. It is scribbled on a piece of paper right now, but it will take time to transfer into coherent thought and words on the screen with pretty graphics to boot.

SCHOOL? No changes to the ideas posted in the previous post. I will present both options...(SNOWSTORM, NO STORM) but I think no school Monday is a done deal.

HOW MUCH SNOW AGAIN? I already told you, 5" minimum in major cities, could be up to 1-3 feet in worst case scenario. Don't go bonkers, just be prudent and prepared for it, so you can enjoy it.

HOW BAD WILL IT GET? Could be very strong winds, downing trees and power lines with the heavy snow on it, coastal and tidal flooding, beach erosion, reduced to limited visibility, etc. Basically what I forecasted about BIG KAHUNA 2, oh about a month ago. Check the archives back to January 31. OK, so I missed on the dates by a couple weeks, but at least it is fun to consider that we knew the atmospheric pattern would end up delivering the ultimate storm.

And here it comes, ready or not. I notice the Baltimore NWS has just issued a 'HEAVY SNOW WARNING" Hmmm, wonder where that came from, must be a typo. Gotta go check that out, and continue with family preparations. Forgive me for the scarcasm, it seeps out from time to time. My back still hopes this does not come true, guess I better add Ben-Gay to the shopping list.

If you are already a consistent reader, then I will include your hometown in the snowfall forecast lineup. If you would like a forecast for your town, request this in the comments with the name of your town. The snowfall period will be from midnight Sunday to midnight Tuesday (early Wed AM).

Sunday, February 27, 2005

97 comments:
"LOOKS LIKE WE MADE IT..."
- Barry Manilow, from the album Ultimate Mantilow

WELL, LOOKEY WHAT WE HAVE HERE THIS SUNDAY MORNING...A MAJOR SNOWSTORM FOR THE I-95 CORRIDOR FROM WASHINGTON TO BOSTON AND THE INTERIOR SECTIONS OF MARYLAND, PENNSYLVANIA, NEW YORK AND NEW ENGLAND. NOW HOW DID THAT HAPPEN? What did I tell you? Did we all not say in the comments on Saturday that the drift east would eventually result in NWS having to admit that the snowier solution was staring them in the face? Did we not say that given all the computer models (except for one) trending off shore and farther east, that it would be impossible to ignore the fact that the bullseye was going to target I-95?

Don't you feel a bit of personal vindication at believing all along that the atmosphere would play out the way YOU envisioned, and not the way that the fancy computer models or the more simpler fruit cup forecast had. Mark my words... all the forecasters are going to change their tune today, from Accuweather to WeatherMatrix to WxRisk to anyone else I don't know of. In fairness to the business, Mr. Cosgrove of WeatherAmerica had this one pegged pretty well before Accuweather or NWS, in the sense that he was willing to admit what no one else had the guts to say... a potential blizzard for the east coast major cities. So here's the super early Sunday morning rough guide.

SNOWFALL : This will be a heavy wet snow for all locations, so downed power lines and outages are likely.

NORTH CAROLINA...4 TO 8 INCHES IN THE RESEARCH TRIANGLE, 10 INCHES OR MORE IN MOUNTAINS.

VIRGINIA...AROUND 10 INCHES IN CENTRAL/NORTHERN VA, 2-4 INCHES AROUND RICHMOND, 1-3 ALONG TIDEWATER AREA AS STORM MOVES AWAY TO THE NORTH.


MARYLAND...5 TO 10 INCHES OF HEAVY WET SNOW LIKELY THROUGHOUT CENTRAL MD. 10 - 15 INCHES IN MOUNTAINS OF WESTERN MARYLAND, VIRGINIA, WEST VIRGINIA, NC.

PENNSYLVANIA... 5-10 INCHES FROM PHILADELPHIA N AND W INTO THE SUBURBS. 4-8 INCHES IN CENTRAL AND SOUTHWEST PA, HIGHER AMOUNTS IN THE SW PA MOUNTAINS. 10-15 INCHES IN EAST CENTRAL PA INTO SE NEW YORK STATE.

NEW YORK CITY...3 TO 5 INCHES. INTERIOR NEW ENGLAND 12 INCHES OR MORE

BOSTON AND SURROUNDING AREAS...6 TO 12 INCHES AND MUCH MORE POSSIBLE.

NORTHERN NEW ENGLAND / DOWNEAST MAINE MAY RECEIVE UP TO 2 FEET.

These are preliminary numbers which I will refine tonight with actual storm grade amounts based on the QPF and snow ratios, which are expected to be low, perhaps around 8:1 or even 6:1 in the big cities.

SCHOOL: FUGGETABOUTIT. All Central/Northern Maryland Schools, All Central Western/Northern Virginia Schools, All Central/Southeast/East Central Pennsylvania Schools.....CLOSED AT LEAST MONDAY, AND VERY POSSIBLY INTO TUESDAY. WEDNESDAY...2 HOUR DELAY.

AND NOW... FAMOUS LAST WORDS

"SORRY SNOW FANS IN THE I-95 CITIES of the NE.... NEXT EVENT WILL BE SNOW to RAIN ON THE COAST-- SNOW INLAND & OVER APPALACHIAN MTS" - from DT on Weather Risk

"NO BIG SNOWSTORM FOR THE MAJOR CITIES..." Henry Margusity, Accuweather (paraphrasing the intent of his forecast... such as 1 to 3 inches for Baltimore, then over to rain)

WE SHALL SEE, WE SHALL SEE INDEED. With my more detailed update later today, I will post an analysis of the two opposing scenario...how the forecast could bust AND how it could become a historical event.


WHAT YOU SEE DEPENDS
ON HOW YOU PERCEIVE IT



Yes I know the headline above says "Sunday" I am trying to fix that as the problem has been whenever a new post comes on for a current day, comments from that day are deleted. Until that is corrected, the posts will be a day ahead. But consider it a glimpse into the future, you'll know what's going to happen with the weather a full day before anyone else.

For a Saturday morning, I thought you would enjoy a few illusions as we head into this next Winter Storm situation. I think the computer models, and the forecasters who interpret them, are having some illusions of their own. I will explain in Analysis Part 2 of the storm ahead. from 10:15 AM until about 5:00 PM, I will be out with family, so continue to post your questions and comments, but don't expect a reply until around dinner time. But first...

JUST THE WEATHER FOR THIS WEEK
graphics from Accuweather.com




SUNDAY: Very cold to start throughout the Northeast with morning lows in the 20's from Baltimore on south, in the upper teens around Philly, and mid to lower teens into single digits from NYC north. Clouds on the increase later in the day as storms approach from the west and south. Temps warming into the mid 30's, except for DC, which will creep towards 40.

MONDAY: (I-95 CORRIDOR ONLY) Overnight Sunday is when the problems begin. Precip will move in from southwest to northeast, starting in all locations as snow, sleet and freezing rain. In the southern cities of the I-95 corridor (Richmond, DC, Baltimore) a changeover to rain may not occur until the latter half of the rush hour, so expect very slippery and treacherous conditions, as road surfaces may be at or just below freezing. Philly north to NYC and interior sections of eastern PA and southeast NY will be spared the AM rush hour madness, but the real McKoy is coming later in the day.


Frozen precip SHOULD go over to all rain no later than noon. Rain becomes heavy in the major cities and inland, but near and west of I-81, precip will remain all snow. That is a different arrangement I will discuss in more detail in the next section. The drive home Monday should be free of frozen precip, but windy conditions will make for difficult driving. As the storm passes to the north, colder air rushes back in behind, turning any leftover rain to snow overnight into Tuesday. K2 goes on to hammer Pennsylvania, New York and New England.

TUESDAY: Windy and much colder with scattered snow showers along I-95, accumulating up to 3 inches. Interior PA, NY and New England will be hammered with at least 6-12" of snow and probably much more. At present I believe areas north and west of I-95 and I-90 will see the heaviest snow, except for Boston, which is likely to be just inside the heavy snow bands.
Overnight into Wednesday, stiff northwest winds will freeze over any daytime slush, making for another round of icy conditions.

WEDNESDAY: Continued windy and much colder with scattered flurries and snow showers continuing as K2 keeps hammering Northern New England and slowly lifts north into Canadian maritimes.

THURSDAY: Northwest flow continues with cloudy and cold conditions. Temperatures not rising above 40 from DC north.

FRIDAY: Some moderation in temperatures is likely, but still several degrees below normal. Upper air flow becomes more west-east, allowing Pacific air to inflitrate the Northeast.


K2 ANALYSIS PART 2....MONDAY


WHAT WE KNOW

UNCERTAINTY ABOUNDS: Computer models are all still in great disagreement over evolution of the Monday situation, but a few things are becoming clear. While there is high pressure nearby, it does not appear to be in the classic location for a big time major city snowstorm. That having been said, there is also the concern that the high pressure squeeze between the Great Lakes system and the Coastal system does a dipsy-doodle... instead of being pinched out to the west... it drops east in front of the approaching coastal Low. This strongly enhances the pressure gradient, which in turn could draw cold air into the storm, deepening it faster farther south (a solution the European model has alluded to). Hence the changeover to rain in the big cities is short-lived, or never happens at all. Here's a key sign of uncertainty.. when the Weather Channel puts up a graphic that says "Snow MAY change to rain in the major cities" That gives us reason to be concerned that something wicked this way comes.


DRIFTING EAST: All major models continue to DRIFT EAST with the storm's track. NWS has mostly discounted the NAM model with it's track up the western Appalachians. The other issue is the influence of the Great Lakes system, which if it were not there, would spell a massive snowstorm with no doubt. But that system complicates things. The current thinking which is keeping NWS offices away from raising the storm flag for the Northeast cities is... the upper level energy from this system arrives TOO LATE in the game to energize it for a major east coast snowstorm. Sounds like famous last words, does it not? Remember the Jan 22 storm, remember how Paul Kocin on the Weather Channel said that same scenario I just described was the reason the storm would not blow into a big coastal storm but a general 4-8" snowfall? Then just hours later he had to totally reverse course and say that the "unlikely" scenario was going to come true after all.

HISTORY REPEATING? We know this winter that in complex situations, the US models fairly much worse than the foreign models. Given the continued eastward drift of the models, is this a sign that a major coup is once again on the table for the Euro? The only difference this time appears to be the lack of the classic strong high in upstate NY. The NAM has been able to nail a few storms this year, but it is odd that is the only model acting as the outlier, with the GFS, European, UKMET and other programs all calling for a double-barrel coastal low. I think it is likely you will see the NAM suddenly shift east in line with the other computers, and then forecasters will come out guns blazing with their definitive calls.

WHAT WE DON'T KNOW

ACCUMULATIONS: While not know for sure at this point, I can make some general statements for interior PA, NY and central/northern New England. These are preliminary calls and will be adjusted at least twice, once later tonight, again Sunday morning, and then the final numbers Sunday night. 12 inches of snow or more is very likely from anywhere west of I-81, as well as north and west of I-90. This would include our readers in Altoona, State College, Binghampton, Woburn, Boston. This is likely to be a heavy, wet snow, hard to shovel... so make plans to do several rounds of shoveling to keep you out of the chiropractor's office.

Along the coast, the current thinking is a mix of snow, sleet, freezing rain changing over to rain but accumulating possibly 1-2 inches before the changeover.

SCHOOL: DC, Northern Virginia, West Virginia and Baltimore area schools will have the toughest time figuring out how to call this one. Onset of precip will begin in the early morning hours of Monday, and with a cold ground and roads at or below freezing, snow, sleet and freezing rain is very likely to cause delays with the morning rush. It would seem prudent to start with a 2-hour delay, depending on temperatures. As always the timing is critical. A later start to the precip would seem to make for schools closed, except that it could change to rain sooner due to daytime heating from sun.

For those wishing for a 5 day weekend, an earlier start time would be ideal because the precip can take advantage of overnight cooling, thus hamper the changeover to rain until it is clear than a 2-hour delay would not be effective. If a delay is called at 5:30, the decision to change it over to closed has to be made really no later than 7:00 AM, because by then buses are rolling to pickup high school students. If we still observe sleet and freezing rain by that time, schools will have to close even though most precip SHOULD go over to rain by 10 AM or so. Tuesday? That is still too much up in the air as it depends on how much cold air gets in behind the storm to refreeze any standing water overnight, certainly possible but not a lock yet.

STRENGTH OF THE COLD: The final factor to impact the outcome of this entire situation will be the strength of the cold in the East on Sunday and Monday. While Saturday should be cool, Sunday is supposed to be colder due to radiational cooling and snowpack enhancing the cold. If the cold air gets trapped underneath advancing clouds on Sunday night, big cities would be looking at more of an icing event than snow. If overnight lows Saturday are not as cold, then the warmth on Sunday will get trapped under those same clouds, which prevent overnight temps into Monday from dropping as much. Thus a faster changeover to rain, or perhaps like last Sunday, we (DC Baltimore) start as mostly light sleet and then go over to rain.

THE NEXT UPDATE SOMETIME AFTER DINNER SATURDAY, NOT BEFORE 5:00 pm. The tell-tale sign to watch for between now and then is what the North American Mesoscale (NAM) decides to do. If it jumps to the coast, then look for a snowier solution to creep into your local forecasts. Remember I will be out from 10:15 AM to 5:00 PM, so I won't be able to respond to your comments during that time.

Saturday, February 26, 2005

113 comments:
SUNSHINE AND SNOWFLAKES
Friday afternoon 2/25 update: Reveling in a 4, or 5, or 6 day weekend

and now, the moment you've been waiting for....

K2...AS BIG AS THE MOUNTAIN IS TALL



This is an actual picture of the famed K2 mountain in Pakistan, the SECOND tallest mountain in the world. Will this upcoming series of storms translate into the second largest snowfall ever? Hard to tell, but not impossible. What we do know is that a very significant and possibly historic situation will be setting up over the eastern third of the country starting Sunday night and lasting into....a while, perhaps a week. A more detailed analysis is coming over the next 24 hours, but here is the rough guide for now:

1. A MAJOR WINTER STORM TO AFFECT MOST OF THE I-95 CORRIDOR AND INTERIOR MID-ATLANTIC/NORTHEAST WITH HEAVY SNOW, HEAVY RAIN, STRONG WINDS AND COASTAL FLOODING from Sunday night to Tuesday.

2. NAO LOST IN A BLACK HOLE MEANS SOUTHEAST REORGANIZATION OF THE POLAR VORTEX over Ohio and Pennsylvania for the period Tuesday-Friday. This will result in intensely cold air of 10-20 degrees below normal for most of the Northeast from South Carolina up the coast.

3. BIG KAHUNA 3 MIGHT BE THE ULTIMATE GRAND FINALE OF THE WINTER WITH ANOTHER SIGNIFICANT SNOWFALL for the major east coast cities from Richmond, VA to Portland, ME in the Friday-Monday period of late next week.

K2 ANALYSIS PART 1...SUNDAY NIGHT
I will post a series of maps to show the differences between the major models battling it out for supremacy over the life cycle of this storm. My comparison is between NOAA's GFS and the European Center for Medium Range Weather Forecasts.. the ECMWF or the European. Please feel free to post your questions and reactions to this analysis. There will be two more parts in the next 12 hours... Part 2 is the Monday analysis, Part 3 is the Tuesday analysis.


LIKELY TO HAPPEN

- A large storm will move up and/or along the Eastern Seaboard from the Gulf Coast. Precipitation is likely to start in areas from North Carolina on northward as snow on Sunday night or Monday morning.


- Every meteorologist on the East Coast, real or imagined, will find it hard to pick one solution or the other given the implications of a forecast for heavy rain that turns out as snow, or vice versa. Weather outlets will hedge and alter their forecast and timing of the storm's onset until the moment it begins.

- A second system moving in from the Great Lakes will meet up with the primary Gulf Low, and energize it significantly, which is when the snowstorm/blizzard aspect of the event will get underway. Snowfall in the area where that occurs will likely be in excess of 12 inches and some locations will exceed 2 feet.

NOT LIKELY TO HAPPEN

- Predictions for 1-2 feet of snow in the major I-95 cities are not likely to be issued until the event is underway, such as was the case with the February 2003 Blizzard. I am not saying this much snow is going to fall, I am saying that enough moisture will be present in the atmosphere, that given the right conditions and timing, this much snow is THEORETICAL in the major cities.

- Computer models all resolving on one clear-cut solution early on, such as 24 hours before the event. Already major differences exists as depicted in the graphics above, with the GFS having mostly a rainstorm along I-95 and heavy snow in the interior, whereas the European would be a repeat of the January 1996 or 2005 storm.

- School closing on Monday, as the forecast for that day will vary wildly from one agency to another, making the public very uneasy and confused about the evolution of the storm in general.

BEFORE I POST THE NEXT UPDATE, CAN YOU PICK OUT THE SUBTLE OR GLARING DIFFERENCES IN THE GRAPHICS ABOVE? What is your reaction to this given the track record of the GFS and European on storms this winter? I look forward to your responses as we inject a little politics into the forecast.

Friday, February 25, 2005

103 comments:
LOOKING LIKE A 4-DAY WEEKEND FOR SOME...
PERHAPS A 6-DAY WEEKEND FOR OTHERS?

9:45 PM Thursday update

The faculty parking lot at Dundalk High School in Baltimore County was empty on Thursday, will there be an encore on Friday? Reports are coming in that area schools are beginning to call the whole thing off. Snow is still falling, quite heavily in some areas, and our storm has (surprise, surprise) moved farther north than anyone or any computer model even alluded to. Now getting into the game are New York state, southern/southeastern New England and perhaps even New Hampshire and Maine. Thank you to everyone who posted observations today, it was fun to read. Although the calendar is waning, there is lots more winter in the pipeline, which will be the subject of a major post on Friday (pending outcome of school). I personally think the low temps, the refreezing and the redevelopment of snow will hamper the ability of school and road crews to prevent the ice from affecting travel Friday morning, so the call is... FOUR DAY WEEKEND FOR MOST MARYLAND SCHOOLS, AS WELL AS THOSE WHO CLOSED THURSDAY IN SOUTHEAST PA, NEW JERSEY.



"JUST WHEN I THOUGHT OUR CHANCE HAD PASSED,
YOU GO AND SAVE THE BEST FOR LAST."
-Vanessa Williams, from 'Save the best for last'


10:05 AM Thursday update

WELL, IT IS FINALLY HERE. A REAL SNOWSTORM FOR THE DC / BALTIMORE I-95 CORRIDOR. We've been waiting 2 months and 3 days for this, so it is nice that Mother Nature saved the best for last. It's not a smackdown kind of snow, but we'll take 4-8 inches anytime.

Snowfall forecasts are in the previous post. Please continue to post your observations on snow or no throughout the day, especially if you are a "storm grade location" Also want to send out a special thanks to Matt, a loyal reader in somewhereville who helped me with the formatting to get the comments link reorganized in the date header.

Yes, I know that the date at the top says Friday. Only way I can preserve the comments is to move the post date ahead. Or maybe that's an omen that we'll be doing this same thing on Friday, sleeping in, blogging, watching the snow, talking about K2. If you have to be out working today in the snow, enjoy and be careful. We are going out to do a few things and I'll be back with a midday update and a discussion about K2, and/or K3.

The picture? That is the back porch of our daughter's Godmother... we call her Mumsy. She lives right next door and her flag looks much nicer than my porch, which is why I used it. If this forecast verifies for Dundalk, MD... I will post a picture of my daughter and I to celebrate our first real snow together.

Thursday, February 24, 2005

22 comments:
"IT'S EITHER THIS OR THAT WAY, IT'S ONE WAY OR THE OTHER.
IT SHOULD BE ONE DIRECTION, IT COULD BE ON REFLECTION."
- Enya, in "Anywhere Is" from the album Memory of Trees

THERE IS SO MUCH TO SAY AND SO LITTLE TIME TO SAY IT. As with so many other storms, it's either this way or that way, one way or the other. I have chosen the slightly higher way, with a tad bit more snow than is forecasted, due to enhanced snow ratios from evaporative cooling, more wrap-around than expected, and and earlier start time than expected. Since we now have a FULL SNOW DAY for Baltimore County Schools (thank you very much), Later on, I will update my totals below slightly and add in the QPF rationale for these. Then sometime today will be a brief discussion of KAHUNA 2. Can't wait to show you the graphics I have prepared for this. Winter ain't done by a long shot.

THE BOTTOM LINE ? WE HAVE AN I-95 SPECIAL

SNOWFALL ACCUMULATIONS FOR THE PERIOD 5 AM 2/24 TO 5 PM 2/25: Revised as of 8AM Thursday.

NORTH CAROLINA: Sorry folks, light snow in mountains only.

VIRGINIA: Roanoke...3 / Hayes...1.5 / Richmond...2 / Loudon County...5.5

WASHINGTON, DC...6 / WEST VIRGINIA: Harper's Ferry...4

MARYLAND: Odenton...6 / Baltimore...5 / Dundalk...5 / Myersville...4.5

Towson...4 / Hereford...4.5 / Aberdeen...6 / Bel Air...5

PENNSYLVANIA: Pittsburgh...3 / Altoona...2.5 / State College....2 / Bucks County...6

York...6 / Paoli-Frazer-Exton...5 / Philadelphia....5 / NEW JERSEY: Rutgers U...6

NEW YORK: Binghampton...1 / NYC...4.5 / MASSACHUSETTS: Boston...4.5 / Woburn...4

I will revise this with an explanation of how I arrived at these numbers, as well as a storm overview Thursday later morning, after I get some more SLEEP. As of 5:05 AM, Flurries had begun in Dundalk.

8:00AM revision as it seems storm is now on a fairly consistent northeast track but is also moving a tad bit faster out to sea, snowfall amounts are being trimmed back a bit so that the numbers forecasted are on the high end but will fall within a margin of a passing grade (C or better, I don't consider D passing)

AND NOW... FOR THE BURNING QUESTION OF THE DAY...SCHOOL?

FUGGETABOUTIT. No School in Baltimore / DC Metro areas for THURSDAY and possibly even FRIDAY. Yes you read that correctly, the first 4 day snow weekend since December 2002. Why am I so confident? In Baltimore County, MD On December 4 of that year, we had a 7 inch snowfall occur on a Wednesday night-Thursday morning. It ended by late Thursday afternoon. But there was no school Thursday or Friday because it simply takes too long to clear 7 inches from the bus lots and school parking lots. So that is the key. 5 inches = school on Friday, 6 inches = 2 hour delay Friday. 7 or more inches = FOUR DAY WEEKEND!

And then lurking at the end of your local forecast is...............Kahuna 2

The next update around Lunch today, along with snow pictures from Dundalk, MD.

Wednesday, February 23, 2005

106 comments:
"SO YOU'RE SAYING THERE'S A CHANCE?"
-Jim Carrey from 'Dumb and Dumber'
or:
"I SAY IT HERE, IT COMES OUT THERE"
Albert Brooks, in the 1987 Movie Broadcast News

WEDNESDAY EVENING UPDATE: Taking care of some important family items, like fixing the car seat which is one of a few things that takes priority over the weather. It is taking longer than I anticipated, so will get back to you with updated snowfall amounts by 10PM. Keep an eye on radar, as that and not models, will reveal true colors of storm.

SCHOOL: No School Thursday or Friday for most of central Maryland, northern Virginia, and south central PA. Many other school will not take the storm seriously, and be caught with an early dismissal that will make life very hectic for a few hours Thursday afternoon/evening. No School Friday for many PA, NJ, NY, New England Schools. NWS forecasting onset of snow now sometime after 4AM in Dundalk, MD, up from a 10AM-12 Noon. I think many Baltimore Metro districts will see the handwriting on the wall and close instead of risking a messy delay-early dismissal situation. Or perhaps they will start with a two-hour delay and then give it up once the radar becomes more ominous with time. Districts farther north and east will see the situation developing on Thursday and realize Friday is a wash.

TRAVEL: BIG MESS COMING ALL DAY THURSDAY. NWS HAS MOVED UP START TIME OF SNOW TO EARLY THURSDAY MORNING. That means a tough travel day, with problems increasing throughout the day. Hence the reason why I think many schools will close outright Thursday morning. Many airport delays from DC north to Boston.

ACCUMULATIONS: Large complex storm with many precip factors, but here is the skinny for now.

Maryland... my earlier 6-12" guesstimate was not too far off as NOAA/HPC Heavy Snow Discussions call for at least 6-8" in DC/Baltimore Metro with local amounts even higher. Will do a statewide overview of amounts for specific locations. Leaning on 7" for Dundalk, 8" for DC, 10" for Hereford Area. Less on Eastern Shore and in western mountains.

Virginia/West Virginia...Tough call as many factors influencing precip type, timing, temps, etc. Complicated arrangement with downsloping, cold air damming, warm air advection from SE and overrunning upper level precip over cold dome. Basically a mixed bag with snow and sleet holding down accumulations to less than 6" overall.

Pennsylvania...Bullseye might be central and southern PA, and SE PA, where 534 dm thickness line is over area of upward motion due to mountains, which wrings out lots of snow and raises ratios to perhaps 25:1. 12 inches not out of the question, but in the 8-12" range overall.


New Jersey/New York/New England: You wanna come and play too? I think throwback and NAO perhaps trending back a touch may allow for more snow in all areas than originally forecasted. 8-12" for SE Coastal New England not unreasonable. I-95 NY to Boston I am leaning closer to a 4-8" but seems low given northern trend, and it that keeps going, could be an overall DC-Boston I-95 special. Right now 6-12" from Mass Pike south and southwest seems acceptable given QPF trends and higher ratios given colder air. Also don't overall ocean effect throwback which always seems to add another 1-3" on top of storm totals.

It appears the northwest drift has begun and our storm is getting more and more likely with each passing hour. So for fun, just sing to the tune of that song: "Do you see what I see? A coastal storm trending north with time." Do I see Winter Storm Watches ? Hmmm, where did they come from for a storm that was supposed to stay south of DC? I say it here and it comes out there... you watch and see what happens. By 9PM Thursday, Winter Storm Warnings will be posted for much of central Maryland, Virginia, south central PA, and Watches will go up for Southeastern PA. Watches will extend north above I-90 as well as encompass NYC by daybreak. Even Andy in York County will dust off his storm flag and check the gas in snowblower. You watch and see. Make sure you have 32:1 mix in that thing. Mine is ready to haul.

INFORMATION BELOW IS FROM 6:40 am POST. READ FOR COMPARISON TO WHAT IS NOW FORECASTED.

Lots of model madness and forecaster frustration with the upcoming mini Kahuna. I ask you this... if all our previous storms this winter (except for the SE Virginia surprise on Dec 26) went much farther north than originally forecasted, why should this one be any different? Why would the NWS put out all these Special Weather Statements if this storm is supposed to stay south of DC? And WHY oh why would every other model show a considerable snowstorm in the DC corridor, with some making it to Baltimore, while the GFS is heading OTL (out to lunch?). Yes there are still reasons to be skeptical, but I think this storm will show it's true colors very soon, and those colors are those of the Ravens and Redskins, perhaps even the Eagles. Let me go out on a limb and say that the heavy snow band is going to eventually fall about 75-100 miles farther north than where it is forecasted... so that means Richmond to Washington and not lower central Virginia.

"DO YOU SEE WHAT I SEE...?"
SAID THE SHEPHERD BOY TO THE MIGHTY KING
(Wednesday evening model maps, for comparison)


WHAT'S THE BOTTOM LINE WITH THIS STORM ?

SCHOOL: VERY STRONG POSSIBILITY OF NO SCHOOL BOTH THURSDAY AND/OR FRIDAY FOR MOST OF VIRGINIA and DC METRO AREAS. Baltimore Metro to see early dismissal Thu and possible no school Friday. I may take the unusual stance today of issuing a "Happy Friday" alert to my students depending on what I see the liquid equivalents doing by mid day. At the bare minimum these areas will get an early dismissal Thursday and 2 hour delay Friday for those districts that really want to squeeze the calendar. The next likely situation I see is an early dismissal Thursday, and no school Friday. Teachers: turn in your interim reports ON TIME and take extra work home, or get it done now so you don't have to. Students: Take home your A and B day binders to be prepared.

TRAVEL: WITH TEMPERATURES TRENDING DOWN QUICKLY, TRAVEL WILL BE POOR SOON AFTER SNOW BEGINS BECAUSE IT WILL STICK TO ROADS AND CREATE SLIPPERY CONDITIONS.

SNOWFALL: PRELIMINARY CALL BELOW WILL BE REVISED TONIGHT WITH STORM GRADE AMOUNTS, AND OVERALL RANGES.

MARYLAND: Overall preliminary is 4 to 8 inches. For example, in the Dundalk area, I am leaning on 5" but may have to raise that. The trend will be more snow the farther south you live, so 6-8 inches across southern and central Maryland, 4-6 inches in Baltimore Metro, 2-4 near PA border. I have a feeling these numbers will have to be revised upward, as our storm is taking a similar track to the Feb 2003 Blizzard. I will revise these numbers tonight

PENNSYLVANIA: Any accumulating snowfall will be south of I-80. Southeast and southcentral PA I expect to see no more than 3 inches.

VIRGINIA: Heaviest snow to setup in a band from Richmond to Washington, where amounts will range 6-10 inches.

WEST VIRGINIA: Panhandle area 3-6 inches, western mountains 1-3 inches as you are on western fringe, just like you were in the 2003 storm and it's a darn good thing you didn't get that 30-40 inches of snow, huh?

NORTH CAROLINA: A maximum of 6 inches in interior mountain areas, with 2-4" in the Research triangle area. Again these are preliminary numbers which will be revised tonight

ANALYSIS...Please check back around 5:00 PM for late afternoon update, followed by storm grade amounts at 8:00 PM.

Tuesday, February 22, 2005

34 comments:
"AND GIVE ME SOMETHING TO BELIEVE IN..."
-Poison, from the Album 'Flesh & Blood'


FIRST, JUST THE WEATHER

TUESDAY: Continued snowy in northern New England, clearing and cool to mild for rest of Northeast and Mid-Atlantic.

WEDNESDAY: Warm to start, then colder by nightfall as a front sweeps east. Some scattered snow showers with this front producing a coating of snow.

THURSDAY: Fun begins as Gulf Coast Low moves to a position near Cape Hatteras. Much colder air in place over all of the Northeast means a chance of snow late in the day from the Carolinas on north over night.

FRIDAY: Is a surprise snowstorm in the offing? Only time will tell, but at least you know it is possible, or that you are possibly going to be disappointed yet again.


Just when you thought that winter had exhaled it's last, there might be something to believe in for later this week. A tell tale sign that something interesting will happen is when you notice all your Weather Channel and NWS forecasts are "Partly Cloudy" right through the week. I am not jumping on a Red, White or Blue Bandwagon just yet, as I want to be the proper scientist I am and see if I can make a case for either storm. Then I will sit back a day and read over that to see which one REALLY seems plausible. So no promises, just some investigation of the evidence first. I do notice as of Tuesday morning that Baltimore NWS now has chance of snow Wednesday through Friday when yesterday at this time it was Partly Cloudy.

It is odd to think that the model HPC and NWS offices leaned on a lot in the recent storm was the NAM, and now they are discounting it in favor of the GFS, which says Partly Cloudy. That was the forecast for New York City the day or two before their crippling blizzard of 1888. Oh wait, no I think it actually said, "Partly Cloudy, then rain later." 25 inches later....

EVIDENCE FOR A BIG STORM IN THE MID-ATLANTIC/ NORTHEAST

1. North Atlantic Oscillation is strongly negative (-3 deviations). It cannot stay that negative for long, much like a Category 5 hurricane cannot maintain that strength for long as the conditions creating it get broken down. What we will see as this week progresses is a retreating of the NAO from -3 to perhaps -1.5. That is going to allow computer models to begin trending north and northwest with the eventual track of the storm. The result will be that you observe your local forecasts...from the TV, TWC, NWS etc all will begin hinting more and more at a possible snowstorm late this week. Friends, this is the same setup that occured with the January 22 storm, which is why I was more confident with time of a New England blowout. This might also be why Mr. E.H. in Boston has his sixth sensors on alert, he senses the same signals we saw leading up to that storm. Remember the weather this season seems to behave opposite of the forecast.

2. Fresh cold air will be in place at the storm's arrival. This is due to a series of cold fronts which will cross the Mid-Atlantic and Northeast this week as depicted by the Accuweather graphics above. Unlike the setup this weekend, which was retreating cold air and we had more faith in that the air would stay and it just was not to be.


3. The atmosphere has a way of balancing things out over time. Like the old saying that "red Sky at morning, sailors' warning, red sky at night, sailors' delight." Only in a STRONG El Nino winter when water temps off Peruvian/Central American Pacific coast are 3 and 4 degrees above normal do you get a much-less-snowy winter in the Mid-Atlantic, as was the case in 1997-98 and 98-99. Everybody knows in their gut the I-95 corridor is due, and though time is quickly running out, "it has happened before, and will happen again, just a question of
when." Thank you Charleton for bringing that up again.


EVIDENCE AGAINST A BIG STORM IN THE MID ATLANTIC/NORTHEAST


1. Trends this winter do not favor big storms. Each storm this season has either gone way north and snowed only on New England, or it was briefly cold enough to deliver snow for everyone, but only a little bit. The pattern seems to continue producing under-performing snowstorms because the Mid-Latitude blocking signal is haphazard at best as evidenced by the NAO being mostly positive for the average period of the winter.

2. Sun angle is creeping higher these days. This induces more natural ground level warming, making it harder for snow to stick or requiring colder and colder air masses to keep the atmosphere cooler longer. Hard to do when you are in the last third of winter. There would have to be a real strong shot of cold Arctic air to hang around for 2-3 days prior to the storm's arrival.

3. Limited snowcover reduces effectiveness of Canadian highs. While the recent storm did refresh the northeast snowpack somewhat, it did nothing in the Mid-Atlantic. Not a good sign for a big snowstorm right out of the blue. Snow usually falls where it has already been falling, and that is in New England. You could say that means this storm would be heading for New England again, but a positively tilted upper level trough (the bands of color showing wind movement high up in the atmosphere are angled out into the ocean) would indicate our storm is going merrily out to sea instead of up the coast. Another consequence of weak High pressure.

SO WHEN WILL WE KNOW IF THIS STORM HAS ANY LEGS OR NOT ?
I foresee more model madness and forecasting fumbles this week. Everyone is going to play the waffle game as some models will trend north, others will not, and still others will show a giant storm. Looks like another Marty Bass Alert has to go out. The tell tale sign of what's going to begin playing out is the NAO. If it starts creeping toward neutral, that is a giveaway for a northern trend and then New England, look out. If it stays strongly negative, as is the Arctic Oscillation also, then I'd say it will stay south and leave us from Washington on north high and dry. Check back later tonight for an update on what awaits us late this week.

Monday, February 21, 2005

16 comments:
"PREPARE THE WORLD FOR BAD NEWS"
Harry Stamper, played by Bruce Willis in the movie 'Armaggedon'



Time to throw in the towel on the winter? I think we are getting to that point. There are a few notable examples of how a winter like ours went out with a blockbuster storm...1993 is the best and most recent case. Another classic storm was March 9, 1984, which dropped 9 inches at my home in suburban Philly. Before that you have to go back to March 1958, in which Philly only saw 3-4 inches, but the western suburbs where my grandparents lived it was 4 FEET! The all time greatest March storm was the Blizzard of 1888 in New York City and throughout the Northeast, which was the event that changed the way the government forecasted winter storms and prepared the public.

THE FINAL WORDS ON THIS CURRENT NO STORM ARE... 'DANG, WHACK." As the dang thing missed most of us again (except for Central, Northeastern PA, central NJ and Southeast New England), and many forecasts got whacked with embarrassment.

ROUNDUP OF STORM GRADE TOTALS
WEST VIRGINIA: All locations...E MARYLAND: All locations...E VIRGINIA: All locations...E
PENNSYLVANIA: Altoona...2.0/4.0 = 50 % E State College...4.0/5.0 =80% B
York, PA...0.0/5.0= 0% E Paoli...2.5/3.0 =83 % B Philadelphia...2.8/3.0=93% A
Bucks County...5.5/6.0=91 % A. Statewide Average: 2.33 = C+
NEW JERSEY...Forecast for Rutgers U next time NY CITY: (Central Park) 5.0/4.0=80 % B

MASSACHUSETTS: Read spotter reports of the area. Logan Airport...4.5/6.1 = 73 % C
Woburn...5.0/5.0 = 100% A Statewide Average: 3.50 = B+

WHY DID THIS HAPPEN? WHAT DO HURRICANES HAVE TO DO WITH IT? That's a more complicated answer which will take time to process and explain, but I can say this much right now. What happened in Florida last summer is headed for the Gulf Coast and Texas in particular this summer. I have sound evidence to back up my theory, which I will explain later. If you want a snippet of the hurricane season ahead of us, read Dr. William Gray's preliminary forecast for land-falling tropical cyclone activity on the East Coast.

Sunday, February 20, 2005

22 comments:


IS THIS A COUP, A BUST OR SOMEWHERE IN BETWEEN ?

LOOKS LIKE THE WEATHER AND THE FORECAST ARE ONCE AGAIN, MUTUALLY EXCLUSIVE OF EACH OTHER. This storm has confounded most meteorologists from the get go, it's trends have eluded detection by the computer models, it has successfully avoided being correctly forecasted by even the world's best weather service, Accuweather, who have had to revise their snowfall projections for this event at least 3 times now. With the NWS yanking Winter Storm Warnings, something that is embarrassing to do, I think we're all ready to throw in the towel and as Andy said, "Write this winter off altogether."

Radars indicate the storm has split into two parts. The bulk of frozen precip has progressed through PA, going into New York and New England later tonight. To the south of Maryland is a large area of rain. Both of these precip swaths are heading mostly east. In between them is this large twilight zone encompassing most of Maryland. The infamous, much scowled-upon "dry slot" has found a home. Perhaps the moisture got forced out trying to get over the mountains, and downsloping on the east side in central Maryland dried the air further. With dewpoints already 20 degrees or so away from temps, it is highly unlikely that anyone in Maryland will get much of anything, so those of you near Baltimore, forget the "1-3 inches of wet snow" idea on TWC. This will be a bust for Maryland, a coup for the GFS, and a touchdown for New England. Hmmm, that sounds familiar.

I'M MORE CONFUSED THAN DISAPPOINTED...THIS IS SUCH A BIZARRE STORM

Three items I indicated earlier made me think this was going to turn out weird.

First item is the NAO continuing it's strong negative trend Unusual for a storm to just totally go against the grain and head into northern New England on a neg NAO signal. The Jan 22 storm went north because NAO was beginning a slow trend back to neutral, allowing more northerly track with time. This is totally opposite of that situation, and yet it continues to head north.

Second item are the talk of a secondary Low. While I was expecting this, it now seems unlikely that will even happen. Seems to me the overall system is moving too quickly to the east, and there is too much west to east zonal flow for a secondary to develop anywhere.

Third item is that current observations show the Canadian high is now parked in the classic spot for a good Nor'easter...just over upstate New York. It is a secondary piece of the main High, but with a 1 millibar difference (1032 v. 1033) I'd say that's not really much. Another high off the DelMarVa would argue AGAINST coastal redevelopment in that same area, thus the further south idea for the secondary. Unless we are going to violate all laws of physics and have two different parcels of air occupying the same exact place at the same time. Isn't that the Heisenberg Uncertaintly Principle?

It would now seem that High is what the storm will tap for a good snow in central New York, Massachusetts and into Boston. I am going to revise/cancel some of my snowfall totals, as I doubt we will be seeing anything near what I advertised for certain areas, while others are probably going to be right on target.

CHANGES TO THE SNOWFALL AMOUNTS

Maryland/West Virginia: All forecasted amounts have been cancelled. Sleet indicates there will be virtually no snow at all, or any that does will be less than 1 inch. Storm Grade: E

Pennsylvania: Amounts for York lowered to 1 inches, Paoli 3 inches, Philadelphia 3 inches. Other amounts stay as forecasted.

New York: 4 inches in Central Park, up from 2 inches before. Binghampton: 4 inches

Massachusetts: All previous amounts remain. No changes will be made.

I may add a few new cities for fun given the new storm dynamics.

WHAT'S THIS ABOUT ANOTHER STORM LATER THIS WEEK ?

As if you really want to hear about "another possible storm." It reminds me of the final scene in "Hunt for Red October" when the Russian Ambassador speaks privately with the U.S. National Security Advisor about the loss of a second sub, and the advisor says, "General.... you've lost ANOTHER submarine?"

25 comments:

WHAT'S THE DIFFERENCE BETWEEN
A BAD GOLFER AND A BAD SKYDIVER?

ONE SAYS, “WHACK, DANG!” AND THE OTHER SAYS, “DANG, WHACK!”

WHAT DOES THAT HAVE TO DO WITH THE WEATHER?

Well, for powderhounds and commuters alike, this storm will be a case of “Whack, Dang” as the Mid-Atlantic gets whacked by a quick snowstorm and everything is pretty for a couple hours, then the dang thing changes over to sleet, freezing rain and then rain. So your enjoyment of the snow will only last a few hours. Then you have to go grumbling into your car and drive to work in a lot of you-know-what and find yourself wishing that you could be a student, teacher or "non-essential" government worker, just for one day.

The other case would be that the dang thing misses us altogether, and forecasters get whacked with all the criticism of yet another winter NO storm.

Also.. a warm welcome back to the comments feature. Let's keep it for a while this time. Glad to see our "regulars" are back on line with us.

THE FINAL WORD ON THIS STORM

I am happy to see storms like this one from time to time. It does not take a lot of effort to forecast, if you don't let yourself get hokeyed by any promises of big snow. This will be a classic political storm, since it occurs on Presidents’ Day in the I-95 corridor, as it will undoubtedly make a lot of promises, many of which will not be realized and it all get washed away in the end. But at least we who thirst for snow finally do get SNOW. That promise will be fulfilled at last.

EVOLUTION OF THE FORECAST

I started analysis with this event earlier in the week by saying computer models were trending the primary low too far north into the Great Lakes due to not seeing changes in the North Atlantic Oscillation. The original ballpark call was 3 to 12 inches, but the latter part of that was just an upper boundary to set a limit on the realm of possibility with this storm. On Friday I narrowed this to a general 2-3” for the I-95 corridor, with higher amounts in the Appalachians.

Now that the NAO has tanked as shown above, I think this happened too late in the game for models to adequately pick up on the rapid switch to negative. As a result, our storm will probably cut over to Erie or perhaps even Pittsburgh, then a secondary develops around Delaware, and moves east-north-east out to sea. Some wraparound precip will clip Southern New England, but it is a fast moving system. Warm air intrusion in the second phase of development will cut down on heavy accumulations due to a lower liquid to snow ratio, as well as a changeover of snow to sleet and freezing rain. Computer models have been trending back to a warmer solution the past few days, but as of late, the NWS has decided to interpret that as model error because of their concern over the computers not picking up on the impact of evaporative cooling, which tends to allow more snow than models indicate.

As a result, some of my amounts will be adjusted slightly since I think the negative NAO and high pressure issues are going to enhance snow rates for a couple hours before it changes over and departs.

STORM GRADE TOTALS FOR SNOWFALL

I doubt that any widespread 6 inch amounts will be observed. Those amounts can occur in the Pennsylvania Poconos and in some spots of northwestern and central Pennsylvania. I believe the overall trend will be 3-4 inches throughout the “WHITE OVAL” that circles portions of the Mid-Atlantic on the graphic above. Snow rates may be 1-2 inches an hour for perhaps 2 hours, hence the idea of up to 4 inches. There is always the possibility that that snow falls a little longer than we think it will, thus the reason for isolated spots of 5-6 inches, but I emphasize this will be extremely isolated and I really have no idea where those places might be.

For our regular readers, this is a roundup of forecasted amounts for your area by Monday noon after which all snow changes to rain from south to north.

Martinsburg, WV: 3 inches / Altoona, PA: 4 inches / State College, PA: 5 inches

Paoli, PA (SE area): 4 inches / York, PA: 5 inches / Bucks County, PA: 6 inches

Philadelphia: 3 inches (measured at PHL airport)

Northern Virginia/Loudon County/Washington: 3 inches (measured at Dulles)

Baltimore, MD : 2 inches (at BWI) / Towson, MD: 4 inches / Parkton, MD: 5 inches

Dundalk, MD : 3.5 inches (measured in Mr. Foot's backyard)

New York City: 2.5 inches (Central Park) / Boston, MA: 4.5 inches (Logan Airport)

Woburn, MA: 5 inches (revision...measured at a reader's home)

THE AMOUNTS SEEM LOW? WHY?


Because the timing of the storm will allow for snow from southwest to northeast, but since the northeast portions, Philly to Boston will be occurring later on Monday, I believe that daytime heating will make for a changeover to rain before ending, limiting accumulations. I also have a suspicion that this will not come as far north if it ends up going more south, the jet stream would have a tendency to send it out to sea instead of curving up the coast.

The introduction of the second High may recharge the storm with enough cold air to raise liquid-to-snow ratios to the normal 10:1. I have made a final set of adjustments to my numbers to reflect this. In Boston for example, a QPF of .6 with a 10:1 ratio means 6 inches, which seems high to me, so I'm knocking it back a bit to 4.5". I use this example to illustrate that I want to post a number that I feel very confident is a guaranteed minimum amount for a certain area.

IS THERE A CHANCE THIS STORM COULD CHANGE AND SURPRISE US ALL?

You mean like will you wake up to 6 inches of wind-whipped powder because the secondary formed sooner than expected and stayed longer, pulling in cold air from Canada which increased liquid to snow rations, hence 6 inches instead of 2-4? I don’t think so because the semi-Arctic high will be departing with the storm, and the big fresh one waiting in the winds in upstate New York is going to be overrun by warm air instrusion from the southwest. Were that to somehow magically occur, we would be looking at a different setup, but it is not in the cards this time. In all fairness to powderhounds, IF something weird starts to happen, I will be on it like hair on a gorilla.

Sunday Morning Comment: Now that Winter Storm Warnings are blanketing northern/central MD, and most of PA except for SW corner, I think that my forecasting for this storm will fall in line with expectations. I would like to point out that you got an advance knowledge of a snowfall range first, and then direct accumulation numbers were posted HERE before NWS or Accuweather made public statements about it.