Tuesday, December 6, 2005

THIS MIGHT NOT BE THE ONE!
UPDATED WED 6:30 am
Dec Storm 2


WEDNESDAY MORNING UPDATE:
Well lookey what we have here...last night, a potentially bigtime snowstorm was on the books. What one good night's sleep will do, huh? (for NWS forecasters, not me). It seems NWS has ramped the storm back down to earth overnight, and mostly removed words being used yesterday like,"dangerous, very significant, etc...6 or more inches." For example, Balt/DC NWS was really sounding the alarm last night, and now has an innocuous "light to moderate snow" Special Weather Statement. Cancelling the hype was a good idea, because there remains the possibility the Ohio Valley Low and the Southern Rockies Low never link up the way we want them to.. and the Mid Altantic High nudges offshore more than we want it to. Throw in the fact that this storm is moving faster, thus limiting time for it to drop precip. Result? Our big storm never materializes and we get KaDUDa # 2. That's why I and other online forecasters were hesitating. Granted Winter Storm Watches may still be hoisted for a large area, but we may very well see a repeat...as in Snow Advisories and a final tally around 4-5 inches. I'll bet when Accuweather updates this AM, they dramatically scale back the 6-12 inches they painted for the Mid-Atl and NE on Friday. You know I'm a born and bred powderhound, and I hate to be a party pooper, but I'm not going to get you all riled up for a storm that might not live up to the hype.

Let me add that while many areas may not get the 6-12 inches we hope for, the timing of this will be that even 5 inches occuring overnight from 9PM to 6AM will be just perfect to cancel many schools for Friday from Virginia to New York City and everywhere in between. Main reason is that this will be a quick snow, and crews will not be able to keep up, thus they will give up until it is over. Then you'll be able to roll over and go back to sleep. Now that's a Happy Friday! (Forecast note: I will be out the entire morning delivering a toddler to a grandmother, so no updates until at least 1pm.)


TUESDAY EVENING POST:
Already the drumbeats have started for another major winter storm and Special Weather Statements are starting to fly out the gate. I am still digesting and reviewing the previous storm to see what went wrong, as my grades are coming in about a D- average on snow totals (although I did score big time with Richmond, 4" forecasted and a result of 4.2" !). We have all seen the pre-storm hype end up bigger than the storm itself, so I am going to look over the data for this one more closely. The interesting thing favoring the powderhounds is that both Accuweather and the National Weather Service are sounding the trumpet for a potential major snowfall in the Mid-Atlantic and up I-95. Keep in mind the Dec 5 Dud did not officially qualify as an "I-95 Special" as no one along my favorite highway saw at least 6" (sorry, Ocean Twp NJ's 6.7" does not count). A true-blue I-95 Special is where all the megalopolis cities (and their surroundings counties) receive a good solid 6+ from DC to Boston. This storm appears to have the potential to deliver that as there will be plenty of cold air in place, and radiational cooling in advance of the storm caused by Storm 1's snowfall will help to keep temps down right up to the onset of snow Thursday night. I am not ready to issue preliminary accumulations as I have to review the QPF maps, but the elements are slowly coming together. In fact, before we go over the numbers on Storm 2, we will first discuss what are "the elements" required for a good shovel-smackin' snowstorm along the East Coast.

Some of the basic items I and every other serious forecaster looks for is the classic dome of High pressure parked over New England or New York. The current realm of blue skies shining above is that High, except that it is nudging far enough south to create the tell-tale "cold air damming" down the east side of the Appalachians. This bodes well for powderhounds in the southern portion of the Northeast Corridor (from Richmond to Philly). However, what concerns me is the trajectory of the storm, whose end game will be the combination of several Low pressure systems coming together by Friday morning. It is possible this storm will move just simply straight east, and though it will throw a big shield of snow out for hundreds of miles, it MAY miss the northern sections of 95 from Connecticut on north to Boston. Go run the computer models I have linked to the right to see what I am talking about. For those in interior sections, such as West Virginia, central Virginia, central and eastern PA, and especially the mountains of NC and SC, depending on your location, upsloping may yield higher snowtotals for you, along with a significant ice storm in the Carolinas.


All the way around, this storm looks to be a block/backbuster event, PROVIDING that the key element, that High Pressure dome, does not detach itself from the picture too soon, right? That would allow a return flow on the backside to link with the onshire flow of the approaching Low, and thus our storm starts as snow and changes to all rain for the big cities. I have seen that kind of situation before...we got all excited about a big storm coming from the MidWest, only to have our 4-5 inches get all washed away as the warm front passed over.
THAT's the piece I want to investigate further before I sound the trumpets on a 6-12" Early Season I-95 Kahuna. Yes, I am resurrecting that term because this may definitely qualify as a Big K.

26 comments:

Hokiehop said...

Things are looking up...hot off the presses from the heavy snow discussion room...


DAY 3...

MODELS ARE SLOWLY TRYING TO CONVERGE ON A COMMON SOLUTION
REGARDING CYCLOGENESIS ALONG THE CAROLINA AND MID-ATLANTIC COASTS
THIS PERIOD. THE PREFERRED GFS SHOWS RAPID DEEPENING OF THE MAIN
SFC LOW AS IT MOVES OUT OVER THE GULF STREAM DURING THE DAY
FRIDAY...BUT EVEN BEFORE THIS OCCURS THERE WILL LIKELY BE AN AREA
OF SIGNIFICANT SNOW EXCEEDING 6 INCHES EXTENDING FROM THE CNTRL
APPALACHIANS EWD THROUGH THE MID-ATLANTIC AND DELMARVA
PENINSULA...CURVING NEWD ALONG THE SRN NEW ENGLAND COAST.
CONFIDENCE IS MODERATE GIVEN THAT BOTH THE NAM AND GFS INDICATE
0.50 TO 1.0 INCH LIQUID EQUIVALENTS CLOSER TO THE COAST...BUT WE
DO NOT ANTICIPATE THE HEAVY SNOW OVER SWRN AND CNTRL PA THAT THE
NAM WOULD SUGGEST. ATTM EXPECT POSSIBLY 6-8 INCHES FOR THE
DCA/BWI/PHL METRO AREAS BEGINNING LATE THURSDAY NIGHT...WITH
SIMILAR TOTALS FOR BOS AND 8-12 INCHES POSSIBLE OVER NYC AND LONG
ISLAND AS THE SFC LOW BOMBS OUT ON FRIDAY MORNING.

THERE IS ALSO THE POTENTIAL FOR SERIOUS ICING DIFFICULTIES OVER
MUCH OF THE HIGHER TERRAIN OF WRN NC AND NWRN SC THIS PERIOD WITH
TREMENDOUS AMTS OF WARM AIR MOVING INLAND AND OVERRIDING THE COLD
AIR WEDGED IN ALONG THE ERN SLOPES OF THE APPALACHIANS. BOTH THE
NAM AND GFS INDICATE A WELL DEFINED AREA OF ABOVE FREEZING 850 MB
TEMPS OVER THE COLD AIR DURING THE FIRST 6-12 HRS OF THE PERIOD.
HPC QPF SUPPORTS THE POTENTIAL FOR UP TO 0.50 INCH OF FREEZING
RAIN OVER W-CNTRL NC.


MAUSSER

Julee said...

YIKES! That Friday snowfall looked so insignificant yesterday!
We're having a Craft Fair on Friday afternoon at HMS!!!
I've made 30 pairs of earrings!!!!
Are you saying we should have the fair on THURSDAY?????

p.s with two kids, I hope you have a Home Depot credit card!

terpguy said...

I was looking at the HPC map about noon..what a MAJOR change!!

FYI, neophyte snowbirds, 00Z Friday is 7PM our time...wait and see.

As my dear ol' dad was fond of saying: "many a slip, 'tween the cup and the lip!"

(that means we're still 60 or so hours out...)

Mr.B said...

Mr. foot what about up here in pa just over the boarder accu says 6-12". GFS says 4-8" and NAM is 6-12"

Julee said...

TerpGuy,

I just checked the HPC and
may I say . . .WHAT?
Like reading sanskrit -- only harder.

Help!

E.H. Boston said...

Read this from Accuweather (just updated!!!)

This will be a week to remember in terms of cold and storminess. This graphic focuses on the big storm that you have probably been hearing all kinds of rumors about. Hopefully, this will shed some light on the facts. The storm is in its initial stages now and will take on much greater stature as the week progresses. The result will be an expanding area of snow, ice and rain from the south-central states all the way to the East Coast. This major disturbance has the potential to produce more that 10 inches of snow over a broad area from the Ohio Valley to southern New England. The Deep South will also have bitter taste of winter with temperatures running 20 to 30 degrees below normal not to mention the risk of a major ice event.

I am shaking in my seat!!!!!!

Mr. Foot, I love this time of year...the spring, summer and fall were tough to get to this, but we are finally back to powderhound season. Yes, it may be the DC to Boston I-95 Special that we have all been waiting for since 2003, I believe.

terpguy said...

Julee-

Try this

http://www.hpc.ncep.noaa.gov/wwd/winter_wx.shtml

There is a nine map array of snowfall prob.

The rows are Day 1,2, and 3

The columns are at least 4, 8, and 12 inches.

The % are color-coded.

TG

DerbsATerp said...

i seem to not be the only Terp present here, but this certainly looks great, seeing as i have a paper due friday afternoon

Mr. Foot said...

See gang...look what one good night's sleep does (for NWS forecasters, not me).

Seems they wholescale ramped the storm back down to earth overnight, and mostly removed words being used yesterday like,
"dangerous, very significant, etc...6 or more inches."

For example, Balt/DC NWS was really sounding the alarm last night, and now has the wimpiest Special Weather Statement I've seen... "light to moderate snow"

Their overhype concerns are warranted. There remains the possibility the Ohio Valley Low and the SW Low never link up the way we want them to.. and the Mid Altantic High nudges offshore more than we want it to. Throw in the fact that this storm is moving faster, thus limiting time for it to drop precip. Result? Our big storm never materializes and we get KaDUDa # 2. That's why I was hesitating, and now I see others doing the same.

Granted Winter Storm Watches may still be hoisted for a large area, but we may very well see a repeat...an in Snow Advisories and a final tally around 4-5 inches.

I'll be when Accuweather updates this AM, they dramatically scale back the 6-12 inches they painted for the Mid-Atl and NE on Friday.

You know I'm a born and bred powderhound, and I hate to be a party pooper, but I'm, not going to get you all riled up for a storm that might not live up to the hype.

I will be out the entire morning delivering a toddler to a grandmother, so no updates until at least 1pm.

Mr. Foot said...

Let me add that while many areas may not get the 6-12 inches we hope for, the timing of this will be that even 5 inches occuring overnight from 9PM to 6AM will be just perfect to cancel many schools for Friday from Virginia to New York City and everywhere in between. Main reason is that this will be a quick snow, and crews will not be able to keep up, thus they will give up until it is over. Then you'll be able to roll over and go back to sleep. Now that's a Happy Friday!

Mr.B said...

Foot don't doubt the storm because winter storm watch for over 6" up here in greencastle and over 5" in maryland.

E.H. Boston said...

Hey, news weathermen are getting nervous round these parts. One forecaster is saying that we have a very good chance of seeing over 6 inches throughout SNE. The QPF maps are starting to agree with that prediction as well as the NAM. We'll see. Mr. Foot, when is your next post to come out?

kristine said...

NOOOOO...I have a birthday party for my son who is turning 6...please say if we do get the snow that it will be gone by Saturday? It is no fun cancelling a party especially with family out of town...

E.H. Boston said...

Here is a run down of the forecast models for the Boston area...keep in mind that I will be using a 10:1 standard ratio, but since most of the snow may be falling into an enviornment colder than 28 degrees the ratios could actually be quite higher, maybe 14:1 or 18:1.

First Model:

NAM/ETA
Liquid throughout the Storm: 1.6 to 2.4"
Snowfall Equivalency: 16-24"

AVN/GFS
Liquid: .4 to .5" (conservative? extremely progressive with the storm)
Snowfall: 4-5"

MRF
Liquid: .75 to 1.005"
Snowfall: 7-10"

QPF
Liquid: .75 to 1.00"
Snowfall: 7-10"
HOWEVER on the line of Liquid of 1.00 to 1.25" (10-13" of snow)

Odds look like they are favoring a major winter storm as winter storm watches have already been posted for the states of PA, WV, VA, MD, NJ, NY, CT, and the westernmost county (Southern Berkshire Co.) of MA.

Batten down the hatches...looks like Mr. Foot's next post will be a tale of lots of snow and warnings for us to prepare for what is to come: A MAJOR NOR'EASTER!!!

Mr. Foot said...

Just got home from a whirlwind family trip, about to check in on the models (not chick models, I mean the computers). WSW for most of NE? why did NWS have such a change of heart today? My next post... uh, 7, 8 or 9. You pick one. Sometime before 9 PM.

Mr.B said...

How about 7:30-8. Foot looking like good storm for area. I see at least 7" for greencastle and 6-7" in dundalk.

Julee said...

(Poor Tired)Mr. Foot,

I hope YOU can provide definitive info! My *neck* hurts from the back and forth this storm has gone through in ONE day!
Twelve inches, no inches, three inches, six inches, heavy snow with little to no accumulation (honestly, I heard this on the radio!), nor'easter, and a no show.
HELP!
We've already postponed Friday's Craft Show, so my interest is purely academic (heh).

Andy, Southern York County PA said...

Hey I'm ready for anything after Moday nights plastering! I mean we had sustained winds of 2 mph with gusts up to five. Snow was as high as an inch with "TWO" inch drifts in spots! BRING IT ON! Mr. Foot can muster up the energy for an early evening post. I understand new born infants are a lot of work. Trust me I know first hand, as I used to be one 30 years ago. ANYWAY, We are long overdue for a real snowstorm and this time I'll forecast 12 inches for York, PA, 8 inches for BWI 9 inches for Towson, 12 for Boston with 6 inches for DC (sleet mix).

Mr.B said...

The latest
http://www.hpc.ncep.noaa.gov/qpf/p120i00.gif

Hpc
.6-.7 Dundulk
.7-.8 Greencastle
.7-.8 York
1.4 Cape of Mass.

Looking good. What do you say foot?

Mr. Foot said...

Yes the QPF looks good, but there is this handoff issue that worries me. I have an update in progress...perhaps 15 more minutes. Look over the Winter Storm Watch statement issued by Philly, they describe what is supposed to happen but may not as perfectly as we hope. This storm has got nearly 2000 miles to cover by 6AM Friday...and transfer energy to an as yet undeveloped Low Pressure in the Gulf, then these two lows attack the Mid-Atlantic in tandem while the secondary Low becomes the main storm. Sounds good, right? Guys I have seen that a thousand times, and only 10 times did it result in a great big snowstorm. I hope to prove myself wrong. Anyone remember March 2001? The 12-24" predicted for everywhere, turned into 3" or less. Computer models were all in agreement for that one and they were ALL WRONG. I will do more snooping and continue with the update.

Mr. Foot said...

kristine..whatever happens with this storm, it will be WAY over by Friday late afternoon, so if I were planning a party for my daughters on Saturday, I would definitely be going ahead with it.
Roads will be clear by Friday PM rush, just the AM will be a mess.

The sun will probably even come out Friday before it sets.

anonymous21 said...

8:55 Fcast Disc LWX: MODELS INDICATE .5-1.0" OF LIQUID PRECIPITATION. MEANWHILE...THE
GARCIA METHOD USING THE 12Z GFS INDICATES A GENERAL 6-10" POTENTIAL.
THE SPEED OF THE MIDLEVEL SYSTEM IS A NEGATIVE FACTOR FOR HEAVIER
SNOWFALL. EXPECTING TO SEE A WARM NOSE OFF THE SURFACE PENETRATE OUR
SOUTHEAST ZONES...WHICH WOULD LIKELY SUPPORT SLEET MIXING IN GIVEN
THE DEPTH OF THE COLD LOWER LAYER

I am confused mr. foot, 6-10 but going too fast knocking it down to 3-5?

Mr.B said...

Greencastle,pa forecast just updated Heavy Snow thursday night 5-9"
I am guessing if this trend continues a WSWW or a HSW will be issued around 12am or 1am.

Anyways I hope at least 5" but would of course love more.

E.H. Boston said...

Mr. Foot, if I am not mistaken, in March of 2001, didn't the Boston area receive lots and lots of snow on the tune of 12-24"+ with more on the North Shore?

Would this 1 in a 100 chance be confined to the Mid Atlantic or the entire east coast?

My general prediction that I have been telling people is 8-12", is that too much?

Paul Kocin said that somebody in SNE is going to see a foot or more. Oh well, we will see.

Looking forward to that next update.

Andy, Southern York County PA said...

Heavy Snow warning for SOuth cental pa. 5 to 9 inches forecasted. We will see.

Mr. Foot said...

Sorry gang, rough night last night as baby was very fussy and not cutting Mommy any slack or rest, so had to stop my update and help a while. Then my brain lost power. Back on line and update in progress. I do see Winter Storm Warnings across the board..first time since Feb. I agree Andy.. I take HSW's with grain of salt as I have seen TWO of them fizzle last winter in Balto area. EH..the March 2001 bust I was talking about was primarily in Philly area...many 4casters calling for 1-1-2 feet and end of the world. All computer models going berzerk, then storm turned and dumped on you (as you accurately pointed out).

I also see TWC has upped our accums in Balt.. a general 4-8 now. I think this will be a heavy wet snow as we will not have high ratios, maybe just 10:1. In western MD and WV mountains, they could have 15:1 though.