Sunday, January 25, 2015

Best of times, worst of times

"It was the best of times, it was the worst of times."
- Charles Dickens, Tale of Two Cities


  • COASTAL LOW FORMATION ABOUT 6 HOURS LATER THAN EXPECTED DELAYS ARRIVAL OF SNOW IN MID-ATLANTIC. 
  • COLD AIR PRESSING SOUTH INTO EASTERLY FLOW REACTIVATED SNOW ACROSS MARYLAND, DELAWARE AS ENERGY WORKS NORTH WHILE CAROLINA LOW FORMS.
  • HEAVIER BANDS EXPECTED TO FORM OVER DELMARVA AND I-95 CORRIDOR AFTER 6 PM AS COASTAL HUGS DELAWARE AND JERSEY COAST TONIGHT. 




10:15 AM 1/26 - UPDATE FROM THE WINTER STORMCAST TEAM

1) Easterly flow has established across the southern Mid-Atlantic while the front that was stalled earlier in central PA moved south past 12 hours. National Weather Service has extended advisories in MD and VA southward to account for likelihood of wintry precipitation impacting area farther south than first expected. 

2) The enclosed surface streamline map shows easterly flow has setup across almost the entire state. This is bringing moist Atlantic air west across Delmarva and over the Bay into the western shore. This is also evidenced on your local radar with snow filling in east to west.



3) With the coastal taking a while to get underway, this easterly flow in place, and energy transfer slow from the primary lows in Virginia, we expect a light steady snow to be the rule of the day for much of the state. Roads may stay wet in eastern counties, but could become snow covered in western counties as they are in the colder sector to the north of the Low.


THE KEY FACTOR TODAY: Sun angle. Those experiencing snow will see it continue at present intensity for another 5-6 hours. 

  • Toward early afternoon it may actually decrease some. Then as the coastal Low picks up in speed and intensity, Sun angle will be dropping toward evening. 
  • After 3 PM, in a surprisingly magical way, snow will suddenly start to whiten the ground everywhere. 
  • We have seen this many times before, and with plenty of Atlantic moisture to work with, there's probably no way out of a snowy, but somewhat manageable day, in Maryland.
TONIGHT AND TOMORROW? We don't like to say "It's up in the air" but honestly, it still is. Since so many computer models have led forecasts astray, we are leaning more on a nowcasting and upper level analysis approach with only very short range model data in small time increments. 

The first image is a projection for Precipitation Type at 9 PM Tonight from the North American Mesocale. This suggests snow continues in the I-95 corridor but changing to rain in the Eastern shore and southern Maryland.

The second image below is the "broadbrush" Precipitation forecast from the NOAA Weather Prediction Center for 7 PM tonight, this shows a more widespread and much snowier solution for a large part of the Mid-Atlantic, with snow likely in many areas.



So the game is a-foot. It will be interesting to see how things stack up. We welcome your take on the situation. It's a nowcast event plain and simple.

Forecasters Foot, Connor M., Joe F., Jolene W., Jason M., Advisors Pete W. and Keith K. 







SIGNIFICANT WINTER STORM TO IMPACT EASTERN MID-ATLANTIC 
AND NORTHEAST SUNDAY NIGHT INTO TUESDAY
6:00 PM 1/25 - WINTER STORMCAST TEAM STATEMENT 


SYNOPSIS A highly fluid and rapidly changing forecast situation over the next 24-48 hours is going to require (or test) a high level of patience across the Northeastern U.S. At issue is an eastward traveling clipper moving along a the southern periphery of a large Arctic High pressure system. As you can see from the NOAA Surface Projection for Monday morning, this large scale dynamic will create widespread easterly flow of moist Atlantic air into the much colder Arctic air being pressed southward.

SITUATION Starting later this evening into Monday morning, this storm will first produce round of heavy snow in western and central Maryland, the West Virginia panhandle and southern PA. This first period of snow from the clipper is likely to produce 4-8" in western areas, and 2-4" near metro areas by dawn. 

* By Monday night, bands of snow should begin to fill back in over the I-95 corridor and the Eastern shore at first. An additional 3-6" is possible in counties on west side of the Chesapeake Bay, while the Philly metro region and the Upper Eastern Shore gets clocked with 6-12". 


In the event the storm slows and stalls near the Jersey coast, accumulations could be significantly higher, depending on the track of the storm.

Were that to occur, all forecasts will have to be completely revised. We seek not to over-amplify the situation, but to highlight the significant uncertainty inherent in a rapidly evolving winter storm that will cover a geographic spread larger than most hurricanes. 



COMPARISON The most basic comparison we can make to a setup resembling this could be February 17, 2003. A southern stream system overran a cold High pressure dome. What started out as snowfall projections of 3-6" early in the event ended around 18-24" as the easterly flow, southern energy and moist air all collided over the northeast. 

While this situation is much different in terms of moisture source, the fact that a High pressure looks to bleed out into the Atlantic and stall the storm somewhat may have prompted Blizzard Watches and Warnings along the Mid-Atlantic coast. That is a troubling similarity between this event and the February 2003 and February 10-11, 2010 storms.

So if you are an Emergency Manager or Facilities Operator, it looks to be the worst of times, but for Powderhounds... well, no argument there. They'll be in powder heaven celebrating the best of times. And just think, February is not even here yet! 

ROUNDUP Since this multi-day complex winter storm will have wide ranging impacts across numerous states, and many of our readers, we have assembled this listing of forecast zones from our Mid-Atlantic Team, with an enclosed link for your reference.
DISCLAIMER: Please always remember to consult official statements at your local NWS forecast office, and be advised that information we post here is for educational purposes only. Decisions by local governments are made following the latest official guidance provided by the National Weather Service and the NOAA Weather Prediction Center, as well as State Emergency Management Agencies

57 comments:

weed said...

I'm back from my trip to the store...hubby is firing up and testing the snow blower......tubs are filling with water in case of power outages since we are on a well....we are ready....I'm in Hampstead by the way....I SAY BRING IT!!!!

genser95 said...

In your evening update you need to make clear to people that the main focus of this storm will not be in Maryland. A historic blizzard is headed to NJ up through Mass., not here.

BioPat said...

There are still many variables to be worked out in calling totals for this storm in the Balto metro areas. It is going to be a major storm just north of us but we will have some impact. If we do get 6 10" of snow it will be significant for Baltimore. Again just how closely this hugs the coast will be the key to its impact. No question it bears watching - and of course waiting.
We just got word that Baltimore County schools are closed tomorrow so we follow Howard County at MSJ. This could prove to be interesting.

Butch Dynomite said...

Ok gang, I just want to contribute: the farmers alminac says that the best time to fish today is the evening...oh and also there are several good days next week to get married.

NeedaSnowday said...

hmmmm, only see BCPS closing PM activities... Howeird Co. will wait till 5AM.. Hang tough BP!

NeedaSnowday said...

Bwhahah Butch! Good stuff!!

ravensbbr said...

Attaboy to Butch. Good to know. ;-p

NeedaSnowday said...

This event is causing a slight meltdown for AMWX forum, https://www.facebook.com/mike.masco has his latest post, JB still 2 hours ago...

Have I mentioned my loathing of all things NE? Hope the blizzard deflates them...and they are grounded and cant get to AZ...

kristia35 said...

BCPS was closed already for prof development I believe.

BioPat said...

Correct Baltimore County is already closed tomorrow. Mt. St. Joseph usually follows the Baltimore County protocol but tomorrow we will be following Howard County and not making an independent call. This is always difficult for catholic schools during the winter months. So, this should prove to be interesting, the first storm coming from the west and the second from the coast.
There are all kinds of advisories and watches posted but until we see snow won't make a whole lot of difference.

kristia35 said...

Catholic school here as well. They'll be making an independent call tomorrow and if it's not good, I'll make my own independent call. They have always erred on the side of caution in the past so I'm not too worried

Amy said...

HoCo can feel like a crap shoot sometimes. I've got a sick kiddo so a snow day would be nice in lieu of being absent the first day of a new quarter.

And snow would be great to finally feel like winter. This powderhound has been very disappointed thus far.

Westsidehideaway said...

7:20pm Sunday and it is spitting out there but 43 degrees in West Baltimore. Here it comes. Whatever "it" is. I will say this. I want snow, but not the 2-3 feet NYC is expecting. Ugh.

kyleZ said...

I hate this wait and see game just hoping for more than 4 inches.

Tara said...

What about between Baltimore and Frederick? By the sound of all the articles Baltimore and east, and western Maryland will be hit but not so much in the middle?

Tara said...

What about between Baltimore and Frederick? By the sound of all the articles Baltimore and east, and western Maryland will be hit but not so much in the middle?

ssmd said...

I am waiting to hear what andy says...... There are sooo many different scenarios and forecasts!

Brian carlberg said...

Baltimore city schools 2 hour delay for Monday.

notsofreestate said...

Dating myself a bit, but here"s a headline for you:

"The waiting is the hardest part."Tom Petty

Faith in the flakes!

Westsidehideaway said...

I have no professional or amature forecasting experience. Now that this is out of the way, I think tonight's forecast may not hold up. It is 10pm and it is 43 degrees in West Bmore. The radar shows that the rain /snow line is north of the PA line and the forecast says the low for tonight is. 30 degrees in Bmore metro. Tonight looks like a bust. Just sayin.

Anonymous said...

"It was the best of times, it was the blurst of times? What? You stupid monkey!"

Name that quote.

Charles Fluharty said...

The quote is from Mr. Burns of The Simpsons.

Andy, Southern York County Pa said...

I think this system under performs for the entire Baltimore region. Warmer surface temps as the bulk of the clipper precip arrive will limit any accumulation. Fast flow and low bombing off the coast will also limit wrap around banding. Models have been wholly inconsistent with this and not reliable with the evolution hence all of the terrible or non committal forecasts.

Would not surprise me if the NWS cancels watches and keeps advisories rolling. As a snow enthusiast I will nowcast this storm as it evolves as it is very interesting, but significant snow from the coastal seems highly unlikely anywhere near central MD. I never turn my back on a coastal, especially when the models have struggled terribly, but it is hard to get excited about this set-up for our region. The next few hours will be interesting to see how the transfer of energy takes place on the coast.

I think this will be a big extended nuisance for us, but have little confidence in anything significant at this point.

Andy, Southern York County Pa said...

Statement as of 3:00 AM EST on January 26, 2015

... Winter Weather Advisory now in effect until 10 am EST
Tuesday...
... Winter Storm Watch is cancelled...

The National Weather Service in Baltimore MD/Washington has
cancelled the Winter Storm Watch.

* Precipitation type... snow.

* Accumulations... 3 to 6 inches.

* Timing... snow will begin between 5 and 8 am this morning. Snow
will continue through tonight before ending Tuesday morning. The
heaviest snowfall will occur tonight.

* Temperatures... in the upper 20s to lower 30s.

* Winds... northeast 10 to 20 mph with gusts up to 30 mph today
becoming north tonight into Tuesday.

* Impacts... roads will be snow covered and slippery with
visibilities being reduced to near one-quarter mile at times.
The combination of snow covered roads and low visibility will
make traveling dangerous.


Precautionary/preparedness actions...

A Winter Weather Advisory means that periods of snow will cause
travel difficulties. Be prepared for slippery roads and limited
visibilities... and use caution while driving.

Andy, Southern York County Pa said...

The NWS also ingested all the 0z data and did cancel the Watch as I was typing the above. I think the 3-6 inches the NWS has forecasted is the best case scenario at this point, but that might be a long shot with this strung out mess.

Andy, Southern York County Pa said...

1-3 inches is our most likely outcome for this system. This has been the pattern that we have been in for a long time with a series of minor nuisance events. This storm is for New England.

Julee said...

Thanks for staying up so late to give us info Andy. You are a weather warrior.
For some reason, predicted storms just never make it here. We always get whomped by surprise.

Chris @ Flipping A Dollar said...

Snow started in Frederick around 6AM. Roads are just wet for now.

kristia35 said...

Woke up to nothing in Perry Hall. Crushed. Skunked again. Hopefully we get a little something out of today. I took off the first 3 weeks of February in hopes of a HECS or MECS. Please don't fail me, Mother Nature.

Andy, Southern York County Pa said...

I think we salvage something but nothing major. From DC, through Baltimore, into Pa the clipper aspect looks to drop around 3 inches. Enough for some snow play.

Mike Cheuvront said...

Andy--What do you think is wrong with the forecast models. This is ridiculas! The clipper came in farther north than we were told.
It did not dive south towards the coast. The mountains seem to have broken up the clipper to a certain extent also. It was not supposed to be this warm and that's because the storm came farther north. I respect your 6-10 prelim call. It all looked suspicous to me that's why I wrote what I did about no one really knowing about this system. The models have been so bad this year. We can't trust them. Do you have any thoughts as to what dynamics they are not considering to get the forecast so wrong so often?

genser95 said...

I'm not sure the models did a bad job at all when it comes to the Baltimore area. Starting about yesterday morning, they consistently showed the best forcing from the clipper up in PA, and then the coastal low being too far north/east. The only question is whether the coastal will retrograde enough to throw snow back on the Western Shore, which doesn't look likely now.

Andy, Southern York County Pa said...

Euro was close to a big hit with its precip shield hence all the watches etc. in many ways this was a very easy forecast for NYC north. The tough part is the fringes. On the fringe a shift west would be huge, while a shift east leaves you high and dry. With no model agreement and the euro shifting west but then adjusting east the NWS had to keep the public notified of the potential. 6 to 10 was the max potential here but once the euro had a better handle on the western coastal shield it pulled it back east. With no deform band and energy being transferd to the coastal

Andy, Southern York County Pa said...

end up with 24 hours plus of snow showers.

Andy, Southern York County Pa said...

I liked the NWS approach of the dual advisory with this storm. The winter weather advisory and the Winter Storm Watch. This was never a great set-up for our area for a big storm, but the Euro heavy QPF that it showed for our area could not be ignored either. I'm excited to watch this unfold further north and it is a great learning tool. When you are on the fringe of a large system and one model shows a big hit, you have to be suspect of it, but can't ignore it. This is a coastal redeveloper or what is called a Miller B. Miller B storms generally hit north of Philly and dry slot us, or develop too late at our latitude, unless there is blocking and further south development. The radar today looks fantastic for an east coast storm, unfortunately for us it develops too late and far east.

ravensbbr said...

"DANG YOU, DRY SLOT! DANG YOU TO HECK!"

(apologies to Charlton Heston and Alex the Lion from Madagascar)

#slottedagain #dangit

Andy, Southern York County Pa said...

I am just now casting this storm. Models can only do so much at this rate with this large scale system and us in the outer fringe. Will watch how it develops and hope for some banding or any last minute surprises. I never turn my back on a coastal, even if it appears to be a miss on most models.

BioPat said...

Kooks like this storm is really going to be a New England storm, Even New York may have dodged a major bullet. If we get any banding it may be minimal due to the distance factor but it should still prove to be an interesting evening.

Mike Cheuvront said...

Yeah, we'll see what happens with the developement.Looking at the radar, it's got to go a long way to be a boom for the NE IMHO. doesn't look impressive right now. There is no defined storm. There is lots of mositure but not organized. Time will tell. Maybe it's yet to form fully but I have doubts it will be what they thought it would.

wvm said...

Test. I just a had a long post that would not post

wvm said...

Ok sorry. Spent lots of time on the last post only to have it lost in internet land. Sort of like this storm. Just wanted check in since I have been an avid reader of this sight for at least 10 years maybe more. What is goin on with this storm. We have 2 inches of snow and it is 26 degrees. Just watched the noon weather report about ho we were to get 5 to 7 inches or more to now we have our storm warning replaced with an advisory. I must say THe trend of Friday's storm made me worry about this one. I guess my instinct was right. Please tell me that it Is possible for the bands to develope more moderate than expected snow.
Wvmommyof5

Mike Cheuvront said...
This comment has been removed by the author.
Mike Cheuvront said...

ANDY- What do you make of that energy coming down from the upper midwest???

Andy, Southern York County Pa said...

Tonight there will be random snow showers. Less than 3 inches will accumulate in most spots. Some spots will see less than an inch.

Andy, Southern York County Pa said...

Mike that will have no impact on our weather.

Mike Cheuvront said...

Okay then---Time to move on to the next snow threat. I'm ready to put this disappointment behind us.

NeedaSnowday said...

With you Mike.... watched TV coverage of snow in NYC... boo!
I have no need for this snowblower considering the sidewalks and such are clearing themselves.......haha!

Anthony Foppiano said...

Just noticed a big band of moisture (rain) heading west across DELMARVA. I'm wondering if it will make it all the way to me in extreme Southern Calvert County, and if it will be cold enough to snow when it gets here. Weather station 2 doors down from me is reporting 35.1 degrees right now.

NeedaSnowday said...

Andy....saw the picture you posted on AMWX...awesome!

NeedaSnowday said...

Hmmm, light snow falling again.... refreeze on roads?

Mike Cheuvront said...

Needa- Feb 2nd maybe??

NeedaSnowday said...

I posted about a possible SUPERBOWL storm days ago, but it was too far out to believe in it... After this event I dunno if I should be invested..... Argh!

ravensbbr said...

Next chance for any NAO blocking at this point to let one of these truly both bomb out and not escape out to the NE right away looks to be around Feb 11 or so...check it here...

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.shtml

NeedaSnowday said...

Of course that is the case BBR.... Yanno why... The annual field trip to Orlando starts on February 10th! :-}~

wvm said...

Light to moderate snow since about 5pm. Roads are a mess. Temperature is 22. Getting a bit excited The bands are reaching eastern panhandler of wv. Grand total of about 3 to 4 inches
Wvmommyof5

Andy, Southern York County Pa said...

Best storm in years for me. Best storm for tracking. Models just struggled with all the moving parts. NYC went from 24 to 36 inches to likely 8 to 12.

Andy, Southern York County Pa said...

I will not even look at the weekend threat until this storm clears. Fast flow and no blocking really are a nightmare for the models this year. Needy, we aim to please in our football life ;)