February 12-13 Storm, Part II

[mitchnick]

0Z Euro has a sleet sounding, though not as bad as 12Z yesterday, at 66 hrs tomorrow; don't know how long it lasts

DCA....no sleet sounding again at any of the 6 hr intervals

there could be sleet in there at DCA at some point but it would have to be for <6 hrs

 

EDIT: soundings are a bit colder than 12Z yesterday but I guess you all knew that by now

[winterymix]

A half of the GFS ensemble members give us really good snow.

Here is an example.

 

 

[snowdude]

03z SREFS are at a mean of 5" of snow in Salisbury. I was surprised. They're slowly bumping up totals with each run. Hmm...

[nj2va]

[mdsnowlover]

A half of the GFS ensemble members give us really good snow.

Here is an example.

 

 

gfsens.jpg

I seem to remember a storm that was giving us 20 in of snow before the shortwave was sampled then we got a lot of sleet instead or snow, as the snow was moved north of  40 n . Isn't this possibly the same idea?? 

[Bob Chill]

Rgem puts down nearly .5 southern half of md by 1am thurs. Rgem and ggem are the fastest outliers though.

Gfs just not as good with the phase and upperlevels as other guidance. We'll see what happens there at 0z.

[mitchnick]

Rgem puts down nearly .5 southern half of md by 1am thurs. Rgem and ggem are the fastest outliers though.

Gfs just not as good with the phase and upperlevels as other guidance. We'll see what happens there at 0z.

12z....go back to bed!  

[stormtracker]

I love everybody and am sorry when I don't act like it.

Even me?

[nj2va]

So with the NS vort coming onshore, will 12z NAM/GFS have the updated data or will we have to wait until 18z?  

[Bob Chill]

12z....go back to bed!

Lol. No coffee yet.

Wxbell mslp and 850 euro ens mean maps aren't up for some reason. Precip panels look pretty sick. We get crushed. Not sure global ens guidance adds much value at this lead but fun to look at nonetheless.

[NorthArlington101]

FWIW Good Morning America gives us 3-6. That is the lowest I will accept at this point.

[MN Transplant]

 

DCA:

THU 00Z 13-FEB  -2.9    -6.3    1026      62      71    0.00     555     534    THU 06Z 13-FEB  -3.0    -2.9    1018      90      98    0.22     552     538    THU 12Z 13-FEB  -0.2    -1.3    1007      91      99    0.57     548     542    THU 18Z 13-FEB   0.1    -3.3     995      87      96    0.34     537     540    FRI 00Z 14-FEB   1.2    -3.6     996      89      97    0.62     532     535    FRI 06Z 14-FEB  -0.9    -2.1    1001      69      23    0.08     535     534    

 

Let's take the (realistic) worst case scenario from last night's euro.  12z to 18z we lose to sleet, and the deformation band after that misses your backyard.  Still looking at 8" + sleet + something on the backside.  Now we are looking at a worst-case scenario that is in the ballpark of the GFS.  Our envelope is tightening, with 6-8" on the low side, and that is a beautiful thing.

[needbiggerboat]

Even me?

That and his "I'm tingly" update were the oddest posts from the overnight.

[snowfan]

So with the NS vort coming onshore, will 12z NAM/GFS have the updated data or will we have to wait until 18z?  

According to ohleary, yes, 12Z.

[needbiggerboat]

AM heavy snow disco from wpc....worth saving...you don't often seen some of the language used in this one

A HIGH SOCIETAL IMPACT WINTER STORM IS IMMINENT ACROSS THE SRN

TIER OF THE COUNTRY AND VERY LIKELY TO PROCEED UP THE EAST COAST

ON WED AND THURS... BASICALLY EXTENDING FROM TX/LA TO NEW ENGLAND.

A VERY COMPLEX UPPER PATTERN WITH SPLIT FLOW REGIME ACROSS THE ERN

TWO-THIRDS OF THE COUNTRY... WHILE A MAMMOTH DOME OF SURFACE

ARCTIC HIGH PRESSURE CONSUMES THE ENTIRE REGION AND ESPECIALLY

EAST OF THE APPALACHIANS. AN IMPRESSIVE AND DYNAMIC IMPULSE OVER

THE MID MS VALLEY WILL GLIDE ALONG THE NRN STREAM AND REACH THE

NORTHEAST COAST ON TUES. MEANWHILE... THE LAST SHORT WAVE THAT

IMPACTED THE CENTRAL CA COAST WILL ADVANCE DOWNSTREAM ALONG THE

ACTIVE SRN BRANCH AND TRACK ACROSS TX TO THE LOWER MS VALLEY.

ALREADY MOISTURE IS OVERRUNNING THE QUASI-STATIONARY FRONT NEAR

THE GULF COAST FOR A WELL-ESTABLISHED PRECIP SHIELD ACROSS THE

SOUTH CONTAINING SNOW AND FREEZING RAIN. THIS SHIELD OF MOISTURE

WILL ADVECT DOWNSTREAM DURING THE DAY INTO THE SOUTHEAST OR WITH

THE PACE OF THE NRN STREAM IMPULSE. THIS WILL RESULT IN LOCALLY 1

TO 3 OR 4 INCHES OF SNOW FROM NRN AL/GA THROUGH UPSTATE SC INTO

SERN/ERN NC WITH POSSIBLE .10 TO .50 INCH OF ICING THREAT FROM

NRN/CENTRAL GA THROUGH MUCH OF SC INTO SERN NC AND THE BEGINNING

OF A PARALYZING ICE STORM. AS THE SRN STREAM FEATURE CROSSES TX TO

THE LWR MS VALLEY... SOME SLIGHT AMPLIFICATION WILL OCCUR AS PAC

DYNAMICS NEAR THE NW WILL DIG DOWN THE FRONT RANGE OF THE ROCKIES

INTO THE CENTRAL PLAINS. THUS THE GENERALLY SUPPRESSED PRECIP

SHIELD ACROSS TX/LA WILL BEGIN TO EXPAND AND LIFT ACROSS THE SOUTH

AND TOWARD THE SRN APPALACHIANS... WHILE INDUCING A WAVE OF LOW

PRESSURE NEAR THE CENTRAL GULF COAST. THIS WOULD RESULT IN SOME

LIGHT AND MINIMAL ACCUMULATIONS OF SNOW ACROSS NORTH TX BUT A

DECENT AMOUNT OF ICING FROM THE HILL COUNTRY OF TX THROUGH ERN

TX/MUCH OF LA TO NORTH CENTRAL MS. WPC STAYED VERY CLOSE TO A

COMPROMISE OF THE 00Z GFS... ECMWF AND 21Z/10 SREF MEAN.

THE DIGGING UPSTREAM DYNAMICS OVER THE CENTRAL PLAINS WILL RAPIDLY

CATCH UP WITH THE SRN STREAM DYNAMICS TO POTENTIALLY PHASE OVER

THE SERN PORTION OF THE COUNTRY. THIS WILL ALLOW A SIGNIFICANT

INCREASE IN MOISTURE ADVECTION FROM THE GULF OF MEXICO AND

ATLANTIC TO INTERACT WITH A DEVELOPING

COASTAL LOW ALONG THE SOUTHEAST COAST... WHILE ONE OF THE MORE

IMPRESSIVE CONFLUENT ZONES ALOFT KEEPS THE ARCTIC AREA OF HIGH

PRESSURE ENTRENCHED OVER THE EAST. A TRUE BAROCLINIC LEAF PRECIP

SHIELD WILL EVOLVE FEATURING MAJOR ICING FROM ATL TOWARD CAE THEN

SHIFTING NORTH TOWARD RDU AND A VERY HEALTHY DEFORMATION ZONE OF

BANDING SNOWFALL FROM NRN GA/SWRN NC/NWRN SC NEWRD TO SWRN/CENTRAL

VA BEFORE REACHING THE DC/BALT/PHIL METRO AREAS. THE ICE

ACCUMULATIONS REMAIN MIND-BOGGLING IF NOT HISTORICAL WITH

ADDITIONAL .50 TO 1 INCH AXIS FROM ATL/AHN/AGS TO CAE TO RDU AND 8

TO 10 INCHES OF SNOW FROM AVL/GSP TO ROA/LYH/CHO AND JUST SOUTH OF

IAD/DCA WITH A POSSIBLE FOOT NEAR SWRN NC/NWRN SC. WPC CONTINUED

THE COMPROMISE OF THE GFS/ECMWF/UKMET WITH SUPPORT FROM THE SREF

MEAN FOR THE BEGINNING OF A CLASSIC EAST COAST WINTER STORM.

[mitchnick]

I'm surprised the NAM has a pesky warm layer at 925mb for a while imby, even on its 6Z run

[BristowWx]

AM heavy snow disco from wpc....worth saving...you don't often seen some of the language used in this one

A HIGH SOCIETAL IMPACT WINTER STORM IS IMMINENT ACROSS THE SRN

TIER OF THE COUNTRY AND VERY LIKELY TO PROCEED UP THE EAST COAST

ON WED AND THURS... BASICALLY EXTENDING FROM TX/LA TO NEW ENGLAND.

A VERY COMPLEX UPPER PATTERN WITH SPLIT FLOW REGIME ACROSS THE ERN

TWO-THIRDS OF THE COUNTRY... WHILE A MAMMOTH DOME OF SURFACE

ARCTIC HIGH PRESSURE CONSUMES THE ENTIRE REGION AND ESPECIALLY

EAST OF THE APPALACHIANS. AN IMPRESSIVE AND DYNAMIC IMPULSE OVER

THE MID MS VALLEY WILL GLIDE ALONG THE NRN STREAM AND REACH THE

NORTHEAST COAST ON TUES. MEANWHILE... THE LAST SHORT WAVE THAT

IMPACTED THE CENTRAL CA COAST WILL ADVANCE DOWNSTREAM ALONG THE

ACTIVE SRN BRANCH AND TRACK ACROSS TX TO THE LOWER MS VALLEY.

ALREADY MOISTURE IS OVERRUNNING THE QUASI-STATIONARY FRONT NEAR

THE GULF COAST FOR A WELL-ESTABLISHED PRECIP SHIELD ACROSS THE

SOUTH CONTAINING SNOW AND FREEZING RAIN. THIS SHIELD OF MOISTURE

WILL ADVECT DOWNSTREAM DURING THE DAY INTO THE SOUTHEAST OR WITH

THE PACE OF THE NRN STREAM IMPULSE. THIS WILL RESULT IN LOCALLY 1

TO 3 OR 4 INCHES OF SNOW FROM NRN AL/GA THROUGH UPSTATE SC INTO

SERN/ERN NC WITH POSSIBLE .10 TO .50 INCH OF ICING THREAT FROM

NRN/CENTRAL GA THROUGH MUCH OF SC INTO SERN NC AND THE BEGINNING

OF A PARALYZING ICE STORM. AS THE SRN STREAM FEATURE CROSSES TX TO

THE LWR MS VALLEY... SOME SLIGHT AMPLIFICATION WILL OCCUR AS PAC

DYNAMICS NEAR THE NW WILL DIG DOWN THE FRONT RANGE OF THE ROCKIES

INTO THE CENTRAL PLAINS. THUS THE GENERALLY SUPPRESSED PRECIP

SHIELD ACROSS TX/LA WILL BEGIN TO EXPAND AND LIFT ACROSS THE SOUTH

AND TOWARD THE SRN APPALACHIANS... WHILE INDUCING A WAVE OF LOW

PRESSURE NEAR THE CENTRAL GULF COAST. THIS WOULD RESULT IN SOME

LIGHT AND MINIMAL ACCUMULATIONS OF SNOW ACROSS NORTH TX BUT A

DECENT AMOUNT OF ICING FROM THE HILL COUNTRY OF TX THROUGH ERN

TX/MUCH OF LA TO NORTH CENTRAL MS. WPC STAYED VERY CLOSE TO A

COMPROMISE OF THE 00Z GFS... ECMWF AND 21Z/10 SREF MEAN.

THE DIGGING UPSTREAM DYNAMICS OVER THE CENTRAL PLAINS WILL RAPIDLY

CATCH UP WITH THE SRN STREAM DYNAMICS TO POTENTIALLY PHASE OVER

THE SERN PORTION OF THE COUNTRY. THIS WILL ALLOW A SIGNIFICANT

INCREASE IN MOISTURE ADVECTION FROM THE GULF OF MEXICO AND

ATLANTIC TO INTERACT WITH A DEVELOPING

COASTAL LOW ALONG THE SOUTHEAST COAST... WHILE ONE OF THE MORE

IMPRESSIVE CONFLUENT ZONES ALOFT KEEPS THE ARCTIC AREA OF HIGH

PRESSURE ENTRENCHED OVER THE EAST. A TRUE BAROCLINIC LEAF PRECIP

SHIELD WILL EVOLVE FEATURING MAJOR ICING FROM ATL TOWARD CAE THEN

SHIFTING NORTH TOWARD RDU AND A VERY HEALTHY DEFORMATION ZONE OF

BANDING SNOWFALL FROM NRN GA/SWRN NC/NWRN SC NEWRD TO SWRN/CENTRAL

VA BEFORE REACHING THE DC/BALT/PHIL METRO AREAS. THE ICE

ACCUMULATIONS REMAIN MIND-BOGGLING IF NOT HISTORICAL WITH

ADDITIONAL .50 TO 1 INCH AXIS FROM ATL/AHN/AGS TO CAE TO RDU AND 8

TO 10 INCHES OF SNOW FROM AVL/GSP TO ROA/LYH/CHO AND JUST SOUTH OF

IAD/DCA WITH A POSSIBLE FOOT NEAR SWRN NC/NWRN SC. WPC CONTINUED

THE COMPROMISE OF THE GFS/ECMWF/UKMET WITH SUPPORT FROM THE SREF

MEAN FOR THE BEGINNING OF A CLASSIC EAST COAST WINTER STORM.

 

That and the KOCIN map from last night are worth printing and framing...we only see this a handful of times in our lives

[WxMan1]

Let's take the (realistic) worst case scenario from last night's euro.  12z to 18z we lose to sleet, and the deformation band after that misses your backyard.  Still looking at 8" + sleet + something on the backside.  Now we are looking at a worst-case scenario that is in the ballpark of the GFS.  Our envelope is tightening, with 6-8" on the low side, and that is a beautiful thing.

 

Yeah, I have to agree.  My thoughts from early yesterday morning haven't changed much in 24 hours, except for probably much higher probabilities on the 6-8" amounts, and still higher probs for the upper bound.

 

As you noted, I still think we're all good for at least 6-8" on the front side before any mixing/changeover issues, which if we dry slot it wouldn't be that big of a deal because the pcpn/rates would be lighter anyway.  That deformation zone/comma head potential has me most intrigued.  This is what could potentially make for an overperforming system.  I'm still thinking more like 2-4" on the back side IMBY (northern AA County), but I think we I95ers to the Bay have got a shot at the higher end of that, possibly even more.

 

So I'm optimistically holding onto a 8-12" total IMBY, hoping to at least break double digits. Either way, this would essentially at least double what the 1/2 and 1/21 Miller Bs did IMBY (I received 5.25 and 5 inches with those respectively).

[WinterWxLuvr]

I hope everyone here gets what they want from this storm.  For me, that's 6 inches.  Pretty, not much work.

 

With all the talk of data input, I guess this mornings runs at 12z will give a very clear picture of what to expect.

 

Keep the posts coming.  Love to read it.  Not much I can add to the discussion.

[SomeguyfromTakomaPark]

Yeah, I have to agree.  My thoughts from early yesterday morning haven't changed much in 24 hours, except for probably much higher probabilities on the 6-8" amounts, and still higher probs for the upper bound.

 

As you noted, I still think we're all good for at least 6-8" on the front side before any mixing/changeover issues, which if we dry slot it wouldn't be that big of a deal because the pcpn/rates would be lighter anyway.  That deformation zone/comma head potential has me most intrigued.  This is what could potentially make for an overperforming system.  I'm still thinking more like 2-4" on the back side IMBY (northern AA County), but I think we I95ers to the Bay have got a shot at the higher end of that, possibly even more.

 

So I'm optimistically holding onto a 8-12" total IMBY, hoping to at least break double digits. Either way, this would essentially at least double what the 1/2 and 1/21 Miller Bs did IMBY (I received 5.25 and 5 inches with those respectively).

Sounds good to me! I'm hoping we get smoked with the deform band like the EURO is showing.

[H2O]

Let's take the (realistic) worst case scenario from last night's euro.  12z to 18z we lose to sleet, and the deformation band after that misses your backyard.  Still looking at 8" + sleet + something on the backside.  Now we are looking at a worst-case scenario that is in the ballpark of the GFS.  Our envelope is tightening, with 6-8" on the low side, and that is a beautiful thing.

 

yup.  .75" of precip in before the warm layer intrusion is a good slug of snow.  Was talking to a couple people this morning that the higher end of a 4-8" warning criteria(meaning 8") is def a possibility based on the overnight runs

[winterymix]

Yeah, I have to agree.  My thoughts from early yesterday morning haven't changed much in 24 hours, except for probably much higher probabilities on the 6-8" amounts, and still higher probs for the upper bound.

 

As you noted, I still think we're all good for at least 6-8" on the front side before any mixing/changeover issues, which if we dry slot it wouldn't be that big of a deal because the pcpn/rates would be lighter anyway.  That deformation zone/comma head potential has me most intrigued.  This is what could potentially make for an overperforming system.  I'm still thinking more like 2-4" on the back side IMBY (northern AA County), but I think we I95ers to the Bay have got a shot at the higher end of that, possibly even more.

 

So I'm optimistically holding onto a 8-12" total IMBY, hoping to at least break double digits. Either way, this would essentially at least double what the 1/2 and 1/21 Miller Bs did IMBY (I received 5.25 and 5 inches with those respectively).

 

What will you look for in the 12Z GFS?   Do you suppost it will consolidate the low more than it has in recent runs?

[CAPE]

Even Wakefield pretty bullish:

 

[twim19]

03z SREFS are at a mean of 5" of snow in Salisbury. I was surprised. They're slowly bumping up totals with each run. Hmm...

Still having a hard time figuring that out. Every model seems to leave this nice little slice of rain from Lewis to VA Beach.  

Here's to hoping the Euro continues it's nudge East.  Really, just need like 25 miles. 

[weathafella]

Great storm incoming for your region folks...potential classic. Contemplating an excuse to come down......

[Bob Chill]

Great storm incoming for your region folks...potential classic. Contemplating an excuse to come down......

You are quite welcome to join us. Jim Cantore on the other hand....notsomuch

Euro ens mean slp track about the same. Over the N.C. sounds to off of acy. However, 850 temps much improved. Worst panel runs 0c along 95 in VA but cuts across far s md up the bay and across the northern delmarva. Awesome.

[aldie 22]

Wusa9 must factor in mixing and such...this euro total seems different

[mappy]

Even Wakefield pretty bullish:

 

totalsnow.png

 

Here is the snowfall map from State College

[Swiscaster]

Here is the snowfall map from State College

That 1-2" area north of Garrett County collides into the Euro's 12"+ band on the post above, hahaaaa!

[SomeguyfromTakomaPark]

Wusa9 must factor in mixing and such...this euro total seems different

image.jpg

 

Yeah....even with some significant mixing I don't see how we don't get a foot in DC if the EURO is right.