Jan 22-23 East Coast Storm Discussion

[strongwxnc]

Word. Thanks for posting this.. The Line in this type usually cuts my county is half. That is what happens when you have an elevation less than 600'in the east to close to 3500' in the west. 

 

No Problem. Yes it does lessen and in fact it shows very little in the way of freezing rain by the time you get to Rutherfordton where you start getting sleet and even some snow as the predominate precipitation type.

[wxduncan]

From Brad P. Blog Update:

http://wxbrad.com/weekend-winter-storm-potential-but-details-still-very-uncertain/

[PackGrad05]

Another question about how much impact this will have is what temperatures look like AFTER.  Will it be a quick thaw or stick around a while/  Obviously, this also depends on what is on the ground, with albedo.

[MillerA]

From Jeff crum, twc Charlotte.

http://www.twcnews.com/nc/charlotte/weather.html

[jburns]

Here is the long term afternoon discussion from RAL.
 
 
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 355 PM MONDAY...

THURSDAY AND THURSDAY NIGHT WILL BE A FAIRLY QUIET PERIOD
WEATHER WISE AS COLD HIGH PRESSURE MOVES THROUGH THE OHIO VALLEY
TRYING TO SUPPLY SOME COLD AIR AHEAD OF A LOW PRESSURE SYSTEM MOVING
OUT OF THE DEEP SOUTH WHICH COULD GIVE US THE POTENTIAL FOR SOME
WINTER WEATHER EARLY THIS WEEKEND. STILL...WITH PLENTY OF
INSOLATION...HIGHS SHOULD REACH THE MID 40S TO NEAR 50 DEGREES ON
THURSDAY AFTERNOON WITH LOWS OVERNIGHT NEAR FREEZING.

ON FRIDAY THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL TRACK ACROSS
THE DEEP SOUTH AND BEGIN TO MOVE INTO THE CAROLINAS BY EARLY FRIDAY
MORNING. MODELS ARE IN FAIRLY GOOD AGREEMENT AS FAR AS THE TIMING
AND TRACK OF THE SYSTEM WITH AN UPPER LEVEL LOW DEVELOPING WEST OF
THE SURFACE LOW AND DRIVING THE SURFACE LOW UP THE CAROLINA
COASTLINE BY LATE FRIDAY INTO SATURDAY MORNING AND THEN OFF TO THE
NORTHEAST. THE UPPER LEVEL LOW THEN HOVERS OVER CENTRAL NC ON
SATURDAY BEFORE MOVING OFF TO THE EAST AS WELL. MOST ENSEMBLE
MEMBERS SHOW A SIMILAR SETUP AND THUS CONFIDENCE IS HIGH THAT A
STORM WILL AFFECT CENTRAL NC THIS WEEKEND.

WHAT IS LESS CONFIDENT IS HOW MUCH PRECIPITATION WE WILL HAVE AND
WHAT TYPE OF PRECIPITATION THAT WILL BE. WE ARE STILL FIVE TO SIX
DAYS OUT ON THIS SYSTEM WHICH AUTOMATICALLY INTRODUCES A LOT OF
UNCERTAINTY INTO THE PRECIPITATION FORECAST...AND EVEN MORE INTO THE
FROZEN PRECIPITATION FORECAST. HERE IS WHAT WE KNOW SO FAR. THERE
WILL BE TWO CHANCES FOR FROZEN PRECIPITATION WITH THIS SYSTEM...ONE
ON THE VERY FRONT END...AND THE OTHER ON THE BACK END. AS FAR AS THE
FRONT END IS CONCERNED...FORECAST SOUNDINGS AND THICKNESS INDICATE
THAT THE BEST CHANCE FOR SNOW WOULD BE ACROSS THE NORTHWEST PIEDMONT
WHERE TEMPERATURES ARE NEAR OR BELOW ZERO CELSIUS THROUGH MUCH OF
THE ATMOSPHERE WITH STRONG LIFT IN THE SNOW GROWTH ZONE. THAT BEING
SAID THERE IS STILL A FAIRLY DEEP BUT WEAK WARM NOSE FROM THE
SURFACE THROUGH 850 MB AT 6Z FRIDAY. THIS WARM NOSE INCREASES BY 12Z
AND THUS ANY PERIOD OF SNOW ON THE FRONT END WOULD BE SHORT LIVED
AND CONFINED TO THE TRIAD BUT TRANSITIONING TO RAIN FOR MUCH OF THE
DAY ON FRIDAY. IMPACTS FROM THIS INITIAL SNOWFALL WOULD BE VIRTUALLY
NIL.

OF MORE CONCERN WOULD BE THE CHANCE FOR SNOWFALL ON THE BACK END OF
THE SYSTEM WHICH COULD SEE SOME TRANSITIONAL P-TYPE FRIDAY NIGHT
INTO SATURDAY MORNING BEFORE CHANGING OVER TO SNOW SATURDAY
MORNING...FIRST IN THE NORTHWEST PIEDMONT...THEN POINTS SOUTH AND
EAST LATER SATURDAY MORNING THROUGH EARLY AFTERNOON. LIFT WILL BE
BEST EARLIER IN THE MORNING AND THEN WANING AS THE SYSTEM PULLS OFF
TO THE NORTHEAST. WITH THE TRACK OF THE UPPER LOW ACROSS THE
STATE...THE BEST CHANCE FOR MORE PROLONGED SNOWFALL WILL BE ACROSS
THE NORTHERN COUNTIES BUT ALL COUNTIES SHOULD HAVE AT LEAST A SMALL
CHANCE OF SEEING SOME SNOW WITH THIS SYSTEM EVEN IF IT IS NOT
ACCUMULATING.

WHAT WE DONT KNOW: IT IS EXTREMELY EARLY TO START PREDICTING
SNOWFALL AMOUNTS AS ANY SHIFT IN TRACK OR STRENGTH OF THE STORM
DURING THE NEXT 5 DAYS WILL ALTER THESE PREDICTIONS DRAMATICALLY.
ALSO THE AMOUNT OF RAINFALL AND HOW HIGH TEMPERATURES GET DURING THE
DAY ON FRIDAY WILL PLAY A ROLE IN ANY ACCUMULATION PREDICTIONS AS
WELL. THE DIURNAL TIMING AND FORWARD SPEED OF THE SYSTEM WILL ALSO
FACTOR IN TO FINAL PRECIPITATION FORECASTS.

THE SYSTEM WILL BE EXITING ON SUNDAY MORNING TO THE NORTHEAST AND
HIGH PRESSURE OVER THE SOUTH WILL MOVE IN FOR SUNDAY AND
MONDAY...OPENING THE DOOR FOR A RETURN TO DRIER AND WARMER WEATHER.

&&

 

 

Not exactly bullish.

[SN_Lover]

GFS amping up more. :/

[Jon]

18z GFS hanging back more than the 12z, will go negative earlier and more west...WV/DC/PA hit incoming.

Edit: by earlier I mean more west, not time...it will actually take longer to go neg

[rduwx]

I don't think the 18z gfs is going to cut it.  The trough axis is already neutral back in east Texas.  

[SN_Lover]

Even VA would have issues with this run. Rain for even the mountains of NC this run. 

[Jonathan]

So now it's doom, gloom, depression and despair until 2am.

Edit: this is banter...I'm on my phone...sorry!

[PackGrad05]

I'm not buying the new GFS.  I think it is overdoing the energy coming out of the midwest.  Not wish casting...  but I'd go for a blend of GFS and EURO at the moment.

[Blue_Ridge_Escarpment]

So it's the GFS versus.....well every other model haha. If the GFS was the one showing snow for us it would be thrown out. What's different?

[NCSU_Pi]

Here is the long term afternoon discussion from RAL.

 

 

.LONG TERM /THURSDAY THROUGH MONDAY/...

AS OF 355 PM MONDAY...

THURSDAY AND THURSDAY NIGHT WILL BE A FAIRLY QUIET PERIOD

WEATHER WISE AS COLD HIGH PRESSURE MOVES THROUGH THE OHIO VALLEY

TRYING TO SUPPLY SOME COLD AIR AHEAD OF A LOW PRESSURE SYSTEM MOVING

OUT OF THE DEEP SOUTH WHICH COULD GIVE US THE POTENTIAL FOR SOME

WINTER WEATHER EARLY THIS WEEKEND. STILL...WITH PLENTY OF

INSOLATION...HIGHS SHOULD REACH THE MID 40S TO NEAR 50 DEGREES ON

THURSDAY AFTERNOON WITH LOWS OVERNIGHT NEAR FREEZING.

ON FRIDAY THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL TRACK ACROSS

THE DEEP SOUTH AND BEGIN TO MOVE INTO THE CAROLINAS BY EARLY FRIDAY

MORNING. MODELS ARE IN FAIRLY GOOD AGREEMENT AS FAR AS THE TIMING

AND TRACK OF THE SYSTEM WITH AN UPPER LEVEL LOW DEVELOPING WEST OF

THE SURFACE LOW AND DRIVING THE SURFACE LOW UP THE CAROLINA

COASTLINE BY LATE FRIDAY INTO SATURDAY MORNING AND THEN OFF TO THE

NORTHEAST. THE UPPER LEVEL LOW THEN HOVERS OVER CENTRAL NC ON

SATURDAY BEFORE MOVING OFF TO THE EAST AS WELL. MOST ENSEMBLE

MEMBERS SHOW A SIMILAR SETUP AND THUS CONFIDENCE IS HIGH THAT A

STORM WILL AFFECT CENTRAL NC THIS WEEKEND.

WHAT IS LESS CONFIDENT IS HOW MUCH PRECIPITATION WE WILL HAVE AND

WHAT TYPE OF PRECIPITATION THAT WILL BE. WE ARE STILL FIVE TO SIX

DAYS OUT ON THIS SYSTEM WHICH AUTOMATICALLY INTRODUCES A LOT OF

UNCERTAINTY INTO THE PRECIPITATION FORECAST...AND EVEN MORE INTO THE

FROZEN PRECIPITATION FORECAST. HERE IS WHAT WE KNOW SO FAR. THERE

WILL BE TWO CHANCES FOR FROZEN PRECIPITATION WITH THIS SYSTEM...ONE

ON THE VERY FRONT END...AND THE OTHER ON THE BACK END. AS FAR AS THE

FRONT END IS CONCERNED...FORECAST SOUNDINGS AND THICKNESS INDICATE

THAT THE BEST CHANCE FOR SNOW WOULD BE ACROSS THE NORTHWEST PIEDMONT

WHERE TEMPERATURES ARE NEAR OR BELOW ZERO CELSIUS THROUGH MUCH OF

THE ATMOSPHERE WITH STRONG LIFT IN THE SNOW GROWTH ZONE. THAT BEING

SAID THERE IS STILL A FAIRLY DEEP BUT WEAK WARM NOSE FROM THE

SURFACE THROUGH 850 MB AT 6Z FRIDAY. THIS WARM NOSE INCREASES BY 12Z

AND THUS ANY PERIOD OF SNOW ON THE FRONT END WOULD BE SHORT LIVED

AND CONFINED TO THE TRIAD BUT TRANSITIONING TO RAIN FOR MUCH OF THE

DAY ON FRIDAY. IMPACTS FROM THIS INITIAL SNOWFALL WOULD BE VIRTUALLY

NIL.

OF MORE CONCERN WOULD BE THE CHANCE FOR SNOWFALL ON THE BACK END OF

THE SYSTEM WHICH COULD SEE SOME TRANSITIONAL P-TYPE FRIDAY NIGHT

INTO SATURDAY MORNING BEFORE CHANGING OVER TO SNOW SATURDAY

MORNING...FIRST IN THE NORTHWEST PIEDMONT...THEN POINTS SOUTH AND

EAST LATER SATURDAY MORNING THROUGH EARLY AFTERNOON. LIFT WILL BE

BEST EARLIER IN THE MORNING AND THEN WANING AS THE SYSTEM PULLS OFF

TO THE NORTHEAST. WITH THE TRACK OF THE UPPER LOW ACROSS THE

STATE...THE BEST CHANCE FOR MORE PROLONGED SNOWFALL WILL BE ACROSS

THE NORTHERN COUNTIES BUT ALL COUNTIES SHOULD HAVE AT LEAST A SMALL

CHANCE OF SEEING SOME SNOW WITH THIS SYSTEM EVEN IF IT IS NOT

ACCUMULATING.

WHAT WE DONT KNOW: IT IS EXTREMELY EARLY TO START PREDICTING

SNOWFALL AMOUNTS AS ANY SHIFT IN TRACK OR STRENGTH OF THE STORM

DURING THE NEXT 5 DAYS WILL ALTER THESE PREDICTIONS DRAMATICALLY.

ALSO THE AMOUNT OF RAINFALL AND HOW HIGH TEMPERATURES GET DURING THE

DAY ON FRIDAY WILL PLAY A ROLE IN ANY ACCUMULATION PREDICTIONS AS

WELL. THE DIURNAL TIMING AND FORWARD SPEED OF THE SYSTEM WILL ALSO

FACTOR IN TO FINAL PRECIPITATION FORECASTS.

THE SYSTEM WILL BE EXITING ON SUNDAY MORNING TO THE NORTHEAST AND

HIGH PRESSURE OVER THE SOUTH WILL MOVE IN FOR SUNDAY AND

MONDAY...OPENING THE DOOR FOR A RETURN TO DRIER AND WARMER WEATHER.

&&

 

 

Not exactly bullish.

 

Best part about this to me is that they didn't throw in the I-word. Or Zr-word, I guess.

 

Is RAH trying to save from raising alarms, or is there good reason to think the transition zone will be narrow, and Zr accumulations relatively small?

[DopplerWx]

wow, yea much of va is rain this run.

[Bsudweather]

Well after all it is the 18z GFS we can toss it.

[Jon]

Even VA would have issues with this run. Rain for even the mountains of NC this run.

They should do alright, maybe a bit less precip but nothing too different so far

[SN_Lover]

wow, yea much of va is rain this run.

Gonna hop over to the mid-atlantic side to see the meltdown XD jk 

[wxduncan]

Well after all it is the 18z GFS we can toss it.

Already thrown in the trash.

[RubiksDestroyer]

I'd only begin worrying about what the 18z GFS is showing if its ensembles support it.

[Blue_Ridge_Escarpment]

Gonna hop over to the mid-atlantic side to see the meltdown XD jk

Yeah I'm sure they're melting down over one model run of a model suite that is totally different than every other model. They may be over here laughing at us.

[UNCCmetgrad]

Glad to see balance has returned to the force and the GFS is back in everyone's dog house again after it was crowned a few day ago.

[HWY316wx]

LPS is running up around the GA / TN border

[DopplerWx]

well, gfs has been really consistent with todays runs in regards to the lp placement. similar to last weekends storm.  

[Blue_Ridge_Escarpment]

18Z GFS actually colder at the surface by 2 degrees versus 12Z run in CAD areas. 33 degrees now

[Tacoma]

I don't think the 18z gfs is going to cut it.  The trough axis is already neutral back in east Texas.  

I'm no expert but I've read from the ones that are suppose to be that the worst time for all the models is the 18z, that it can't be trusted, I hopes they are right. 

[GlaringSun]

Where did the Euro and the EPS track the LP?

[jburns]

I'm no expert but I've read from the ones that are suppose to be that the worst time for all the models is the 18z, that it can't be trusted, I hopes they are right. 

10 years ago they were right.  Not so much these days.

[superjames1992]

I'm no expert but I've read from the ones that are suppose to be that the worst time for all the models is the 18z, that it can't be trusted, I hopes they are right. 

 

I don't think there's any statistically significant difference in the verification scores between any of the GFS model runs.  They're all about the same.

 

That being said, it's one run and the GFS is the outlier... but it is concerning.

[strongwxnc]

All the talk about the GFS 18Z being invalid or BS has been explained. This is a great link about it. 

http://www.americanwx.com/bb/index.php/topic/32149-gfs-12z-and-0z-runs-compared-to-6z-and-18z-runs/

But the inner me wants to throw it out

 

 

I'm no expert but I've read from the ones that are suppose to be that the worst time for all the models is the 18z, that it can't be trusted, I hopes they are right. 

[rduwx]

Well right now we have the gfs, cmc, and I believe the ukie all cutting with a miller b type storm.  Then we everyone's favorite, euro showing a the southern track miller a.  Am I remembering this correctly? It'll be interesting to see how this one turns out.