Christmas Storm V

[snowlover91]

well it's not about samples, it's about that it's not even formed yet. The myriad of vorts up in Canada will form the wave in the next day or so.

The bomb solution always relied on a phase just in the nick of time. The modelling of the intensity and timing of the phasing of 2 streams has always been difficult. We've had plenty of instances where models failed to model this corrently even in the short term.

That's what I mean though, until the vort is sampled the models won't have a good handle on it, and that won't be until later tomorrow sometime. That's why I expect some big shifts tomorrow possibly.

[beanskip]

To your point (and in all seriousness) -- and speaking of the RUC -- looking at this map for tomorrow from 21z RUC, it's not hard to imagine there might be some confusion on the northern shortwaves. I count 17 potential phasers.

That's what I mean though, until the vort is sampled the models won't have a good handle on it, and that won't be until later tomorrow sometime. That's why I expect some big shifts tomorrow possibly.

[superjames1992]

URGENT - WINTER WEATHER MESSAGE

NATIONAL WEATHER SERVICE NASHVILLE TN

301 PM CST THU DEC 23 2010

...A LOW PRESSURE SYSTEM WILL MOVE ALONG THE GULF COAST CHRISTMAS

EVE NIGHT AND CHRISTMAS DAY AND INTERACT WITH AN UPPER LEVEL

SYSTEM TO OUR NORTH AND SPREAD SNOW ACROSS THE MID STATE.

.MOISTURE WILL BE DRAWN NORTH AHEAD OF THE STORM SYSTEM AS COLDER AIR

SINKS SOUTHWARD. A MIX OF SNOW...SLEET AND RAIN IS EXPECTED FRIDAY

NIGHT...WITH SNOW CONTINUING INTO SATURDAY NIGHT AND EARLY SUNDAY. AT

THIS TIME...AN ACCUMULATING SNOW IS EXPECTED WITH UP TO TWO INCHES

OVER MOST PARTS OF THE MID STATE AND THREE TO FOUR INCHES ALONG

THE CUMBERLAND PLATEAU AND NORTHEAST MIDDLE TENNESSEE BY SUNDAY

MORNING.

TNZ010-011-031>034-065-066-240400-

/O.NEW.KOHX.WS.A.0004.101225T0600Z-101226T1200Z/

CLAY-PICKETT-JACKSON-PUTNAM-OVERTON-FENTRESS-WHITE-CUMBERLAND-

INCLUDING THE CITIES OF...CELINA...BYRDSTOWN...GAINESBORO...

COOKEVILLE...LIVINGSTON...JAMESTOWN...SPARTA...CROSSVILLE

301 PM CST THU DEC 23 2010

...WINTER STORM WATCH IN EFFECT FROM LATE FRIDAY NIGHT THROUGH

LATE SATURDAY NIGHT...

THE NATIONAL WEATHER SERVICE IN NASHVILLE HAS ISSUED A WINTER

STORM WATCH...WHICH IS IN EFFECT FROM LATE FRIDAY NIGHT THROUGH

LATE SATURDAY NIGHT.

* GEOGRAPHIC AREA: NORTHEAST MIDDLE TENNESSEE AND PLATEAU.

* TIMING: FROM MIDNIGHT CHRISTMAS EVE NIGHT UNTIL 6 AM CST SUNDAY

MORNING.

* ACCUMULATIONS:3 TO 4 INCHES...WITH LOCALLY 5 INCHES.

* IMPACTS:SNOW COVERED ROADS WILL IMPACT TRAVEL THROUGH THESE

AREAS...MAKING DRIVING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT

SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.

CONTINUE TO MONITOR THE LATEST FORECASTS.

&&

$$

BOYD

[jaxjagman]

I have a question for you pros.If these two pieces on this time frame were to merge,phase.What would likely happen?Thanks

http://raleighwx.americanwx.com/models/gfs/18zgfs500mbvort024.gif

[Rankin5150]

With this type of pattern we are in...anything is possible and we will see some changes. I witnessed different solutions the past couple of systems we had roll through. Like Wow said, we need to see what tonights 00z show. Me personally? I am not giving up on this till the end. I want to see what happens and which model was the closest. There is a lot to be learned form this. Good luck everyone...

[WidreMann]

I no longer have that feeling that this will come back from the dead. La Nina wins again. Somehow Rocky Mount will still get 6", of course.

[HKY_WX]

I no longer have that feeling that this will come back from the dead. La Nina wins again. Somehow Rocky Mount will still get 6", of course.

I'm gonna go start shining up my sled now.

[dsaur]

well it's not about samples, it's about that it's not even formed yet. The myriad of vorts up in Canada will form the wave in the next day or so.

The bomb solution always relied on a phase just in the nick of time. The modelling of the intensity and timing of the phasing of 2 streams has always been difficult. We've had plenty of instances where models failed to model this corrently even in the short term.

That's kept running thru my head... reading Robert describe the phase as seeming to barely get under the tent. Seems like the models have been consistent in keeping it right at the edge of not happening.... on one side or the other...but always real close to the edge. So I kept thinking this would come down to the last minute as to how it played out...once all the players were in the country, and near by.

[CaryWx]

beanskip, the RUC has that 'faster' s/w closed too. Open on all other models? FWIW

[lilj4425]

I have a question for you pros.If these two pieces on this time frame were to merge,phase.What would likely happen?Thanks

http://raleighwx.ame...00mbvort024.gif

It depends where it phases. If it phased where the Euro showed a few runs ago, we'd be golden. If it phases too far east, we're SOL except for maybe in central/eastern NC.

[beanskip]

Yeah, I've been toggling between the 18z NAM at 18 hours and the 21z RUC at 15 for 5 minutes.

I really only see two things -- the southern shortwave looks more impressive and there is more ridging in the west -- at 5h, the NAM has the 558 line a hair south of the Canadian border, the RUC has it well into Canada -- a couple hundred miles. The northern shorwaves seem oriented the same, although the one droping down from Canada is off the RUC's screen.

I don't know, doesn't look like anything earth-shattering.

beanskip, the RUC has that 'faster' s/w closed too. Open on all other models? FWIW

[snowlover91]

To your point (and in all seriousness) -- and speaking of the RUC -- looking at this map for tomorrow from 21z RUC, it's not hard to imagine there might be some confusion on the northern shortwaves. I count 17 potential phasers.

Exactly what I'm saying, this phasing is very difficult for the models to handle, even high resolution ones like the RUC. Also of note, the RUC is much stronger with the southern vort and weaker/less amped with the northern energy. Going to be interesting to watch play out, I expect some big model changes tomorrow just like we saw last night.

[CaryWx]

beanskip, thanks...just sifting through straws right now.

[snowlover91]

beanskip, thanks...just sifting through straws right now.

It does make a difference though, the RUC is much stronger with the southern vort and a little weaker with the northern stream. Might not affect phasing, but it might. It's hard to say since the RUC only goes out 18 hours, but I've known it to be the best model to use in short range, much much better than the NAM. It's SIM reflectivity is very good at predicting where the axis of heaviest precip will occur and how it will play out as well.

[strongwxnc]

Love the outlook Wow. I also am feeling a little weenie. Such a trend with the euro for 6 runs. I understand that we have the players on the table know. But do we? Skip made a great point by showing the RUC setup and all the energy coming down from the old North.

Hope you get to feeling better man!!

[HKY_WX]

Perfect example of phasing below. NOrthern stream comes in behind the southern s/w and energizes it. In the current situation, the southern vort is coming into the harsher northern stream (unless the mods are wrong and some rogue northern s/w shows up).

Jan 22, 1987, biggest hky snowfall of my lifetime 15-20 inches

http://www.meteo.psu.edu/~gadomski/NARR/1987.html

[MotoWeatherman]

Perfect example of phasing below. NOrthern stream comes in behind the southern s/w and energizes it. In the current situation, the southern vort is coming into the harsher northern stream (unless the mods are wrong and some rogue northern s/w shows up).

Jan 87, biggest hky snowfall of my lifetime 15-20 inches

http://www.meteo.psu...1987/us0122.php

Link does not work for me. Anyone else??

[WeatherNC]

beanskip, the RUC has that 'faster' s/w closed too. Open on all other models? FWIW

I am taking notice to this also... This is the 23z RUC valid 12z 12/24 (+13hrs) The RUC progs the vorticity max at 40 10^-5/s, I have not seen another model come even close to this strength.

and the 18z UKIE for comparison, slower, and no where near as intense

[weatherfide]

That's kept running thru my head... reading Robert describe the phase as seeming to barely get under the tent. Seems like the models have been consistent in keeping it right at the edge of not happening.... on one side or the other...but always real close to the edge. So I kept thinking this would come down to the last minute as to how it played out...once all the players were in the country, and near by.

I agree with you. Normally I would lose interest at 48 hours if nothing of significance is on tap. This time it seems too close to call. I will continue to watch closely. I really want to see how this story ends-for better or for worse..

[HKY_WX]

Link does not work for me. Anyone else??

http://www.meteo.psu.edu/~gadomski/NARR/1987.html

try that one, checkout jan 22

[Wow]

Link does not work for me. Anyone else??

it works

[Rankin5150]

http://www.meteo.psu.../NARR/1987.html

try that one, checkout jan 22

Was that one reconized early or was it a surprise of sorts? I looked that storm up and the snow cutoff line is AMAZING. Tells me that the Low tracked inland to throw the Charlotte area into a "screw zone"! Awesome...

[blam49er]

Was that one reconized early or was it a surprise of sorts? I looked that storm up and the snow cutoff line is AMAZING. Tells me that the Low tracked inland to throw the Charlotte area into a "screw zone"! Awesome...

I was living in Kannapolis at the time and we had heavy rain and 32-33 degress all day. I kept hearing reports of foot + snow totals on 95.7 in the Hickory area and could not believe it...

[HKY_WX]

Was that one reconized early or was it a surprise of sorts? I looked that storm up and the snow cutoff line is AMAZING. Tells me that the Low tracked inland to throw the Charlotte area into a "screw zone"! Awesome...

It basically went right up the coastline from the central GOM. It was a beaut, clark!

[eyewall]

I was living in Kannapolis at the time and we had heavy rain and 32-33 degress all day. I kept hearing reports of foot + snow totals on 95.7 in the Hickory area and could not believe it...

Ouch! That hurts (This is how I felt more than once last year). In all honesty 2010 has been one of my worst weather years ever and this La Nina doesn't help.

[Wow]

Looking at the 0z 12/22 Euro, which was the second to last run with the "bomb", here is the map valid 0z 12/25 (I found this in one of the threads posted by phil882):

And for comparision, here's the latest NAM valid at the same time (30 hrs out):

They are both fairly close in the overall setup, but the northern s/w is a bit faster on the NAM. This can help to explain just how the the slightest shifts can make a big difference.

[Rankin5150]

It basically went right up the coastline from the central GOM. It was a beaut, clark!

Well..,have YOU abandoned ship yet?

[HKY_WX]

I was living in Kannapolis at the time and we had heavy rain and 32-33 degress all day. I kept hearing reports of foot + snow totals on 95.7 in the Hickory area and could not believe it...

I was only 3 years old lol. So i don't remember it, but I do know it's the biggest in HKY that i can think of. It's basically the perfect track for western NC(west of 77). Your description reminds me of jan 2000 in reverse. Not even a flurry here and a foot in clt with 20 inches in rdu.

[Rankin5150]

Ouch! That hurts (This is how I felt more than once last year). In all honesty 2010 has been one of my worst weather years ever and this La Nina doesn't help.

AMEN Jeremy! I cannot even remember what little bit of snow we did receive. I was sitting in a screw zone most of the winter, while peeps all around me were getting hammered. WORST EVER.

[HKY_WX]

Well..,have YOU abandoned ship yet?

There's always a chance for the big dog. I still think we could end up with a general 1-3 inches across the state if the big dog fails to show up.