Christmas Storm VII

[strongwxnc]

12NAM give

GSP 5.4 with 23:1 late in the game

CLT also 5.4

AVL over 8.1"

HKY 7.2"

KAKH   NAM MOS GUIDANCE   12/25/2010  1200 UTC
DT /DEC  25/DEC  26                /DEC  27                /DEC  28
HR   18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 21 00 06 12
N/X                    31          38          24          39    22
TMP  35 36 34 34 34 34 33 34 35 35 32 31 30 29 27 30 36 38 30 27 25
DPT  28 30 31 29 28 28 28 29 28 26 25 20 17 17 17 17 16 15 17 14 16
CLD  OV OV OV OV OV OV OV OV OV OV OV OV BK CL SC SC SC FW CL CL CL
WDR  06 05 00 04 02 03 03 03 36 33 36 35 33 32 33 33 31 32 33 33 27
WSP  04 03 00 05 06 10 09 10 09 06 08 07 06 06 04 11 12 10 04 02 01
P06        89    91    88    69 	3 	3 	0 	0 	0  0  0
P12                    95          69       	4       	0 	0
Q06     	2 	2 	1 	1 	0 	0 	0 	0 	0  0  0
Q12                 	3       	1       	0       	0 	0
T06      2/ 1  2/ 3  1/ 0  0/ 0  0/ 0  0/ 0  0/ 3  0/ 1  0/11  0/ 2
T12            2/ 3        1/ 0        2/ 0        0/ 3 	1/11
SNW                 	4                   	1             	0
CIG   6  4  3  3  3  3  2  2  3  6  6  7  7  8  8  8  8  8  8  8  8
VIS   7  5  4  4  5  7  7  4  7  7  7  7  7  7  7  7  7  7  7  7  7
OBV   N BR BR BR BR  N  N BR  N  N  N  N  N  N  N  N  N  N  N  N  N

so the NAM is forecasting anywhere from 5-8" on the MOS

[eyewall]

We are at 45F according to the SOP ob. That is a bit concerning with it only being 11am.

[nchighcountrywx]

Mountains doing fine. Watching the 925s carefully for friends down in Charlotte. The 925s should cooperate in the CLT area later today.

On separate note, looks who's headed to NC:

Tweet from Jim Cantore:

@JimCantore: Christmas ending early as I prepares 4deployment on coastal #snow. Carolinas look most impressive to me. Enjoy your White Christmas :-)

(You know a big one is coming to get Cantore off his vacation)

[buckeyefan1]

We are at 45F according to the SOP ob. That is a bit concerning with it only being 11am.

My forecasted high today is for 51 deg...precip arriving sometime later this evening/overnight..currently at 45 and rising

[burgertime]

I know its nowcast time but unfortunately the new GFS went a little east and seemed slightly weeker. Still good but hope this is not a last minute trend. Moisture was a little less also for many.

Yea GFS looked to throw a damper on things.

[BIG FROSTY]

GFS quiet abit drier this run .42 ? Not seeing any back building of precip in nw AL. and MIss. that's a little concerning

[DeepSouthSC]

My forecasted high today is for 51 deg...precip arriving sometime later this evening/overnight..currently at 45 and rising

Yes, I saw our forecasted high today, buckeye. By the way, I'm located in the Blythewood area. I'm hoping the changeover from rain-to-snow is rather swift, neighbor.

Have a Merry Christmas everyone!

[DaculaWeather]

Would someone that knows tell me... in the upper left corner of this loop, there is a band that just appeared and moving south quickly... could that be the shot from the north that will kick everything off or just another band of snow forming?

http://www.daculawea...east_master.php

[SBUWX23]

Yea GFS looked to throw a damper on things.

Looking at QPF for moisture at this stage of the game is not the best idea. QPF is never going to be accurate. Focus on the actual trends and not the fact the model may have dropped QPF slightly.

[burrel2]

I'm wondering if that convection south of Pensacola,FL explains the less qpf on the GFS in the Central Carolinas?

[burgertime]

Looking at QPF for moisture at this stage of the game is not the best idea. QPF is never going to be accurate. Focus on the actual trends and not the fact the model may have dropped QPF slightly.

Yes sir! Should have quantified my statements...I wasn't saying I was buying it just that the GFS was being the GFS I guess. I know you got to pound it in our heads about the QPF!

[DaculaWeather]

SPC That's some wind...

..NO SVR TSTM AREAS FORECAST......SYNOPSIS/DISCUSSION...A HIGHLY AMPLIFIED WEATHER PATTERN WILL EXIST ON SUNDAY WITH A VERYSTRONG UPPER TROUGH OVER THE ERN U.S...CENTERED ACROSS THE MIDATLANTIC AND WITH 125+ KT MID LEVEL SPEED MAX ACROSS THE NERN GULF

[Buddy]

WV is blowing up, forget about QPF forcast from the models.

[FoothillsNC]

I'm a little nervous here for the first half of the storm. The biggest problem was the precip didn't get started here, but like so many that happened last year, the initial overrunning began to my immediate north. The RUC keeps delaying the arrival here, now its looking like after 1 or 2 pm. This will allow the surface to continue to warm a little more, I'm already 38 and the wetbulb 34. Its frustrating to see so many of our overrunning and Gulf lows end up this way, where the Upstate and 85 corridor takes a long time to fill in. Sometimes theres even a filling in on all sides, but here, leaving a donut hole here the last to fill in. I know temps will drop once the good rates get in here, but I also now think I'm losing a lot of the moisture to whatever is eating these returns as they come out of northeast Ga and evaporate here. Anyway , tonight is when it should get heavy and get atleast some hours of heavy snow I think and temps dropping to freezing or maybe 31.Plus there should be a developing 850 just around the Upstate for a few hours which could enhance rates for this area.

[DaculaWeather]

That confirms to me that what I see on the radar is the leading edge of the "shot" entering NW TN. It needs to hurry.

[sctvman]

Winter Storm Watch down to most of Berkeley and Dorchester Counties.

[WidreMann]

Temps are getting really concerning. There is a high pressure to the north, but it's doing nothing for us right now. We are at the mercy of the clouds and they are not doing a very good job.

[tazaroo]

Looking at QPF for moisture at this stage of the game is not the best idea. QPF is never going to be accurate. Focus on the actual trends and not the fact the model may have dropped QPF slightly.

Thanks for some met insight but what about the low being weeker and bombing later. Do we get any clues from recent trends about the strength and timing of the low deepening or is it too early to tell?

[Wow]

I'm a little nervous here for the first half of the storm. The biggest problem was the precip didn't get started here, but like so many that happened last year, the initial overrunning began to my immediate north. The RUC keeps delaying the arrival here, now its looking like after 1 or 2 pm. This will allow the surface to continue to warm a little more, I'm already 38 and the wetbulb 34. Its frustrating to see so many of our overrunning and Gulf lows end up this way, where the Upstate and 85 corridor takes a long time to fill in. Sometimes theres even a filling in on all sides, but here, leaving a donut hole here the last to fill in. I know temps will drop once the good rates get in here, but I also now think I'm losing a lot of the moisture to whatever is eating these returns as they come out of northeast Ga and evaporate here. Anyway , tonight is when it should get heavy and get atleast some hours of heavy snow I think and temps dropping to freezing or maybe 31.Plus there should be a developing 850 just around the Upstate for a few hours which could enhance rates for this area.

It seems to be filling in pretty quickly. it's already down to I-85 at GSP and moving toward CLT. Looks like you'll be in the band in the next 30 minutes.

[strongwxnc]

Yup. My concern also. Plus im closer to the cut off in Rutherford County...

Are we looking at the SW corner of the upstate for development? Looks like it is.

I'm a little nervous here for the first half of the storm. The biggest problem was the precip didn't get started here, but like so many that happened last year, the initial overrunning began to my immediate north. The RUC keeps delaying the arrival here, now its looking like after 1 or 2 pm. This will allow the surface to continue to warm a little more, I'm already 38 and the wetbulb 34. Its frustrating to see so many of our overrunning and Gulf lows end up this way, where the Upstate and 85 corridor takes a long time to fill in. Sometimes theres even a filling in on all sides, but here, leaving a donut hole here the last to fill in. I know temps will drop once the good rates get in here, but I also now think I'm losing a lot of the moisture to whatever is eating these returns as they come out of northeast Ga and evaporate here. Anyway , tonight is when it should get heavy and get atleast some hours of heavy snow I think and temps dropping to freezing or maybe 31.Plus there should be a developing 850 just around the Upstate for a few hours which could enhance rates for this area.

[burgertime]

I'm a little nervous here for the first half of the storm. The biggest problem was the precip didn't get started here, but like so many that happened last year, the initial overrunning began to my immediate north. The RUC keeps delaying the arrival here, now its looking like after 1 or 2 pm. This will allow the surface to continue to warm a little more, I'm already 38 and the wetbulb 34. Its frustrating to see so many of our overrunning and Gulf lows end up this way, where the Upstate and 85 corridor takes a long time to fill in. Sometimes theres even a filling in on all sides, but here, leaving a donut hole here the last to fill in. I know temps will drop once the good rates get in here, but I also now think I'm losing a lot of the moisture to whatever is eating these returns as they come out of northeast Ga and evaporate here. Anyway , tonight is when it should get heavy and get atleast some hours of heavy snow I think and temps dropping to freezing or maybe 31.Plus there should be a developing 850 just around the Upstate for a few hours which could enhance rates for this area.

Yea wish it would just start early for us for once. I wasn't expecting much this morning but at least my temp dropped by one degree.

[DaculaWeather]

Robert, looks like you're about to get it http://www.daculaweather.com/grlevel3/storm_mode_1.php

[strongwxnc]

I'm a little nervous here for the first half of the storm. The biggest problem was the precip didn't get started here, but like so many that happened last year, the initial overrunning began to my immediate north. The RUC keeps delaying the arrival here, now its looking like after 1 or 2 pm. This will allow the surface to continue to warm a little more, I'm already 38 and the wetbulb 34. Its frustrating to see so many of our overrunning and Gulf lows end up this way, where the Upstate and 85 corridor takes a long time to fill in. Sometimes theres even a filling in on all sides, but here, leaving a donut hole here the last to fill in. I know temps will drop once the good rates get in here, but I also now think I'm losing a lot of the moisture to whatever is eating these returns as they come out of northeast Ga and evaporate here. Anyway , tonight is when it should get heavy and get atleast some hours of heavy snow I think and temps dropping to freezing or maybe 31.Plus there should be a developing 850 just around the Upstate for a few hours which could enhance rates for this area.

This may answer the question

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC

1117 AM EST SAT DEC 25 2010

.SYNOPSIS...

LOW PRESSURE WILL STRENGTHEN AND TRACK EAST ACROSS THE NORTHERN GULF

OF MEXICO TODAY. THIS LOW WILL DEEPEN AS IT TURNS NORTHEAST ALONG

THE CAROLINA COAST EARLY SUNDAY AND CONTINUES TO THE NEW ENGLAND

COAST EARLY MONDAY. COLD CANADIAN HIGH PRESSURE WILL BUILD FROM THE

MISSISSIPPI VALLEY INTO THE FIRST HALF OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...

-- Changed Discussion --SOMETIMES I THINK I SHOULD HAVE BEEN A FARMER. AT LONG LAST...WE

/THINK/ WE ARE GETTING A SOLID HANDLE ON THE UNFOLDING WINTER

WEATHER EVENT ACROSS THE WESTERN CAROLINAS/NORTHEAST GEORGIA.

HOWEVER...IT SHOULD BE NOTED THAT CONFIDENCE DROPS OFF SHARPLY AFTER

THE FIRST 6 HOURS OR SO...AS MUCH OF THIS EVENT WILL BE DOMINATED BY

MESOSCALE AND EVEN CONVECTIVE SCALE PROCESSES.

AS OF 16Z...A BAND OF MODERATE TO HEAVY SNOW WAS WELL ESTABLISHED

OVER THE MOUNTAINS AND ALONG THE I-40 CORRIDOR EAST OF THE BLUE

RIDGE. THIS WILL ONLY GRADUALLY DRIFT/EXPAND TO THE SOUTH AND EAST

WITH TIME. IN FACT...THE BACK EDGE OF THE FRONTOGENETICALLY FORCED

PRECIP WILL PROBABLY NOT MAKE SIGNIFICANT EASTWARD PROGRESS UNTIL

THE SURFACE LOW MAKES THE JUMP TO OFF THE SOUTHEAST COAST THIS

EVENING. THEREFORE...THE SNOW WILL CONTINUE TO PILE UP WHERE ITS

ALREADY FALLING...AND ACCUMULATIONS WILL NEED AN UPWARD ADJUSTMENT.

WE WILL NOW ADVERTISE 8-12 INCHES THROUGH TONIGHT ACROSS A GOOD

CHUNK OF THE MOUNTAINS...AND BUMP THE I-40 PORTION OF THE

PIEDMONT/FOOTHILLS TO 5 TO 8 INCHES. AS USUAL...THE LOCALLY HIGHER

AMOUNTS CAVEAT APPLIES.

FARTHER SOUTH...TEMPS HAD WARMED TO THE UPPER 30S ALONG THE I-85

CORRIDOR AS OF 16Z. THIS PROBABLY DOESN/T MEAN A GREAT DEAL...AS

NORTH GEORGIA OBS HAVE REVEALED A RAPID DECREASE IN TEMPS FROM THE

UPPER 30S TO LOWER 30S WITH THE ONSET OF PRECIP. GIVEN THE HEALTHY

PRECIP RATES AND STRONG FORCING ACCOMPANYING THE PRECIP...DIABATIC

PROCESSES SHOULD ERADICATE MOST OF THE SHALLOW WARM LAYER AND RESULT

IN A MOSTLY SNOW EVENT. HOWEVER...CONSIDERING THE LATE ONSET OF

PRECIP IN THESE AREAS (MID AFTERNOON)...I/M NOT CONFIDENT ENOUGH TO

START BOOSTING ACCUMS ALONG THE I-85 CORRIDOR...SO WILL STICK TO THE

2-4 INCH FORECAST FOR NOW.

NOTHING HAS CHANGED MUCH REGARDING THINKING FOR THIS EVENING RE: THE

STRENGTHENING FRONTOGENESIS BAND ASSOCIATED WITH BOMBING SURFACE

LOW. WE WILL LOOK AT THIS IN MORE DETAIL THROUGHOUT THE AFTERNOON.

THE PREVIOUS DISCUSSION OF THIS FOLLOWS...

THEN THERE IS PART TWO. A POTENT SRN STREAM SHORT WAVE...WHICH IS

ONLY INDIRECTLY RESPONSIBLE FOR THE HEAVY SNOW TODAY...WILL BE

PICKED UP BY THE NRN STREAM WAVE. AS THE NRN STREAM WAVE IS SLOWER

AND DEEPER...IT LOOKS TO PHASE MORE WITH THE SRN STREAM ENERGY THAN

ORIGINALLY EXPECTED. AS STRONG DEEP LAYER Q-VECTOR CONVERGENCE

DEVELOPS OVER THE REGION TONIGHT...A PIVOTING BAND OF SNOW IS

EXPECTED TO CONTINUE OVER THE EASTERN PART OF THE FA. BOTH NAM AND

GFS CROSS SECTIONS SHOW A GOOD AREA OF NEGATIVE EPV CROSSING THE

FOOTHILLS AND PIEDMONT TOWARD 0600 UTC. AS THIS HAPPENS...A PERIOD

OF HEAVY SNOW IS EXPECTED ACROSS THE I-77 CORRIDOR AND INTO THE

CENTRAL AND SOUTHERN UPSTATE. FOR NOW I/M JUST GOING WITH 2 TO 4

INCHES OF SNOW FOR THESE AREAS...WHICH IS STILL ENOUGH TO WARRANT A

WINTER STORM WARNING UP THE I-85 AND I-77 CORRIDORS. HOWEVER...IF

THIS WESTWARD ADJUSTMENT AND PHASING CONTINUES...THEN HEAVIER SNOW

IS VERY POSSIBLE.

THIS IS SOMETHING TO KEEP IN MIND FOR THE URBAN CORRIDOR FROM

GREENVILLE-SPARTANBURG UP TO THE CHARLOTTE METRO AREAS. IT WILL TAKE

SOME TIME FOR THE LOWEST LEVELS TO COOL TODAY AND FOR ALL SNOW TO

FALL ACROSS THESE AREA. HOWEVER...THIS SECONDARY AREA OF FORCING

WITH THE SRN STREAM WAVE IS LIKELY TO REINVIGORATE THE PCPN THIS

EVENING...RESULTING IN A RAPID TRANSITION TO HEAVY SNOW WHERE THERE

WAS A MIX BEFORE. STILL...I THINK THE URBAN CORRIDOR WILL CHANGE

OVER IN THE 19 TO 20 UTC TIME FRAME...WHICH IS PLENTY OF TIME TO

WATCH THE SNOW FALL AND EXPERIENCE A WHITE CHRISTMAS OVER THE

PIEDMONT.-- End Changed Discussion --

[wxologist]

Not sure how many of the people in this portion of the boards use or know about the Analog Guidance located here: http://www.eas.slu.e...ALOG/analog.php

But there is an interesting graphic we produce based on the top 15 analogs with respect to surface observation temperatures. Notice the high probability of sub-freezing temperatures far into Florida based on similar historical events.

[FoothillsNC]

It seems to be filling in pretty quickly. it's already down to I-85 at GSP and moving toward CLT. Looks like you'll be in the band in the next 30 minutes.

I'm going to hold you to it ! Haha, yes the last few frames the moisture finally lurched into the Upstate. It took it a while though.

Yea wish it would just start early for us for once. I wasn't expecting much this morning but at least my temp dropped by one degree.

Once we get going, i'll be we get going hard. I was thinking the start time would be 7 to 9 am here, from last night when I went to bed, but got up and saw it kept getting delayed. Once our big flake come down, I'm sure we'll make it to around 33 or so and maybe 32 , the time of day and no real good damming source may keep us from reaching 32 for a while I don't know, but tonight is when the UVV really kicks in with better dynamics coming directly over top. Models still show the surface low in a good spot after 7 pm and through the night off GA, which should do us good, and also the inverted trough on the lee side of the Apps extending through us to the low itself offshore. Normally that keeps a deformation snow band somewhre right around here, with gradually decreasing snow bands through the night and early am. We'll see. Of course nobody wants to get dryslotted, and hopefully that stays away. Going to check out the latest RUC.

[DaculaWeather]

GSP AFD Update

RAH AFD Update

[packbacker]

Temps are getting really concerning. There is a high pressure to the north, but it's doing nothing for us right now. We are at the mercy of the clouds and they are not doing a very good job.

Snippet from RAH latest update...

THE POTENTIAL ALSO EXISTS FOR LOCALLY HIGHER STORMTOTAL AMOUNTS TO AROUND SIX INCHES OR SO ACROSS PORTIONS OF THENORTHWESTERN...NORTHERN... AND NORTHEAST PIEDMONT... AND NORTHERNCOASTAL PLAIN... AROUND A LINE FROM NEAR LEXINGTON TO CHAPEL HILL TOROANOKE RAPIDS.

[FoothillsNC]

This may answer the question

My thoughts exactly Mark. Have you had any accums yet? Radar been showing you on the line.

[DCMetroWinston]

I think it is starting earlier in the Triad than expected, as least according to local tv mets. The flurries have turned to light snow already in Winston-Salem and High Point.

[burgertime]

BTW 9z SREF Mean looked great, had all of us in .5 and up.