NC/VA Sunday Snow Threat

[eyewall]

I am dreaming that I'm totally wrong. Knowing that I don't like our odds at all this will probably end of over producing and I'll be painted the fool.

Grids have little or none.

[SBUWX23]

Grids have little or none.

The zone is probably picking the higher amount so it says up to 1 inch but in reality the amounts are light

[DaculaWeather]

Atlanta AFD:

000FXUS62 KFFC 031849AFDFFCAREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE PEACHTREE CITY GA150 PM EST FRI DEC 3 2010.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...DUE TO COMMUNICATIONS PROBLEMS THE GFS IS RUNNING WELL LATE.HOWEVER...MODELS CONTINUE TO FORECAST A SURFACE LOW MOVING ACROSS THE SOUTHERN APPALACHIANS SATURDAY AFTERNOON WITH A COLD FRONT MOVING ACROSS THE AREA SATURDAY AFTERNOON AND NIGHT. THIS WILL BRING A CHANCE OF LIGHT SHOWERS MAINLY TO N GA SATURDAY INTO SATURDAY EVENING...AND POSSIBLY PARTS OF CENTRAL GA. A MUCH COLDER AIRMASS BEHIND THE FRONT WILL GIVE THE CHANCE FOR LIGHT SNOW OR FLURRIES ACROSS FAR N GA. THE CHANCE FOR FLURRIES LOOKS TO CONTINUE INTO SUNDAY FROM COLD CLOUDS ACROSS N GA. WINDY CONDITIONS CAN BE EXPECTED BEHIND THE FRONT MOVING INTO THE AREA SATURDAY NIGHT AND CONTINUING THROUGH SUNDAY NIGHT. FORECAST LOW TEMPERATURES RUNNING NEAR TO AROUND 5 DEGREES BELOW NORMAL TONIGHT AND SATURDAY NIGHT. FORECAST HIGH TEMPERATURES RUNNING NEAR TO SLIGHTLY ABOVE NORMAL ON SATURDAY AND AROUND 8 TO 15 DEGREES BELOW NORMAL ON SUNDAY. OVERALL CONFIDENCE IS MEDIUM.

[BullCityWx]

The zone is probably picking the higher amount so it says up to 1 inch but in reality the amounts are light

Yeah, did they change how they do the zone fxcasts? I thought the zone was much more reliable than the point and click.

[WeatherNC]

MHX dropped the min here for Saturday by 1 degree, to 32F. Also included all zones in the possibility for RN-SN, whereas it was just the northern ones in the previous package. There insight on the saturation in dendritic growth zone is well founded, and I have noticed that on the soundings over the past couple days. Would like to see saturation above 14k ft, which never really happens here.

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC

351 PM EST FRI DEC 3 2010

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...

AS OF 350 PM FRI...A WEAK LOW PRESSURE AREA WILL MOVE FROM

TENNESSEE EARLY SATURDAY ACROSS THE NC/SC LINE SATURDAY NIGHT TO BE

OFF THE COAST BY 12Z SUNDAY. EXPECT INCREASING CLOUDS SATURDAY AS

THE SYSTEM APPROACHES WITH HIGHS IN THE MIDDLE TO UPPER 40S. THIS

WEAK SYSTEM WILL LACK MOISTURE BUT FORCING WILL BE STRONG ENOUGH

TO WRING OUT 1/10 TO 1/4 OF AN INCH OF QPF. TEMPERATURES ALOFT

WILL BE COLD ENOUGH FOR SNOW...ESPECIALLY NORTH...BUT A COUPLE OF

NEGATIVES ARE DECREASING CONFIDENCE. THE NAM SOUNDINGS INDICATED A

LACK OF SIGNIFICANT MOISTURE IN PORTIONS OF THE DENDRITE CRYSTAL

GROWTH REGION WHICH WOULD INHIBIT SNOWFLAKE PRODUCTION. IN

ADDITION LACK OF MOISTURE INFLOW WILL CUT DOWN AVAILABLE MOISTURE

EAST OF THE MOUNTAINS. IN SIMILAR EVENTS IN THE PAST WE HAVE SEEN

BANDS OF LIGHT SNOW DEVELOP IN THE REGIONS OF STRONGEST UVV`S.

WORST CASE SCENARIO WOULD BE A FOR A SLUSHY LIGHT ACCUMULATION

(LESS THAN 1 INCH) ON GRASSY SURFACES. WILL CALL FOR A CHANCE OF

RAIN AND SNOW ALL AREAS FOR NOW AND LET LATER MODEL RUNS BETTER

DEFINE THE THREAT. LOWS WILL BE NEAR OR JUST BELOW FREEZING EVEN

ALONG THE OUTER BANKS. SUNDAY WILL SEE ANOTHER COLD HIGH BUILDING

IN FROM THE NW WITH CLEARING SKIES AND HIGHS ONLY IN THE LOWER TO

MIDDLE 40S.

for KPGV

[superjames1992]

DOT has already pre-treated the bridges here. My tax dollars at work.

Yep. It seems they treat the roads for any threat of anything around here...

From what I understand, their salt budget is based off of how much they used the year prior, so there is an incentive to use as much salt as humanly possible in any given year, which means they lay it out during non-events when it is not needed.

It's open, but they shut it down during snow events, and if it stays it stays shut down.

Thanks for info.

[burgertime]

Grids have little or none.

The failzone will strike again

[strongwxnc]

What's him name that works at GSP i (something) noted last year that the zone picks the higher amount.

I got little to no accum in my zone..

Zone link

The zone is probably picking the higher amount so it says up to 1 inch but in reality the amounts are light

[MillzPirate]

18z GFS looks a little wetter

[FoothillsNC]

Yep. It seems they treat the roads for any threat of anything around here...

From what I understand, their salt budget is based off of how much they used the year prior, so there is an incentive to use as much salt as humanly possible in any given year, which means they lay it out during non-events when it is not needed.

Thanks for info.

I've seen something like this here a lot lately, especially last year when twice the crews spread whatever it is on the roads, needlessly. I'm assuming the official NWS forecast is what they go by and have an in house decision to make, prioritized based on threat. Me and a couple others around my area last season watched them spread here the day before an "event" when it was pretty clear no event was coming. It happened twice, all the roads straight to the Gaston line were doused, including the smaller highways to my neighborhood, and hwy 74 to Gaston line, and that was quite a waste, imo, because nothing fell on one of those occasions, and only light rain fell for an hour on the other ocassion. One of those events was when parts of GA got some snow, and part of central to eastern NC got snow or mix, there was a warm bubble here to northeast GA though, being skipped twice, and what did fall was rain. I got behind one of the spreaders and wanted to tell him to knock it off, but eh, commerce drives the economy I guess.

[wxbrad]

I've seen something like this here a lot lately, especially last year when twice the crews spread whatever it is on the roads, needlessly. I'm assuming the official NWS forecast is what they go by and have an in house decision to make, prioritized based on threat. Me and a couple others around my area last season watched them spread here the day before an "event" when it was pretty clear no event was coming. It happened twice, all the roads straight to the Gaston line were doused, including the smaller highways to my neighborhood, and hwy 74 to Gaston line, and that was quite a waste, imo, because nothing fell on one of those occasions, and only light rain fell for an hour on the other ocassion. One of those events was when parts of GA got some snow, and part of central to eastern NC got snow or mix, there was a warm bubble here to northeast GA though, being skipped twice, and what did fall was rain. I got behind one of the spreaders and wanted to tell him to knock it off, but eh, commerce drives the economy I guess.

I know the Charlotte DOT uses a third party vendor for forecasst which in my opinion is dumb. You should use someone local not to mention they could get free advice from NWS and not have to use tax dollars for an out of state forecast. I sometimes watch the press conferences with Leyton Lamb before an event and wonder where in the world he gets his weather info because it's so off base on whats really going to happen.

[Cyclonicjunkie]

HPC

[WeatherNC]

18z NAM station amounts

nice local max south of CLT on 77

will post the 18z GFS stations once they are out on Allan's site, as has been mentioned, trended a little wetter compared to the past couple runs, but not much...

[MillzPirate]

So GFS is at .20 and NAM is at .32 for PGV....... average it out to around a quarter inch liquid...... take out a tenth to saturate the atmosphere/evaporative cooling.... left with .15...... if it came to fruition using appr. 6:1 ration....... talking a dusting to half inch

[WeatherNC]

So GFS is at .20 and NAM is at .32 for PGV....... average it out to around a quarter inch liquid...... take out a tenth to saturate the atmosphere/evaporative cooling.... left with .15...... if it came to fruition using appr. 6:1 ration....... talking a dusting to half inch

Models already take into account the moisture required to saturate the column, at-least as I understand it...

[phil882]

This clipper is going to be an interesting case study to watch, because it looks like areas further east in the Piedmont might fare much better than the typically more favored areas of snowfall in western North Carolina. The surface low track is really going to spell out everything. Folks just to the north of the feature will not have a significant warm nose at 850mb. Since the low will be sliding to the ESE, areas like metro Asheville, NC might just be too warm as the low moves nearly overhead. However, places like Greensboro, NC and Winston Salem, NC might be cold enough to pick up some measurable snowfall accumulation from the clipper.

One analog that has been thrown around is the January 18th, 2000 event. Look at the snowfall totals distribution. I think these totals won't be nearly as high for this event, but may take on the same area distribution except perhaps shifted a bit further north.

[DCMetroWinston]

DC tv mets really bullish on snowin cnetral NC this weekend. FOX 5 thinks watches/advisories will be extended into Triad and Triangle tomorrow.

[WeatherNC]

18z GFS station amounts

[MillzPirate]

would be nice if this were a solid snow sounding with cold ground temps. would be talking a good 1-3 across NC..... alas, it is but early December and not a climatalogically indicative time for such an event

[WeatherNC]

would be nice if this were a solid snow sounding with cold ground temps. would be talking a good 1-3 across NC..... alas, it is but early December and not a climatalogically indicative time for such an event

Issue with the soundings, at-least here, is the lack of saturation in the 700-500mb dendritic growth zone. From everything I have seen on the american guidance over the past couple days, the majority of what falls should be frozen before it hits the surface. Thickness is in the measurable SN with RN or Wintery mix category, but very close to all SN. As long as we continue to be inside the <1300m 1000-850mb thickness line, I don't see to much to worry about as far as favorable thermal profiles go, moisture however, well that is another story.

[DCMetroWinston]

The Triangle could see some snow flurries or a wintry mix Saturday night, but it's not expected to stick, WRAL Chief Meteorologist Greg Fishel said Friday."It's a really good chance we're going to see flakes. However, in terms of being an impact storm, not so great a chance," Fishel said.

http://www.wral.com/weather/story/8719289/

[WeatherNC]

The Triangle could see some snow flurries or a wintry mix Saturday night, but it's not expected to stick, WRAL Chief Meteorologist Greg Fishel said Friday."It's a really good chance we're going to see flakes. However, in terms of being an impact storm, not so great a chance," Fishel said.

http://www.wral.com/weather/story/8719289/

He must have read RAH's AFD

[FoothillsNC]

This clipper is going to be an interesting case study to watch, because it looks like areas further east in the Piedmont might fare much better than the typically more favored areas of snowfall in western North Carolina. The surface low track is really going to spell out everything. Folks just to the north of the feature will not have a significant warm nose at 850mb. Since the low will be sliding to the ESE, areas like metro Asheville, NC might just be too warm as the low moves nearly overhead. However, places like Greensboro, NC and Winston Salem, NC might be cold enough to pick up some measurable snowfall accumulation from the clipper.

One analog that has been thrown around is the January 18th, 2000 event. Look at the snowfall totals distribution. I think these totals won't be nearly as high for this event, but may take on the same area distribution except perhaps shifted a bit further north.

If I were making a map, it would look something like that as well, just a lot lower amounts. Forecasting things coming across the Apps from the NW are always tough buggers, every once in a while they do the exact opposite of what you expect, or the areas that miss out and get downsloped are misplaced over a 100 miles or so. Nothing would surprise me, but my guess is somewhere along or north of 40 as being the best place for snow, and again toward the coast as a weak surface low maybe helps somewhat. I noticed the GFS had a wk. sfc low near CLT, and another model had bagginess toward upper SC with a trough banked a while against the apps and sfc High over WVa. If the sfc low developed more in the lee, then nw NC and really the 40 corridor and northern sections of NC could get something a lot more substantial. Right now the safest bet is low amounts though. Look how narrow that ribbon is, barely a single county wide over the Midwest.

[burgertime]

Looking at the SREF precip type map off of SV is almost comical for CLT...everyone has the snow type except for one dot which is directly over CLT...but yea for an hour or so on the SV SREF everyone is under snow if it does indeed fall.

[WeatherNC]

Looking at the SREF precip type map off of SV is almost comical for CLT...everyone has the snow type except for one dot which is directly over CLT...but yea for an hour or so on the SV SREF everyone is under snow if it does indeed fall.

Is that from the 15z run? Did note that run was a little more expansive with QPF and somewhat wetter compared to the 9z. 18z GFS ens mean also wetter compared to the past 2 runs, with a slight upward tick in each mean since 6z.

[Poimen]

[Poimen]

the NAM is going bonkers...

[DCMetroWinston]

bring it!

[rduwx]

The nam has really uped the qpf in the RDU area but I just don't trust the nam. It has burned me to many times!

[Cold Rain]

the NAM is going bonkers...

The NAM always goes bonkers. Let some of the other models show heavier precip and then we can begin to get more excited.