Potential December 12th-13th threat

[FoothillsNC]

it appeared to me the Euro had a secondary development on the 00zRun in eastern NC that shoots up the coast. If anyone probably has a shot it would be eastern NC, possibly SC and points north...and again in the mountains. The western piedmont/foothills would miss out regardless of track, due to being so far from the coastal.

[WeatherNC]

This is the link for the 0z Canadian individual members at 120hrs, you can see the spread... Excluding the 0z run, the Canadian has been consistent with a track through the OH Valley, and the ensemble agreement has been much better than what it is with this run.

http://www.weatheroffice.gc.ca/ensemble/charts_e.html?Hour=120&Day=0&RunTime=00&Type=pnm

[CAD_Wedge_NC]

Always nice to wake up to the 192hr z DGEX sn-accum map painting a pretty picture...

In all seriousness though, two camps in the overnight and early am guidance. One south and east on the lee side of the Apps, and the second north and west on the windward side. Ensemble means of both the EC and GFS are south and east of the operational track, and have trended such since the 12z run yesterday, at-least up to the DC area. Canadian and NOGAPS are on the western side of the envelope with a track through Kentucky, before moving ene to near DC at 120hrs. 0z UKMET has a 988 over Fayetteville at 120hrs, and a closed ULL centered near the Upstate of SC. Anyone who sees this low pass to there east and south stands a chance of seeing accum SN baring you don't get slotted. Fun times ahead for the rest of the week...

Thanks for posting this WeatherNC......... This snowfall map shows just what I was referring to in my previous post. Note the lack of snow in the lee of the mtns........ Looks like you guys down in the eastern part of the state are less influenced by downsloping with this model depiction.

[burgertime]

Although I highly doubt we can get a trend south far enough to put us back in the game I do believe that models will begin to trend south either later today or tomorrow. The blocking is so intense that I think models have been to quick in moving it. This is just my opinion but I don't see the storm cutting as much as has been depicted the past several days. It's a bit of a hunch but that is my feels on the matter. Either way some might intense cold is looking to stay around for a while.

While I don't think we will see much of anything out of this, I think it will trend south as well. Wish it would just head south enough to where we could cash in.

Always nice to wake up to the 192hr z DGEX sn-accum map painting a pretty picture...

In all seriousness though, two camps in the overnight and early am guidance. One south and east on the lee side of the Apps, and the second north and west on the windward side. Ensemble means of both the EC and GFS are south and east of the operational track, and have trended such since the 12z run yesterday, at-least up to the DC area. Canadian and NOGAPS are on the western side of the envelope with a track through Kentucky, before moving ene to near DC at 120hrs. 0z UKMET has a 988 over Fayetteville at 120hrs, and a closed ULL centered near the Upstate of SC. Anyone who sees this low pass to there east and south stands a chance of seeing accum SN baring you don't get slotted. Fun times ahead for the rest of the week...

lolz if the DGEX says you're getting a foot you have 50% chance of getting an inch! Gotta love it.

[Amos83]

While I don't think we will see much of anything out of this, I think it will trend south as well. Wish it would just head south enough to where we could cash in.

lolz if the DGEX says you're getting a foot you have 50% chance of getting an inch! Gotta love it.

Agreed..... of course right now I'd take a 50/50 chance of getting an inch

[HWY316wx]

I think if we on the East and NE side of Georgia are to get anything out of this, we need this thing to DIG BABY DIG.

Why oh why do I sense the Canadian is onto something with the Ohio Valley solution?

[burgertime]

Agreed..... of course right now I'd take a 50/50 chance of getting an inch

So true! I was happy just to see a stray flake last Saturday morning.

[tazaroo]

I actually am slightly encouraged by some of the Gfs ensemble members this morning. I checked out the mid atlantic and ny forums and none of them even sound encouraged about their chances or are even mentioning the Ensemble members.

I know we still have a long way to go for the Southeast and the Ohio Valley or Apalachain spine track may end up being correct, but it seems to me the trend so far this season has been South and East for the most part. I am keeping my excitement in check as of now though.

[tazaroo]

Also, I know its the 12z 84hr NAM but it looks South and weaker with our low and what is that showing up in S Canada. Could it be a high?

[WeatherNC]

it appeared to me the Euro had a secondary development on the 00zRun in eastern NC that shoots up the coast. If anyone probably has a shot it would be eastern NC, possibly SC and points north...and again in the mountains. The western piedmont/foothills would miss out regardless of track, due to being so far from the coastal.

This idea has been shown by the EC off and on over the past couple days. The 0z ens means of both the EC and GFS show that redevelopment can't be ruled out at this stage with a surface placement well to the SE of the operational runs, which would argue that some members are displaced as well. This is such a broad area of lp, the models are really struggling with placement of the local min within the area, and possible redevelopment on the tail end. Consensus track from the MS Valley to NE has not shifted much over the past 24 hrs, and that is what the HPC is going with at this point, and rightfully so...

PRELIMINARY EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD

902 AM EST WED DEC 08 2010

VALID 12Z SUN DEC 12 2010 - 12Z WED DEC 15 2010

MEDIUM RANGE GUIDANCE CONTINUES TO DISPLAY GRADUALLY IMPROVING

AGREEMENT REGARDING THE EVOLUTION OF THE POWERFUL STORM SYSTEM

EXPECTED TO TRACK FROM THE PLAINS INTO THE NORTHEAST SAT ONWARD.

FOR THE DAYS 3-5 SAT-MON PORTION OF THE FCST THE 00Z ECMWF HAS

ADJUSTED ITS TRACK SIGNIFICANTLY FARTHER SWD FROM A NUMBER OF

PREVIOUS RUNS TO BRING IT INTO DECENT AGREEMENT WITH THE 00Z GFS.

THE 00Z CANADIAN RUN AND 12Z ECMWF ENSEMBLE MEAN CLUSTER FAIRLY

WELL WITH THE GFS/ECMWF. THE 00Z UKMET/GEFS MEAN TRACK THE SFC

LOW FARTHER SWD ACROSS THE SOUTHEAST WHILE THE 12Z CANADIAN

ENSEMBLE MEAN NOW HAS THE FARTHEST NWD TRACK. THUS FAR A

CONSENSUS/INTERMEDIATE TRACK HAS ULTIMATELY MAINTAINED DECENT

CONTINUITY SO THE GFS/ECMWF CLUSTER APPEARS TO BE THE BEST OPTION

AT THIS TIME. THIS SFC LOW IS FCST TO BE URGED ALONG BY A DEEP

BUT OPEN TROF ALOFT... WITH SOME MID LVL HGT ANOMALIES EXPECTED TO

REACH AT LEAST 5 STANDARD DEVIATIONS BELOW NORMAL IN THE SRN PART

OF THE TROF LATE SUN THRU MON. BY THE LATTER HALF OF THE PERIOD

MOST SOLNS EXPECT AN UPR LOW TO CLOSE OFF OVER/NEAR THE NORTHEAST.

THIS EVOLUTION WOULD MAINTAIN OR RE-DEVELOP SFC LOW PRESSURE OFF

THE NEW ENGLAND COAST.

FARTHER WWD A BROAD TROF OVER THE NERN PAC WILL MAKE ONLY GRADUAL

EWD PROGRESS AS A STRONG DOWNSTREAM RIDGE BUILDS ACROSS WRN NOAM.

A COMPROMISE BETWEEN THE FAST GFS AND SLOW ECMWF APPEARS BEST TO

RESOLVE TIMING DIFFS WITH THE WARM FRONT AFFECTING THE NRN HALF OF

THE WEST COAST ON DAY 3 SAT. THE GFS/ECMWF AND ENSEMBLE MEANS

AGREE FAIRLY WELL THAT THE SFC COLD FRONT AHEAD OF THE MEAN TROF

ALOFT SHOULD ENTER THE WEST BY DAY 6 TUE.

THE DAYS 3-7 FCST USES VARIOUS PROPORTIONS OF THE GFS/ECMWF/12Z

ECMWF MEAN THRU THE PERIOD. DAY 3 SAT AND TO A LESSER EXTENT DAYS

4-5 SUN-MON LEAN MORE TOWARD THE OPERATIONAL DETAILS OF THE

GFS/ECMWF... WHICH IN ADDITION TO DEPICTING THE MOST AGREEABLE

SOLN CLUSTER OVER THE CNTRL-ERN CONUS ALSO PROVIDE THE DESIRED

COMPROMISE FOR THE WARM FRONT NEAR THE WEST COAST ON DAY 3. BY

DAYS 6-7 TUE-WED THE GFS BECOMES SOMEWHAT DEEPER THAN CONSENSUS

WITH THE UPR LOW THAT CLOSES OFF OVER THE NORTHEAST AND SHOWS A

LITTLE MORE SEWD AMPLITUDE WITH THE TROF EDGING TOWARD THE WEST

COAST... SO THE BLEND IS WEIGHTED MORE TOWARD THE ECMWF/12Z ECMWF

MEAN LATE IN THE FCST.

UPDATED MORNING PRELIMS CHANGE THE MIX SLIGHTLY TO REFLECT

AGREEMENT ON THE POSITION OF THE SFC LOW OVER ERN CONUS DAYS 4-5

WHILE SIMLIFYING THE PATTERN AT DAYS 6-7 TOWARDS GFS/ECMWF ENS

MEANS.

VERY STRONG HIGH LEVEL BLOCKING PATTERN PERSISTS THRU THE PERIOD

WITH RIDGES OVER GREENLAND AND ICELAND AND OVER THE WRN ALEUTIANS

KEEPING UP STRONG NEGATIVE AO AND NAO VALUES LOCKING IN A DEEP

ANOMALOUS TROF OVER ERN CONUS AND THE ERN PACIFIC.

AS THE SHORTWAVE DIGS SEWD TOWARDS THE GULF COAST ENHANCED BY

BUILDING UPSTREAM RIDGING AN ARCTIC AIR CRASH PROCEEDS SOUTHWARD

THRU THE PLAINS SAT AND DEEP INTO THE GLFMEX SUN SWEEPING SOUTH

AND EAST TO OFF THE EAST COAST AND LATE SUN AND MON. DEEPENING SFC

LOW MOVING NEWD FROM THE MS VALLEY SAT WILL BE OFF THE NORTHEAST

COAST MONDAY. LARGE AREA OF WINDY AND BITTERLY COLD AIR WILL COVER

THE ERN HALF OF CONUS. THIS WILL THREATEN FLORIDA WITH ANOTHER

FREEZE COLDER AND WINDIER THAN THE RECENT AND CURRENT EVENT WITH

RECORD LOWS POSSIBLE. MOS GUIDANCE TEMPERATURES FROM THE MID ATLC

REGION INTO THE SOUTHEAST FOR MON-WED WHILE AVERAGING 15 DEGREES

BELOW THE NORM ARE WAY TOO WARM AND EXPECT WIDESPREAD AREAS TO

STAY AOB FREEZING THRU MUCH THE PERIOD. HIGH WINDS WILL BRING COLD

PENETRATION INTO MORE VULNERABLE STRUCTURES ALONG THE SOUTHEAST

COAST BRINGING A THREAT OF COLD DAMAGE. IMPROVING CONDITIONS OVER

THE GULF COAST AND FL AS HTS RISE MID WEEK.

A MODERATE TO HVY SNOW SNOW EVENT ACROSS NRN IL/NRN IN AND SRN MI

SAT NIGHT INTO SUNDAY. MUCH WARMER THAN AVERAGE TEMPERATURES OVER

WRN CONUS UNDER MID LEVEL RIDGING WITH THE NEXT ROUND OF FRONTAL

RAINS COMING INTO THE PAC NORTHWEST AND NRN CA MON INTO WED WITH

COOLING ALOFT DUE TO LOWERING HTS MAY CHANGE RAINS TO SNOWS AT

HIGHER ELEVS.

RAUSCH/ROSENSTEIN

Interesting though that they believe the trough will stay open, however 7 of the members from the 6z global off of Allan's site show a close off...

[SBUWX23]

I wonder how much they look at the 6z GFS to make their disco.

[WeatherNC]

I wonder how much they look at the 6z GFS to make their disco.

Probably not at all, as they are going with ens means of the major cycles through day 3, and leaning more towards the operational runs after that.

or, about as much as they look at the DGEX

[eyewall]

[SBUWX23]

Probably not at all, as they are going with ens means of the major cycles through day 3, and leaning more towards the operational runs after that.

I still have a pretty strong belief that this will not be wintry for anyone in the SE or for the I-95 corridor close to me except for those in the mountains from NW upslope snows and for inland areas of the midwest and northeast.. Some of these ensemble members do show solutions that would be a close one for some folks but we have to remember that the ensembles are at a lower resolution than the operational run and some of the tweaks and different schemes within them may not be handling the overall synoptics. I know there is time for things to adjust but I just dont see how something is going to occur in this pattern. Even if a wave or secondary forms , the warm air flowing in will make sure everything is rain. Plus those model fields everyone posts with the blue line and precip behind it is a six hour QPF. That means it has already occurred and the blue line is the current temperature plotted. Even if the 850 zero line is east of you, that does not mean its autmatically snow.

The bigger story is the cold coming after the system wraps up. Some here say its not big deal, mainly because it may not be historic to some past outbreaks and by looking at the 6z GFS run. But the winds from this one will be worse than the current cold outbreak and extend much further south. Florida is in line for a big time cold shot for their standards in December as well as everyone in the eastern US. While we may not have highs in the teens as far south as Georgia and lows in the single digits to break historic records, the cold looks to be very impressive.

[Stovepipe]

The GFS buffkit data for the valley of east Tennessee has been consistently showing between 2 and 4 inches of snow for this system. While that is nothing impressive and we are still a ways out, if it does verify there will be quite a few giddy people over in these parts.

[FLO]

Why would anyone want a miserable cold if there is no precip around? I dont get it.

[lilj4425]

The DGEX dry-slots the upstate so of course it will verify. What did me, burrel, and oconee ever do to deserve this?

[DCMetroWinston]

Because some of us love cold in and of itself. It's even better with snow, but cold itself is worthy of adoration too.

[SBUWX23]

For those who dont think this cold is impressive, how about Willmington North Carolina hitting 19 last night which is two degrees above the record low for this date set in 1882.

[SBUWX23]

Why would anyone want a miserable cold if there is no precip around? I dont get it.

Many weather enthusiasts like when extreme weather events occur because they are rare and fun to discuss and track. Not every cold outbreak comes with snow.

[audioguy3107]

The DGEX dry-slots the upstate so of course it will verify. What did me, burrel, and oconee ever do to deserve this?

You guys, like us in Georgia, chose to live in an unfavorable area for major snowfall. That's about it!

[rduwx]

The DGEX dry-slots the upstate so of course it will verify. What did me, burrel, and oconee ever do to deserve this?

Maybe it's the avatar. You're always saying how it's a good luck charm but I'm not so sure.

[buckeyefan1]

New record low set this morning at CAE Previous record 17, today at CAE...16

[audioguy3107]

Maybe it's the avatar. You're always saying how it's a good luck charm but I'm not so sure.

I've never been sure how a dancing blue blob is good for exciting winter weather, but hey, that's just me!!

[strongwxnc]

You took the words out of my mouth.

I would rather have some winter weather with the cold, but since that is not going to happen. Bring the cold down!

Many weather enthusiasts like when extreme weather events occur because they are rare and fun to discuss and track. Not every cold outbreak comes with snow.

[Marion_NC_WX]

6z model data shows some very interesting things for the escarpment this weekend...

A cold...and I mean COLD rain will come in early Sunday morning, the numerical data for Morganton-Lenoir has the 2M temps of 34 at 9z Sunday with nearly .40 of liquid. Sunday's high accoring to the model data will be 40 degrees at 15z Sunday, from there the 2M temps will free fall...

Sunday 21z: 30 degrees

Monday 6z: 15 degrees

Monday 12z: 8 degrees

The free fall overnight Sunday into Monday is massive cold air advection into this part of the country. This data has me getting no higher than 18 degrees on Monday. It has the foothills reaching single digits again Tuesday morning.

I'm courious as to what the 12z shows.

[burgertime]

So 12z you thinking of going south? 12z, "nah not going to do that. Have fun with the rain".

[SBUWX23]

You took the words out of my mouth.

I would rather have some winter weather with the cold, but since that is not going to happen. Bring the cold down!

Id also like to say that I am sure many of the past cold outbreaks did not come with alot of snow. More times than not, the cold comes in dry. There are a few exceptions of course with the snow helping to cool things down more once its accumulates but overall its rare in the SE.

[kanc2001]

The DGEX dry-slots the upstate so of course it will verify. What did me, burrel, and oconee ever do to deserve this?

its that bouncing blue blobs fault

[strongwxnc]

What are the surface winds showing in this time period for you?

It is giving my area slight wnw around 5...

6z model data shows some very interesting things for the escarpment this weekend...

A cold...and I mean COLD rain will come in early Sunday morning, the numerical data for Morganton-Lenoir has the 2M temps of 34 at 9z Sunday with nearly .40 of liquid. Sunday's high accoring to the model data will be 40 degrees at 15z Sunday, from there the 2M temps will free fall...

Sunday 21z: 30 degrees

Monday 6z: 15 degrees

Monday 12z: 8 degrees

The free fall overnight Sunday into Monday is massive cold air advection into this part of the country. This data has me getting no higher than 18 degrees on Monday. It has the foothills reaching single digits again Tuesday morning.

I'm courious as to what the 12z shows.

Would like to know about past events that had snow upfront then a massive cold outbreak after-wards. I assume this has happened before?

Id also like to say that I am sure many of the past cold outbreaks did not come with alot of snow. More times than not, the cold comes in dry. There are a few exceptions of course with the snow helping to cool things down more once its accumulates but overall its rare in the SE.