Nov. 27th - Nov. 29th Upper Level Low

[SN_Lover]

0z CMC

heavy rain for NC

light snow for TN

Snowfall totals for the 0Z GFS(not definite)

[WilkesboroDude]

NWS Little Rock, Arkansas

Long term...Tuesday through Friday... a complicated upper flow pattern is resulting in above average uncertainty in the long term forecast today. The main concern in the long term will be a potential upper low that could still be lingering just east of the state at the start of the long term period. The question today is whether to base the forecast on NAM/GFS runs or European model (ecmwf)/candadian model solutions. The GFS and NAM... allow the upper wave responsible for the Sat system to move well east of Arkansas before closing off as an upper low over the Ohio Valley early next week. Meanwhile...at the same time...the Gem and European model (ecmwf) both close off an upper low over northern la/southern Arkansas. The GFS is the furthest east of the gefs members with the location of the closed upper low...with most ensemble members showing a solution closer to the European model (ecmwf)/Gem scenario. Will lean toward the European model (ecmwf)/Gem solution... increasing cloud cover on Tuesday...but not yet introducing probability of precipitation. Interestingly...low level thermal profiles in the European model (ecmwf)/Gem could support a bit of tsnow if we were to see any precipitation.

[Gastonwxman]

0z Euro looking good so far. Cut-off is located between MS/AL

EDIT: Looks like it strengthens it a good bit as it travels northeastward.

[dsaur]

Truely bizarre pattern. I've never seen this many 5H cutoffs, ever. Tonights GFS keeps them going, they're absolutely everywhere. I'm curious if anybody has any idea whats going on? I know nina's are known for them, esp. in Spring and Fall , but this is well beyond anything I've ever studied. And at what point in the season do they ease up?

And with the oddly far south, and strong ULL's of the last few years dumping snow down here very late in the season. You can go a lot of years without getting extra helpings from a ULL. And we are getting to know them quite well. T

[Gastonwxman]

Thoughts for next week's system:

http://gwxmanblog.blogspot.com/2011/11/nice-weekend-models-madness-continues.html

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[DaculaWeather]

06Z GFS show a 552 developing SW of Memphis at hour 45

[DaculaWeather]

546 at hour 54 and the low has grown larger and deeper with a vort max just south of Memphis

[DaculaWeather]

By hour 60 it's really starting to deepen. We now have 3 complete height contours around the system. From now through hour 72 the storm is taking on a negative tilt.

[DaculaWeather]

By hour 72, the low is down to 540

[DaculaWeather]

By early Tuesday morning, the low has tracked across north AL and GA to this location. Notice the little vorts traveling around it. Possibly our chance for snow? By this time we're almost on the backside of the low here in Georgia

[DaculaWeather]

At 81 hours the low is starting to move quicker

[NavarreDon]

Thanks for the pbp Steve great job!

[DaculaWeather]

I thought I was the only one up!

[NavarreDon]

I thought I was the only one up!

I am at work already (retail) and after yesterday It feels like getting up at 3:30 is sleeping in. Anyway back on topic. Last nights crew at GSP must have forgot to brew coffee! Not the best afd write up I have seen by them.

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...

AS OF 300 AM SATURDAY...MODELS IN BETTER AGREEMENT BRINGING UPPER

SHORTWAVE TROF ACROSS THE PLAINS TOWARD THE LOWER MS VALLEY SUN.

ASSOC COLD FRONT AHEAD OF IT WILL MOVE E OF THE MS VALLEY WITH

MOISTURE CONTINUING TO SURGE FROM THE GULF AND UP OVER THE AREA.

POPS RAMP UP OVER THE W DURING THE DAY SUN WITH LIKELY POPS OVER THE

MTNS AND W BY LATE AFTN...TAPERING TO CHC OVER THE I-77 CORRIDOR AND

E. EVEN WITH CLOUDY SKIES...CONTINUED LOW LVL S FLOW WILL KEEP TEMPS

AROUND AVG DURG THE DAY. AS DEEP MOISTURE CONT TO SURGE N EXPECT

SHWRS ACROSS THE CWA SUN NIGHT AND MON. MODELS CONTINUE TO SHOW

QUITE A BIT OF SHEAR...MAINLY ALOFT...BUT LITTLE INSTABILITY OR CAPE

AND THERE IS NO MENTION OF TSTMS WITH THIS FCST. SHWRS FINALLY TAPER

OFF FROM THE SW MON NIGHT AND TEMPS DROP. THERE WILL BE SOME SNOW AT

HIGHER MTN ELEVS AND THE COLDEST AIR DOESN`T COME IN UNTIL AFTER THE

BEST MOISTURE HAS MOVED E...BUT AN INCH OR SO ALONG HIGHER RIDGES

WILL BE PSBL AND THIS WILL HAVE TO BE WATCHED.

[Met1985]

I am at work already (retail) and after yesterday It feels like getting up at 3:30 is sleeping in. Anyway back on topic. Last nights crew at GSP must have forgot to brew coffee! Not the best afd write up I have seen by them.

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...

AS OF 300 AM SATURDAY...MODELS IN BETTER AGREEMENT BRINGING UPPER

SHORTWAVE TROF ACROSS THE PLAINS TOWARD THE LOWER MS VALLEY SUN.

ASSOC COLD FRONT AHEAD OF IT WILL MOVE E OF THE MS VALLEY WITH

MOISTURE CONTINUING TO SURGE FROM THE GULF AND UP OVER THE AREA.

POPS RAMP UP OVER THE W DURING THE DAY SUN WITH LIKELY POPS OVER THE

MTNS AND W BY LATE AFTN...TAPERING TO CHC OVER THE I-77 CORRIDOR AND

E. EVEN WITH CLOUDY SKIES...CONTINUED LOW LVL S FLOW WILL KEEP TEMPS

AROUND AVG DURG THE DAY. AS DEEP MOISTURE CONT TO SURGE N EXPECT

SHWRS ACROSS THE CWA SUN NIGHT AND MON. MODELS CONTINUE TO SHOW

QUITE A BIT OF SHEAR...MAINLY ALOFT...BUT LITTLE INSTABILITY OR CAPE

AND THERE IS NO MENTION OF TSTMS WITH THIS FCST. SHWRS FINALLY TAPER

OFF FROM THE SW MON NIGHT AND TEMPS DROP. THERE WILL BE SOME SNOW AT

HIGHER MTN ELEVS AND THE COLDEST AIR DOESN`T COME IN UNTIL AFTER THE

BEST MOISTURE HAS MOVED E...BUT AN INCH OR SO ALONG HIGHER RIDGES

WILL BE PSBL AND THIS WILL HAVE TO BE WATCHED.

Lol that is hilarious! I needed a good laugh. Been up all night.

[DaculaWeather]

Someone in north GA might get a little something

[Met1985]

Ya North Georgia and Northern Alabama could see some snow showers or flurries. The strorm seems to be gaining strength and cold into each run. Very interesting beast this low is.

[MotoWeatherman]

Pretty much the 0z EURO, and the overnight NAM and GFS move the ULL in a pretty similar fashion with it cutting off over the lower MS valley and then moving east towards AL and then NE up the spine of the apps. As stated over and over on this forum by many, the big deal will be the heavy rains. For snow lovers this looks more like a flurry maker for northern MS, AL, GA late Monday into Tuesday. The low is strengthening as is moves from west to east so the cold pool that it brings with it should be colder as it moves west to east. I could see the WNC apps getting 1-2" above 2500 feet. If a deformation band does set up to the north of the ULL then places like Nashville to Crossville to Knoxville could be in the game for 1-2" of snow. The GFS is not all that exciting, regarding QPF, once the main batch of moisture moves thru on Sunday Night/Monday but the 0z EURO shows the possibility of a deformation band in TN.

Just my 2cents...

[Met1985]

Pretty much the 0z EURO, and the overnight NAM and GFS move the ULL in a pretty similar fashion with it cutting off over the lower MS valley and then moving east towards AL and then NE up the spine of the apps. As stated over and over on this forum by many, the big deal will be the heavy rains. For snow lovers this looks more like a flurry maker for northern MS, AL, GA late Monday into Tuesday. The low is strengthening as is moves from west to east so the cold pool that it brings with it should be colder as it moves west to east. I could see the WNC apps getting 1-2" above 2500 feet. If a deformation band does set up to the north of the ULL then places like Nashville to Crossville to Knoxville could be in the game for 1-2" of snow. The GFS is not all that exciting, regarding QPF, once the main batch of moisture moves thru on Sunday Night/Monday but the 0z EURO shows the possibility of a deformation band in TN.

Just my 2cents...

So the for there to be any real possibility for accumulating snow there will have to be a deformation band set up. Also if you could explain what is a deformation band exactly?

[DaculaWeather]

Right now the GFS is showing us in rain from hour 45 through hour 78. It's hard to really tell but maybe 5-6" up here in north Georgia?

[DaculaWeather]

So the for there to be any real possibility for accumulating snow there will have to be a deformation band set up. Also if you could explain what is a deformation band exactly?

An area in the atmosphere where winds converge along one axis and diverge along another. Deformation zones (or axis of deformation as they are sometimes referred to) can produce clouds and precipitation.

What you'll have in this case are winds wrapping counter clockwise around the low running into the winds that will be coming in from the north/nw. In that zone, which will form in the NW quadrant of the storm usually, is where the band of precip will setup. That is the deformation zone.

[Met1985]

An area in the atmosphere where winds converge along one axis and diverge along another. Deformation zones (or axis of deformation as they are sometimes referred to) can produce clouds and precipitation.

What you'll have in this case are winds wrapping counter clockwise around the low running into the winds that will be coming in from the north/nw. In that zone, which will form in the NW quadrant of the storm usually, is where the band of precip will setup. That is the deformation zone.

Oh ok. Thanks for explaining that to me!

[DaculaWeather]

Here we go!!!!

[Wow]

Ack. Gotta fly into GSP Monday afternoon. Hopefully this will slow down (or speed up) a bit avoid delays.

[strongwxnc]

Pulled over from Robert's cut-off thread..

Did anyone read the HPC's discussion? Very interesting....and they seem to like the European and NAM solutions...

STRONG LOW-LEVEL COLD ADVECTION BENEATH THE DEVELOPING H5 LOW ANDDECENT MID-LEVEL SHEAR ACROSS THE NORTH AND NORTHEAST QUADRANT OFTHE H5 CIRCULATION CONTAINING M20C COLD POOL WILL PERIODICALLYBECOME ENTRAINED WITH GULF MOISTURE ALONG/AHEAD OF THE DEEP COLDFRONT. ISENTROPIC ANALYSIS...BETWEEN 305K AND 320KSURFACES...SUGGEST DYNAMICAL LIFT...INCREASING INSTABILITY ANDPOSSIBLE CONVECTIVE ACTIVITY SUPPORTING BRIEF PERIODS OF RAIN/SNOWMIX AND SNOW/SLEET SHOWERS ACROSS PORTIONS OF THESOUTHEAST...INITIALLY ALONG THE COLD FRONT IN EASTERNOKLAHOMA...WESTERN ARKANSAS AND SOUTHERN MISSOURI...BEFORESHIFTING EAST SOUTHEASTWARD INTO NORTHEAST LOUISIANA...NORTHERNMISSISSIPPI...WESTERN TENNESSEE AND NORTHWEST ALABAMA. MUCH IF NOTALL THE ELEVATED RAIN BANDS MOVING NORTHWARD INTO THE COLD POOLALOFT WILL BE ENHANCED BY THE STRONG DYNAMICAL PROCESSES/LIFT.BASED ON THE ECMWF/UKMET/CANADIAN/GFS...SFC TO H5 MASSFIELDS...THERMO-DYNAMIC PROFILES SUGGEST THE BETTER PROSPECTS FORACCUMULATING SNOWFALL TO BE ACROSS NORTHEAST MISSISSIPPI...SOUTHWESTERN TENNESSEE...AND NORTHWEST ALABAMA...FOLLOWING THE LOWTRACK AND COLD FRONT. POSSIBLE SNOWFALL ACCUMULATIONS SHIFTEASTWARD INTO THE SOUTHERN APPALACHIANS...INCLUDING NORTHERNGEORGIA AND SOUTHWEST NORTH CAROLINA ON MONDAY WITH BROAD WRAPAROUND DEFORMATION PRECIPITATION AND BANDING EXPANDING NORTH ANDWEST ACROSS PORTIONS OF THE COLD SECTOR...ENCOMPASSING A LARGEPORTION OF THE SOUTHEAST...INCLUDING THE LOWERMISSISSIPPI/TENNESSEE VALLEYS.

Where's the popcorn??

[burgertime]

Let's remember one thing, ULL never take the exact track the models say. Someone is going to be surprised by this. Euro really amped up the qpf as the low gets moving and gets stronger the rain just pivots across the state. It's was pretty awesome scrolling through the frames and really seeing the qpf just blossom right over NC.

[DaculaWeather]

-30c 500 mb temps as far south as CO

[DaculaWeather]

Let's remember one thing, ULL never take the exact track the models say. Someone is going to be surprised by this. Euro really amped up the qpf as the low gets moving and gets stronger the rain just pivots across the state. It's was pretty awesome scrolling through the frames and really seeing the qpf just blossom right over NC.

As it starts rotating and most of the time it is, we're in just the right spot (for now) to get hammered with rain.

At 78 hrs it's pretty cold, with wrap around moisture, who knows?

[burgertime]

As it starts rotating and most of the time it is, we're in just the right spot (for now) to get hammered with rain.

At 78 hrs it's pretty cold, with wrap around moisture, who knows?

I believe last year that ULL was supposed to hit us up until about 24 hours when it suddenly moved west and nailed Kentucky. I believe the ULL of 2009 ended up taking a more easterly track? Robert can verify that one. Just saying by tomorrow night the ULL might be further east or further west. I'll be hoping for a little back side snow as well that's for damn sure!

[FoothillsNC]

Let's remember one thing, ULL never take the exact track the models say. Someone is going to be surprised by this. Euro really amped up the qpf as the low gets moving and gets stronger the rain just pivots across the state. It's was pretty awesome scrolling through the frames and really seeing the qpf just blossom right over NC.

Yep. and the GFS Sunday night has a wave of LP develop in western GA overnight to goes due north to near CHA Monday morning, putting a pretty good slug of high winds from the surface up to to 850, so some pretty gusty winds are going to surge north overnight from GA then into SC and then NC east of the low. Should be great rainmaker.

I believe last year that ULL was supposed to hit us up until about 24 hours when it suddenly moved west and nailed Kentucky. I believe the ULL of 2009 ended up taking a more easterly track? Robert can verify that one. Just saying by tomorrow night the ULL might be further east or further west. I'll be hoping for a little back side snow as well that's for damn sure!

If you're wanting snow you need that 5H cutoff to track to your south on this side of the mtns. If it goes overhead directly , there's a slight chance of snow here but usually the mtns will wring out most of the moisture and we'd need really good rates to get the flake to make it to the ground. The mtns themselves though, no problem. Its going to snow unless the 5H goes well west of there (even then upslope will kick in for them) . The GFS takes the core of the 5h across nw GA to near AVL....so the best chance at snow would be immediately north and west of the side, however since no mtns block nw GA, easily the bands can rotate down to northern Ga. in that setup. We have to see exactly where this goes. Because the 5h track means everything, obviously if it ends up further south and east then ATL would be in the chance at getting some snow and the mtns of TN and NC would really get decent snow synoptically not just upslope.