January 17th-18th Winter Storm Discussion

[BullCityWx]

Right now, looks like best shot at accumulations is across northern MS, northern AL and middle tennessee. Still a long way to go.

[DixieBlizzard]

That's the NAM you are referring to?  Jeremy, I would love to see the NAM just a bit East but I know that robs someone else. I just hope someone gets something out of this. Good luck everyone!

[BIG FROSTY]

CMC way south, just rain se NC, SC and Ga.

 

[DixieBlizzard]

I was loving the look of the Canadian last month and it never panned out. Watch it be right this time. That's pure ugliness.

[Rankin5150]

Wishing us SE Peeps some luck and some good mojo!

[GaffneyPeach]

Every good event comes with a complimentary "Storm Drop". Don't forget that...

I would also like to direct your attention to my signature. One of my favorite lines ever, even since Eastern, was by our thread starter.   

[Marion_NC_WX]

0z Euro only has a 1 contour over Mississippi that's getting ready to open by hour 66. A bit slower and weaker compared to GFS. 

[Marion_NC_WX]

Euro overall weaker and a tad south with the 500mb features, never goes negative tilt and it opens up over GA at 78. Moisture never makes it into North Carolina. This run did not cave in to the NAM/GFS idea.

 

Gotta get some sleep now.

[BullCityWx]

Euro overall weaker and a tad south with the 500mb features, opens up over GA at 78. Moisture never makes it into North Carolina. This run did cave in to the NAM/GFS idea, yet.

Gotta get some sleep now.

Actually, it does. It's close in Charlotte, the SFC temps are just a killer.

[Marion_NC_WX]

Actually, it does. It's close in Charlotte, the SFC temps are just a killer.

 

 

Yeah...you are right. Moisture does make it just above the NC/SC border...but it don't make it as far northwest as IMBY. Anyway...we got some time to let it trend a bit more.

[BullCityWx]

Yeah...you are right. Moisture does make it just above the NC/SC border...but it don't make it as far northwest as IMBY. Anyway...we got some time to let it trend a bit more.

It's about half an inch difference in QPF from AKH to MRN.

[Pack83]

To the untrained eye 6z NAM looks sweet for NC. Of course I haven't looked at temp profile.

[valkhorn]

6z NAM nails East Tn. 6z GFS says no snow for anyone as it takes it too far to the south. The GFS didn't budge, and the NAM is moving to the GFS. I'd say until the GFS bends towards the NAM we could stick a fork in this one.

[burgertime]

NAM looked really good for CLT to HKY just IMHO. We need these temps to just get a little cooler.

[burgertime]

Shocked no one mentioned the Euro ENS. The EPS control run keeps that energy strong and dumps on CLT..wow! It keeps it cutoff as a two contour low through GA and one contour in NC. 

[DaculaWeather]

Need to keep this a little further south for me. Not too worried about this one though, the fireworks are just beginning.

[strongwxnc]

At 69, it is loving the foothills and upstate

With just under 1" . I assume bl are an issue, but the bam continues to hold the course !

NAM looked really good for CLT to HKY just IMHO. We need these temps to just get a little cooler.

[RevDodd]

It's rough when your sensibilities say "Ignore the NAM." Then your neck of the woods gets jilted by everyone else. It's like the NAM is the nerdy guy asking you to the dance ... but the ONLY guy asking.

 

GFS looks a bit too fast for the cold to catch over NC, and the EURO just laughs in our face. So ... shall we dance, NAM?

[burgertime]

I don't have access to it. I didn't check the 00z euro either. I'm playing the IMBY method. If it doesn't get east TN, I'm uninterested, and will be watching the next arctic front for anything.

 

It also slams TN due to TN being on the NW side of the low. 

[valkhorn]

It also slams TN due to TN being on the NW side of the low. 

I'd have to see the maps to believe it. No offense. HPC thinks the NAM has some merit, too. TYS is quite a distance from Charlotte.

[burgertime]

I'd have to see the maps to believe it. No offense. HPC thinks the NAM has some merit, too. TYS is quite a distance from Charlotte.

 

Sorry slam was probably too strong. It does paint some snow across TN...probably eastern TN would fare better.

[packfan98]

Definite trend over the past 24-hours is a stronger system making it further east. If it stays closed, there should be enough dynamics for some area to get snow. Obviously, the devil is in the details and the temperatures are problematic. Lets keep a close eye on the temperatures today to see if they trend slightly cooler which often happens as we get closer to go time.

[FallsLake]

Congratulations to everybody (mid south) getting wintery precipitation. Little jealous here but still hopeful we can pull something out Thursday night. RAH from last night still not excited BUT has kept the mention of something mixing in (..this covers them just in case). I think most on the Atlantic side of the south will have to wait until the true cold air can get established east of the mountains.

  

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 350 AM TUESDAY...

INCREASING CONFIDENCE OF A QUICK-HITTING SWATH OF PRECIPITATION
ACROSS DIXIE...INCLUDING CENTRAL NC...THURSDAY-THURSDAY NIGHT.

THURSDAY AND THURSDAY NIGHT:
SOUTHERN STREAM SHORTWAVE/COMPACT LOW FORECAST TO RESIDE OVER THE
LOWER MS VALLEY THURSDAY MORNING WILL SHEAR EASTWARD...CROSSING THE
DEEP SOUTH DURING THE DAY ON THURSDAY AND THEN THROUGH THE SOUTHEAST
STATES THURSDAY NIGHT.

MODELS CONTINUE TO EXHIBIT RUN-TO-RUN VARIABILITY WITH THE EXACT
TIMING AND AMPLITUDE OF THIS SYSTEM...BUT THE STRENGTHENING
INFLUENCE OF THE POLAR VORTEX SINKING OVER SE CANADA/NORTHEAST US
SHOULD SUPPRESS THE SURFACE LOW REFLECTION SOUTH AND EAST OF THE
AREA. EVEN STILL...THE LATEST 00Z/15 MODEL ITERATIONS ALL SHOW A
NORTHWARD SHIFT IN THE PRECIP SHIELD...WITH A SIGNIFICANT
DEFORMATION PRECIP BAND(0.50 TO 1.0")POSSIBLE ACROSS THE SOUTHERN
HALF OF THE STATE. THE 00Z/15Z MODEL ITERATION IS ALSO QUICKER WITH
THE ONSET OF PRECIP FROM THE SOUTHWEST...QUITE POSSIBLY REACHING THE
SOUTHWESTERN PIEDMONT BY THE LATE MORNING HOURS...AND THEN SPREADING
NORTHEASTWARD INTO THE REMAINDER OF THE FORECAST AREA BY MID
AFTERNOON. PARTIAL THICKNESSES/NOMOGRAM SUPPORT ALL RAIN THURSDAY
AFTERNOON AND INTO EVENING...WITH IT THEN TRENDING TOWARDS A BRIEF
WINTRY MIX OVERNIGHT AS COOLING THROUGH THE ENTIRE LAYER IS
REALIZED...IN THE LOW-LEVELS VIA THE BUILDING COOL SURFACE HIGH FROM
THE WEST...AND IN THE MID AND UPPER LEVELS WITH THE ARRIVAL COLD
CORE ALOFT. SOUNDINGS HOWEVER INDICATE THAT IT IS HIGHLY
QUESTIONABLE IF THERE IS EVER ICE NUCLEI ACTIVATED IN THE
CLOUD...WHILE MEANWHILE...THE SURFACE FREEZING WET-BULB TEMPS STAY
WEST OF THE TRIAD. SO IT SEEMS MORE LIKELY IT WILL BE A COLD RAIN
FOR CENTRAL NC...WITH THE CAVEAT THAT SOME NORTHERN/CENTRAL AREAS
COULD SEE A QUICK/BRIEF BURST OF A RAIN/SNOW MIX OR RAIN/SLEET MIX
IN A HEAVY PRECIP BAND ASSOCIATED WITH INTENSE UVV. FOR NOW WILL
KEEP IT ALL RAIN...WITH CATEGORICAL POPS ACROSS THE SOUTH...TAPERING
OFF TO CHANCE ACROSS THE NORTH AS THE SURFACE LOW TRACKS OFF THE
SOUTHEAST COAST. EARLIER ONSET OF TEMPERATURES DURING THE DAY ON
THURSDAY COULD RESULT IN COLDER HIGHS THAN CURRENTLY ADVERTISED...SO
WILL ADJUST DOWN A BIT. HIGHS RANGING FROM MID TO UPPER 40S
NORTHWEST TO LOWER/MID 50S SOUTHEAST. LOWS IN THE MID TO UPPER 30S.
-CBL

FRIDAY THROUGH MONDAY:
A POLAR FRONT WILL MAKE A RUN INTO NC SUNDAY NIGHT...THEN BRIEFLY
RETREAT NORTHWARD IN ADVANCE OF A DRY CLIPPER WAVE ON MON. THE
TRAILING BOUNDARY -- AN ARCTIC ONE -- WILL BE POISED TO SURGE INTO
NC JUST BEYOND D7 WITH WELL BELOW AVG TEMPERATURES...OWING TO THE
AMPLIFICATION OF AN UPSTREAM OVER WESTERN NOAM (POSITIVE PNA) THAT
THE MEDIUM RANGE GUIDANCE HAS INSISTED WILL OCCUR EARLY-MID
WEEK. -MWS

 

[DaculaWeather]

MESOSCALE DISCUSSION 0035

NWS STORM PREDICTION CENTER NORMAN OK

0632 AM CST TUE JAN 15 2013

AREAS AFFECTED...PARTS OF NE TX...NRN LA...SRN AR AND ADJACENT AREAS

OF THE MS DELTA

CONCERNING...FREEZING RAIN

VALID 151232Z - 151630Z

SUMMARY...FREEZING RAIN IS EXPECTED TO DEVELOP ACROSS THE REGION

THROUGH THE MID AND LATE MORNING HOURS...WITH CONVECTIVELY ENHANCED

RATES OF .1 TO .3 INCHES PER HOUR POSSIBLE.

DISCUSSION...DOWNSTREAM OF A VIGOROUS UPPER TROUGH NOW TURNING

EASTWARD ACROSS THE SOUTHERN ROCKIES...LOWER/MID TROPOSPHERIC WARM

ADVECTION WILL CONTRIBUTE TO STRENGTHENING AND CONSOLIDATING UPWARD

VERTICAL MOTION ACROSS PARTS OF THE ARKLATEX EAST NORTHEASTWARD

TOWARD THE MISSISSIPPI DELTA REGION THROUGH THE 15-18Z TIME FRAME.

COUPLED WITH THE CONTINUING RETURN OF GULF MOISTURE ON SOUTHERLY

FLOW...ABOVE A COLD/STABLE SURFACE BASED LAYER ENTRENCHED TO THE

NORTH OF A STALLED SURFACE FRONT ACROSS THE NORTHWESTERN/NORTH

CENTRAL GULF OF MEXICO...THIS WILL LEAD TO A DEVELOPING

PRECIPITATION SHIELD. CONVECTIVELY ENHANCED PRECIPITATION RATES ARE

LIKELY AS MODEST STEEPENING OF MID-LEVEL LAPSE YIELDS WEAK

CAPE...AND THERMODYNAMIC PROFILES THAT COULD BECOME SUPPORTIVE OF

LIGHTNING /WEAK THUNDERSTORM ACTIVITY IS CURRENTLY OCCURRING ACROSS

PARTS OF NORTH CENTRAL TEXAS/. THOUGH MOST OF THE COLUMN BELOW 700

MB WILL BE ABOVE FREEZING...AT LEAST A SHALLOW SURFACE BASED LAYER

IS EXPECTED TO REMAIN BELOW FREEZING IN AREAS AFFECTED BY

CLOUDS/PRECIPITATION...TO THE NORTH OF A LINE ROUGHLY FROM LONGVIEW

TX THROUGH SHREVEPORT AND MONROE LA...INTO SOUTHERN ARKANSAS AND THE

MISSISSIPPI DELTA...THROUGH AT LEAST MID DAY. SIGNIFICANT ICING IS

POSSIBLE...BUT MAINLY ON VEGETATION...POWER LINES AND ELEVATED ROAD

SURFACES...AS GROUND TEMPERATURES REMAIN RELATIVELY WARM.

[beanskip]

Question for a met: Why does the 850 low not close off until the 500 low is weaker. That is, the 500 low is at its strongest over Miss./Ala., but there is no closed 850 feature.The 850 low only closes off over E. Ga./SC when the 500 low is on the downswing in terms of strength. Thanks.

[MichaelJ]

Looks to me like a classic case of threading the needle here like we almost always do. The areas North and West of 1-40 will be close to snow in temps but on the precip but will not have much to work with, if any. Conversely, those in the sweet spot of Upper SC and Eastern NC will have the precip but not the temps. Looks like this was close but will be no cigar unless things trend differently and Dr. No gets on board

[Cold Rain]

Has anyone thought about how ridiculous it is that in the heart of winter, we're tracking a system that's battling suppression and temps STILL aren't really supportive of snow?

Usually, when we're dealing with these types of systems that might remain suppressed, it's usually the case of it being cold enough for snow but not getting the moisture in. I just thought that it's odd that suppression doesn't really equal cold in this case.

[NavarreDon]

Just on fellas & haven't really looked at anything yet except the gsp afd. Here is part of the mid term.

THE MOST INTERESTING AND LEAST UNCERTAIN PART OF THE FORECAST IS

THURSDAY AND THU NIGHT...AS UPPER LOW IS EXPECTED TO EJECT FROM THE

SOUTHERN PLAINS/ LOWER MISS VALLEY. WITH STRONG CONFLUENT FLOW IN

PLACE ACROSS THE EASTERN CONUS...IT STANDS TO REASON THAT THIS

FEATURE WILL BEGIN TO OPEN AND SHEAR OUT AS IT PROGRESSES ACROSS THE

SOUTHEAST. HOWEVER...THE MODELS ARE COMPLETELY AT ODDS AS TO HOW

SOON/WHERE THIS WILL HAPPEN. A GENERAL CONSENSUS IS EMERGING THAT

CYCLOGENESIS WILL OCCUR IN THE VICINITY OF THE EASTERN GULF COAST

SOMETIME THURSDAY. A NOTABLE EXCEPTION IS THE NAM...WHICH IS MUCH

MORE INTENSE WITH THE UPPER LOW THAN THE OTHER MODELS...AND IS MUCH

FARTHER NORTH WITH THE SURFACE CYCLONE. IT HAS ESSENTIALLY BEEN

THROWN OUT AS AN OUTLIER. OUR TIMING OF PRECIP INTO THE AREA ON

THURSDAY WILL BE GENERALLY BASED UPON AN ECMWF/GFS CONSENSUS...WITH

POPS INCREASING TO CATEGORICAL ACROSS SW ZONES BY THU AFTERNOON...

WITH LIKELY POPS ACROSS MOST OF THE REMAINDER OF THE FORECAST AREA

BY THE END OF THE DAY. WHILE PARTIAL THICKNESSES FAVOR RAIN IN THE

PIEDMONT/FHILLS...THE MTNS WILL BE A POTENTIAL PROBLEM AREA FOR

WINTRY PRECIP...AS GFS FORECAST SOUNDINGS FEATURE A DEEP ISOTHERMAL

LAYER NEAR FREEZING ABOVE ABOUT 2000 FEET. FORTUNATELY...THE HIGHEST

QPF IS EXPECTED OVER THE PIEDMONT...BUT THERE IS NEVERTHELESS THE

POTENTIAL FOR SIGNIFICANT ACCUMULATIONS OF SNOW ACROSS THE MTNS...

ESP IN THE HIGHER ELEVATIONS. IT IS TOO SOON...AND UNCERTAINTY STILL

TOO HIGH TO CONTEMPLATE ANY WATCH PRODUCTS AT THIS TIME...BUT THE

POTENTIAL WILL BE MENTIONED IN THE HWO.

[Wow]

Has anyone thought about how ridiculous it is that in the heart of winter, we're tracking a system that's battling suppression and temps STILL aren't really supportive of snow?

Usually, when we're dealing with these types of systems that might remain suppressed, it's usually the case of it being cold enough for snow but not getting the moisture in. I just thought that it's odd that suppression doesn't really equal cold in this case.

 

Suppression for us down in the SE is when the PV is nearer to SE Canada or the NE.  With the SE ridge still around (though on its way out) we will still have temp issues.

[nchighcountrywx]

Has anyone thought about how ridiculous it is that in the heart of winter, we're tracking a system that's battling suppression and temps STILL aren't really supportive of snow?

Usually, when we're dealing with these types of systems that might remain suppressed, it's usually the case of it being cold enough for snow but not getting the moisture in. I just thought that it's odd that suppression doesn't really equal cold in this case.

 

+1

 

I work with a company down in Charlotte that is highly impacted by winter weather events when they occur.     For Charlotte/Southern Piedmont, this one is not even being discussed on the table by internal operations as a threat.   There was one comment that In the far NW Piedmont/Foothills, should the heavier precip come at night, a few flakes possibly mixing in with heavier precip pockets with boundary layer and air/surface temperatures well above freezing.

 

In the mountains, temperatures will be supportive of some snow, but moisture appears to be the problem in the mountains.

 

At least there is something to discuss here on our board and it is neat a lot of people enjoy it and have the flexibility to put a lot of time into the discussions.   Hopefully the pattern over the next few weeks will bring us a genuine winter weather threat.