January 17th-18th Winter Storm Discussion

[deltadog03]

12z GFS nowhere even close outside of the mountains verbatim on temps. 

 

Agreed!  Its going to be SUPER close outside of mountains.  IMO, I think, its going to take a longer closed ULL, but also some elevation

[BullCityWx]

Just looking at the snow it dropped in NC it would appear to have been a clipper... but that could be completely wrong. 

 

Actually, it had a strong low also. Rain went to thunderstorms and sleet which went to thundersnow.

[MillerA]

12z GFS nowhere even close outside of the mountains verbatim on temps.

Allan Huffman Just tweeted those same thoughts.

[oconeexman]

I can only hope her in the far NW corner of SC we get lucky enough to be under some heavy rates and stay on the NW quadrant of this rascal. Not expecting anything but this is the type that can deliver enough action to suffice a man for a few weeks!

[calculus1]

12z GFS nowhere even close outside of the mountains verbatim on temps. 

 

This run doesn't keep the 500 mb low closed off as long.  It's not as strong.  Only one contour at hours 54 and 60.  No closure by hour 66.

[FoothillsNC]

I find it very mysterious that the GFS suddenly loses its cold thikness and 850 core once it leaves eastern Alabama, Georgia. Most upper lows won't do that, especially when they hold together. NAM holds it completely together. GFS mostly holds it together and has been trending toward NAM.

[burgertime]

I find it very mysterious that the GFS suddenly loses its cold thikness and 850 core once it leaves eastern Alabama, Georgia. Most upper lows won't do that, especially when they hold together. NAM holds it completely together. GFS mostly holds it together and has been trending toward NAM.

 

Agreed about it trending towards the NAM. Both the Euro and GFS fell to the NAM in this situation. All eyes on the NAM. 

[DaculaWeather]

Memphis

 

THE NATIONAL WEATHER SERVICE IN MEMPHIS HAS ISSUED AN ICE STORM
WARNING...WHICH IS IN EFFECT UNTIL 6 AM CST WEDNESDAY.

* ICE ACCUMULATIONS...FREEZING RAIN POSSIBLY MIXED WITH SLEET
  INITIALLY WILL PRODUCE ICE ACCUMULATIONS AROUND A QUARTER OF AN
  INCH THROUGH EARLY EVENING...MAINLY ON TREES...POWER LINES AND
  ELEVATED ROAD SURFACES.

* TIMING...THROUGH 6AM CST WEDNESDAY MORNING WITH THE GREATEST
  POTENTIAL FOR ICING THIS AFTERNOON.

* IMPACTS...HAZARDOUS ROAD CONDITIONS WILL LIKELY DEVELOP ON
  ELEVATED SURFACES SUCH AS BRIDGES AND OVERPASSES.

[NEGa]

wow something to watch and post about finally lol.  other than the rain (and a ton of it) not much winter excitement the last two years (well last year and so far this year).  cant give a rainfall total since i forgot to empty the gauge from the other day and its over flowing (6" at least) 

 

looks like a lot of people might see something, but for ne ga and the upstate am not liking what i am seeing with the snow stopping about a county away.  hopefully things will start looking better since its just as few days away

[DaculaWeather]

Nashville too...

 

...ICE STORM WARNING IN EFFECT UNTIL 8 AM CST WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN NASHVILLE HAS ISSUED AN ICE STORM
WARNING, WHICH IS IN EFFECT UNTIL 8 AM CST WEDNESDAY.

* PRECIPITATION WILL INCREASE DURING THE AFTERNOON AND CONTINUE
  OVERNIGHT AS TEMPERATURES DROP BELOW FREEZING BY NIGHTFALL.

* ICE WILL ACCUMULATE ON EXPOSED SURFACES, INCLUDING ROADS,
  BRIDGES, AND OVERPASSES.

* TIMING...THIS AFTERNOON THROUGH TONIGHT.

* ICE ACCUMULATIONS...ONE-QUARTER TO ONE-HALF INCH.

[EmersonGA]

NAM extracted data gives Gastonia 3.9" of snow:

http://68.226.77.253/text/NAMSFC/NAM_kakh.txt

LOL.  It spits out 2" of thundersnow for me.  One can dream. Station ID: KVPC Lat:   34.12 Long:  -84.84                                                         NAM Model Run: 12Z 15JAN 2013  HR Valid     2m Tmp 2m Dpt 10m Dir 10m Spd TPrcp CPrcp 1000-500 500mb 850mb 500mb MSLP TCC PRS WX   Tot    Snowfall  Vis                Deg F  Deg F   deg      kt    in.   in.     Thk    GPH   Tmp   Tmp   mb   %  TEXT    Clouds      in    SM   0 01/15 12Z   45     44     348       3    0.00  0.00    563    579   10.8 -10.7 1019 100 -RA   015OVC208    0.0    9.5   3 01/15 15Z   45     44     348       3    0.15  0.02    563    579   12.3 -10.8 1019 100 -TSRA 011OVC242    0.0    4.2   6 01/15 18Z   47     46      52       3    0.21  0.05    564    579   12.9 -10.3 1018 100 -TSRA 012OVC376    0.0    7.3   9 01/15 21Z   47     46     318       5    0.24  0.10    564    578   13.4 -10.1 1017 100 TSRA  012OVC398    0.0    3.6  12 01/16 00Z   47     47     102       1    0.06  0.01    564    578   12.5  -9.8 1016 100       015OVC395    0.0   10.8  15 01/16 03Z   51     50     163       3    0.03  0.03    564    578   12.2 -10.1 1016  84       064BKN147    0.0    9.1  18 01/16 06Z   55     55     182       4    0.01  0.01    564    576   11.9  -9.8 1015  84       026BKN289    0.0    9.5  21 01/16 09Z   60     59     198       7    0.10  0.03    563    575   11.5 -10.2 1013 100 -TSRA 013OVC238    0.0    6.0  24 01/16 12Z   59     58     230       6    0.07  0.03    562    574   10.9  -9.9 1014 100 -TSRA 014OVC103    0.0   11.1  27 01/16 15Z   53     52     290       5    0.05  0.03    560    575   10.3 -10.0 1017 100       011OVC104    0.0   14.6  30 01/16 18Z   52     50     291       6    0.01  0.00    560    574   10.4  -9.6 1017 100       016OVC096    0.0   14.1  33 01/16 21Z   50     48     315       4    0.05  0.00    559    574   10.3  -9.5 1017 100 -RA   018OVC146    0.0   13.6  36 01/17 00Z   49     48     322       3    0.01  0.00    559    574    9.7  -9.0 1017 100 -RA   018OVC119    0.0   12.0  39 01/17 03Z   48     47     340       5    0.04  0.00    559    573    9.8  -9.7 1017  98       020BKN100    0.0   15.1  42 01/17 06Z   46     45     318       7    0.05  0.00    557    572    9.1 -10.6 1017  99       016OVC148    0.0   11.3  45 01/17 09Z   44     43     338       7    0.03  0.00    556    569    9.2 -11.3 1015 100 -RA   017OVC132    0.0   11.4  48 01/17 12Z   42     40     329       9    0.21  0.00    554    566    6.5 -13.3 1014 100 RA    016OVC160    0.0    6.1  51 01/17 15Z   39     38     347      10    0.27  0.00    552    564    5.6 -14.6 1015 100 RA    023OVC213    0.0    3.3  54 01/17 18Z   39     37     294      13    0.11  0.00    541    553    0.0 -17.9 1014 100 RA    014OVC116    0.0    6.0  57 01/17 21Z   34     32     322      20    0.21  0.01    538    552   -3.3 -22.8 1018 100 TSSN  007OVC141    2.2    0.9  60 01/18 00Z   34     32     338      15    0.08  0.00    541    559   -1.6 -19.0 1022 100       015OVC050    0.0   15.1  63 01/18 03Z   33     30     342      12    0.00  0.00    546    566    0.8 -13.8 1024  12       057FEW091    0.0   15.0  66 01/18 06Z   30     28     348      10    0.00  0.00    549    569    3.1 -13.8 1025   7       145FEW148    0.0   15.0  69 01/18 09Z   27     25     341       7    0.00  0.00    549    571    2.9 -14.3 1027   0          CLR       0.0   15.0  72 01/18 12Z   24     23     325       6    0.00  0.00    549    572    2.4 -15.2 1029   0          CLR       0.0   15.0  75 01/18 15Z   32     25     358       4    0.00  0.00    548    573    2.3 -16.4 1031   4       199FEW245    0.0   15.1  78 01/18 18Z   43     28     316       3    0.00  0.00    548    572    2.5 -16.9 1029   2       089FEW148    0.0   15.1  81 01/18 21Z   45     30     326       4    0.00  0.00    548    570    4.6 -16.7 1027   0          CLR       0.0   14.9  84 01/19 00Z   40     31     329       3    0.00  0.00    548    570    5.4 -17.6 1027   0          CLR       0.0   15.0

[DixieBlizzard]

LOL.  It spits out 2" of thundersnow for me.  One can dream. Station ID: KVPC Lat:   34.12 Long:  -84.84                                                         NAM Model Run: 12Z 15JAN 2013  HR Valid     2m Tmp 2m Dpt 10m Dir 10m Spd TPrcp CPrcp 1000-500 500mb 850mb 500mb MSLP TCC PRS WX   Tot    Snowfall  Vis                Deg F  Deg F   deg      kt    in.   in.     Thk    GPH   Tmp   Tmp   mb   %  TEXT    Clouds      in    SM   0 01/15 12Z   45     44     348       3    0.00  0.00    563    579   10.8 -10.7 1019 100 -RA   015OVC208    0.0    9.5   3 01/15 15Z   45     44     348       3    0.15  0.02    563    579   12.3 -10.8 1019 100 -TSRA 011OVC242    0.0    4.2   6 01/15 18Z   47     46      52       3    0.21  0.05    564    579   12.9 -10.3 1018 100 -TSRA 012OVC376    0.0    7.3   9 01/15 21Z   47     46     318       5    0.24  0.10    564    578   13.4 -10.1 1017 100 TSRA  012OVC398    0.0    3.6  12 01/16 00Z   47     47     102       1    0.06  0.01    564    578   12.5  -9.8 1016 100       015OVC395    0.0   10.8  15 01/16 03Z   51     50     163       3    0.03  0.03    564    578   12.2 -10.1 1016  84       064BKN147    0.0    9.1  18 01/16 06Z   55     55     182       4    0.01  0.01    564    576   11.9  -9.8 1015  84       026BKN289    0.0    9.5  21 01/16 09Z   60     59     198       7    0.10  0.03    563    575   11.5 -10.2 1013 100 -TSRA 013OVC238    0.0    6.0  24 01/16 12Z   59     58     230       6    0.07  0.03    562    574   10.9  -9.9 1014 100 -TSRA 014OVC103    0.0   11.1  27 01/16 15Z   53     52     290       5    0.05  0.03    560    575   10.3 -10.0 1017 100       011OVC104    0.0   14.6  30 01/16 18Z   52     50     291       6    0.01  0.00    560    574   10.4  -9.6 1017 100       016OVC096    0.0   14.1  33 01/16 21Z   50     48     315       4    0.05  0.00    559    574   10.3  -9.5 1017 100 -RA   018OVC146    0.0   13.6  36 01/17 00Z   49     48     322       3    0.01  0.00    559    574    9.7  -9.0 1017 100 -RA   018OVC119    0.0   12.0  39 01/17 03Z   48     47     340       5    0.04  0.00    559    573    9.8  -9.7 1017  98       020BKN100    0.0   15.1  42 01/17 06Z   46     45     318       7    0.05  0.00    557    572    9.1 -10.6 1017  99       016OVC148    0.0   11.3  45 01/17 09Z   44     43     338       7    0.03  0.00    556    569    9.2 -11.3 1015 100 -RA   017OVC132    0.0   11.4  48 01/17 12Z   42     40     329       9    0.21  0.00    554    566    6.5 -13.3 1014 100 RA    016OVC160    0.0    6.1  51 01/17 15Z   39     38     347      10    0.27  0.00    552    564    5.6 -14.6 1015 100 RA    023OVC213    0.0    3.3  54 01/17 18Z   39     37     294      13    0.11  0.00    541    553    0.0 -17.9 1014 100 RA    014OVC116    0.0    6.0  57 01/17 21Z   34     32     322      20    0.21  0.01    538    552   -3.3 -22.8 1018 100 TSSN  007OVC141    2.2    0.9  60 01/18 00Z   34     32     338      15    0.08  0.00    541    559   -1.6 -19.0 1022 100       015OVC050    0.0   15.1  63 01/18 03Z   33     30     342      12    0.00  0.00    546    566    0.8 -13.8 1024  12       057FEW091    0.0   15.0  66 01/18 06Z   30     28     348      10    0.00  0.00    549    569    3.1 -13.8 1025   7       145FEW148    0.0   15.0  69 01/18 09Z   27     25     341       7    0.00  0.00    549    571    2.9 -14.3 1027   0          CLR       0.0   15.0  72 01/18 12Z   24     23     325       6    0.00  0.00    549    572    2.4 -15.2 1029   0          CLR       0.0   15.0  75 01/18 15Z   32     25     358       4    0.00  0.00    548    573    2.3 -16.4 1031   4       199FEW245    0.0   15.1  78 01/18 18Z   43     28     316       3    0.00  0.00    548    572    2.5 -16.9 1029   2       089FEW148    0.0   15.1  81 01/18 21Z   45     30     326       4    0.00  0.00    548    570    4.6 -16.7 1027   0          CLR       0.0   14.9  84 01/19 00Z   40     31     329       3    0.00  0.00    548    570    5.4 -17.6 1027   0          CLR       0.0   15.0

Sold! Nice Emerson!

[GreensboroWx]

 

MESOSCALE DISCUSSION 0036   NWS STORM PREDICTION CENTER NORMAN OK   1048 AM CST TUE JAN 15 2013      AREAS AFFECTED...PARTS OF THE MID-SOUTH      CONCERNING...FREEZING RAIN       VALID 151648Z - 152115Z      SUMMARY...SCATTERED SHOWERS OF FREEZING RAIN WILL LIKELY YIELD ICE   ACCUMULATION RATES OF 0.02-0.10 IN/HR DEVELOPING INTO NWRN MS/WRN TN   THROUGH MID-AFTERNOON.      DISCUSSION...DOWNSTREAM OF A POSITIVE-TILT LONG WAVE TROUGH FROM THE   UPPER MIDWEST TO THE SRN HIGH PLAINS...PERSISTENT LOW/MID-LEVEL   ISENTROPIC LIFT HAS SUPPORTED A BROAD SWATH OF SCATTERED TO NUMEROUS   SHOWERS DEVELOPING E/NEWD ACROSS THE LOWER MS VALLEY. WITH MODEST   N/NELY SURFACE WINDS AND ABUNDANT DOWNSTREAM CLOUD COVERAGE   RETARDING SURFACE HEATING...MORNING MODEL GUIDANCE APPEARS LARGELY A   FEW DEGREES TOO WARM WHEN COMPARED TO 16Z SURFACE OBSERVATIONS WITH   THE OBSERVED FREEZING LINE RUNNING ROUGHLY FROM MLU TO BNA. GIVEN   THE PRONOUNCED WARM NOSE SAMPLED IN 12Z BNA/SHV RAOBS ATOP THE   SURFACE BELOW-FREEZING LAYER...FREEZING RAIN THAT HAS BEEN OCCURRING   IN SRN AR AND FAR NRN LA WILL LIKELY BECOME MORE PREVALENT IN NWRN   MS AND WRN TN IN THE EARLY AFTERNOON...INCLUDING THE MEMPHIS METRO   AREA.      ..GRAMS.. 01/15/2013

 

 

 

.MORNING MODEL GUIDANCE APPEARS LARGELY A   FEW DEGREES TOO WARM WHEN COMPARED TO 16Z SURFACE OBSERVATIONS WITH   THE OBSERVED FREEZING LINE RUNNING ROUGHLY FROM MLU TO BNA.

 

 

 

Not sure how this plays out for GA/SC/NC for the upcoming system, but it could mean the difference between rain and snow. It's going to be razor thin!

[Blue Ridge]

Is anyone else not amazed at the precip this is putting out?  3.77 on the NC,SC,GA border from what was suppose to be a "light" event.  Our area has already had 3.4 inches and should get 1-2 more BEFORE this event.  It's shaping up to be a month with MUCH ABOVE normal precipitation here in east TN.

 

...as has been the overall pattern for the last six-plus months. I'm not sure the area has completely dried out from the early August flooding. Be it snow or rain, more precipitation for the Tri-Cities and southern Apps is not necessarily a good thing at this point.

 

MRX is somewhat non-committal to snow chances, and sides with the GFS/Euro portrayal:

 

 

.LONG TERM (THURSDAY THROUGH MONDAY)...THE NAM MODEL CONTINUES TO BEMORE AGGRESSIVE WITH THE SHORT-WAVE TROUGH MOVING ACROSS THE LOWERMISSISSIPPI VALLEY INTO THE NORTHERN GULF COAST STATES FOR THURSDAY.GFS AND ECMWF ARE IN GOOD AGREEMENT IN PULLING MOISTURE BACK INTOTHE SOUTHERN AND EASTERN FORECAST AREA..SO WILL UP POPS FORCAT-LIKELY FOR SOUTHEAST TENNESSEE AND ALONG THE TENNESSEE/NORTHCAROLINA STATE-LINE FOR THURSDAY. VERTICAL TEMPERATURE PROFILE SHOWSA POTENTIAL MIX OF RAIN/SNOW FOR THE HIGHER ELEVATIONS BY LATETHURSDAY AND THURSDAY NIGHT. SNOW ACCUMULATIONS ACROSS THE HIGHERELEVATIONS OF THE FAR EASTERN MOUNTAINS ARE POSSIBLE LATE THURSDAYAND THURSDAY NIGHT.

[HKY_WX]

This storm has quite a bit of potential especially over eastern TN/western and the northern parts NC. It all depends on the strength of the vort and how long it stays cutoff. The euro ensemble looked pretty good at 00z, especially over NW NC.

[Tacoma]

This from GSP on the extended forecast for the NC Mtns. Thursday night and Friday.

BUT THERE IS NEVERTHELESS THE
POTENTIAL FOR SIGNIFICANT ACCUMULATIONS OF SNOW ACROSS THE MTNS..

[valkhorn]

Looks like the NAM is giving Knoxville a good snow. Unfortunately that's the only model I can find which is doing this.

 

 

[lilj4425]

I am just glad that the rain is going to return. BTW, I REALLY think the big winner could be the northern upstate of SC. *Higher Country*

I will believe that when I see it. Honestly, I think the qpf amounts are being way overdone again also.

[deltadog03]

I will believe that when I see it.

You are going to have to have elevation though.  at or above 2k for anything to stick...IMO  Everybody else....mainly rain

[ColdRainsStr8cashhomey]

I find it very mysterious that the GFS suddenly loses its cold thikness and 850 core once it leaves eastern Alabama, Georgia. Most upper lows won't do that, especially when they hold together. NAM holds it completely together. GFS mostly holds it together and has been trending toward NAM.

 

 

I would tend to agree, except now the NAM is trending weaker and slightly positively tilted at 5H from previous runs... looks to me like the NAM is going toward the GFS at 500mb late in the game here

 

this 500mb trend toward a slightly weaker solution (shown below) isn't good if you live outside of the Western NC high country because the temperature profiles in the mid-levels will fade quickly once this system weakens and eventually opens up

 

the good thing is that high precip rates are still generated on both models, but most places (outside of the mountains) will need as robust of a look as possible to get the column to crash dynamically with the 1C to -1C at 5000ft as shown outside of Western NC

 

I agree that the GFS likely isn't handling the cold-core properly, but to me the cold-core isn't near cold enough or expansive enough (NAM trending toward GFS on showing a smaller core to this system) to support snow outside of NC mountains... I love snow as much as anyone else, but these dynamics likely won't get it done

 

edit:  12z Euro just trended stronger at 500mb... so there's that... very tough marginal event to forecast

[ColdRainsStr8cashhomey]

I will believe that when I see it. Honestly, I think the qpf amounts are being way overdone again also.

 

 

when's he last time a rain event under-performed on precipitation?  last winter most likely

 

all events (at least near Greenville, SC) since December 1st or so have OVER-performed

[eyewall]

We will be shooting blanks outside of the mountains at least through the end of the month in my view. At this point we are nearly looking to February for the last great hope before this horrid 2nd consecutive winter season comes to a close.

[lilj4425]

when's he last time a rain event under-performed on precipitation? last winter most likely

all events since December 1st or so have OVER-performed

Fair enough. Just being conservative with this system.

[LithiaWx]

This from GSP on the extended forecast for the NC Mtns. Thursday night and Friday.

BUT THERE IS NEVERTHELESS THE

POTENTIAL FOR SIGNIFICANT ACCUMULATIONS OF SNOW ACROSS THE MTNS..

What was said before this to cause the nevertheless qualifier?

[DaculaWeather]

What was said before this to cause the nevertheless qualifier?

http://www.daculaweather.com/4_afd_gsp.php

It's long...

[HurricaneTracker]

What was said before this to cause the nevertheless qualifier?

 

That it was to be a mainly rain event below 2000'.  That is to say, elevation dependent snows, as has been stated in this thread today.

[deltadog03]

Hello Euro!!!

[packfan98]

OK, who's got the Euro Play-by-play? The suspense is killing me!

[beanskip]

Was hoping for some comment from those with access beyond the 24 hours frames -- at 48h the s/w looked stronger and then you still see remnants of it (and pretty cold 850s) on the coast at 72h. Care to share what it shows in between?

 

Hello Euro!!!

[franklin NCwx]

hour 48!