Deep South Winterwx Discussion 2015-2016

[Dionne]

Hmmmmm....??? We're already at 10.44".

[Brent]

The 12z GFS is the best run in 2 days for the Southeast. Showing a moderate snow(2-4 inches) for AR/LA/MS/AL/GA on Thursday. I really hope this verifies. With the very cold air it will likely stick around for days.

and look at this little gem...







<<<Snow on the beach!

The other story is the amazing cold snap... temps don't look THAT extreme(as in 1985/1989 cold) but the duration looks record-breaking. 10+ days with lows in the teens/low 20's. The wildcard is that if we do get a snow cover Thursday, next weekend could potentially be extreme with records falling. Something to ponder...

[RNGR]

Totally agree with the snow cover keeping temps down. 2 years ago I recorded a high of 28 at my house just NE of Atlanta. might see something like that if theres 4 inches of snow on the ground. also the snow might melt durring the day and refreeze at night, maybe a week of icy roads in the morning. that could cause major travel issues around here.

[Dean4Storms]

Next weekend is going to be a cold one the way it is looking and the front bringing that cold could give a dusting of snow as it moves through.

[Ivanhater]

This is record breaking cold....Mobile/Pensacola AFD

WHILE LAST NIGHT`S MEDIUM RANGE GUIDANCE APPEARED TO BE COMING INTO
A CONSENSUS OF A LOW MOVING ACROSS THE NORTHERN GULF...TONIGHT`S 00Z
GUIDANCE HAS VERY MUCH CHANGED ITS TUNE. THERE ARE A MYRIAD OF
SOLUTIONS RANGING FROM COLD AND DRY TO TEMPORARILY WARM AND WET. EVEN
THE MORE RELIABLE ECMWF IS SUFFERING FROM A LACK OF CONSISTENCY. EVEN
WITH THE DISAGREEMENT...WE STILL HAVE TO WATCH THIS PATTERN CLOSELY
CONSIDERING THE STRONG SHORTWAVE ENERGY THAT IS SUPPOSED TO DIVE
SOUTH OUT OF CANADA LATE IN THE WEEK. ENOUGH OF THE GUIDANCE IS
SHOWING ENOUGH MOISTURE AND COLD AIR TO SUPPORT A SLIGHT CHANCE OF
RAIN AND SNOW LATE THURSDAY INTO THURSDAY NIGHT OVER INLAND
LOCATIONS. THIS IS SLOWER THAN PREVIOUS THINKING. HAVE CAPPED
EVERYTHING AT 20 PERCENT SIMPLY BECAUSE THERE IS NO CONFIDENCE AT
THIS JUNCTURE. WE WILL LIKELY SEE MODEL OSCILLATIONS UNTIL THE
SHORTWAVE ENERGY IN QUESTION MOVES INTO THE NORTH AMERICAN UPPER AIR
NETWORK...WHICH IS STILL A COUPLE OF DAYS AWAY. REGARDLESS...THERE
ARE STRONG INDICATIONS OF ANOTHER SHOT OF ARCTIC AIR ENTERING INTO
THE AREA BY FRIDAY...AND THIS AIRMASS MAY BE EVEN COLDER THAN THE ONE
WE ARE ABOUT TO EXPERIENCE. 34/JFB

[Extremeweatherguy]

The 00z GFS continues to look "fun" for the southern plains into the southeast next week..

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_114l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_120l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_126l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_132l.gif
http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_138l.gif

[RNGR]

...THE ATLANTA CLIMATE SUMMARY FOR JANUARY 2 2010...
VALID AS OF 0800 PM LOCAL TIME.

CLIMATE NORMAL PERIOD 1971 TO 2000
CLIMATE RECORD PERIOD 1878 TO 2010


WEATHER ITEM OBSERVED
VALUE
..........................
TEMPERATURE (F)
TODAY
MAXIMUM 33
MINIMUM 23

PRECIPITATION (IN)
TODAY 0.00


WOW high of 33 in Atlanta. they forecasted 39

[Brent]

http://www.alabamawx.com/?p=25782

No real changes in the thinking.

With each consistent model run, our confidence increases that this will be a very severe cold event with the chance of a significant snow thrown in for Thursday.

From the 0z run of the GFS…fresh off the press…

Thursday noon:

1014 mb low near New Orleans. We are near freezing in the I-59 corridor. Snow is about to begin in earnest across Central Alabama.

Somewhere between 0.25-0.50 inches of water equivalent between noon and 6 p.m. Using a ratio of 14:1, that’s between 3.5 and 7 inches of snow for parts of the area. Throw in a little before noon and another inch of two during the overnight from snow showers, and we could have a significant snow across Central Alabama.

MODEL COMPARISON
The 12z run of the European is slower with the system, bringing it in Thursday night, with the heaviest snow north of along and north of I-20 (about same amounts). I could see folks stranded at BCS parties Thursday night in a worst case scenario. But we will have plenty of time to worry about that.

Now I caution everyone… a lot could go wrong with this forecast. This system is a long way off. But the more consistent depictions we see of this scenario gives us increasing confidence to up snow chances and the possibility of accumulation.

We always show our work here.

For those who will say we are hyping another snow event…it’s not hype when we tell you what we think, show you why and let you interpret along with us. Bottom line, it is a snow event that bears watching, because it makes sense from a synoptic standpoint, we have cold like we have not seen in a long time and it could be disruptive to travel, school and business on Thursday, Friday and into the weekend. We want our audience to have the most possible time to prepare for whatever we are forecasting, whether it is extreme cold, a snowstorm, severe weather or a hurricane. It’s why we do what we do for the best weather audience in the world.

As we look at the possibility of snow, I don’t want you to forget the extreme and dangerous cold, both before and after Thursday. Some notes:

…Central Alabama may not see 40F again until January 13th…and maybe not until January 16th!
…Parts of the Tennessee Valley may not get above freezing except for a few hours in the next two weeks!
…We could be flirting with zero next Saturday and Sunday morning if we get a snow cover. Single digits look inevitable.

Stay warm, be safe, and think of others…

Thursday - 01/07
snow
A good chance of snow. Accumulations possible.
Low: 27 High: 34
Wind: NW 5-15 mph Sun Percentage: 0% Hours Of Rain: 4
Rain Potential: 0.45" Severe Weather Threat: None
Friday - 01/08
partly_sunny
Clearing, windy and cold.
Low: 21 High: 26
Wind: NW 10-20 mph Sun Percentage: 45% Hours Of Rain: 0
Rain Potential: 0.00" Severe Weather Threat: None
Saturday - 01/09
clear
Sunny and frigidly cold.
Low: 5 High: 18
Wind: NW 8-16 mph Sun Percentage: 90% Hours Of Rain: 0
Rain Potential: 0.00" Severe Weather Threat: None

[icicle]

From MEG....


CURRENTLY THE GFS TRACKS THE CENTER FURTHER SOUTH
REACHING NORTHERN ARKANSAS BY THURSDAY EVENING. THE ECMWF TAKES
THE LOW AS FAR SOUTH AS NORTHERN MISSOURI. BOTH MODELS SHOW A GOOD
24 HOURS OF SUBSTANTIAL DIVERGENCE OVER A MORE SOUTHERLY FETCH OF
GULF MOISTURE. WITH THIS BEING SAID...MODELS INDICATE TEMPERATURES
AND THICKNESSES OVER THE AREA WILL BE LOW ENOUGH TO SUPPORT FROZEN
PRECIPITATION...WITH ACCUMULATIONS LIKELY BEGINNING THURSDAY
MORNING. THE GFS SHOWS A SWATH OF HIGHER QPFS OVER NORTHERN
MISSISSIPPI WHERE A INVERTED SURFACE TROUGH IS EXPECTED TO
DEVELOP. IF THAT PANS OUT...UPPER FRONTOGENESIS MAY MAKE FOR
WARNING ACCUMULATING SNOWS OVER THE SOUTHERN AND FAR EASTERN CWA
COUNTIES. SNOW IS EXPECTED TO SLOWLY TAPER OFF THURSDAY
NIGHT

[attallaman]

From MEG....


CURRENTLY THE GFS TRACKS THE CENTER FURTHER SOUTH
REACHING NORTHERN ARKANSAS BY THURSDAY EVENING. THE ECMWF TAKES
THE LOW AS FAR SOUTH AS NORTHERN MISSOURI. BOTH MODELS SHOW A GOOD
24 HOURS OF SUBSTANTIAL DIVERGENCE OVER A MORE SOUTHERLY FETCH OF
GULF MOISTURE. WITH THIS BEING SAID...MODELS INDICATE TEMPERATURES
AND THICKNESSES OVER THE AREA WILL BE LOW ENOUGH TO SUPPORT FROZEN
PRECIPITATION...WITH ACCUMULATIONS LIKELY BEGINNING THURSDAY
MORNING. THE GFS SHOWS A SWATH OF HIGHER QPFS OVER NORTHERN
MISSISSIPPI WHERE A INVERTED SURFACE TROUGH IS EXPECTED TO
DEVELOP. IF THAT PANS OUT...UPPER FRONTOGENESIS MAY MAKE FOR
WARNING ACCUMULATING SNOWS OVER THE SOUTHERN AND FAR EASTERN CWA
COUNTIES. SNOW IS EXPECTED TO SLOWLY TAPER OFF THURSDAY
NIGHT

Which NWS office was this issued from?

[One Eye]

From MEG....


CURRENTLY THE GFS TRACKS THE CENTER FURTHER SOUTH
REACHING NORTHERN ARKANSAS BY THURSDAY EVENING. THE ECMWF TAKES
THE LOW AS FAR SOUTH AS NORTHERN MISSOURI. BOTH MODELS SHOW A GOOD
24 HOURS OF SUBSTANTIAL DIVERGENCE OVER A MORE SOUTHERLY FETCH OF
GULF MOISTURE. WITH THIS BEING SAID...MODELS INDICATE TEMPERATURES
AND THICKNESSES OVER THE AREA WILL BE LOW ENOUGH TO SUPPORT FROZEN
PRECIPITATION...WITH ACCUMULATIONS LIKELY BEGINNING THURSDAY
MORNING. THE GFS SHOWS A SWATH OF HIGHER QPFS OVER NORTHERN
MISSISSIPPI WHERE A INVERTED SURFACE TROUGH IS EXPECTED TO
DEVELOP. IF THAT PANS OUT...UPPER FRONTOGENESIS MAY MAKE FOR
WARNING ACCUMULATING SNOWS OVER THE SOUTHERN AND FAR EASTERN CWA
COUNTIES. SNOW IS EXPECTED TO SLOWLY TAPER OFF THURSDAY
NIGHT

Memphis NWS.

[Extremeweatherguy]

I think the funniest thing is how both the Charlotte and Raleigh AFDs seem quite concerned about snow on Thursday into Friday, yet their actual point and click forecasts do not reflect their concerns at all. Charlotte's current point and click forecast has Thursday being mostly sunny, followed by Thursday night being mostly cloudy and then Friday being partly cloudy. No mention of snow. And Raleigh's point and click forecast is identical. The only part of the state currently under a point and click forecast of snow is the mountains, but the percentage chance even there is being kept at a low 30%.

Here are some segments from the two area's morning AFDs that will make the point and click forecasts seem odd:

From the Raleigh AFD:

ALTHOUGH MUCH UNCERTAINTY REMAINS WITH THE EVOLUTION OF THE UPPER
LOW AND THE MSLP PATTERN OVER THE SOUTHEAST STATES ON THU/FRI...
GIVEN THAT ALL OF THE LONG RANGE MODELS HAVE TRENDED WETTER AND SHOW
0.15" TO 0.30" OF QPF OVER CENTRAL NC...HAVE DECIDED TO INTRODUCE A
SLIGHT CHANCE (20%) POP ACROSS THE ENTIRE AREA THU NIGHT INTO
FRIDAY. THICKNESSES AND FCST SOUNDINGS OFF THE LONG RANGE MODELS
WOULD INDICATE A PTYPE OF PREDOMINATELY SNOW ACROSS MOST OR ALL OF
CENTRAL NC. GIVEN THE PROLONGED/UNUSUALLY COLD AIRMASS EXPECTED TO
BE IN PLACE...THAT SEEMS PRETTY REASONABLE. HOWEVER...PTYPE MAY
STILL ULTIMATELY DEPEND ON THE TRACK OF ANY LOW PRESSURE SYSTEM OVER
THE SOUTHEAST/MID-ATLANTIC STATES...PARTICULARLY IN SOUTHEAST
PORTIONS OF THE FORECAST AREA. ALTHOUGH TIME WILL TELL...A
SIGNIFICANT WINTER WEATHER EVENT FOR CENTRAL NC IS NOT OUT OF THE
QUESTION THU NIGHT/FRI.

From the Charlotte AFD:

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 220 AM SUNDAY...NOT MANY CHANGES ARE NEEDED FOR THE EXT RANGE
FCST AS THE MODELS CONTINUE TO SHOW GOOD AGREEMENT WITH THE OVERALL
LARGE SCALE PERSISTENCE TYPE PATTERN. THERE IS DEEPER MOISTURE
BEGINNING TO SHOW UP IN THE SOUNDINGS ACROSS THE NON/MTNS WHICH IS
SUPPORTED WELL BY THE SREF PLUME DIAGRAMS SHOWING ALL SNOW FOR ALL
LOCATIONS AFTER 00Z FRI. HOWEVER...THE 12Z ECMWF IS STILL INDICATING
A HESITATION OF LOWERING THICKNESSES AS MUCH AS THE 00Z GFS AND THE
EC IS ALSO SUPPORTED BY THE 00Z GGEM IN THIS REGARD. SO...STILL
ANTICIPATE -SN THU MORNING TEMPORARILY TRANSITIONING TO A MIX IN
THE AFTERNOON OUTSIDE THE MTNS AS THE WARN NOSE JETS IN...THEN ALL
-SN BY 00Z FRI FOR ALL LOCATIONS. THE GOING POPS WERE ADJUSTED ONLY
SLIGHTLY AND WERE BLENDED WITH 18Z GUIDANCE 1 TO 1. THIS GAVE CHANCE
POPS ALL THE WAY TOWARD I-77...THEN SLIGHT TO THE EAST OF THAT. THIS
SEEMS OKAY FOR NOW AS THE INCREASED DEEPNESS OF THE SATURATED
MOISTURE IS A NEW IDEA AND THE STRONGEST FORCING IS STILL 5 DAYS
AWAY.

[Lowpressure]

Laughing at the same thing here in CLT. As it moves into the less than 120 range which will be the next run 12z. If GFS still shows event, I think they would need to start considering adding snow to the forecast. They will then coordinate with other area NWS offices. They are being cautious at this point.

[timNms]

NWS Jackson, MS for Thursday

HERE IS WHERE THINGS GET INTERESTING AND THEN SHIFT TO VERY COLD AS
THE ARCTIC PLUNGE MOVES THROUGH THE AREA. A STRONG DISTURBANCE WILL
DIVE S WITHIN THE NW FLOW AND PHASE WITH THE DUMBBELL POLAR VORTEX
AND SHIFT SOUTHWARD A CHUNK OF ARCTIC AIR. THIS STRONG S/W WILL
INCITE A SFC WAVE ALONG THE N GULF. THE COMBINATION OF STRONG ASCENT
AND LOW LEVEL ATMOSPHERIC RESPONSE WILL HELP DEVELOP AT LEAST LIGHT
PRECIP LATE WED NIGHT AND INTO THUR. DETAILS ARE AS
EXPECTED...SKETCHY...BUT INDICATIONS ARE THAT THE NORTHERN 1/3RD OF
THE CWA WILL BE COLD ENOUGH FOR ALL SNOW WITH THE SOUTHERN 2/3RDS
SEEING SOME SORT OF MIX. THINGS COULD START AS A COLD RAIN THEN
BECOME ALL SNOW OR THERE COULD BE A REGION OF FREEZING RAIN...THEN A
SHIFT TO SNOW OR IT COULD JUST BE ALL SNOW. I WON'T GET CAUGHT UP IN
THE DETAILS SINCE IT IS 5 DAYS OUT AS I EXPECT THE SPECIFIC
INFORMATION WE NEED TO DETERMINE PRECIP TYPE WILL CHANGE/SHIFT WITH
EACH MODEL RUN. WHAT I DO KNOW IS IT WILL BE COLD WITH CONDITIONS
BECOMING COLDER AS WE HEAD INTO FRI. DUE TO THE CLOUD COVER AND FACT
THAT I FEEL CONFIDENT THERE WILL BE PRECIP FALLING AND EVAP COOLING
GOING ON AT SOME POINT...I HAVE LOWERED TEMPS THU. THE NW/N AREAS
COULD EASILY STAY BELOW 30-32 DEGREES WITH CENTRAL SECTIONS NOT EVEN
REACHING 34-35 DEGREES. AS FOR THE S...THEY SHOULD BE COLD AS WELL
WITH UPPER 30S LIKELY BEING TOUGH TO COME BY AS WELL. AT THIS
TIME...I WILL INTRODUCE SOME LOW END WINTRY PRECIP ACCUMULATION...BUT
NOT GET TOO CARRIED AWAY JUST YET.

[attallaman]

From MEG....


CURRENTLY THE GFS TRACKS THE CENTER FURTHER SOUTH
REACHING NORTHERN ARKANSAS BY THURSDAY EVENING. THE ECMWF TAKES
THE LOW AS FAR SOUTH AS NORTHERN MISSOURI. BOTH MODELS SHOW A GOOD
24 HOURS OF SUBSTANTIAL DIVERGENCE OVER A MORE SOUTHERLY FETCH OF
GULF MOISTURE. WITH THIS BEING SAID...MODELS INDICATE TEMPERATURES
AND THICKNESSES OVER THE AREA WILL BE LOW ENOUGH TO SUPPORT FROZEN
PRECIPITATION...WITH ACCUMULATIONS LIKELY BEGINNING THURSDAY
MORNING. THE GFS SHOWS A SWATH OF HIGHER QPFS OVER NORTHERN
MISSISSIPPI WHERE A INVERTED SURFACE TROUGH IS EXPECTED TO
DEVELOP. IF THAT PANS OUT...UPPER FRONTOGENESIS MAY MAKE FOR
WARNING ACCUMULATING SNOWS OVER THE SOUTHERN AND FAR EASTERN CWA
COUNTIES. SNOW IS EXPECTED TO SLOWLY TAPER OFF THURSDAY
NIGHT

Memphis NWS.

Two NOLA TV mets said this morning the likelihood of any form of winter precipitation in the NOLA area and along the MS GC is now minimal. Our local TV met here said last night there was a 40% chance of some form of winter precipitation here next Thursday night late into early Friday morning.

[timNms]

NWS Jackson Hazardous weather outlook:

DAYS TWO THROUGH SEVEN
MONDAY THROUGH SATURDAY

A VERY COLD AIRMASS WILL CONTINUE TO FILTER INTO THE REGION FOR THE
UPCOMING WEEK. LOW TEMPERATURES MONDAY NIGHT ARE EXPECTED TO FALL
INTO THE UPPER TEENS AND LOWER 20S.

WINTRY PRECIPITATION WILL BE POSSIBLE ACROSS THE REGION ON THURSDAY.
MOISTURE WILL INCREASE ACROSS THE AREA FOR THE MIDDLE OF THIS
WEEK...AS LOW PRESSURE MOVES EASTWARD ACROSS THE GULF OF MEXICO AND A
COLD FRONT MOVES ACROSS THE REGION. COLD AIR THROUGHOUT THE
ATMOSPHERE WILL INTERACT WITH THIS MOISTURE TO RESULT IN THE
POTENTIAL FOR WINTRY PRECIPITATION ON THURSDAY.

IN THE WAKE OF THE COLD FRONT...FRIGID ARCTIC AIR WILL BE POSSIBLE
ACROSS THE AREA FOR THURSDAY NIGHT INTO THE WEEKEND. LOW TEMPERATES
SHOULD EASILY MAKE IT INTO THE TEENS BOTH FRIDAY AND SATURDAY
MORNINGS WITH SINGLE DIGITS POSSIBLE. ADDITIONALLY...HIGH
TEMPERATURES WILL STRUGGLE TO REACH 30 DEGREES...THUS A PROLONGED
PERIOD OF TEMPERATURES BELOW FREEZING IS EXPECTED.

[timNms]

From MEG....


CURRENTLY THE GFS TRACKS THE CENTER FURTHER SOUTH
REACHING NORTHERN ARKANSAS BY THURSDAY EVENING. THE ECMWF TAKES
THE LOW AS FAR SOUTH AS NORTHERN MISSOURI. BOTH MODELS SHOW A GOOD
24 HOURS OF SUBSTANTIAL DIVERGENCE OVER A MORE SOUTHERLY FETCH OF
GULF MOISTURE. WITH THIS BEING SAID...MODELS INDICATE TEMPERATURES
AND THICKNESSES OVER THE AREA WILL BE LOW ENOUGH TO SUPPORT FROZEN
PRECIPITATION...WITH ACCUMULATIONS LIKELY BEGINNING THURSDAY
MORNING. THE GFS SHOWS A SWATH OF HIGHER QPFS OVER NORTHERN
MISSISSIPPI WHERE A INVERTED SURFACE TROUGH IS EXPECTED TO
DEVELOP. IF THAT PANS OUT...UPPER FRONTOGENESIS MAY MAKE FOR
WARNING ACCUMULATING SNOWS OVER THE SOUTHERN AND FAR EASTERN CWA
COUNTIES. SNOW IS EXPECTED TO SLOWLY TAPER OFF THURSDAY
NIGHT

Memphis NWS.

Two NOLA TV mets said this morning the likelihood of any form of winter precipitation in the NOLA area and along the MS GC is now minimal. Our local TV met here said last night there was a 40% chance of some form of winter precipitation here next Thursday night late into early Friday morning.

For Lawrence, Jefferson Davis, Covington and Jones Counties, NWS Jackson says:
THURSDAY
LIGHT RAIN AND LIGHT SNOW LIKELY THROUGH MID
AFTERNOON...THEN A CHANCE OF LIGHT SNOW IN THE LATE AFTERNOON.
CLOUDY. HIGHS IN THE UPPER 30S. THE CHANCE OF PRECIPITATION
60 PERCENT.

For Coastal Counties, NWS New Orleans says:
THURSDAY
CLOUDY WITH A 40 PERCENT CHANCE OF LIGHT RAIN. HIGHS
IN THE UPPER 40S.
THURSDAY NIGHT...CLOUDY. CHANCE OF LIGHT RAIN IN THE EVENING

THEN SLIGHT CHANCE OF LIGHT RAIN AFTER MIDNIGHT. LOWS IN THE
UPPER 20S. CHANCE OF RAIN 30 PERCENT.

[lrak]

This sounds like my last Sunday to get ready for the cold snap. Is Corpus Christi in the path of this outbreak? I haven't lost any tropical plants since the 1980s IIRC, maybe one or two since then but I lost everything back in 1989. We had ICE and below 32F for like 3 days. The chill killed all the Redfish in the shallow salt flats. Next south wind was nasty smelling for the whole city. I can dig up my most delicates and move them into the garage, only problem is I'm 20years older now and lazy.

I don't want to loose my Plumerias.

http://i246.photobucket.com/albums/gg10 ... Flower.jpg



I can read the maps and to me they only show a 24 hr dip into the freeze event, I've seen some post indicate a few days of sub freezing temperatures down here. What about Brownsville's valley of citrus?

http://forecast.weather.gov/MapClick.ph ... it=0&lg=en

This forecast shows only 32F one night along the coast. I know this is 6-8 days out but whats your best guess, should I throw out my back today?

[RNGR]

[Brent]

Good news is the 12z GFS is colder, but also drier. Does look like a widespread light snow event though. I think that's a good compromise, my fear with a heavier event is warm air advection causing the dreaded r word for MS/AL/GA(at least to start)

There is still a long way to go though. My confidence is however increasing.