Deep South Winterwx Discussion 2015-2016

[Brent]

WHOA... I'll wait for another run or two before I get excited but my interest is peaked again.

[jcool]

Ivanhater.... I just love to see even a chance of snow. We missed seeing snow where I live in south MS in 2004. j

[Brent]

NWS Peachtree City:

OKAY...ONTO THE EXTENDED WHICH ISN`T MUCH EASIER. AFOREMENTIONED
SOUTHERN CALIFORNIA UPPER LOW GETS CAUGHT INTO THE MAIN TROUGH AND
WANTS TO CUT OFF BEHIND THE INITIAL FRONT. THE GFS IS THE
STRONGEST WITH THIS FEATURE...A BIT OF AN OUTLIER...BUT ALL THE
EXTENDED MODELS NOW HAVE SOMETHING. IN DOING THIS...A SECONDARY
LOW DEVELOPS IN THE GULF AND MOVES NORTHEAST...HUGGING THE COAST
DUE TO THE LOCATION OF THE UPPER LOW. THIS PUTS GEORGIA TO THE
NORTHWEST OF THE SURFACE LOW...IN THE COLD AIR BEHIND THE FRONT.
AGAIN...THE GFS IS THE STRONGEST AND COLDEST OF THE EXTENDED
MODELS...BUT IT WANTS TO GIVE US A QUICK SHOT OF A COUPLE OF
INCHES OF SNOW ON THURSDAY ACROSS NORTH GEORGIA. HAVE OBVIOUSLY
NOT BITTEN OFF ON THIS...BUT WITH AGREEMENT FROM THE ECMWF AND
UKMET ON THE GENERAL PATTERN...DID INCLUDE A BRIEF MIX FOR SOME
AREAS IN THE COLD AIR BEHIND THE FRONT EARLY THURSDAY MORNING...
OTHERWISE JUST A COLD RAIN. MIX POTENTIAL WILL BE DEPENDENT ON
STRENGTH OF UPPER LOW AND MOISTURE ASSOCIATED WITH IT PLUS SPEED
OF SURFACE FRONT...OBVIOUSLY CONFIDENCE IS LOW AT THIS POINT.
ECMWF IS MUCH SLOWER WITH THIS SYSTEM AND IF THIS IS ACCURATE IT
IS POSSIBLE THAT PRECIP COULD LINGER INTO THURSDAY NIGHT BUT HAVE
NOT INCLUDED ANY FOR NOW.

Wednesday Night: Rain showers likely before 1am, then rain and snow showers likely. Mostly cloudy, with a low around 34. Chance of precipitation is 60%.

[Ivanhater]

12z GFS keeps pushing the storm back and now develops one hell of a low in the gulf coming into Pcola, but now no support of cold air....figures

[Brent]

LOL, I knew better than to get excited last night. Oh and look, snow in Houston?

Blah, 3 days of rain.

[Ivanhater]

Nam switches back to snow for the gulfcoast states

[Ivanhater]

...

[LaBreeze]

Snow??? I haven't heard about this happening - no mets around here are even mentioning anything close to that.

[Brent]

Snow??? I haven't heard about this happening - no mets around here are even mentioning anything close to that.

The models are different every run... one run shows snow, the next doesn't, so the mets are wise to not mention it right now. It may not even happen. The 0z GFS dumps 6-12 inches of snow in South Mississippi and nada here. The last 3 runs showed nothing for anyone, while last night the GFS showed 2-3 inches here, so who knows what will happen. ULL's have a history of producing totally surprising snows around here(I remember one in MS in December 1997 and then one here in February 1998, and another on the first day of spring in 2001), and on the other hand if snow is forecast it can easily not happen. They are nicknamed weatherman's woes for a reason. Until the models get some consistency I'm not buying it.

Regardless, it's looking like a ton of rain here starting late tomorrow through Thursday or maybe even Friday.

I think Peachtree City sums it up well this morning:

THE SECONDARY UPPER LOW THAT DEVELOPS AND CUTS OFF OVER THE
SOUTHERN PLAINS IS A BIT OF A PAIN. THE GFS CANNOT MAKE UP ITS
MIND FROM RUN TO RUN WHAT TO DO WITH THIS THING. THE ECMWF HAS
BEEN THE MOST CONSISTENT BUT THE 00Z RUN THAT JUST CAME IN HAS
SPED IT UP CONSIDERABLY. IMPLICATIONS WITH ALL OF THIS ARE PRETTY
EXTREME WITH THE TEMPS...WITH WED NIGHT AND THU NIGHT TEMPS MUCH
MUCH WARMER THAN PREVIOUSLY ADVERTISED. HAVE TAKEN A COMPROMISE...
NOT WILLING TO INCREASE TEMPS AS MUCH AS INDICATED...BUT FOR NOW NO
MIXED PRECIP IN THE FORECAST WEDNESDAY NIGHT/THURSDAY MORNING...AND
NO MAJOR COOL-DOWN FOR THURSDAY NIGHT (UNLESS OF COURSE THE NEW 00Z
ECMWF IS RIGHT IN SPEEDING IT UP). CONFIDENCE NOT PARTICULARLY
HIGH FROM WEDNESDAY NIGHT ON GIVEN THESE SIGNIFICANT SWINGS.

[Ivanhater]

12z GFS and Nam are back on board..going to be interesting

[Stormcenter]

Ivanhater can you post some graphics....thanks.

[Dean4Storms]

I'm going to be traveling up 65 to 59 through Alabama to Ft. Payne on Thursday, I would expect this snow if it occurs there in AL not be a road problem, would you agree?

[Ivanhater]

Ivanhater can you post some graphics....thanks.

Sure...

Nam



GFS

[Brent]

I'm not getting excited... this is going to be one of those last-minute type things, though ULL's do have a history of surprises. My last 3+ inch snow came from one 10 years ago.

Re Alabama roads: Well people freak when they see a flurry so if it does snow most people will stay home. The roads will *probably* be just wet in most areas though(watch the bridges which were a mess in Birmingham during the January and March events). Of course, a lot can change

Birmingham HWO:

A DEEP AND COLD UPPER LOW WILL MOVE ACROSS CENTRAL ALABAMA ON
THURSDAY. THE AIR IS EXPECTED TO BE COLD ENOUGH ALOFT FOR RAIN TO MIX
WITH SNOW AND POSSIBLY CHANGE OVER TO ALL SNOW DURING THE DAY. NO
TRAVEL PROBLEMS ARE ANTICIPATED AT THIS TIME DUE TO SURFACE
TEMPERATURES REMAINING WELL ABOVE FREEZING.

[Brent]

Mississippi gets BURIED if you take this at face value:



Though this differs slightly(same model):



NWS Birmingham:

FIRST SIGNIFICANT WINTER WEATHER EVENT OF THE SEASON MAY BE COMING
TOGETHER FOR NORTH CENTRAL ALABAMA. MODELS ARE ALL SHOWING A DEEP
500MB LOW MOVING ACROSS CENTRAL ALABAMA ON THURSDAY WHICH WILL BRING
WITH IT MOISTURE AND LIFT. MAIN MODEL DIFFERENCES ARE DEVELOPMENT
AND TRACK OF SURFACE LOW. GFS TRACKS LOW FARTHER WEST THAN ECMWF AND
NAM WHICH MEANS PRECIPITATION WILL BE MORE RAIN THAN SNOW. THIS TYPE
OF COLD DEEP UPPER LOW WILL MANY TIMES FORM THERE OWN COLD POCKETS
AT THE THE LOW LEVELS DUE TO ENHANCED SNOWFALL RATES. THE MAIN
LIMITING FACTOR WILL BE THAT THE EVENT WILL OCCUR DURING THE DAY
WHEN HEATING WILL KEEP TEMPERATURES ABOVE FREEZING. AS MENTIONED IN
EARLIER DISCUSSION...MODELS ARE SHOWING AREA OF ENHANCED
PRECIPITATION NORTH OF 500MB UPPER LOW...IN AREA REFEREED TO AS A
TROWEL. THERE IS POTENTIAL FOR HEAVY SNOWFALL WITHIN IN THIS
TROWEL...BUT FOR NOW MODELS ARE KEEPING THIS AREA NORTH OF CENTRAL
ALABAMA. AT THIS TIME WILL KEEP PRECIPITATION IN THE FORM OF A
RAIN/SNOW MIXTURE...BUT THERE COULD VERY WELL BE A PERIOD OF TIME ON
THURSDAY WHEN IT IS ALL SNOW.

and James Spann:

SNOW ON THURSDAY? The models are trending colder with a cold core upper low moving right over us Thursday. You can’t ignore the possibility of dynamic cooling with this feature, and the 18Z runs just in are showing 850 mb temperatures well below freezing. At this point we pretty much have to mention a chance of rain Thursday, changing to snow Thursday afternoon and early Thursday night before ending.

A few points to consider:

*The ground is warm and temperatures will be above freezing; so accumulation or travel problems most likely won’t be an issue if we do see a change to snow. The only way we get serious accumulation is if the snow becomes heavy under the cold core upper low, which is not out of the question. The December 1997 event comes to mind.

*Snow as a result of dynamic cooling is a very complicated set-up, and skill in forecasting this kind of event is not the best. But, we have seen enough evidence that it could very well happen this time.

*This won’t be a long lasting event since no real Arctic air is involved with the system; sunshine returns Friday with a high around 50.

[PTPatrick]

These couple weeks leading up to christmas and new years have created many-a suprise storm in the Gulf states. Of course my favorite that comes to mind was December 18 1996, where I left school the last day until christmas to find 3 inches of white stuff on my car (just west of Mobile, AL). That was kind of a crazy storm because it was SO cold afterward...literally I think the coldest I have seen in that area since 1989. My house got down to 12, and that was on the bayou in Jackson Co Mississippi. but I degrees...no arctic outbreaks like that on the horizon.
Of course the Christmas 04 snow miracle comes to mind...1/2 inch on the bayou on christmas afternoon.
I remember 1997 Dec 14th well, although it didnt effect me. 8 inches in Philadelphia MS I believe.

But lesser known snow events include one Christmas week Hattiesburg Snowfall of about 2 inches, which I believe was probably 1993 or 94. I was up there visiting Auntie on Christmas break and got quite a gift.
Then there was the new years day snow in Hattiesburg around 2003.
I know in the 63 quite a storm dumped snow on the coast around new years(like 12 inches in Wiggins, MS).
I know these events are probably a little more common in January/Feb up the central parts of MS/AL but seems like to be December sticks out with more crazy events.
In my years on the coast I would almost say that mid December into the first week of January is the MOST likely time for one of these freak events.

[Dean4Storms]

Yea my biggest concern will be NE Alabama in the higher terrain come late in the day on Thursday but we should make it to our destination by 6pm or so.

[HarlequinBoy]

So any opinions on the Memphis area over the next couple of weeks?

I think there's a slight chance of snow tomorrow night/Thursday, depending on where the ULL sets tracks. I also keep hearing about an Arctic outbreak next week, but the Memphis forecasts show nothing of the sort. Does it get caught up over the Ozarks?

[Ivanhater]

00z NAM spinning the Upper Low further South and east in this run..smacking New Orleans..hmmm

[Brent]

Bizarre. New Orleans is about the only place it looks better. No snow for Jackson, Huntsville, Birmingham etc. which got a good bit last run, lol.