Possible Winter Weather Jan 20-22?

[Ron_Jarrell]

GFS hinting at some possible precip overrunning arctic cold pool which will be in place after Jan 15 time frame. High temps appear to be just above freezing with possible snow on 20th and Frz rn, slt, -sn event on 22nd. Way too early to call it, especially with GFS's long range cold bias, but something to hope for in this boring winter season.

Servo let's have a snowdance -- or would that scare the snow gods away???  

[servocrow]

Based on last year's Snowdance performances...I think I scared away more than I enhanced our probabilities...

so...for now....methinks I'll keep my hoverskirt in check..(or at least until the hub-bub gets-a-bubbin' a bit more) :wink:

[Thundersnow]

I think the next couple of weeks may bring our best chances for winter weather we've seen in a while.  The cold air seems to be coming, so the pieces appear to be coming into place.  I'm not one to get my hopes up on specific events over seven days out, though.  But, we will see!!!

[kailynleto | Nightwolf]

GFS 12z warms up our 850s...it may be a very close call; then again, it doesn't handle shallow cold air very well, I have noticed.  It just may be that we see 30 and thunderstorms  :8-0:

[Reneezelle]

SHOW ME THE SNOW!!!!!!!!!!!!!!   :lol:  :lol:  :lol:  :lol:          :lol:  :lol:  :lol:  :lol:  :lol:  :lol:            

[Thundersnow]

Tonight's 00Z GFS is showing this puppy on 1/18:



If only that would verify...  :shock:

The EasternWx board is going nuts over this run.

[Thundersnow]

The last few nights, I developed a habit of following discussion threads as the models come out.

Apparently, the "ensembles" didn't show this storm scenario like the "operational" did (what is depicted in the image above).  Anyway, next week will probably be pretty interesting.  It's still far enough away that anything could change.

[Reneezelle]

Yeah, well. It better be a BIG SCENARIO. Im telling you. BIG. Or Im gonna be mad.

[Thundersnow]

The 6z GFS this morning is now showing a couple of systems possibly affecting the Southeast next week.

The most interesting looking is for Saturday, January 20.  If I'm looking at this right, it looks like a potential overrunning setup with moisture coming in from the Southwest.  But, there are questions as too how cold it will be at that time, as we will be between cold shots at that point... as the models are indicating now.

[servocrow]

I'm tell ya, TS, THIS system just about wore me out just trying to figure out the different model info.  

WHEW!

 :scratch

[Thundersnow]

OK.  I've just seen the latest 12z GFS ensembles.  It's a week away, so we need not get excited about it at this point.

But, it is showing for us the most "interesting" scenario I've seen so far in this whole thing.  If I'm understanding these maps right, the GFS is showing snow for much of Middle TN a week from Sunday.  

In the map I'm seeing, the 850 mb 0-degree line is across northern AL (which means it will be below freezing in the upper levels over Middle TN).  And, the lower level 0-degree line is right across Middle TN (which, if I understand correctly, means that northern Middle TN, at least, would be at or below freezing at the surface or at least the lower levels of the atmosphere).

With those temperature profiles in place, the graphic is showing precipitation over all of TN and even most of KY at the same time.

Do the math.

But, this is over a week away.  The next model run could be very different.

Someone who can read model maps, please correct me if I'm way off base.  This is in the 192 hour maps, by the way.

[servocrow]

I'm hoping to look at some models a bit later...

I think hubby is going to take the boys shopping in a bit for their report card reward so I'll have a chance to look too.

[Thundersnow]

I got some input from someone who is a little more knowledgeable on these things.  According to him, the model does indicate light snow possible over northern Middle TN during that time period.  So, I wasn't too far off the mark.

We'll have to see what later model runs say.  It could become moot.

At least the GFS isn't as dry as a bone behind the front like it was a couple of days ago.  There are some features to look at now.

[servocrow]

From Meteorolgist John Belski, he's recapping today's storm (remember he's in the Louisville market):

For us the cold is certainly coming with much of the coming week with highs in the 30s and a day or 2 in the 20s. No big storms brewing yet although there may be a rain or snow system Friday night or next Saturday.

[Thundersnow]

OK.  The latest models have raised the stakes on the possible storm this weekend.  It's still a few days away, of course, and things could still change.  But, if last night's model run is correct, then we could be looking at a significant winter storm across the Midsouth on about Sunday.

Here are statements from this morning's AFDs (Area Forecast Discussions) put out by Nashville and Memphis.

Nashville:

LOW PRESSURE BEGINS TO FORM OVER THE WRN
GULF OF MEXICO THU NGT THRU FRI NGT AS THE H5 LOW...CURRENTLY ALONG
THE CA COAST...PUSHES EWD OUT OF THE SRN ROCKIES INTO THE SRN PLAINS
BY SUN AM. THIS WILL BRING THE WEST GULF LOW NEWD INTO THE DEEP
SOUTH AND ACROSS MS/AL/GA SUN AND SUN NGT. THIS THE COMBINATION
OF GULF MOISTURE WITH COLD AIR TO THE NORTH WITH GIVE US A MARGINAL
RAIN/SNOW SITUATION FOR THIS TIME PERIOD. FORECAST WAS WORDED
ACCORDINGLY. LOW PUSHES ON TO THE EAST BY MON AM...ONLY TO HAVE
ANOTHER WEST GULF LOW FORM IN RESPONSE TO ANOTHER H5 WAVE COMING
OUT OF THE LOWER ROCKIES ON TUE.

Memphis:

.LONG RANGE...(SUNDAY THROUGH TUESDAY)...UPPER AIR PATTERN WILL
FEATURE SOUTHWEST FLOW ALOFT ACROSS THE LOWER MISSISSIPPI VALLEY AT
THE START OF THE PERIOD WITH A LONGWAVE TROUGH MOVING THROUGH THE
AREA BY THE LATTER HALF OF THE PERIOD. AT THIS TIME IT APPEARS THAT
SOME PRECIPITATION TYPE ISSUES WILL BE PRESENT SATURDAY NIGHT AND
SUNDAY NIGHT ACROSS THE MID SOUTH AS MODEL SOUNDINGS LEAN TOWARDS
SNOW ACROSS THE NORTH AND SLEET ACROSS THE SOUTH. WILL WAIT FOR
ADDITIONAL MODEL RUNS TO PIN DOWN PRECIPITATION TYPE AS FORECAST IS
8 TO 10 PERIODS AWAY.

Nashville is saying it's a marginal situation.  Memphis is playing it up a little more.

Here's the model map that shows what I'm talking about: