More cold air on the way next week!?

[don]

Yea what the CMC suggest is that the low tracks closer to the coast and there for we get under the cold core of the low as rain changes to snow on the backside of the system similar to the 2008 snow event.But i dont think that will happen though...

On a Sidenote some of the GFS Esembles also show the same scenario playing out FWIW...

[txsnowmaker]

Thank you for the feedback srain and don. I read on another forum that some of the GFS ensembles appear to be in agreement with the Canadian run. At this point, I will keep my expectations quite low for anything interesting this week. Of course, I am always happy to see expectations surpassed.

[srainhoutx]

Updated HPC 5 Day QPF Totals...
(Click to enlarge) We are working on some issues if you haven't guessed.

[srainhoutx]

HPC Model Peference...hmmm...

...SYSTEM INITIALLY NEAR THE CALIFORNIA COAST...

PREFERENCE: ECMWF/UKMET/CMC COMPROMISE

THE NAM BECOMES A SLOW OUTLIER WITH THE UPR LOW COMPARED TO THE
GFS AND MAJORITY OTHER SOLNS FROM TUE NIGHT ONWARD. SOME 09Z
SREF/06-12Z GEFS MEMBERS DO OFFER POTENTIAL FOR THE SLOWER TIMING
THOUGH. THE NAM HAS YET TO DISPLAY A TREND TOWARD THE MAJORITY
FASTER SOLN BUT GIVEN A TYPICALLY SLOW BIAS WHEN THE NAM IS ON THE
SLOW EDGE OF THE GUIDANCE SPREAD... WOULD FAVOR LEANING AWAY FROM
THE NAM WITH THE UPR SYSTEM AND EVENTUALLY THE SFC LOW THAT TRACKS
OVER THE GULF. AMONG THE NON-NAM GUIDANCE THE GFS BECOMES MORE
SUPPRESSED WITH THE GULF SFC LOW THAN MOST SOLNS ASIDE FROM THE
06-12Z GEFS MEANS... WHILE THE ECMWF/UKMET/CMC AND 00Z ECMWF
ENSEMBLE MEAN SHOW FASTER TIMING THAN THE GFS. THE
UKMET/CMC/ECMWF ARE ALL SOMEWHAT DEEPER THAN THE GFS WITH THE CORE
OF THE SHRTWV ALOFT BY LATE FRI. OVERALL THE GFS FCST APPEARS
BETTER THAN THE NAM... BUT GFS FLOW FROM THE PLAINS TO APLCHNS BY
LATE IN THE FCST IS NOT THE MOST PREFERRED. AS THE 12Z ECMWF
MAINTAINS GOOD CONTINUITY WITH ITS PREVIOUS RUN... WILL ULTIMATELY
RECOMMEND A COMPROMISE AMONG THE ECMWF/UKMET/CMC WHICH TRACK THE
GULF OF MEXICO SFC LOW FARTHER NWD THAN THE GFS.

[sleetstorm]

Why would that wave of low pressure warm the atmosphere up in the mid and upper levels, Portastorm, Mr. T, srainhoutx, wxdata?

[Portastorm]

Why would that wave of low pressure warm the atmosphere up in the mid and upper levels, Portastorm, Mr. T, srainhoutx, wxdata?

Sleet, it will be pumping warm gulf air over our heads ... and slowly but surely working its way down to the surface so that the entire air column is saturated.

[srainhoutx]

Lets set a realistic, but not too easy target for ourselves, and forget about Houston and maybe a few pellets or flakes in all the rain, but instead follow instead whether winter weather can cancel school this week for the DISD.

Maybe a bit further S than Dallas Ed. Del Rio to Austin to College Station to Huntsville to Lufkin and points N may very well get in on the action IMHO. Anything S would be icing on the cake at this point IMHO...

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
204 PM EST TUE FEB 09 2010

VALID 12Z FRI FEB 12 2010 - 12Z TUE FEB 16 2010


...WINTER STORM FOR THE CENTRAL GULF COAST STATES AND SOUTHEAST...


PRELIMINARY UPDATE...

USED THE 00Z/09 ECMWF FOR DAYS 3 AND 4 ACROSS THE NATION...WITH A
GRADUAL INCORPORATION OF THE 00Z/09 ECENS MEAN THEREAFTER TO
ADDRESS THE UNCERTAINTIES IN SYNOPTIC DETAIL INHERENT TO THAT TIME
RANGE. PREFER THE NORTHERN MOST GUIDANCE WITH THE WAVE CROSSING
THE GULF OF MEXICO EARLY IN THE PERIOD...WITH MANY WAVES IN THE
SOUTHERN STREAM THIS WINTER ULTIMATELY TRACKING LESS SUPPRESSED
THAN THE MODELS INITIALLY PROG. THE MANUAL PROGS INDICATE SNOW
AND ICE ACROSS PORTIONS OF THE INTERIOR SOUTH...EXCEPT FOR SOUTH
CAROLINA WHERE WINTRY PRECIPITATION IS LIKELY TO SPREAD ALL THE
WAY TO THE COAST. CLIPPER SYSTEMS WILL BE THE ORDER OF THE WEEK
FOR THE PLAINS AND MIDWEST...WITH THE MEAN LONGWAVE RIDGE HOLDING
OVER THE ROCKIES. FRONTS ARE EXPECT TO COME INTO THE NORTHWEST
OFF THE PACIFIC...WITH LESS ENERGY DIVING INTO CALIFORNIA.


FINAL...

THE 12Z/09 GEFS MEAN...ECMWF...AND GEM GLOBAL ALL TRENDED
NORTHWARD WITH THE GULF WAVE DURING THE FIRST HALF OF THE
PERIOD...SO BUMPED UP PRECIPITATION ALONG THE SOUTHEAST COAST FOR
THE FINAL ISSUANCE. THE GEM GLOBAL IS THE MOST AGGRESSIVE WITH
THE LOW ONCE IT REACHES THE ATLANTIC...LIFTING A DEEP CENTER A
GOOD BIT OF THE WAY TOWARD CAPE HATTERAS. THIS IS CERTAINLY A
TREND TO WATCH...WITH LARGE IMPACTS FOR THE SOUTHEAST COAST IN
TERMS OF WINTER WEATHER. ELSEWHERE...STUCK WITH THE EARLIER BLEND
FOR THE WESTERN AND CENTRAL STATES...RULING THE GEM GLOBAL AS AN
AMPLIFIED OUTLIER AT THIS POINT WITH THE CLIPPER DIVING INTO THE
MIDWEST DAY 6.


CISCO

[harpman]

Local mets are giving us a decent chance of sleet/snow/rain/mix in the New Orleans area Thursday night into Friday.

[Mr. T]

At 72 hours (day 3), the 12z GFS is by far the warmest in the upper levels of any global model. Why HGX is following it the closest, I have no idea, but I think at least areas north of Conroe will see some snow by friday morning... The 12z CMC and UKMET like this idea. I cannot see Euro QPF maps, but it looks closer to the CMC and UKMET than the warm GFS.

[TxLady]

Just got back from Leakey yesterday.

Completely O.T.: redneckweather, have you ever driven the "3 Sisters" drive, in/around, Leakey? I had lunch in Leakey, back in July...a little family-owned place...quite tasty!

[sleetstorm]

Why would that wave of low pressure warm the atmosphere up in the mid and upper levels, Portastorm, Mr. T, srainhoutx, wxdata?

Sleet, it will be pumping warm gulf air over our heads ... and slowly but surely working its way down to the surface so that the entire air column is saturated.

That was not the way that is was during last December fourth's snowstorm or December tenth of 2008? So what is different about this time?

[sleetstorm]

The wave of low pressure that generated the snowstorm of December tenth 2008 was completely over land.

[wxman57]

This passing feature doesn't have nearly the cold air aloft that the December 2008 feature did. As the wave approaches, south and southeasterly winds in the lower levels (just above the surface) will advect warmer air aloft. Too warm for any significant winter precip here. Once the low/wave axis passes, the air aloft will cool. But the moisture will decrease very quickly after the low passes.

So, for Houston, lots (and lots) of cold miserable rain from tomorrow evening through late Thursday night, possibly mixed with a few sleet pellets at times.

But winter isn't over. Long-range guidance suggests some very cold air moving south out of Canada late next week, and that cold pattern may persist for a while. The southern stream will probably remain active. It's just a matter of timing as far as any future winter precip chances here this month.

[wxman57]

Why would that wave of low pressure warm the atmosphere up in the mid and upper levels, Portastorm, Mr. T, srainhoutx, wxdata?

Sleet, it will be pumping warm gulf air over our heads ... and slowly but surely working its way down to the surface so that the entire air column is saturated.

That was not the way that is was during last December fourth's snowstorm or December tenth of 2008? So what is different about this time?

The difference is in the vertical profile of the atmosphere over Houston ahead of each feature. The air aloft was significantly colder ahead of the 2008 system, enough so that the low-level warm advection wasn't enough to bring the air column aloft above freezing.

[C2G]

Great, more cold, cloudy, wet weather.
I have never wanted spring and summer as much as this year.
You know it would be almost tolerable with a snowflake now and then..........but noooooo.

[sleetstorm]

This passing feature doesn't have nearly the cold air aloft that the December 2008 feature did. As the wave approaches, south and southeasterly winds in the lower levels (just above the surface) will advect warmer air aloft. Too warm for any significant winter precip here. Once the low/wave axis passes, the air aloft will cool. But the moisture will decrease very quickly after the low passes.

So, for Houston, lots (and lots) of cold miserable rain from tomorrow evening through late Thursday night, possibly mixed with a few sleet pellets at times.

But winter isn't over. Long-range guidance suggests some very cold air moving south out of Canada late next week, and that cold pattern may persist for a while. The southern stream will probably remain active. It's just a matter of timing as far as any future winter precip chances here this month.

Okay, thank you, wxman57. Now, how many hours of sleet, snow, or rain snow mix could southeast Texas get prior all it turns to liquid from around noon to evening? And how many hours during the evening before all of the precipitation exits Texas?

[poobear55]

what's up? no replies since 7:37. trying to post to see if something is wrong with forum.

[poobear55]

after reading everyone's post this afternoon i thought this event was close but no cigar. then i watched the news tonight and gene norman seemed to be hyping or teasing us with a better chance for some type of frozen precip. so i got on line to see if something had changed. to get the real scoop. i am surprised at the lack of activity. i guess it really is a non-event.

[wxdata]

after reading everyone's post this afternoon i thought this event was close but no cigar. then i watched the news tonight and gene norman seemed to be hyping or teasing us with a better chance for some type of frozen precip. so i got on line to see if something had changed. to get the real scoop. i am surprised at the lack of activity. i guess it really is a non-event.

Since the NAM and GFS has been downers on snow chances here, interest has waned a bit..

[biggerbyte]

Funny how as some of the models are downplaying the event, some of the local mets, including the fellow from Fox26, are giving the idea an uptick. The fact of the matter is, noone knows for sure about the winter precip. possibilities just yet. Everybody has their own idea, but all of it is just speculation.

Wednesday night will tell us much, but even then things could change as quickly as the night before. That is just how it is down here. You will not find much going on in this forum unless there is more certainty than we have now. Watching the models flip/flop gets old after a while.