December: Warm Days & Cool-Foggy Nights To End 2011

[JackCruz]

This mystery is unraveling day by day. Hope Houston does get some snow or sleet out of this. Probably sleet. And yeah next week we can see a similar case.

It's not even winter yet though...

I've noticed everyone brought their low temps up for Tuesday/Wednesday especially Tuesday...

[djmike]

This mystery is unraveling day by day. Hope Houston does get some snow or sleet out of this. Probably sleet. And yeah next week we can see a similar case.

It's not even winter yet though...

I've noticed everyone brought their low temps up for Tuesday/Wednesday especially Tuesday...

Not us here in Beaumont! NWS dropped us another two degrees to 33 Tues and 30 Wed nights...

[biggerbyte]

Porter either. They have come down a few degrees. The forecasted temps with the NWS are still a bit too high. I can appreciate their reluctance to speak about winter precip. It is not part of the forecast, but there is chatter about the possibilities. Watch them change their tune on precip. and temps come Saturday, and especially on Sunday. Don't expect Snow out of this one, folks, but sleet, sleet/rain mix, and/or freezing rain would be something to watch for as the next couple of days evolve. Still too early to tell if we can get the moisture over us as we also get below freezing temps. Depending on the atmosphere, sleet could fall with ground temps above freezing.

Taking a look ahead beyond this event looks interesting. However, there is no way to accurately forecast it this far out.

[wxman57]

Sleet is A LOT easier to get than freezing rain, as it doesn't require sub-freezing air at the surface during the precip. Just a slight chance of a few sleet pellets as the rain ends Tuesday morning. Best chances north and west side of Houston.

[helloitsb]

Sleet is A LOT easier to get than freezing rain, as it doesn't require sub-freezing air at the surface during the precip. Just a slight chance of a few sleet pellets as the rain ends Tuesday morning. Best chances north and west side of Houston.

so the Tomball area or further NW?

hoping we can get something out of this other than rain but even if that is all we get I'll be pleased

[srainhoutx]

The main challenge this morning via over night guidance is when will the front arrive and just how much rainfall will occur? There still remains some questions regarding the timing and strength of the front and exactly when will the upper disturbances to our SW eject E and begin to shear out. Another fly in the ointment is if and where a coastal low/trough will develop. The Canadian is becoming an outlier as it holds too much upper air energy to W in Arizona/N MX and has trended away from other guidance. The NAM is still performing poorly and has not been very useful as of late with the upper air pattern as well as being to progressive with the storm pattern and tracks. The GFS has slowed the progression of the front until Sunday evening and the Euro as slowed things down a bit as well. So what does all that mean for us in SE TX? Rain chances and even some storms are possible on Sunday afternoon as the front slowly sags S into S TX and along the Coastal Plain. Elevated storms may be possible with a few rumbles of thunder as the front passes. Rain fall amounts look to be from the ½ inch to 1 inch range with some areas, mainly N and E with some 1-2 inch amounts or a bit higher with some possible isolated near 3 inch amounts, mainly in the NE areas. The rains look to end from W to E late Monday night into very early Tuesday morning. While wintry mischief does not look likely for our area, parts of the Permian Basin, NW of Austin to W of Dallas could see a wintry mix very early Monday morning into the day. San Angelo mentions a rain/snow mix chance as far S as I-10. The sensible weather on Monday here will be cold and raw with over running rains and temps in the 40’s. Low temps early Tuesday look to drop into mid 30’s. Freezing temps still look likely Tuesday night/Wednesday morning with some areas dropping to the upper 20’s for lows. There still remains some questions, so further fine tuning will likely occur as we see how all this plays out. As we have said all along, this is a complicated forecast and still evolving, so stay tuned as the say…looking ahead…another strong cold front appears to be in the works for next weekend…



DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1215 AM CST SAT DEC 03 2011

VALID 041200Z - 051200Z

...NO SVR TSTM AREAS FORECAST...

...SOUTH CENTRAL U.S...

A BROAD ZONE OF WARM ADVECTION WILL BE ONGOING AT THE BEGINNING OF
THE PERIOD ACROSS TX INTO THE LOWER MS VALLEY...ALONG AND NORTH OF A
COLD FRONT THAT SHOULD EXTEND FROM NEAR DRT...NEWD ALONG THE
ESCARPMENT OF CNTRL TX INTO CNTRL AR. MOIST ISENTROPIC ASCENT ATOP
THIS COLD DOME SHOULD PROVE SUFFICIENT IN GENERATING CONVECTION
ROOTED NEAR 850 MB JUST NORTH OF THE FRONT WITH MORE ELEVATED
ACTIVITY OVER THE TX SOUTH PLAINS INTO SRN OK WHERE TSTMS MAY BE
ROOTED NEAR 700 MB. WARM ADVECTION SHOULD BE THE PRIMARY FORCING
MECHANISM FOR EPISODIC TSTM DEVELOPMENT THROUGH THE PERIOD NORTH OF
THE SFC WIND SHIFT.

OF SOME CONCERN WILL BE THE MARGINALLY UNSTABLE WARM SECTOR NEAR THE
FRONTAL ZONE. FORECAST SOUNDINGS SUGGEST BOUNDARY LAYER MAY WARM
JUST ENOUGH FOR THE POSSIBILITY OF NEAR-SFC BASED CONVECTION.
HOWEVER...LATEST GUIDANCE IS NOT PARTICULARLY AGGRESSIVE IN
DEVELOPING PRECIP ACROSS THE WARM SECTOR AND IT/S NOT ENTIRELY CLEAR
WHETHER SUSTAINED UPDRAFTS CAN ORGANIZE SOUTH OF THE WIND SHIFT. SO
DESPITE VERTICAL SHEAR MORE THAN ADEQUATE FOR ROTATING UPDRAFTS IT
APPEARS MARGINAL INSTABILITY AND MEAGER FORCING MAY PRECLUDE DEEP
CONVECTION CAPABLE OF PRODUCING SEVERE. IF NEW MODEL GUIDANCE
SUGGESTS THE WARM SECTOR WILL BECOME SUBSTANTIALLY MORE
MOIST/BUOYANT THAN CURRENTLY FORECAST THAN SEVERE PROBS MAY NEED TO
BE ADDED TO ACCOUNT FOR MORE ROBUST CONVECTION NEAR THE SAGGING
FRONTAL ZONE.

[srainhoutx]

While the Canadian has been a bit discounted, a closer inspection does suggest that over running could linger into Tuesday as a coastal low develops. What does raise an eyebrow and HGX does mention some hesitance to remove precip chance for Tuesday, is the moisture suggested at 700 and 850mb's which could lead to a bit of sleet mixed with rain, if it is correct. We will see...

[djmike]

Wow...well from what I am reading this morning, it sounds like this cold front is fizzling out a bit. Less rain, not as cold temps (as we thought) and "for sure" no wintery precip of any sort! This will be like all the other cold fronts we've gotten so far. Seriously, this might be my first "very small" letdown for this winter season for SETX. Oh well.... I'm sure many more to come

[wxman57]

Wow...well from what I am reading this morning, it sounds like this cold front is fizzling out a bit. Less rain, not as cold temps (as we thought) and "for sure" no wintery precip of any sort! This will be like all the other cold fronts we've gotten so far. Seriously, this might be my first "very small" letdown for this winter season for SETX. Oh well.... I'm sure many more to come

The 06Z GFS seems to have had a problem with the front. Check out the 00Z run meteogram below. It's a bit colder than yesterday's runs but doesn't have the precip in with the coldest air. Could still be having a problem advancing the upper trof too quickly. Canadian keeps the precip here a lot longer. Note that this is the type of airmass that gives the models fits. They are frequently way too warm on temps, holding back the cold air to our north due to the incorrect perception that southerly winds at the surface or SW winds aloft won't let the cold, dense air sink southward.

[Andrew]

12Z GFS looks like junk. The progression of the cold air and "intensity" of the cold air even after the precipitation ends looks underdone quite a bit.

http://mag.ncep.noaa.gov/NCOMAGWEB/appc ... mageSize=M

[srainhoutx]

There are some new wrinkles in the 12Z GFS and Canadian. Both models are latching on to a bit deeper Upper Air disturbance to our W. The GFS has joined the Canadian solution suggesting a coastal low/trough forming along the Middle TX Coast somewhere near Corpus. The models continue to struggle with the cold air mass as well as timing, but as wxman57 mentioned, this is a common under estimation in model world. Also of note is the moisture appears to want to hang around a bit longer with over running clouds and perhaps some light precip into Tuesday. Another factor is the strengthening of the Coastal low and merging with the upper air (500mb) disturbance/trough as it ejects to the E. We’ll see if this trend continues with the Euro and on into the overnight suite. This still remains a challenging forecast with a lot of variables, but rain/storm chances appear to be increasing as well as some possible wintry mischief to our N and W.

[srainhoutx]

The 12Z Euro is suggesting a slower progression E with the upper air disturbance to our W and is coming in colder...that model also suggests ending any over running precip on Monday as well...

[JackCruz]

PREV DISCUSSION... /ISSUED 424 AM CST SAT DEC 3 2011/

DISCUSSION...
TIGHT PRES GRADIENT WILL LEAD TO A BREEZY DAY TODAY. DESPITE THE
INCREASED ONSHORE FLOW & MOISTURE THERE`S REALLY NO FOCUS FOR
PRECIP SO THINK 20% POPS SHOULD BE MORE THAN SUFFICIENT. SFC LOW
PRES IN W TX SHOULD TREK NE INTO THE PLAINS TODAY AND TONIGHT. A
COLD FRONT WILL FILL IN BEHIND IT. EXPECT SHRA WITH SOME EMBEDDED
TSRA TO DEVELOP ALONG THE BOUNDARY OVERNIGHT AND FOR IT TO APPROACH
EXTREME NRN PARTS OF THE CWA TOWARD SUNDAY MORNING.

CURRENT THINKING (WHICH IS SOMEWHAT DIFFERENT THAN PREVIOUS DAYS)
IS THE THE FRONTS SOUTHWARD PROGRESS WILL REALLY SLOW DURING THE
DAY SUNDAY AS PRESSURES FALL ACROSS NRN PARTS OF MEXICO (SOUTH OF
THE BIG BEND AREA). AND IT ALSO LOOKS LIKE THE COLD DENSE CANADIAN
AIRMASS WILL JUST BEGIN DIPPING INTO THE NRN US AT THAT TIME WHICH
GIVES ME SOME CONFIDENCE THE SLOWER ECMWF/NAM12 WAS PROBABLY ON
TO SOMETHING YDAY. SO THAT BEING SAID...TWEAKED THE TEMPS UPWARD
ACROSS SOME SOUTHERN PARTS SUNDAY NIGHT INTO EARLY MONDAY. STILL
ANTICIPATE PERIODS OF PRECIP ALONG/AHEAD OF THE FRONT.

LOOKING FOR A SHORTWAVE AND LOW PRESSURE AREA MENTIONED ABOVE TO
EJECT NORTHEASTWARD ACROSS THE STATE LATE SUNDAY NIGHT AND MONDAY
BRINGING ANOTHER WELCOME BOUT OF RAINFALL. EXPECT FALLING TEMPS
TEMPS THRU THE AFTERNOON ON MONDAY AS THE COLDER/DENSER AIRMASS
CATCHES UP TO THE FIRST FRONT AND GETS ITS NEEDED SOUTHWARD PUSH
THRU THE REMAINDER OF SE TX AND OFFSHORE. MODELS HAVE BACKED WAY
OFF ON CONTINUED OVERRUNNING PRECIP ON TUES - NOW ENDING THE
PRECIP MON EVNG. HESITANT TO COMPLETELY REMOVE POPS JUST YET BUT
HAVE LOWERED THEM INTO THE SLT CHC CATEGORY. THE UPPER TROF ITSELF
ISN`T FCST TO PUSH EAST OF US UNTIL TUE AFTN (GFS) OR EVEN WED
AFTN (ECMWF).

LOOKING LIKE FAIRLY WIDESPREAD FREEZES TUE/WED NIGHTS ALONG WITH
MUCH COOLER DAYS NEXT WEEK. ANOTHER FAIRLY STRONG FRONT HINTED AT NEXT
FRIDAY. 47
http://forecast.weather.gov/product.php ... glossary=1

Come on.......need some precip on Tuesday.....

[JackCruz]

000
FXUS64 KHGX 032142
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
342 PM CST SAT DEC 3 2011

.DISCUSSION...
WHILE IT LOOKS LIKE A GOOD CHANCE OF RAIN FOR TOMORROW AND MONDAY
THE FORECAST IS STILL QUITE CHALLENGING. WARM AIR ADVECTION OVER
SE TX WITH THE RETURN OF GULF MOISTURE HAS SUPPORTED A FEW
SHOWERS ACROSS THE AREA TODAY. EXPECT THIS ACTIVITY TO CONTINUE
OVERNIGHT. SFC ANALYSIS HAS WEAK SFC LOW IN THE C PLAINS WITH A
SFC FRONT PUSHING THROUGH C OK INTO N TX AND C TX. STRONGER COLD
FRONT WITH THE BEGINNINGS OF A CANADIAN AIRMASS IS WORKING SOUTH
THROUGH THE FRONT RANGE OF THE ROCKIES INTO THE TX PANHANDLE. THIS
SURGE OF COLDER AIR WILL CATCH UP WITH THE WEAK FRONTAL BOUNDARY
IN C TX OVERNIGHT TONIGHT AND SLOWLY PUSH THE FRONT TOWARDS SE TX
TOMORROW. ALOFT THE UPPER LEVEL PATTERN REMAINS RATHER AMPLIFIED
WITH AN UPPER LOW OVER THE DESERT SW AND TROUGH AXIS EXTENDING
ALL THE WAY INTO C CANADA. THE FIRST OF SEVERAL SHORT WAVE
TROUGHS HAS ALREADY MOVED INTO THE PLAINS WITH AT LEAST TWO OR
THREE MORE POSSIBLY MOVING OUT OVER TX AND S PLAINS OVER THE NEXT
COUPLE OF DAYS. OVERALL THE UPPER LOW OVER THE DESERT SW WILL BE
QUITE SLOW TO MOVE EAST AND EVENTUALLY SWING INTO THE PLAINS MID
WEEK.

OVERALL THE PATTERN IS QUITE SUPPORTIVE OF PRECIPITATION OVER SE
TX THROUGH TUE. ALL OF THE MODELS SUPPORT DRYING ON TUE/TUE NIGHT
EXCEPT THE GFS WHICH HOLDS ONTO LOW AND MID LEVEL MOISTURE
LONGER. THINK A SECONDARY COLDER CANADIAN AIRMASS WILL PUSH INTO
THE AREA ON MONDAY WHICH WILL BE KEY TO THE DRYING AND ENDING
RAIN CHANCES. THINK THE NAM AND ECMWF ARE MORE ON TRACK WITH THIS
THINKING. THE MAIN QUESTION WILL BE THE FRONTAL PUSH. THE FIRST
FRONTAL PUSH HAS THE FRONT SLIDING INTO SE TX TOMORROW AND SUN
NIGHT. IT LOOKS LIKE THE SECOND COLDER AIRMASS DOES NOT ARRIVE
UNTIL LATER MON. THE NAM HAS BEEN CONSISTENTLY SLOWER THAN THE
GFS WITH THE FRONTAL PUSH. THE ECMWF HAD BEEN SLOWER BUT THE 12Z
RUN HAS PUSHED THE FRONT THROUGH FASTER THAN THE GFS. GIVEN
STRONG SW FLOW ALOFT...THINK THE FRONT WILL TAKE ITS TIME PUSHING
SOUTH BUT ONCE THE CANADIAN AIRMASS ARRIVES...EXPECT THE FRONT TO
DIVE OFF THE COAST RATHER QUICKLY. GIVEN THE SLOW FRONTAL
PUSH...WILL HAVE PLENTY OF LIFT FOR RAINFALL WITH ISENTROPIC
UPGLIDE. AS SUCH...FORECAST WILL KEEP POPS IN THE 60 TO 80
PERCENT RANGE FOR BOTH SUN AND MON. THINK MON WILL HAVE MORE
WIDESPREAD RAINFALL AS FRONT PUSHES THROUGH AND SHORTWAVE ALOFT
MOVES ACROSS THE AREA. RAINFALL SHOULD TAPER OFF DURING THE DAY
TUE WITH MAYBE A FEW PATCHES OF LIGHT RAIN. COLD ADVECTION WILL
LIKELY HOLD MAX TEMPS IN THE 40S FOR MUCH OF THE AREA. MAIN
TROUGH AXIS OF THE UPPER LOW SHOULD PUSH THROUGH SE TX TUE NIGHT
INTO WED MORNING ALLOWING FOR CLEARING. COLD AIRMASS IN PLACE
WITH CLEARING SKIES SHOULD KEEP TEMPS RATHER COLD IN THE 30S FOR
MIN TEMPS.

EXTENDED FORECAST IS STARTING TO LOOK INTERESTING AS WELL. GFS IS
NOW DEVELOPING A NW GULF LOW FRI MORNING WHICH SHOULD INCREASE
RAIN CHANCES. THE ECMWF HAS INCREASED ONSHORE FLOW AS ANOTHER
COLD FRONT PUSHES SOUTH. GFS AND ECMWF LOOK ON TRACK WITH THIS
NEXT COLD FRONT JUST A QUESTION OF HOW RETURN FLOW SETS UP OR IF
A NW GULF SFC LOW DEVELOPS. ADDED 20 POPS FOR FRI AND KEEP TEMPS
ON THE COOL SIDE WITH INCREASED CLOUDS. COLD FRONT PUSHES THROUGH
FRI NIGHT SO NEXT WEEKEND LOOKS TO BE ANOTHER COLD ONE.







So I guess this week is a no go for snow....but next week something maybe? Let it snow! lol

[biggerbyte]

It was never a go for snow this week. We'll see how things turn out for next week when we get closer to it. Sleet was the talk for this event, and that has not been entirely ruled out at some point before this round is all said and done.

Let me remind everyone to look at the big picture and not be disappointed if we end up with just rain this week. A: We need the rain. B: You all might notice that we've been slowly transitioning into a wetter and colder pattern. That transitioning looks to continue, and each event gets more interesting. Next event is coming up.

[Andrew]

I think tonight's 00Z packages should be telling mainly due to the fact that a lot of the runs for the 12z and 18z looked a little off. The 18z GFS looks pretty "weird" and really modifies the cold air as it makes its way south. The upper level trof at 500mb is not nearly as amplified as previous runs and I feel like this is being underdone. Moisture levels through all heights look promising for some decent rains. I think at least 1-2 inches widespread look probable and hopefully we can continue to have overrunning of moisture through Tuesday night. Lets see what the Euro and Canadian have to show at 00Z. After the moisture clears out we should have some good cold air advection as temperatures really drop Wednesday and Thursday possible putting temperatures into the mid to upper 20's for north and northwest of Houston. This winter might get interesting later on also but that is talk for later.

[Ptarmigan]

Much as I like snow, I can live without this winter as we really need the rain. A rainy winter is fine with me.

[Ptarmigan]

I think tonight's 00Z packages should be telling mainly due to the fact that a lot of the runs for the 12z and 18z looked a little off. The 18z GFS looks pretty "weird" and really modifies the cold air as it makes its way south. The upper level trof at 500mb is not nearly as amplified as previous runs and I feel like this is being underdone. Moisture levels through all heights look promising for some decent rains. I think at least 1-2 inches widespread look probable and hopefully we can continue to have overrunning of moisture through Tuesday night. Lets see what the Euro and Canadian have to show at 00Z. After the moisture clears out we should have some good cold air advection as temperatures really drop Wednesday and Thursday possible putting temperatures into the mid to upper 20's for north and northwest of Houston. This winter might get interesting later on also but that is talk for later.

Looks to be interesting in the weather world.

[biggerbyte]

NWS is raising the temp forecast. They are not confident at all in something. They are obviously model forecasting. I'm not going to jump on any bandwagon until Sunday night.

[skidog38]

snow monday night