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

[Andrew]

Now it is time for Houston to put out their own statement or watch....

[biggerbyte]

NWS has me down for 31. I expect them to lower that as the day wears on. A 29 would not be out of the question.

[wxman57]

... snip ...

On another note, it may be mist but it may not be. Whatever was coming down was bigger than mist. While the profiles showed the upper atmosphere to be too warm, there just might have been a cold pocket aloft. Who knows. But I'm not going to be quick to debunk the snow. It certainly is interesting.

I saw the video last night. Sure looked like something more than drizzle. Then I checked out the upper air temps (model interpolations for Atascocita) and the upper air was well above freezing - not even close. So how could it appear to be snowing if the air aloft wasn't even close to freezing in the clouds/precip? Two possibilities. One, I think it may have been an optical illusion of flakes caused by some of the drizzle drops moving in and out of focus. The lighting coming from the camera area would make the drops appear larger on the video, and if they were slightly out of focus at times then they'd appear to be larger white disks. I think that's most likely what happened.

Second possibility is that the upper air interpolation of temps was way off, and there was a rather deep layer of sub-freezing air aloft, at least for a short period of time. It couldn't be just a shallow layer, or the precip would fall as sleet. I don't think this is likely. Can't 100% rule it out, though. As we saw with last February's "snow event" here, the models' interpolation of our upper air temps (between Lake Charles, Longview and Corpus Christi upper air soundings) can be 2-3 degrees off. Thus the freezing rain last winter vs. snow here. But we're talking a lot more than 2-3 degrees off last evening, more like 5-6 deg.

[djmike]

Beaumont topped out at 39.9 for today! Temps have already begun to drop and we are down to 37.4 as of now! Our forecasted NWS temps are a BUST big time! They also finally lowered are high for today from 49 to 47...lol. Ummm, temps are going DOWN! lol

[srainhoutx]

No Freeze Warning tonight for the Houston/Galveston CWA. A Freeze Warning/Watch may be issued tomorrow. The weekend extended discussion is worth the read...

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
304 PM CST TUE DEC 6 2011

.DISCUSSION...
CLOUD COVER AND COLD ADVECTION TODAY HAVE KEPT TEMPERATURES IN
THE UPPER 30S TO LOW 40S ACROSS SE TX THIS AFTERNOON. IN FACT A
COUPLE OF RECORD LOW MAXIMUM TEMPERATURES MAY BE BROKEN. KCLL
CURRENTLY SITS AT 38 DEGREES AND THEIR RECORD IS 40. LATEST VIS
SATELLITE IMAGERY DOES SHOW SOME CLOUDS BREAKING UP OVER C TX AND
MOVING IN THIS DIRECTION. IT LOOKS LIKE CLOUDS SHOULD BE ON TRACK
TO BREAK UP OVERNIGHT.

UPPER LEVEL LOW AND TROUGH AXIS STRETCHING FROM THE GREAT LAKES
TO THE TX PANHANDLE WILL BE MOVING ACROSS TX TONIGHT. CLOUDS
SHOULD REALLY CLEAR OUT THROUGH THE MORNING HOURS AS THE TROUGH
AXIS PASSES. MIN TEMPERATURES FOR TONIGHT AND WED MORNING WERE
ADJUSTED DOWN A COUPLE OF DEGREES BUT SOMEWHAT WET GROUND MAY
HOLD TEMPS HIGHER. OVERALL EXPECT TO KEEP AN AMPLIFIED UPPER
LEVEL PATTERN WITH BROAD POLAR LOW/TROUGH OVER CANADA/US WITH A
RIDGE OVER THE E PACIFIC.

SFC RIDGE SHOULD BUILD OVER TX WED NIGHT INTO THU. THIS SHOULD BE
A GOOD SET UP FOR ANOTHER WIDESPREAD FREEZE. MIN TEMPS IN THE
MID/UPPER 20S LOOK ON TRACK WITH LOW 30S ALONG THE COAST. MAY
NEED A FREEZE WARNING FOR ANY REMAIN AREAS THAT HAVE NOT HAD A
FREEZE SO FAR THIS WINTER.

EXTENDED FORECAST IS LOOKING A BIT MORE DICEY BUT GFS/ECMWF SEEM
TO BE IN PRETTY GOOD AGREEMENT. UPPER LEVEL PATTERN SEEMS TO TAKE
ON AN OMEGA BLOCK BY FRI WITH A SHORTWAVE TROUGH RIDING IN THE
SOUTHERN BRANCH OF THE JET. SHORTWAVE MOVES THROUGH TX ON FRI AND
HELPS INCREASE RETURN FLOW WHICH LOOKS TO INCREASE ISENTROPIC
LIFT. ISENTROPIC ANALYSIS AT 290K AND 295K SUPPORT SOME LIFT THU
NIGHT INTO FRI SO INTRODUCED 20 POPS AGAIN FOR LIGHT RAIN.
FRONTAL BOUNDARY SHOULD PUSH INTO THE AREA AND TURN WIND FIELDS
DOWN ISENTROPIC SFC WHICH SHOULD ALLOW FOR A DRY PERIOD SAT AND
SAT NIGHT. ANOTHER STRONGER SHORTWAVE TROUGH MOVES INTO TX SUN
WHICH INCREASES ISENTROPIC LIFT EVEN MORE THAN BEFORE. ALSO GET A
COASTAL LOW TO FORM ALONG THE MIDDLE TX COAST. SHOULD BE PLENTY
OF LIFT AND MOISTURE FOR WIDESPREAD RAIN. DECIDED TO INCREASE
POPS TO 30 FOR NOW BUT SHOULD THIS PART OF THE FORECAST CONTINUE
IN FUTURE MODEL RUNS...COULD SEE MUCH HIGHER POPS FOR THIS TIME
FRAME. THE HIGHER POPS WERE KEPT MAINLY SUN/MON AS LOOKS LIKE IT
COULD BE A PROLONGED RAIN EVENT BUT STILL QUITE A BIT OF
UNCERTAINTY IN THE TIMING OF THE SHORTWAVE AND HOW QUICKLY IT
MOVES THROUGH THE AREA. TEMPERATURES FOR THE WEEKEND WERE
ADJUSTED DOWN TO ACCOUNT FOR RAIN AND CLOUD COVER BUT THIS WILL
BE AT ODDS WITH ANY WARM ADVECTION THAT MAY DEVELOP. MODEL
SOUNDING SUPPORT COOLER LOW LEVELS WITH DEEP MOISTURE RIDING OVER
IT MUCH LIKE THE ISENTROPIC ANALYSIS SUPPORTS.

[Snowman]

we keep on referring to this weekend and early next week as "interesting" is this because there is a possibility for some sort of frozen precipitation? or is it just because it may rain?

[srainhoutx]

we keep on referring to this weekend and early next week as "interesting" is this because there is a possibility for some sort of frozen precipitation? or is it just because it may rain?

I think at this moment it's due mainly to rain chances in a weak/moderate La Nina. What we are seeing is that of what one would expect in an El Nino pattern. Interestingly EWX made mentioned of this in their afternoon AFD. One of the main reasons for mentioning model mayhem the past several weeks has been the atmosphere is not behaving as one would typically expect. For those that love all things weather, you have to enjoy watching events unfold that are different than the 'norm'.

Austin/San Antonio snip:

THE MEDIUM RANGE MODELS...SUGGEST ANOTHER COOL AND DAMP WEEKEND
NOT MUCH DIFFERENT FROM THE PAST WEEKEND. AVAILABLE MOISTURE
SHOULD BE LESS THAN THAT OF THE PAST WEEK...BUT A WEAK DISTURBANCE
IN THE ZONAL PATTERN IS EXPECTED TO ENHANCE THE POTENTIAL FOR
MODERATE RAINS SUNDAY INTO EARLY MONDAY. THUS THE FORECAST FOR THE
NEXT WEEK CONTINUE TO RESEMBLE THAT OF AN EL NINO WINTER PATTERN
DESPITE THE CONTINUED LA NINA STATUS AND PROJECTION.

[Andrew]

From looking at visible satellite I think our lows tonight (especially North and west of Houston) are going to bust by a couple of degrees. Clouds are rapidly clearing out and dew points continue to drop as cold air advection continues. With clearing skies and winds calming I see little mixing and good radiative cooling overnight. I can see temps dropping into the mid to upper 20's around here (college station) and around 30 degrees for Houston. It also helps that today's high busted across the region.

[biggerbyte]

Agreed!

[JackCruz]

Accuweather.com has Jersey Village and Cypress down for 27 degrees...Katy down for 28 degrees tonight ...also they have Beaumont down for 29 degrees also.

It's already down to around 37 degrees now.

[skidog38]

what about ocean effect snow.

[Andrew]

The NWS has lowered temps across the area. Houston now is expected to have a low of 30 while College Station is expected to get down to 26

[JackCruz]

I don't know if you guys follow the weather examiner but this is what he has to say:

Discussion

That word dreaded by residents of Southeast Texas has returned! No, not "snow", which many of "previously northern residence" tend to miss greatly. It is "cold", and its wintry presence in the local speech patterns looks to make return trips to Houston fairly often through the rest of the month.

High pressure is bringing the modified Arctic air mass to Texas, and since the air mass is dry sunshine will be abundant during the next two days. The sun is a valuable ally at low latitudes, and should allow afternoon readings to safely reach the 50s and perhaps the 60s. But some changes in the 500MB longwave pattern are coming up which should allow more cold intrusions this month.

I suspect that after the next arrival of IcA air on early Friday will not have the same impact as the current cold regime. For one, the incoming air mass is headed toward the East Coast. Secondly, a flow of moisture may get started from the Gulf of Mexico. If so, then cloudiness at night would stop any big drop in temperature from occurring. Another disturbance in the subtropical jet stream will bring cloudiness, southeast winds and eventually some rain to Houston as we close out the weekend. It is that system which may bring another round of heavy rain and thunderstorms early next week, followed by yet another shot of Arctic air.


Continue reading on Examiner.com Weather Forecast For Houston TX And Vicinity, Wednesday, December 7, 2011 - Houston Weather | Examiner.com http://www.examiner.com/weather-in-hous ... z1foLWufCV

[biggerbyte]

Wow! I said 29 for Porter. NWS now has 28. I believe upper 20s are spot on. Mid. to upper 20s tomorrow night as well.

BRRRRR!

[helloitsb]

Yup, NWS has my area at 26 and has issued a freeze warning.

[Andrew]

Yup, NWS has my area at 26 and has issued a freeze warning.

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
857 PM CST TUE DEC 6 2011

...FREEZE WARNING FOR ALL OF SOUTHEAST TEXAS THROUGH MID MORNING
WEDNESDAY...

.THE COMBINATION OF CLEARING SKIES AND A VERY COLD AND DRY AIRMASS
SPREADING INTO SOUTHEAST TEXAS WILL RESULT IN FREEZING
TEMPERATURES OVER ALL BUT THE IMMEDIATE COAST TONIGHT.

TXZ163-164-176>179-195>200-210>214-226-227-235>238-071600-
/O.NEW.KHGX.FZ.W.0003.111207T0257Z-111207T1600Z/
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-COLORADO-FORT BEND-
GALVESTON-GRIMES-HARRIS-HOUSTON-JACKSON-LIBERTY-MADISON-MATAGORDA-
MONTGOMERY-POLK-SAN JACINTO-TRINITY-WALKER-WALLER-WASHINGTON-
WHARTON-
INCLUDING THE CITIES OF...ALVIN...ANAHUAC...ANGLETON...BAY CITY...
BELLVILLE...BRENHAM...BROOKSHIRE...BRYAN...CALDWELL...CLEVELAND...
COLDSPRING...COLLEGE STATION...COLUMBUS...CONROE...CORRIGAN...
CROCKETT...DAYTON...EAGLE LAKE...EDNA...EL CAMPO...FREEPORT...
FRIENDSWOOD...GALVESTON...GROVETON...HEMPSTEAD...HOUSTON...
HUMBLE...HUNTSVILLE...KATY...LAKE JACKSON...LAKE SOMERVILLE...
LEAGUE CITY...LIBERTY...LIVINGSTON...MADISONVILLE...
MISSOURI CITY...MONT BELVIEU...NAVASOTA...ONALASKA...PALACIOS...
PASADENA...PEARLAND...PIERCE...PRAIRIE VIEW...RICHMOND...
ROSENBERG...SEALY...SHEPHERD...SUGAR LAND...TEXAS CITY...
THE WOODLANDS...TOMBALL...TRINITY...WEIMAR...WHARTON...WILLIS...
WINNIE
857 PM CST TUE DEC 6 2011

...FREEZE WARNING IN EFFECT UNTIL 10 AM CST WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN HOUSTON/GALVESTON HAS ISSUED A
FREEZE WARNING...WHICH IS IN EFFECT UNTIL 10 AM CST WEDNESDAY.

* TIMING...TEMPERATURES WILL FALL BELOW FREEZING OVER THE NEXT FEW
HOURS AND REMAIN BELOW FREEZING UNTIL MID M0RNING WEDNESDAY.

TEMPERATURES WILL BOTTOM OUT IN THE MID TO UPPER 20S MOST INLAND
AREAS OF SOUTHEAST TEXAS LATE TONIGHT AND EARLY WEDNESDAY.
TEMPERATURES BETWEEN 28 AND 32 DEGREES ARE LIKELY FOR THE HOUSTON
METRO AREA AND COASTAL COUNTIES. ONLY THE IMMEDIATE COAST WILL
REMAIN ABOVE FREEZING THE ENTIRE NIGHT.

TEMPERATURES OVER THE NORTHERN HALF OF SOUTHEAST TEXAS WILL REMAIN
BELOW FREEZING FOR 8 TO 12 HOURS. FOR THE SOUTHERN HALF OF
SOUTHEAST TEXAS TEMPERATURES WILL REMAIN BELOW FREEZING FOR 4 TO 8
HOURS. FOR THE HOUSTON METRO AREA AND COASTAL COUNTIES
TEMPERATURES WILL REMAIN BELOW FREEZING FOR 2 TO 5 HOURS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WARNING MEANS SUB-FREEZING TEMPERATURES ARE IMMINENT OR
HIGHLY LIKELY. THESE CONDITIONS WILL KILL CROPS AND OTHER
SENSITIVE VEGETATION.

&&

$$

[redneckweather]

I already have 23 at my house out near Lake Conroe BB! I know the NWS isn't showing this but I must be in a little cool pocket or something?

[srainhoutx]

The coldest morning of this late fall season for my location this morning with a low so far of 29F. Sunshine returns today for a brief 2 day visit, so enjoy it while it last. Yet another freeze event looks on tap for most of the area tonight with perhaps colder temps reaching near the Coast. A very progressive pattern is shaping up with a front still schedule to arrive Friday. As southerly flow off the Gulf becomes established on Thursday, expect and inversion layer to set up bringing low clouds and milder temps until the front arrives. The next front will be much like the last suggesting a shallow cold air mass with an over running situation yet again. On Saturday a coastal low/trough is suggested by guidance to form along the Lower/Middle Texas Coastal areas. Showers and even a few storms look to linger into Tuesday before another front pushes S. If the guidance is correct, we will be in a damp, cold and dreary pattern until early next week. Looking a bit further out, I don't see much change in this active pattern with the Pacific zonal flow and cut off upper lows to our W with frequent upper air disturbances passing from W to E along with a noisy Sub Tropical Jet. We need the rain and it appears we are headed into a pattern that will help in the ongoing drought situation.

[wxman57]

what about ocean effect snow.

What about it? Were you here in 1983 when Clear Lake got 1" of lake-effect snow on Christmas Eve during the big Arctic outbreak?

[srainhoutx]

27F this morning in NW Harris County with a fairly decent frost.