SW LA/SE TX Winter 2012-2013

[CajunMama]

Coldest morning of the cold snap is supposed to be Tuesday morning. Low of 51 expected. I'll take that!

[somethingfunny]

I see what you did there by re-ordering the name of the thread.

[vbhoutex]

We've had 52f the last 2 mornings here at the house. Downright chilly for this early in the season, but I'll take it over the 90s or high 80s expected later this week. Thanks Kathy for doing this thread.

[PTrackerLA]

Reached 49 this morning but moderating temps have begun. Don't see the next cool spell on the horizon as of now but by the time we get another solid front through here it will likely take temps into the mid 40s or lower. I too am hoping for an early frost I got sick of mowing grass after this wet summer!

[CajunMama]

I need a "like" button on this board. FB has me spoiled.

[CajunMama]

We reached 49 again this morning. Glad I made a pot of gumbo last night!

[vbhoutex]

Our low this morning was 47F here in W. Houston. Currently screaming up the thermometer to 49F with BEAUTIFUL clear blue skies. Hoping it warms enough by noon to enjoy the patio at the restaurant we are meeting friends from Atlanta at. Margaritas on the patio!! AAHHH!!! As I thought the locals OCM were hugging the models re our low temps for the weekend and have now come on board my earlier thoughts of lows in the upper 30s and low 40s for the next few days. Highs should gradually warm into the mid 70s over the next few days. One thing we do need is some rain. We've had almost an inch for the month.

[SoupBone]

Any updates or predictions? I see no El Nino this year, but I'm not really interested in snowy conditions (although I would love to see them). I just want to see some evidence that we are at least colder (overall) and with more consistency. I hate getting cold for one day then going back up to 82 for a high the next.

[vbhoutex]

With neutral conditions on tap for the Winter I am expecting an "average" to slightly below "average" Winter temp wise for SE TX with below average precipitation. The reasoning for the below average precip is the way we have started out dry here in October(btdt) and the fact that the STJ probably will not be set up like it would be with a full blown El NIno in place. That is where we get a lot of our moisture during El Nino episodes. We should see some shots of very cold weather, but without the El Nino I don't expect extended periods of "cold".

[jasons2k]

They just freeze warnings for Montgomery County northward - wasn't expecting this so early in the season. Brrrrrrrrr.

[vbhoutex]

WHERE'S WINTER? High was 83f here in W Houston again today. Low expected tonight is 65f, 2 degrees below the normal high for this time of year.

[SaskatchewanScreamer]

WHERE'S WINTER? High was 83f here in W Houston again today. Low expected tonight is 65f, 2 degrees below the normal high for this time of year.

I'll trade (your temps will drop when they bypass mine on the trip up )

[vbhoutex]

WHERE'S WINTER? High was 83f here in W Houston again today. Low expected tonight is 65f, 2 degrees below the normal high for this time of year.

I'll trade (your temps will drop when they bypass mine on the trip up )

About to take you up on this!! Actually, according to some there is hope.
From Jeff Lindner we get:

A chance for strong thunderstorms this afternoon.

Warm and muggy air mass that has been in place since late last week will be lifted by an incoming frontal boundary this afternoon. Radar currently shows showers along and east of a moisture plume off the SE TX coast extending from near Sabine Pass to offshore of High Island. This plume of deeper moisture has been very slowly working its way WNW over the last 24 hours and should spread inland along and south of US 59 today. Expect scattered showers to develop along the coast and begin to move inland over the next few hours as the dense fog burns off and surface heating starts to bubble up the low levels.

Weak cool front over NW TX will move SE today and enter our NW counties by late morning and sweep off the coast by early evening. Lift along the front will combine with an increasingly unstable air mass and increasing moisture to produce a showers and thunderstorms along and ahead of this boundary. Meso scale models are in good agreement on widespread development around noon from College Station to Lufkin which spreads SE this afternoon across most of the area. Parameters are in place for a few strong storms, but the severe threat is on the low side with weak shear. Once again this looks like a fairly decent shot at rainfall, but given the lack of rainfall with the past few events I am somewhat hesitant that widespread wetting rains will actually occur. With that said, feel that most areas will see some rainfall with the greatest amounts along and SE of US 59.

Cooling behind this front will be weak and short lived as the fast progressive pattern remains in place across the US. Instead of the record heat from the weekend highs will fall back toward the mid 70’s on Wednesday and Thursday with lows in the 50’s, both of which remain above early December averages. Weak boundary retreats northward on Thursday and this will return well above average temperatures and humidity to the region this weekend. Highs will return to the toasty 80’s by Saturday under southerly Gulf flow…but significant changes will follow.

Long Range:

After weeks warmth…some record…across much of the nation, the upper air pattern looks to finally break down from its fast progressive west to east flow to more amplification of a ridge of high pressure off the western US coast. This newly developing upper air pattern will shut off the parade of storm system into the W coast and direct the development of a downstream trough over the western US and plains. Cold air which has been bottled up in NW Canada will be unleashed into the US by this weekend and spread rapidly down the plains and into TX by early next week. Long range global models are having a hard time resolving the timing of this strong old front and how cold the post frontal air mass might be. Given past history with shallow cold air masses, will take the faster and colder solutions and expect a strong front to push into SE TX sometime early Monday and sweep off the coast during the day. Highs will be prior to the front with rapidly falling temperatures behind the boundary into the 40’s and 50’s under strong cold air advection. Some degree of energy does look to lag back in the base of the trough over the SW US post front which may keep clouds around behind the front and temper the temperature rise during the day. Still plenty of time to fine tune the affects of this pattern change and eventual air mass change…but finally some longer lasting cold air looks to be headed this way.

We shall see. We have seen this before and nada. With all of the snow cover still up in Canada I don't expect this to be way below normal or long lasting even though many are calling for a pattern change. Yes I have turned into negative Nancy when it comes to Winter weather coming to SE TX.

[Jagno]

At this point I'd just be happy to wear a long sleeve shirt and need it. Thank you for keeping us updated with Jeff's forecasts.

[PTrackerLA]

I'm seriously having doubts that we even have a freeze before Christmas this year which would be pretty remarkable. Looking at the 16 day GFS I see some bouts of colder air but nothing that would indicate a freeze in these parts. I honestly can't ever remember this happening. The good news is it looks like we'll be getting fairly regular rainfall after our drenching earlier this week. I was starting to get concerned about drought conditions returning if we continued to stay dry this winter. We'll see.

[vbhoutex]

Portion of the discussion from Houston/Galveston NWS-

MODELS DIFFERING ON THE DETAILS OF THE EVOLUTION OF THE TROUGH
OVER THE ROCKIES FOR SUN/MON TUE. GFS IS FASTER PUSHING THE TROUGH
EAST ON SUN/SUN NIGHT. ECMWF HAS A STRONG VORT MAX MOVING OVER N
TX MON BEHIND THE COLD AIRMASS. BOTH MODELS HAVE STRONG COLD
ADVECTION MON INTO TUE AS HIGH PRESSURE SETTLES OVER TX. MODELS
ARE ALSO SLOWER WITH THE TROUGH MOVING INTO THE PLAINS THAN
PREVIOUS RUNS WHICH MEANS THE FRONT IS ABOUT 6 HOURS SLOWER THAN
PREVIOUS MODEL RUNS. DECIDED TO SLOW DOWN THE FRONT 6 HRS BASED ON
THIS. THE NAM WAS FASTER WITH THE FRONT BUT BASED ON SREF DATA
THINK IT MAY BE FASTER WITH OTHER SREF MEMBERS IN AGREEMENT WITH
THE GFS. SLOWER FRONT ALSO MEANS PUSHING PRECIP CHANCES MORE FOR
SUN NIGHT. KEPT RAIN CHANCES AT 40 PERCENT MAINLY DUE TO
UNCERTAINTY IN THE FORECAST BUT ALSO BECAUSE OF POSSIBLE
CAPPING...DRY AIR IN MID LEVELS AND UPPER LEVEL FORCING BEING
NORTH OF THE AREA. LIKELY SEE A NICE LINE OF SHOWERS AND A FEW
THUNDERSTORMS BUT GIVEN THE REASONS ABOVE...THINK STRONG/SEVERE
THUNDERSTORM THREAT WILL BE LOW.

HIGH PRESSURE IS SLOWER TO MOVE ACROSS THE AREA AS WELL FOR
TUE/WED SO WILL KEEP TEMPS ON THE COLD SIDE. THINK FREEZE A GOOD
POSSIBILITY TUE MORNING. MAY NEED TO RE-EVALUATE FREEZE WARNING
FOR THE AREA WITH TEMPS IN THE 80S FOR THE LAST WEEK OR SO. MODELS
REALLY OUT OF PHASE FOR LATE NEXT WEEK SO WILL KEEP FORECAST
STATUS QUO UNTIL THERE IS MORE AGREEMENT.

Basics are they still aren't sure how cold it will get. Mid 30s seems a good bet to me, but anything below that in the Metro from Spring or Tomball South would be surprising to me. Do like the idea that there could be a line of showers with passage. We need all we can get.
I have to pretty much agree with PTrackerLa and what he is saying. Houton/SE TX did not get the drenching SW LA did, so we do still have to worry about going further into drought than we already are.

[vbhoutex]

Jeff says it is going to get cold-

Strong Canadian cold front will sweep across the region Sunday night ending this warm and muggy weather. Highs on Monday will struggle to reach 50 under strong cold air advection and cloud cover.

However before Sunday evening we must continue with this warm and humid air mass and the daily cycle of morning low clouds and fog followed by afternoon partly cloudy skies. Lows in the 60’s and high near 80/low 80’s may approach record values over the weekend. Moisture return off the Gulf will continue with the potential for a few scattered showers Saturday and Sunday. Amplification of the western US ridging sends a cold Canadian air mass down the plains and into TX Sunday. Will likely see a thin line of showers/thunderstorms along the front Sunday night, but once again the coverage looks meager with areas east of I-45 favored for the most activity. Maybe a few locations will squeeze out .50 of an inch.

While models have been slowing down the frontal timing, such cold air mass tend to plow southward faster than models suggest and expect the front to be off the coast by early Monday morning. The temperature will fall a good 10-15 degrees with the front and then continue a steady decline on Monday under strong cold air advection. Upper level trough remains west of the area into Monday and Monday night and this should keep clouds in place over top of the deepening frontal inversion. The combined effects of clouds and strong cold air advection will result in a cold Monday with highs in the 40’s to low 50’s with gusty NW winds of 10-25mph.

Skies might clear out early enough Monday night/Tuesday morning for near freezing conditions over parts of the area. Still expect winds to stay up some with the ridge axis just to our west, so conditions are not completely perfect for strong cooling. Better setup may come Tuesday night/Wednesday morning with ridge axis nearly overhead and mainly clear skies. Could see temperatures near or below freezing all the way to I-10 and in the rural areas away from Houston. May need a freeze warning for this time period…but much can change over the next few days especially with cloud cover.

After Tuesday, the models diverge on the prospect of the next trough affecting the area. A few models develop a coastal storm off the lower TX coast and keep the cold air locked in place with overrunning rains while other bring the warm sector inland and are much drier. I am tending to lean toward the drier solutions given the ongoing pattern this fall and the worsening drought conditions.

Fire Weather:

Some concern on Monday for fire weather conditions, but current expected cloud cover and higher RH should help mitigate strong gusty winds. Additionally, some rainfall is likely on Sunday night which should help to wet the finer fuels. Will keep an eye on this aspect over the weekend, in case RH values fall more than expected.

[vbhoutex]

Afternoon discussion from Hou/Gal NWS

Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
353 PM CST SAT DEC 8 2012

.DISCUSSION...
GENERAL SHALLOW UPPER TROUGHING ACROSS THE MAJORITY OF THE
CONUS...WITH A 250-300MB JET STREAMING OVER STATE THE FEATURE
LIKELY AIDING TO THE DEVELOPMENT OF WIDELY SCATTERED INTERIOR
SHOWERS. ANOTHER PARTIALLY CLOUDY DAY WITH ENOUGH SUN ALLOWING
MANY COMMUNITIES TO AGAIN REACH THE LOWER 80S FOR AFTERNOON
MAXIMUM TEMPERATURES. ONSHORE FLOW IS STEADILY INCREASING (OR
MAINTAINING) PWAT VALUES IN THE 1.2-1.3 INCH RANGE...THAT IS
STILL SLIGHTLY ABOVE NORMAL FOR DECEMBER. ONE MORE DAY OF THIS
SPRING-LIKE WEATHER PATTERN AND THEN THE WEATHER WILL ABRUPTLY
TRANSITION TO WINTER.

AN AGGRESSIVE COLD FRONTAL PASSAGE DURING THE OVERNIGHT HOURS
MONDAY MORNING...WITH A VERY COLD AND DRY BACKING CANADIAN-ORIGIN
AIR MASS...IS STILL ON SCHEDULE. IN THE MEANTIME...INCREASING
RAIN CHANCES (SHOWERS WITH ISOLATED STORMS) SUNDAY AFTERNOON WILL
SIGNIFICANTLY INCREASE SUNDAY EVENING AS THE BOUNDARY ENTERS
CENTRAL TEXAS. THERE IS A POSSIBILITY OF EITHER A DISTURBANCE
MOVING UP WITHIN THE SOUTHWEST FLOW PATTERN AHEAD OF THE MAIN
FRONT ITSELF...AND/OR A PRE-FRONTAL TROUGH LEADING THE MAIN COLD
FRONT...ON SUNDAY THAT WILL ENHANCE THE PROBABILITY OF MORE
THUNDERSTORM COVERAGE AND INTENSITY. AS OF NOW...RAIN WITH
STRENGTHENED STORMS ARE EXPECTED JUST AHEAD OF THE COLD FRONT
DURING THE OVERNIGHT HOURS SUNDAY NIGHT THROUGH MONDAY MORNING.
THE PROGGED DOWNSTREAM THERMODYNAMICS ARE NOT OVERLY IMPRESSIVE
ALTHOUGH THERE WILL BE ENOUGH DYNAMICS RIGHT ALONG THE PRE-FRONTAL
TROUGH/MAIN COLD FRONT TO PROVIDE AMPLE ENOUGH LIFT WITHIN A VERY
MOISTENED ENVIRONMENT (FORECAST 1.6-1.7 INCH PWAT) TO INITIATE
STRONG CELLS. PER FORECAST WEAK RIGHT-CURVED HODOGRAPHS EARLY
MONDAY MORNING...SHEAR PROFILES JUST DOWNSTREAM OF THE WIND SHIFT
DO DISPLAY THE POTENTIAL TO RACHET UP SOME STRONG TO BRIEF SEVERE
THUNDERSTORMS. DUE TO THE PROGRESSIVE NATURE OF THE FRONT TO THE
COAST...RAINFALL TOTALS WILL REMAIN IN THE AVERAGE 0.5 INCH TO
INCH RANGE...WITH LOCALLY 1 TO 2 INCH AMOUNTS OVER AREAS THAT
RECEIVE MORE THAN ONE GOOD DOWNPOUR/STORM.

MONDAY WILL BE A COLD AND OVERCAST DAY AS MOISTURE TRAPPED UNDER
THE FRONTAL INVERSION WILL NOT SCOUR OUT UNTIL LATTER IN THE
DAY...OR ONCE THE MID-LEVEL FRONT CLEARS THE REGION. TUESDAY AND
WEDNESDAY WILL BE THE COLDEST DAYS OF THE WEEK...WITH MANY NON-
COASTAL LOCATIONS FALLING TO BELOW FREEZING FOR A GOOD 5 TO 8
HOURS BOTH MORNINGS. A FREEZE WARNING WILL LIKELY BE IN EFFECT
BOTH TUESDAY AND WEDNESDAY MORNINGS AS WE WILL FEEL THE FULL
EFFECT OF THIS COLD NORTHERLY AIR MASS...WINDS WILL DIE OUT PER
THE RIDGE AXIS FALLING OVER SOUTHEASTERN TEXAS. AFTERNOONS WILL
ONLY WARM INTO THE AVERAGE UPPER 40S (NORTH) TO LOWER 50S (SOUTH)
BOTH MONDAY AND TUESDAY...THE ONLY DIFFERENCE WILL BE THE CLOUD
COVER...MONDAY WILL BE MOSTLY CLOUDY AND TUESDAY IS FORECAST TO BE
MOSTLY SUNNY. ALTHOUGH THERE ARE 6 COUNTIES IN OUR NORTHERN ZONES
THAT HAVE ALREADY REACHED (OR DIPPED BELOW) FREEZING IN MID-NOVEMBER
...THE WARNING WILL STILL INCLUDE THEM. THIS WILL ELIMINATE ANY
CONFUSION AND...SINCE THERE HAS BEEN THIS MINI-GREEN UP THIS PAST
WEEK (PER VERY WARM AND MILD CONDITIONS)...VEGETATION WILL BE EVEN
MORE SUSCEPTIBLE TO FREEZE BURN. A VERY COLD BEGINNING TO THE WORK
WEEK WILL WARM BACK UP IN TO THE 60S THURSDAY AS RIDGING MOVES OFF
TO THE EAST AND ONSHORE FLOW RESUMES. THE NEXT COLD FRONTAL PASSAGE
IS BEING PENCILED IN FOR SATURDAY.

[vbhoutex]

Jeff Lindner's morning email:

Powerful Canadian cold front sweeping down the plains will end the record warmth tonight!

Freezing temperatures expected both Tuesday and Wednesday mornings.

Surface observations show the strong cold front plowing through the TX panhandle and moving S at 25-35mph. Temperatures ahead of the boundary are in the 60’s and 70’s and fall rapidly into the 40’s behind the front with strong NW winds. Front may slow up a little today with warm air mixing along the leading edge, but there should be a good push after dark to bring the boundary and its associated weather into SE TX tonight. While the front approaches from the north, moisture continues to increase from the Gulf ahead of a short wave disturbances currently approaching the Rio Grande. Large scale lift will be increasing this afternoon and expect to see scattered showers begin to develop and move northward from the coast. By this evening strong surface lift with the frontal boundary will come to bear across the area with numerous showers and thunderstorms developing. A few storms could be strong to severe. SPC has placed areas along and north of I-10 in a slight risk for wind damage this evening, but the overall severe threat is on the low side given only marginal instability and shear. System looks fairly similar to the one this past Tuesday with greatest rain chances and coverage mainly across our central and eastern counties with amounts to the west and southwest less as drier mid level air and SW winds in the mid level affect this region.

Front blasts off the coast by sunrise with strong cold air advection ensuing. Highs temperatures will be a midnight with temperatures falling through much of the morning on Monday into the low 40’s north to near 50 at the coast under strong N winds of 15-25mph and gusty. Clouds will slowly clear from WNW to ESE during the afternoon and this clearing may result in a small rebound in temperatures from 3-5pm on Monday if at all.

Center of the large polar high will be west of SE TX on Monday night and expect weak N winds to continue. Given the very dry air mass in place with dewpoints forecasted well into the 20’s, sub-freezing temperatures can be expected for nearly all areas except within the 610 loop (urban heat island) and right along the coast. Many areas will see freezing temperatures for 3-6 hours and a freezing warning will be required for most counties even those that have already had a freeze due to the recent warmth. Highs on Tuesday even under sunny skies will only reach the low to mid 50’s.

Tuesday night and Wednesday morning look to be near ideal for maximum cooling with the polar high nearly overhead and calm winds under crystal clear skies. Temperatures will plunge after sunset and many areas will fall below freezing for 4-8 hours. Could see mid 20’s up north to near 30 at the coast with mainly 29-32 for most areas. Pipes will not be an issue with this cold event, but sensitive tropical plants will likely sustain damage if not protected.

Slow warm up begins on Thursday with highs recovering into the 60’s and the 70’s by Friday under increasing chances of rainfall.

[vbhoutex]

Jeff Lindner's morning email:

Freezing warning will be issued this afternoon for all areas except inside the 610 loop and the immediate coastal areas.

Long awaited and well advertised cold blast arrive overnight with current temperatures running some 20-30 degrees colder than this time on Sunday.

Strong Canadian cold front continues to plow across the Gulf of Mexico as large polar high builds down into central TX. Strong cold air advection continue early this afternoon under slowly clearing skies from the NW. Even under sunny skies temps. remain in the 40’s with gusty NNW winds of 15-25mph. Large surface high will expand into SE TX this evening with winds weakening, but not likely going calm. Air mass is already very dry with dewpoints in the 20s and once the sun sets, temperatures will begin to fall toward those dewpoints. Weak overnight winds will keep temperatures from bottoming out near the bone dry dewpoints and save most of the region from a hard freeze.

Lows Tuesday/Wednesday AM:

27-29: north of HWY 105
29-32: all other areas
33-35: inside 610 loop and beaches

Temperatures will be at or below freezing for between 3-7 hours. Sensitive tropical vegetation will be impacted and should be protected.

Warming only into the low to mid 50’s on Tuesday with polar high moving nearly overhead by late afternoon. Winds will be weaker (near clam) Tuesday night/Wednesday morning and equally cold temperatures are likely again. Would go a little lower on the Wednesday morning lows, but the surface ridge axis may shift just enough eastward to allow a very weak E wind toward morning which could halt the temperature fall.

Warm up begins on Thursday as the polar high moves eastward and SE winds return to the area. Gulf moisture will begin to deepen as low pr3essure develops over the southern plains supporting southerly flow. Models have been waffling back and forth with rain chances for the Friday-Saturday period. What looked to be a decent chance of rain yesterday is much more questionable today and given the drought conditions in place…will side with the drier side of things for now. Temperatures will rebound back toward the 70’s for highs and 50’s for lows by Saturday ahead of a weak front late Saturday which will return the area to normal.

The freeze warning has been issued.