November Weather Discussion. Rollercoaster Pattern.

[srainhoutx]

HPC:...slowing down the front...

FINAL 500 MB HEIGHT FORECASTS AND SEA LEVEL PRESSURES/FRONTS WERE
COMPOSED USING A BLEND OF THE PRELIMINARY PROGS WITH THE 12Z
GFS/12Z ECMWF/12Z UKMET/12Z CANADIAN GLOBAL MODELS. THESE MODELS
ARE IN BETTER THAN AVERAGE AGREEMENT ON A SLOWING TREND WITH THE
UPPER TROUGH EMERGING OUT OF THE NORTHERN ROCKIES ON DAY 3...AND
WITH THE SFC LOW DEVELOPING ON THE HIGH PLAINS AND PROGRESSING
ACROSS THE UPPER MS VALLEY/UPPER GREAT LAKES...AND THEN INTO
SOUTHEAST CANADA.

[helloitsb]

HPC:...slowing down the front...

FINAL 500 MB HEIGHT FORECASTS AND SEA LEVEL PRESSURES/FRONTS WERE
COMPOSED USING A BLEND OF THE PRELIMINARY PROGS WITH THE 12Z
GFS/12Z ECMWF/12Z UKMET/12Z CANADIAN GLOBAL MODELS. THESE MODELS
ARE IN BETTER THAN AVERAGE AGREEMENT ON A SLOWING TREND WITH THE
UPPER TROUGH EMERGING OUT OF THE NORTHERN ROCKIES ON DAY 3...AND
WITH THE SFC LOW DEVELOPING ON THE HIGH PLAINS AND PROGRESSING
ACROSS THE UPPER MS VALLEY/UPPER GREAT LAKES...AND THEN INTO
SOUTHEAST CANADA.

I can't take another warm Thanksgiving

[wxman57]

If we have a freeze on Saturday, it would be earlier than average. The average freeze date is December 2, which is at KIAH from 1969 to 2009. I have looked at old records and sometimes Houston does not see its first freeze until February! It happened in 1922.

Back in 1922, the thermometer location was "downtown" Houston, I believe. The official Houston location was moved up north to Bush/IAH only in recent decades (IAH opened in 1969). Before then, Hobby airport on the south side was the official observation point (opened in 1927). The location of the official observation point has changed quite a bit over the past century.

I'm still voting for Dec 4th as the first IAH freeze. That way, I win $100 in our first freeze office pool.

[Ptarmigan]

Back in 1922, the thermometer location was "downtown" Houston, I believe. The official Houston location was moved up north to Bush/IAH only in recent decades (IAH opened in 1969). Before then, Hobby airport on the south side was the official observation point (opened in 1927). The location of the official observation point has changed quite a bit over the past century.

I'm still voting for Dec 4th as the first IAH freeze. That way, I win $100 in our first freeze office pool.

The thermometer location was in what is now downtown Houston at the time in 1922.

[srainhoutx]

Afternoon discussion highlights from across TX/OK...

Houston/Galveston...

MODELS NOW APPEAR TO BE SOLIDIFYING AROUND A LATER FRONTAL
PASSAGE...KEEPING UNSEASONABLY WARM CONDITIONS IN PLACE THROUGH AT
LEAST THE BEGINNING OF THANKSGIVING DAY. AS MOISTURE INCREASES THE
POTENTIAL FOR SHOWERS WILL BE PROGRESSIVELY GREATER AS WE HEAD
TOWARDS MID WEEK. MODEL SOUNDINGS SUGGEST THE POTENTIAL FOR
THUNDERSTORMS ON WEDNESDAY...BUT THEY APPEAR TO BE TOO AGGRESSIVE
IN ERODING THE FAIRLY STRONG CAP ACROSS THE REGION. WILL INCLUDE
MENTION OF ISOLATED THUNDER BUT EXPECT THAT MOST AREAS WILL ONLY
SEE STREAMER SHOWERS UNDERNEATH THE CAP.

COLD FRONT NOW APPEARS TO ARRIVE LATE IN THE DAY ON
THANKSGIVING...BRINGING A CHANCE FOR THUNDERSTORMS AND MUCH COOLER
AIR TO THE REGION. DESPITE SOME LINGERING CLOUDINESS BEHIND THE
FRONT EXPECT THAT THE NORTHERN HALF OF THE REGION SHOULD SEE
TEMPERATURES FALL INTO THE UPPER 30S BY FRIDAY MORNING. SATURDAY
MORNING WILL BE EVEN COOLER...WITH MOST INLAND AREAS IN THE 30S
AND THE NORTHER HALF OF THE AREA SEEING BRIEF PERIODS BELOW
FREEZING. TEMPERATURES WILL BEGIN TO WARM BY SUNDAY AS ONSHORE
FLOW DEVELOPS IN RESPONSE TO A DEEPENING SURFACE LOW ACROSS THE
PLAINS.

Norman, OK...

OTHERWISE TEMPERATURES WILL BE THE BIG CHALLENGE THIS WEEK. STRONG
SURFACE FRONT IS NOW ACROSS CO/KS... AND ALL INDICATIONS ARE THAT IT
WILL REMAIN TO OUR N THROUGH MONDAY. THUS AT LEAST ONE MORE MILD-
TO-WARM DAY ON MONDAY. UPPER LOW NOW OVER NV WILL OPEN UP AND MOVE
NE INTO THE N PLAINS... AND THERE WILL BE ENOUGH SFC PRESSURE
RISES IN ITS WAKE TO NUDGE THE FRONT BACK S INTO THE AREA MON
NIGHT AND TUE. HOW FAR S IS HARD TO ASSESS... BUT THIS IS A
REASONABLY-POTENT COLD AIR MASS WITH 20Z TEMPS STILL BELOW ZERO
IN MT. THE TENDENCY USUALLY IS FOR THIS KIND OF COLD AIR TO MOVE S
MORE FREELY THAN IS OFTEN INDICATED BY THE MODELS... AND THEN TO
BE MORE STUBBORN TO LEAVE ONCE IT ARRIVES. THIS WAS SEEN THIS
MORNING IN PARTS OF NW OK WHERE IT TOOK DIURNAL MIXING TO FINALLY
SWEEP IT OUT WELL AFTER 12Z. FOR THIS FORECAST WE WILL GO WITH THE
FLOW... NO PUN INTENDED... AND KEEP THE LOWS MON NIGHT AND THE
HIGHS TUE WITHIN TOLERANCE OF NEIGHTBORING VALUES. BUT WATCHING
WHAT IS HAPPENING TODAY IN THE CENTRAL HIGH PLAINS - DENVER FELL
FROM THE 50S INTO THE 20S IN 2 HRS THIS MORNING WHEN THE FRONT
SLIPPED S - THERE REMAINS A LOT OF CAUTION AND SKEPTICISM HERE AS
TO WHETHER ANY OF THE MODELS ARE GOING TO HAVE A REALLY GOOD
HANDLE ON THIS FRONT. WOULD NOT BE SURPRISED TO HAVE 70S CLOSE TO
40S SOMEWHERE IN THE CWA ON TUESDAY.

SIMILAR DOUBTS PERSIST TUE NIGHT AND WED... BUT LATEST MODEL TRENDS
SHOW THE GFS TRENDING TOWARD THE ECMWF AND A SLOWER ARRIVAL OF THE
COLD-AIR INVASION WED NIGHT. THUS WE ARE COMPELLED TO FOLLOW THE
CONSENSUS AND WARM WEDNESDAY UP CONSIDERABLY FROM WHAT WE HAD
YESTERDAY. IT NOW APPEARS THAT THE ABRUPT TRANSITION FROM
UNSEASONABLY MILD TO BRUTAL COLD MORE LIKELY WILL TAKE PLACE LATE
WED NIGHT INTO THANKSGIVING MORNING... RATHER THAN DURING THE DAY
OR EVENING WEDNESDAY. AS SUCH WE ALSO WILL BACK OFF A LITTLE ON
THE LOWS WED NIGHT... BUT THU AND THU NIGHT CONTINUE TO LOOK VERY
COLD WITH WIND CHILLS DROPPING INTO THE TEENS AND SINGLE DIGITS.
TEMPS MAY STRUGGLE TO REACH THE 40S ON THANKSGIVING. GRADUAL
MODIFICATION OF TEMPS IS LIKELY GOING INTO NEXT WEEKEND AS UPPER
FLOW PATTERN FLATTENS OUT AND COLD AIR SLOWLY MODIFIES WITH S
WINDS RETURNING.



Lubbock...

.LONG TERM...
MAIN ISSUE CONTINUES TO BE TIMING OF COLD ARCTIC AIR MASS INTO THE
FCST AREA. 12Z MODEL RUNS CONTINUE TO DELAY ENTRY WITH BOTH THE
ECMWF AND GFS BRINGING THE FRONT INTO THE NRN ZONES BETWEEN 06Z
AND 12Z THURSDAY. PROGGED POSITION OF THE FRONT AT 00Z THURSDAY
ON THE WRF-NAM WOULD SUPPORT SIMILAR TIMING WITH 06Z DGEX IN
SUPPORT. RELEASE OF THE COLD AIR DEPENDENT ON EJECTION OF UPPER
LEVEL SHORT WAVE TROUGH ACROSS THE NRN PLAINS...SO UNCERTAINTY
STILL FAIRLY LARGE BUT WILL PUSH FRONT BACK CLOSER TO THIS TIMING.
AS A RESULT WILL HAVE TO PUSH HIGH TEMPS WEDNESDAY UP CONSIDERABLY
AS WELL AS NUDGE WEDNESDAY NIGHT LOWS UP SOME.

OTHERWISE PREVIOUS FCST LOOKS TO BE IN GOOD SHAPE WITH WARM AND
BREEZY CONDITIONS PERSISTING TUESDAY /AND LOOKING LIKE INTO
WEDNESDAY AS WELL/ WITH THE COLDEST DAY BEING THURSDAY IN THE
POST-FRONTAL ENVIRONMENT. FRIDAY MAY NOT BE AS WARM AS PREVIOUSLY
ANTICIPATED GIVEN SLOWER ENTRANCE OF THE COLD AIR...BUT IMPORTANT
TO NOTE THAT IT DOES NOT LOOK LIKE AN EXTENDED STAY FOR THE ARCTIC
AIR MASS WITH SHORT WAVE RIDGING ALOFT TAKING SWIFT AIM ON THE
CENTRAL PART OF THE CONUS AND WINDS VEER TO SW.



Dallas/Ft Worth...

MEDIUM RANGE MODEL GUIDANCE IS IN GOOD AGREEMENT TODAY REGARDING
THE EVOLUTION OF THE UPPER LEVEL PATTERN ACROSS THE NW CONUS
DURING THE NEXT FEW DAYS. COLD AIR WILL REMAIN BOTTLED UP IN
WESTERN CANADA AND THE NW CONUS UNTIL THE UPPER TROUGH ACROSS THE
NORTHERN ROCKIES EJECTS OUT INTO THE PLAINS. THIS IS FORECAST TO
OCCUR SLOWER THAN FORECAST YESTERDAY AND THUS THE COLD FRONT LOOKS
ABOUT 12 HOURS SLOWER AS WELL. THIS WILL PUT THE FRONT INTO NORTH
TEXAS THURSDAY MORNING...WITH HIGHS OCCURRING IN THE MORNING AND
TEMPERATURES FALLING INTO THE 40S DURING THE DAY. THE FRONTAL
PASSAGE WILL BETTER COINCIDE WITH LIFT FROM THE UPPER TROUGH AND
THUS THE CHANCE OF RAIN ALSO LOOKS BETTER ALONG AND JUST BEHIND
THE FRONT THURSDAY.

SKIES SHOULD CLEAR FROM NW TO SE THURSDAY EVENING WITH COLD
ADVECTION CONTINUING INTO THE NIGHT. RADIATIONAL COOLING WILL BE
LIMITED A BIT BY CONTINUING NORTHERLY WINDS...BUT STILL TEMPS ARE
EXPECTED TO REACH THE MID 20S TO LOWER 30S ACROSS THE AREA BY
FRIDAY MORNING. BETTER RADIATIONAL COOLING WILL OCCUR FRIDAY
NIGHT. RAPID MODIFICATION OF THE AIR MASS OCCURS BY NEXT WEEKEND
THANKS TO THE INCREASINGLY PROGRESSIVE UPPER LEVEL PATTERN.


San Angelo...

.LONG TERM...
UPPER LEVEL WEST-SOUTHWEST FLOW WILL BRING DRY WEATHER AND ABOVE
NORMAL TEMPERATURES THROUGH MIDDLE OF THIS WEEK. HIGHS WILL MAINLY
BE IN THE 70S...WITH LOWS IN THE 40S AND 50S...LOWER 60S SOUTHEAST
CWFA WEDNESDAY MORNING. LOOKS LIKE MAJOR CHANGE IN STORE LATE THIS
WEEK AS FIRST ARCTIC AIRMASS OF THE SEASON ARRIVES. CURRENT
NORTH AMERICAN SURFACE MAP INDICATES AN ARCTIC AIRMASS ACROSS THE
NORTHWEST TERR WITH TEMPERATURES OF -15 TO -25. THIS VERY COLD AIR
WILL MOVE SOUTH INTO THE NORTHERN ROCKIES AND NORTHERN PLAINS FOR
THE FIRST PART OF THIS WEEK...AND THEN BLAST SOUTH ACROSS THE
CENTRAL AND SOUTHERN PLAINS WEDNESDAY AND THURSDAY...WITH THE HELP
OF A STRONG UPPER LEVEL SHORT WAVE TROF MOVING ACROSS THE CENTRAL
US. THE GFS AND ECMWF MODELS HAVE BACKED OFF A DAY ON MOVING THE
COLD AIR INTO WEST CENTRAL TEXAS. THE ARCTIC FRONT WILL ARRIVE IN
THE TEXAS PANHANDLE WEDNESDAY EVENING...AND BE LOCATED ACROSS
SOUTH AND SOUTHEAST TEXAS THURSDAY MORNING. EXPECT GUSTY NORTH
WINDS BEHIND THE FRONT LATE WEDNESDAY NIGHT AND THURSDAY. NO DOUBT
THE AIRMASS WILL BE MODIFIED SOME...HOWEVER COLDER TEMPERATURES
ARE EXPECTED...WITH HIGHS THANKSGIVING DAY IN THE 40S ACROSS THE
BIG COUNTY TO THE LOWER 60S ALONG THE I-10 CORRIDOR. THE COLDEST
TEMPERATURES WILL BE THURSDAY NIGHT AND FRIDAY NIGHT...WITH LOWS
IN THE UPPER TEENS AND 20S. A FEW SHOWERS WILL BE POSSIBLE ACROSS
THE HEARTLAND AND NORTHWEST HILL COUNTRY ON WEDNESDAY.


Austin/San Antonio...

THE THANKSGIVING DAY FRONT IS EXPECTED TO HAVE VERY LITTLE
MODIFICATION FROM THE CANADIAN ORIGIN...MEANING THE COLDEST AIR SO
FAR THIS SEASON AND VERY DRY DEW POINTS. SOME LIGHT OVERRUNNING
MOISTURE AND CLOUDS ARE POSSIBLE...BUT THE MOISTURE AND CLOUDS
WERE TONED DOWN SLIGHTLY FROM WHAT THE GFS BASED GUIDANCE HAD.
COOL AND DRY WEATHER SHOULD CONTINUE THROUGH SATURDAY NIGHT...WITH
POSSIBLY A RETURN OF GULF MOISTURE AND DRIZZLE FOR NEXT SUNDAY
MORNING.



Corpus Christi...

.LONG TERM (TUESDAY THROUGH SUNDAY)...CONCUR WITH THE GFS/ECMWF THAT
A SERIES OF DISTURBANCES WILL MOVE ACROSS THE PLAINS EARLY IN THE
PERIOD WITH A MAJOR UPPER TROUGH MOVG ACRS THE PLAINS THURSDAY/
FRIDAY. THIS TROUGH WILL ALLOW VERY COLD AIR TO ENTER TEXAS. MUCH OF
THE POLAR AIR (BASED ON THE POLAR JET) WILL REMAIN NORTH OF CWA/MSA.
YET...SHALLOW (GFS THETA/THETA-E CROSS SECTIONS) COLD AIR WILL ENTER
THE CWA/MSA THURSDAY NIGHT. OWING TO INCREASING MSTR/INSTABILITY
AHEAD OF THE FRONT...WILL MAINTAIN PREVIOUS FCST OF SHOWERS FOR
TUESDAY/WEDNESDAY...THEN SHOWER/ISOLATED THUNDER ACTIVITY NEAR/ALONG
THE FRONT. AFTER FROPA...MUCH COLDER CONDITIONS EXPECTED WITH SCA
(POSSIBLY GALE) CONDITIONS OVER THE WATERS. OWING TO THE VERTICAL
EXTENT OF THE FRONT...AND BASED ON GFS/ECMWF ISENTROPIC
PATTERN...ANTICIPATE ISENTROPIC LIFT OVER THE CWA/MSA...ESPECIALLY
BY SATURDAY AND CONTINUING SUNDAY. WILL RETAIN FCST OF LIGHT
STRATIFORM RAIN OVER PORTIONS OF THE AREA FRIDAY. YET WILL NOT
INTRODUCE PCPN SATURDAY/SUNDAY OWING TO UNCERTAINTY REGARDING
CONDENSATION PRESSURE DEFICITS. COLDEST MIN TEMPS EXPECTED SATURDAY
WITH READINGS IN THE 30S OVER MUCH OF THE CWA. LOWERED MAX TEMPS
SATURDAY/SUNDAY OWING TO THE EXPECTATION OF COLD AIR TRAPPED UNDER
FRONTAL INVERSION/MOSTLY CLOUDY SKIES.



Brownsville...

.LONG TERM /6 AM TUESDAY THROUGH SUNDAY/...
THE PERIOD WILL BEGIN WITH WARMTH MORE TYPICAL OF SEPTEMBER AND
EARLY OCTOBER THAN MID NOVEMBER...BUT END WITH SHARPLY COLDER
TEMPERATURES AS THE WELL ADVERTISED COLD FRONT IS NOW COMING INTO
FOCUS IN THE DAY 4/5 PERIOD. RESIDENTS WITH THANKSGIVING WEEKEND
PLANS WILL NEED A VARIETY OF CLOTHING TO COVER EVERYTHING FROM
SUMMER LIKE HEAT TO WINTER LIKE WIND CHILL.

FOR TUESDAY...DEEP SOUTH TEXAS WILL SEE A SLIGHT REPRIEVE IN THE
WINDY CONDITIONS AS SURFACE TROUGH/FRONT WELL TO OUR NORTH SHIFTS
TOWARD THE OHIO VALLEY AND EASTERN SEABOARD...LEAVING A WEAKER
PRESSURE GRADIENT IN PLACE. THE MORNING WILL DAWN OVERCAST...AND
THE LIGHTER WINDS ESPECIALLY ACROSS THE BRUSH COUNTRY THROUGH THE
KING RANCH MAY ALLOW THE CEILING TO FALL BELOW 400 FEET...CAUSING
PATCHY `FUZZY` FOG IN THESE AREAS. THE CLOUD COVER WILL CONTINUE
THE WARM TEMPERATURES BUT MORNING RISES WILL BE LESS THAN THOSE
TODAY AND MONDAY.

BY AFTERNOON...CONSIDERABLE CLOUDS WILL REMAIN IN MANY
AREAS...WITH SOME PARTIAL SUNSHINE FROM WESTERN HIDALGO/BROOKS
COUNTY TO THE RIO GRANDE PLAINS. MODEL SOUNDINGS ACROSS THE LOWER
VALLEY SHOW ONLY A FEW BREAKS IN THE AFTERNOON SO EXPECT
TEMPERATURES TO BE A HAIR LOWER THAN ON MONDAY IN ALL AREAS.

THE REPRIEVE FROM THE WIND ENDS QUICKLY TUESDAY NIGHT AS LOW LEVEL
JET REDEVELOPS WITH THE APPROACH OF AN EVEN STRONGER TROUGH INTO
THE GREAT PLAINS AS MICRO-RIDGE ALOFT SLIDES EAST AND
SOUTHWESTERLY FLOW FROM THE GREAT BASIN NORTHEAST TO TEH UPPER
MISSISSIPPI VALLEY AIDS SURFACE DEVELOPMENT. THE WINDS AND
REMAINING CLOUD COVER WILL BRING ANOTHER WARM NIGHT AS LOWS LIKELY
STAY ABOVE 70 FOR ALL BUT THE BRUSH COUNTRY.

WINDY AND VERY WARM WEDNESDAY AS 1003 MB LOW IN THE LEE OF THE
SIERRA MADRE FOCUSES THE STRONG SOUTHERLIES. MAY GET CLOSE TO
TOUCHING WIND ADVISORY CONDITIONS...BUT FOR NOW HAVE CAPPED AT 24
KNOTS BETWEN 18 AND 21Z. 1000-500 MB THICKNESSES REACHING 579
DECAMETERS COMBINED WITH INCREASING SUNSHINE AS DRIER AIR ALLOWED
TO MIX THROUGH THE COLUMN AND HIGH TEMPERATURE RECORDS MAY BE
THREATENED IN A NUMBER OF LOCATIONS. FOR NOW HAVE CAPPED AT 90 IN
THE WESTERN LOWER VALLEY...MID TO UPPER 80S ELSEWHERE.

WEDNESDAY NIGHT MAY BE THE WARMEST OF ALL IN THE LOWER VALLEY WITH
A WARM STARTING POINT AND CONTINUED MIXING IN PERSISTENT GRADIENT
NEAR THE COAST. BECOMING MORE CONFIDENT FOR GREAT OUTDOOR
THANKSGIVING WITH WINDS BEGINNING TO DROP JUST A LITTLE AS TROUGH
AXIS SLIDES ACROSS THE REGION WITH A GOOD DEAL OF SUNSHINE FOR
MUCH OF THE DAY AFTER PERHAPS STRATUS REFORMING EARLY. HAVE RAISED
TEMPERATURES TO NEAR 90 ONCE AGAIN...AND IT COULD BE HOTTER STILL
THOUGH LATE NOVEMBER SUN ANGLE SHOULD MITIGATE TOO MUCH HEATING
DESPITE REGION BEING IN THE WARMEST ZONE IN THE COLL AHEAD OF THE FRONT.

GFS AND ECMWF IN GOOD AGREEMENT WITH STRONG COLD...YES
COLD...FRONT SWEEPING FROM NORTH TO SOUTH ACROSS DEEP SOUTH TEXAS
BETWEEN MIDNIGHT AND 3 OR 4 AM. OF COURSE THAT TIMING WILL LIKELY
CHANGE A LITTLE OVER THE NEXT THREE DAYS...BUT CONFIDENCE
INCREASING BASED ON OTHER MODEL SOLUTIONS AS WELL INCLUDING THE
CANADIAN GEM AND NOGAPS. GFS RAW 2 M TEMPERATURES PLUMMET
PRODIGIOUSLY BY DAYBREAK...AND COMBINED WITH 15 TO 25 MPH WINDS IT
WILL FEEL LIKE 35 TO 40 IN MANY AREAS TO BEGIN `BLACK FRIDAY`.

AS FOR THAT DAY ITSELF...ANY LIGHT SHOWERS UNDER LOW CLOUDS WILL
QUICKLY END BUT CEILINGS WILL CONTINUE FOR THE BALANCE OF THE DAY
SOUTH/EAST WITH SOME CLEARING NORTH AND WEST BEFORE SUNSET. RAW
GFS TEMPERATURES REMAIN IN THE 40S TO LOW 50S...AND IF CLOUDS ONLY
LIFT RATHER THAN DISSIPATE THESE COULD BE VERY CLOSE TO DAYTIME
HIGHS. FOR NOW...HAVE JUST NUDGED VALUES INTO THE MID AND UPPER
50S SOUTHEAST AND RISEN FROM THE LOWER 40S INTO THE LOWER 50S
ELSEWHERE. HIGHS WILL LIKELY OCCUR BETWEEN MIDNIGHT AND DAYBREAK.

AS THE UPPER TROUGH ASSISTING THE FRONT SWINGS EAST...LOW AND MID
LEVEL FLOW REMAINS NORTH TO WEST BEFORE 850-700 MB FLOW GOES
VARIABLE AND EVENTUALLY MORE EASTERLY (850) INTO SATURDAY. ONCE
AGAIN...THIS SIGNIFIES ANOTHER RELATIVELY DRY FRONTAL PASSAGE WITH
QUICK CLEARING BEHIND IT ESPECIALLY NORTH OF THE VALLEY. DEW
POINTS WILL FALL INTO THE 20S AND 30S FRIDAY...SO ANY LIGHT RAIN
WILL QUICKLY DRY UP.

A CHILLY NIGHT FRIDAY NIGHT AS THE HIGH SETTLES IN. GFS/ECMWF
HINTING AT SOME MID AND HIGH CLOUDS BUT SHOULDN`T BE ENOUGH TO
KEEP TEMPERATURES FROM FALLING TO SOME OF THEIR LOWEST READINGS OF
THE SEASON SATURDAY MORNING.

CONDITIONS RECOVER OVER THE WEEKEND...THOUGH SATURDAY MAY REMAIN
COOL-ISH ESPECIALLY IF AFTERNOON CLOUDS ARRIVE UNDERNEATH THE
INVERSION. SUNDAY LOOKS NOW LIKE A CLEAN FINISH TO THE
WEEKEND...THOUGH SUNSHINE WILL BE DIMMED BY IN AND OUT
STRATOCUMULUS AS SOUTHEAST FLOW RETURNS AND TEMPERATURES REBOUND
BACK TO SEASONAL LEVELS.

[weatherguy425]

NWS Coprus at least appears to be on the ball. They're forecasting several degrees cooler than surrounding offices.



Friday: A 20 percent chance of rain. Partly sunny, with a high near 54.

[wxman57]

Doesn't look like anything spectacular in terms of cold. Just a brief shot of cold air then warming up over the weekend. Another shot at the end of the month, though, could be colder.

[weatherguy425]

I'd still think though, that even with a cool airmass, when you add in clouds, light rain, along with a least decent CAA temps will probably struggle to break out of the 40's on friday.

[redneckweather]

Swinging with the models wherever they go wxman?

[biggerbyte]

Lol

So, the BIG chill is now no big deal? That is why I hate trying to forecast based on models. It is just pure madness. I told folks early on not pay much attention until Monday or Tuesday. Maybe the NWS were on to something???? The models were painting a delicious picture, but long range rarely can be trusted.

At any rate... Let's take a look at it Tuesday, shall we? Then we can get a lock on a temp forecast based on what IS actually happening, instead of what might be. Baring everything in fantasy land, we could get our first light freeze for a night, or maybe that first frost. Cold does not have to mean 20's. It seemed as if the high temps were what the NWS are struggling with, post frontal. We'll see if their reluctantness pays off, or are they all wet.

Again, more in a day or two. Can we keep the Brrrr for breakfast??

Stay tuned!!!!

[Mr. T]

Doesn't look like anything spectacular in terms of cold. Just a brief shot of cold air then warming up over the weekend. Another shot at the end of the month, though, could be colder.

Wait, I'm confused... Who was forecasting spectacular cold?

It's our first blue norther of the season. Of course there will be an uptick of discussion. Personally, I'm looking foward to watching the big temp drops behind the front on Turkey Day. That's always fun to watch. We'll likely see our first freeze of the season, too...

[Mr. T]

Back in 1922, the thermometer location was "downtown" Houston, I believe. The official Houston location was moved up north to Bush/IAH only in recent decades (IAH opened in 1969). Before then, Hobby airport on the south side was the official observation point (opened in 1927). The location of the official observation point has changed quite a bit over the past century

Hobby has never been the official observation spot for Houston. According to the NWS:

Cotton Station (July 1881 - September 1909)
Stewart Building at Preston and Fannin (September 1909 - February 1926)
Shell Building at Texas and Fannin (March 1926 - August 1938)
Federal Building at Franklin and Fannin (August 1938 - May 1969)
Intercontinental Airport (June 1969 - Present)


Also, I'd be willing to bet that the observation point in 1922 was probably a lot cooler than the current UHI-infested IAH location...

[extremeweatherguy]

Below is a comparison of the 12z ECMWF, 00z NAM and 00z GFS surface cold front locations for Thanksgiving morning...

12z ECMWF - valid 6am Thursday morning


00z GFS - valid 6am Thursday morning


00z NAM - valid 6am Thursday morning


The 12z ECMWF and 00z GFS are remarkably similar, while the 00z NAM looks way too slow.

please note that I have not posted all the fronts on the maps, only the cold front section that I have deemed most important to our weather across the southern plains.

[C2G]

Doesn't look like anything spectacular in terms of cold. Just a brief shot of cold air then warming up over the weekend. Another shot at the end of the month, though, could be colder.

Wait, I'm confused... Who was forecasting spectacular cold?

It's our first blue norther of the season. Of course there will be an uptick of discussion. Personally, I'm looking foward to watching the big temp drops behind the front on Turkey Day. That's always fun to watch. We'll likely see our first freeze of the season, too...

It's just a cold front, sheesh.
Not really that spectacular of one either.
Granted, it will be a dramatic departure from what we're experiencing now, but I'll have more fun watching footballs being caught and dropped on the tube Vs. the temperature.

[Mr. T]

It's just a cold front, sheesh.
Not really that spectacular of one either.
Granted, it will be a dramatic departure from what we're experiencing now, but I'll have more fun watching footballs being caught and dropped on the tube Vs. the temperature.

lolz troller be trollin' again

Why are you even on this forum?

It seems like nothing weather-wise excites you. You thought last winter was boring, you don't care about drastic shifts in temps... Why are you even here?

I know this may shock you -- shock you to the point of paralysis, like the really bad kind where you can't eat anything -- but people come onto a weather forum because they are interested in the weather. You'll see it all across the weather interwebs where people are posting their daily obs in threads. There may not be a couple of tornadoes outside damaging some random barn, but dammit that 73 degrees and sunny is still interesting to them. Why? Because it all revolves around the bigger weather picture. It's 73 degrees and sunny here for a reason... The pattern supporting that here is teleconnecting over there to a much more severe picture. Then the pattern begins to shift and here comes some active weather for us, and that 73 degrees we were experiencing here has moved on to some nice family in Florida. And so you look back at everything and you start to realize how patterns work. You begin to find it particularly interesting. Why it's sunny here, why it's snowing there, why there's a random thunderstorm over Lexington, KY. It's just all fascinating...

But you, oh no, you my friend do not see it this way. You don't really care about the weather. You don't really want to talk about it here like everyone else. You're that cool guy in the corner with his leather jacket and grossly overdosed gel hair wanting your EXTREME EXCITING OMGWTF fix, or else! "What? We've got a cold front comming in? Well who cares! I don't see no blizzard forecasted here so wgaf! I'm going down to McD for some Quarter Pounders to contribute to the obesity in this city."

This would be like someone going onto a sports forum after a team just won the Super Bowl and going "well gee guyz it's just a Super Bowl win whatevs not as exciting as [insert irrelevant event here]". You're like the Michael Bay of internet forums; If it's not raining 10 inches or a big blizzard then wgaf

And that is my opening statement.

[biggerbyte]

Good answer, T.


I too think that even simple weather events, especially during winter, are worth the time of a true weather fan.

[Mr. T]

Good answer, T.


I too think that even simple weather events, especially during winter, are worth the time of a true weather fan.

Thank you BB. That was my point... You've been here since the beginning and can definitely appreciate what we do here...

[ticka1]

I agree I love the weather and the changing. Like someone posted above live by the models die by the models. Whatever happens Thursday - I'll be watching the weather - enjoying time with family and posting here at KHOU. I hope its cold (brrrr) makes it feel like the holidays!!!

As with the post about a possible december 1st cold weather blast - its great to talk and discuss and watch each model run with anticipation but when it comes down to it - the actual event is the only thing that will happen!

Good Morning folks!!!

[wxman57]

Swinging with the models wherever they go wxman?

What do you mean? As the event draws near, it's easier to tell just what kind of airmass we'll be dealing with. My comment was to several posters here who are asking about the potential for freezing/frozen precipitation over Thanksgiving. That's not going to happen. There hasn't been any change in the model projections for temps over Thanksgiving. The only change is in the timing of arrival of the cold air. Projections last week had the cold air arriving Wednesday evening. Trend has been later, as late as late afternoon Thursday (ECMWF/Canadian). Current GFS has it arriving around 11AM Thursday. I can't really make an actual calculation of frontal passage until there's a clear boundary moving southward in OK and north Texas early on Wednesday. Having witnessed such frontal passages here in Houston since 1980, I know that most of the time the cold air arrives sooner than the models predict. But the timing does depend somewhat on how cold the air really is.

The less cold the airmass, the better the chance that it could arrive a bit later, waiting for more favorable upper air flow. As I look at the air over the Northern Plains and southern Alberta, it's cold but not nearly as cold as the Thanksgiving 1993 event that did produce freezing rain and sleet all across Texas to just north of Houston. This is heavily-modified early-season Canadian/Arctic air. Such an airmass can result in daytime highs under 50 degrees with clouds and strong cold advection. But if the cold air does hold off until Thursday afternoon, then Friday's high will likely be in the low-mid 50s because the cold air advection won't be as strong 24 hours after FROPA.

The latest GFS doesn't look unreasonable for temps Thu/Fri - assuming it has the frontal passage at the right time (near 11AM Thursday).

[srainhoutx]

lol, Good Morning Folks. So where's this Arctic Air that all the chatter has been about? Let's look up in Canada. IR Imagery is showing the dense Arctic Air spilling S now into Western Canada...



A storm system is taking shape near British Colombia heading S along the Pacific NW and will swing into the Intermountain West today into tomorrow bringing the cold Arctic lobe S. Temps are expected to be in the -20's along with wind-chill indices in the -30 to -40 range in Great Fall, MT. Now that is some mighty cold air. When will that modified air get here? I suspect that when we wake up on Thanksgiving morning that cold air will already be well into TX nearing the northern reaches of SE TX late morning/mid day and off the Coast by early evening. What will be the old shock to the system will be the rapid drop in temps. When we have been in the 80’s for high temps and upper 60’s for lows, a 20+ degree drop in an hour or so will likely occur. While this was never expected to be the coldest air we’ve seen in our area, it is a pretty big change. Heck, we haven’t seen a blue norther like this in a while. So enjoy the warmth of the early week and the weather change there after.