TX/LA summer coming to abrupt end

[Extremeweatherguy]

I do not wish for the bitter cold and the windchills

I do. Is that bad?

no it's not bad. I actually like them too for a day or two, I just don't like when you get a prolonged period of cold combined with wind. It starts to get a little too cold (especially if there is no snow) after more than 1-2 days.

[arizonasooner]

I'll take responsibility for the cold snap when it occurs.

I overseeded my lawn last Saturday, as the 7-day forecast at that time had us in the 90s here in Tulsa for a week or so.

Wrong.

That seed better germinate in the next few days or I will have sent about 100 bucks down the proverbial drain....

[Extremeweatherguy]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
338 AM CDT FRI OCT 6 2006

.DISCUSSION...
BACKDOOR COOL FRONT WILL BE MOVING THRU SE TX TODAY BRINGING IN A
DRIER AIRMASS IN ITS WAKE. SHOULD BE A NICE WEEKEND WITH LOW
DEWPOINTS AND A MID/UPPER RIDGE ANCHORED OVERHEAD PROVIDING MSUNNY
SKIES. ONSHORE WINDS SHOULD RESUME ON TUES...ABOUT THE SAME TIME AS
THE MID/UPPER PATTERN TRANSITIONS INTO A MORE ZONAL TO SW FLOW
ALOFT. GFS DEPICTING SEVERAL EMBEDDED IMPULSES WITHIN THE UPPER FLOW
TUE-THU PROVIDING THE AREA WITH A CHANCE OF RAIN. MAINTAINED THE
LOWER END POPS ALREADY IN THE FCST DURING THIS TIME PERIOD UNTIL
TIMING OF THESE IMPULSES CAN BECOME BETTER ESTABLISHED. ECMWF & GFS
BOTH IN PRETTY GOOD AGREEMENT BRINGING A STRONG FRONT INTO THE AREA
LATE NEXT WEEK. BEST GUESTIMATE AT THIS POINT IS SOMETIME BETWEEN
THU AFTN AND FRI MORNING. THOUGH IT`S TOO FAR OUT FOR THIS MORNING`S
FCST PACKAGE...00Z MEX TEMPS COULD BE SEVERAL CATEGORIES TOO HIGH
BEGINNING NEXT THU NIGHT SHOULD THE CURRENT FRONTAL TIMING/STRENGTH
PERSIST. SOMETHING THAT WILL NEED TO BE ADDRESSED IN THE AFTERNOON
PACKAGE...

[Janie2006]

The forecast offices this far south and east (New Orleans, Jackson, and Mobile) aren't quite ready to jump on this scenario yet. The most I'm getting from them right now is an increased POPs rate.

I think Mobile and New Orleans are generally rather reluctant to go with really cool temps this early in October, given climatology. However, the model runs have been consistent and we have agreement among three major models. I want some of that nice cool air too!

[Johnny]

Jeff had a great discusion on the possibilities of a very strong front pushing through our area by the middle or end of next week. I hope you don't mind me posting this Jeff.



Extended:



Big news this morning is potential unleashing of an unseasonably cold air mass into the US via NW Canada around the early part of next week and its arrival in TX around the middle to end of next week. Hudson Bay polar vortex will pivot SSW and be located over the western Great Lakes by the middle of next week with strong energy in the polar jet driving southward along the front range of the Rockies . Low level highly modified arctic air mass will gather over Canada and then sweep southward under favorable upper air pattern for intrusion into the US . Strong cold front is forecast to reach TX early Thursday and plow SE across the state…but slowing with time as the upper air pattern over this part of North America is more from the SW. Forecasted 850mb isotherms and thickness values support a quite cold air mass entering the state Thursday and arriving into SE TX late Thursday or early Friday…with possible P-type issues in the post frontal air mass over NW TX Thursday night. Current guidance is likely as much as 10-15 degrees too warm given the pattern setup and the potential for overrunning clouds post front. This air mass could provide the first killing freeze across portions of N and W TX and I carefully say highs may not get out of the 50’s as far south as College Station and Austin behind this front.



Of course we are talking about the extended and the 06Z run of the GFS compared to the 00Z run is already suggesting the brunt of the cold air may pass to the east and northeast of TX. We shall see what the next 2-4 days of guidance suggest before fully biting on this potential cold snap.

[gboudx]

This air mass could provide the first killing freeze across portions of N and W TX and I carefully say highs may not get out of the 50’s as far south as College Station and Austin behind this front.

My allergies hope this freeze comes true.

[cctxhurricanewatcher]

Jeff had a great discusion on the possibilities of a very strong front pushing through our area by the middle or end of next week. I hope you don't mind me posting this Jeff.



Extended:



Big news this morning is potential unleashing of an unseasonably cold air mass into the US via NW Canada around the early part of next week and its arrival in TX around the middle to end of next week. Hudson Bay polar vortex will pivot SSW and be located over the western Great Lakes by the middle of next week with strong energy in the polar jet driving southward along the front range of the Rockies . Low level highly modified arctic air mass will gather over Canada and then sweep southward under favorable upper air pattern for intrusion into the US . Strong cold front is forecast to reach TX early Thursday and plow SE across the state…but slowing with time as the upper air pattern over this part of North America is more from the SW. Forecasted 850mb isotherms and thickness values support a quite cold air mass entering the state Thursday and arriving into SE TX late Thursday or early Friday…with possible P-type issues in the post frontal air mass over NW TX Thursday night. Current guidance is likely as much as 10-15 degrees too warm given the pattern setup and the potential for overrunning clouds post front. This air mass could provide the first killing freeze across portions of N and W TX and I carefully say highs may not get out of the 50’s as far south as College Station and Austin behind this front.



Of course we are talking about the extended and the 06Z run of the GFS compared to the 00Z run is already suggesting the brunt of the cold air may pass to the east and northeast of TX. We shall see what the next 2-4 days of guidance suggest before fully biting on this potential cold snap.

What's Jeff's website or does he send an email ?

[cctxhurricanewatcher]

Could it be we MIGHT be seeing the opening shot of a cool to cold winter in Texas and the South. Could it be????????

[Extremeweatherguy]

The 12Z GFS looks frigid! Can you say frost all the way to north Houston!?

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _150.shtml

Seems like this is becoming a trend of the 0Z and 12Z runs now too.

[Extremeweatherguy]

Latest CPC day 6-10 map (even colder looking):

http://www.cpc.noaa.gov/products/predic ... .small.gif

They also now continue to keep it cold into days 8-14:

http://www.cpc.noaa.gov/products/predic ... .small.gif

[gboudx]

Snippet from the afternoon DFW NWS AFD:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
338 PM CDT FRI OCT 6 2006

.DISCUSSION...
THE NEXT 7 DAYS WILL BE INTERESTING...AS WE WILL EXPERIENCE
SEVERAL MAJOR CHANGES IN THE WEATHER. THERE ARE TWO WEATHER
SYSTEMS THAT WILL EFFECT THE NORTH TEXAS AREA.

THE FIRST WILL BE A SHORT PERIOD OF SPLIT FLOW IN THE
WESTERLIES...AS AN UPPER LEVEL TROUGH (STORM SYSTEM) MOVES ACROSS
THE AREA...AFFECTING US MAINLY ON TUESDAY AND WEDNESDAY. THE UPPER
LEVEL DISTURBANCE WILL RESULT IN SEVERAL ROUNDS OF SHOWERS AND
THUNDERSTORMS...AS THE DISTURBANCE MOVES ACROSS WARM...MOIST GULF
AIR POOLING NEAR A STATIONARY FRONT. WE HAVE INCREASED RAIN
CHANCES TO A MIXTURE OF 20...30...AND 40 PERCENT POPS...GIVEN THE
FAVORABLE PARAMETERS OF MOISTURE...LIFT...AND MODERATE INSTABILITIES ACROSS
NORTH TEXAS. THE FAVORABLE SPLIT FLOW WILL RESULT IN A MORE
"DIFLUENT" PATTERN ALOFT, A MORE FAVORABLE SET UP FOR RAINFALL
THAN WE HAVE SEEN LATELY.

THE SECOND EVENT WILL BE A RATHER POWERFUL COLD FRONT FOR THIS
TIME OF YEAR...MOST LIKELY MOVING INTO NORTH TEXAS LATE WEDNESDAY.
THE COLD AIR MASS DOES NOT LOOK QUITE AS IMPOSING AT IT DID 24
HOURS AGO...BUT IT STILL APPEARS THAT WE WILL SEE SOME 40 DEGREE
LOWS...AND HIGHS IN THE UPPER 50S AND 60S FOR SEVERAL DAYS. ANY
PRECIPITATION THAT OCCURS WITH THE FRONT WILL BE MINIMAL...AS THE
RAIN BEARING SYSTEM EARLIER IN THE WEEK WILL HAVE CONSUMED MUCH OF
THE AVAILABLE MOISTURE.

[Extremeweatherguy]

how doesn't it look as impressive as 24 hrs. ago I wonder? The 12Z model run looked like one of the coldest yet.

[double D]

If we can get some post-frontal clouds to hang around and strong northerly winds, it could feel pretty winter like for Thursday and possibly Friday.

[gboudx]

how doesn't it look as impressive as 24 hrs. ago I wonder? The 12Z model run looked like one of the coldest yet.

I don't know, but maybe it was looking like highs in the 50's mostly.

My parents are coming up from New Orleans to visit next Wed. I better tell them to bring some warm clothes along with the Abita Root Beer they're bringing.

[Extremeweatherguy]

If we can get some post-frontal clouds to hang around and strong northerly winds, it could feel pretty winter like for Thursday and possibly Friday.

That's what i'm thinking too. Clouds (in this case) could mean possibly a 10F difference in high temps.

[Extremeweatherguy]

I just posted this in the Houston weather thread, but this is crazy enough that I am going to post it here too:

WOW! The 00Z GFS is now rolling in, and at hr. 126 it is EXTREMELY cold! In fact, this is the coldest I have seen it yet. If this verifies...we could be looking at a historic mid October cold event.

hr. 126 (day 6): http://www.nco.ncep.noaa.gov/pmb/nwprod ... _126.shtml

It even has winter precip falling in parts of the TX panhandle and northern TX!

Then, at hour 138, it has the 0C 850 line all the way south into parts of NE and even SE Texas:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _138.shtml

[Yankeegirl]

Ill take it, I am going to the Airshow on Sat or Sun the 21 or 22 (which ever day is nicer) ..I dont think I can remember a time when its been cool... I always come back with a sunburn and sunglass lines... Bring it on, I hope it keeps the pattern and makes for a cool airshow!! the Thunderbirds are going to be there!!

[Janie2006]

My local WSFOs are finally taking the bait this morning concerning this cool (maybe downright cold?) wx event. The pieces of the puzzle are nearly in place. New Orleans offers a good discussion this morning:

TO SEE WHAT WILL BE THE NEXT WX MAKER WE NEED TO LOOK TOWARD THE
ASIAN CONTINENT. A COUPLING JET IS BEGINNING TO CAUSE WINDS TO
SCREAM AT ABOUT 160KT AT JET LEVEL ~300MB AS THEY MOVE AWAY FROM
THE EASTERN ASIAN CONTINENT OUT OVER THE WESTERN PACIFIC. THIS
CAN BE SEEN VERY WELL IN WATER VAPOR LOOPS. THESE WINDS ARE
CURRENTLY MOVING TO THE SOUTH SIDE OF A WEAK UPPER TROUGH OVER THE
WESTERN PAC. EVENTUALLY THESE STRONG JET WINDS WILL MOVE NORTHWARD
CAUSING A RIDGE TO EXTEND AND AMPLIFY ALL THE WAY TO THE NORTH
POLE...WOW. THIS CAN ONLY MEAN ONE THING...THE DOWNSTREAM REACTION
TO THIS WILL BE TO AMPLIFY AN UPPER TROUGH OVER THE CENTRAL NORTH
AMERICAN CONTINENT. AS THESE STRONG JET WINDS TOP THE RIDGE MON
EVENING THEY WILL BEGIN TO MOVE VERY QUICKLY DOWN THE BACK SIDE OF
THE AMPLIFYING UPPER TROUGH IN CANADA CAUSING THE TROUGH TO DIG
SOUTHWARD VERY FAST. JUST HOW FAST WILL IT BE...WHEN WE GO TO BED
WED EVENING THE CANADIAN COLD FRONT WILL BE OVER NW ARKANSAS. BY
THE TIME WE WAKE UP THU MORNING IT WILL BE IN THE GULF WITH NW
WINDS SCREAMING TO THE TUNE OF 20 TO 25 MPH OVER LAND AND PROBABLY
CLOSE TO GALE OVER THE COASTAL WATERS. THE POLAR FRONT MOVES SO
FAST TO THE SE THAT THE AIR WILL NOT BE ABLE TO MODIFY ENOUGH TO
KEEP COLD AIR FROM SPILLING ACROSS THE REGION. ALL IN ALL...WE ARE
GOING TO FEEL THIS ONE. LOWS MAY BOTTOM OUT IN THE LOW 40S WITH A
FEW UPPER 30S NOT OUT OF THE QUESTION AS WINDS DIE DOWN THOWARD
THE LATER PART OF THE WEEK.

Nice, no? On the other hand, it appears that a severe wx situation may set up, depending on exactly where the greatest lift as well as moisture flow occurs. It "bears watching".

Edited to add: The discussion is nicely illustrative of a "real-time" wx event (an early season "blocking" pattern) that is often refered to in meteorology textbooks. This front is a fall classic.

[Extremeweatherguy]

Houston was forecasting a low of 55F Thursday night as of yesterday...this morning they have dropped it to 44F!!!! Seems like they are starting to take the bait too! Also, they lowered the high from 78F to 72F for Thursday...and this may only be the beginning.

[Portastorm]

Right now, our Austin/San Antonio NWS guys have us with a high on Thurs in the upper 60s. We'll probably see lows here in the metro area Thurs night/Fri morn in the upper 40s ... and Hill Country will see lower 40s.

We should probably wait another few model runs before getting too hitched to these temps though. The 6z run of the GFS today (Sat) looks a bit warmer. Not much, but a bit.

Regardless the front is coming and summer will end for us in Texas.