SE TX/SW LA weather: Much cooler and WET after Tuesday

[Ed Mahmoud]

15Z RUC sounding still predicts a cap, but extreme mid-level instability, and some speed shear in the unstable layer. Looks like a potential hail sounding, for any cells that can break the cap.


Only thing is, RUC suggests storms will be very isolated.

[Ed Mahmoud]

Yeah and the dryline is still WAY west of here...

The dryline doesn't seem to sharp yet. Low 40s dewpoints and Southwest winds just West of DFW.

Moderate sunshine here through a solid mid-deck overcast, with scattered low clouds around

[jasons2k]

You are right, it has been diffuse most of the day but it is sharpening now quite a bit. Dewpoint in Sweetwater is down to 9F with a relative humidity of 7%. Brownwood still has a DP of 50F.

Now, if we could just get rid of these pesky high clouds we'd have a setup.

[Ed Mahmoud]

You are right, it has been diffuse most of the day but it is sharpening now quite a bit. Dewpoint in Sweetwater is down to 9F with a relative humidity of 7%. Brownwood still has a DP of 50F.

Now, if we could just get rid of these pesky high clouds we'd have a setup.

Thicker cloud cover now than this morning. Local radars showing some light returns, probably high level stuff. I'm starting to think 'very isolated' will be the word of the day around here...

[jasons2k]

Not looking too promising with all the clouds. Oh well, I'll take 87 degrees in March though!

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
318 PM CDT THU MAR 13 2008

.DISCUSSION...
A PROGRESSIVE FLOW PATTERN ALOFT WILL CHANGE AS A LOW PRESSURE
TROUGH FORMS OVER THE SOUTHWESTERN STATES OVER THE WEEKEND. AFTER
A CHANCE OF RAIN EARLY THIS EVENING...A CAP WILL KEEP RAIN CHANCES
DOWN FRIDAY INTO THE WEEKEND AS A DOWNSTREAM RIDGE FORMS AHEAD OF
THE SOUTHWESTERN SYSTEM. TEMPERATURES BEGINNING FRIDAY INTO SUNDAY
WILL BE ABOVE NORMAL AS A RESULT. SUNDAY NIGHT AND MONDAY THE
UPPER TROUGH WILL BEGIN MOVING OVER NORTHERN MEXICO INTO WESTERN
TEXAS AND HELP TO BRING MORE MOISTURE AND COOLER TEMPERATURES
ALOFT OVER SE TX. LATE MONDAY INTO TUESDAY LOOKS TO BE A STORMY
WEATHER PERIOD WITH TUESDAY POSSIBLY SETTING UP FOR STRONG STORMS.

IN THE SHORT TERM...THE SHORTWAVE TROUGH WAS PUSHING TOWARD SE TX.
THE CAP HAS APPEARED TO BE RATHER DIFFICULT TO OVERCOME AS THE
CLOUD DECK HAS KEPT THE HEATING DOWN. WILL KEEP THE ISOLATED TO
SCATTERED POPS IN PLACE DUE TO THE INCREASING INSTABILITY AND
MOISTURE LEVELS. HOWEVER...RAIN CHANCES WILL DECREASE DURING THE
EARLY EVENING.

OTHERWISE...TEMPERATURES ARE THE MAIN CONCERN ON FRIDAY. 850 MB
TEMPERATURES WILL BE WARMING TO OR JUST ABOVE 20 CELSIUS ALONG
SOUTHWESTERLY WINDS. THE RECORDS FOR FRIDAY AT THREE OF THE
CLIMATOLOGICAL SITES ARE...

KCLL...90 IN 1936
KIAH...86 IN 1936
KGLS...80 IN 1922

FOR NOW KIAH LOOKS TO BE THE RECORD IN JEOPARDY.

.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 59 87 60 80 54 / 10 10 10 0 0
HOUSTON (IAH) 61 87 61 85 55 / 20 10 10 0 0
GALVESTON (GLS) 64 77 66 75 63 / 20 10 10 0 0

[Ed Mahmoud]

I can see where the dryline is on satellite, and the GRK radar showed a shower or two trying to pop, but it looks like most/all the action stays in far NE Texas and points North and East.

[Ed Mahmoud]

Nothing in South Texas, except I think I see the bats moving out for the night West of San Antonio...

[KatDaddy]

We may not be so fortunate the next week as we have missed the severe weather outbreaks in SE TX. Here is an excerpt from this mornings Hou-Gal AFD. Rather ominous.

A
VIGOROUS UPPER LEVEL TROUGH WILL SWING THROUGH NRN CA SATURDAY AND
INTO ARIZONA SUNDAY AFTERNOON. THIS SHOULD BRING A STIFF EAST WIND
INTO THE COASTAL AREA ALONG WITH INCREASING MOISTURE. THIS STORM
SYSTEM BEGINS TO BEAR DOWN ON TX MONDAY AND SHOULD BRING A ROUND
OF SEVERE WEATHER TO THE REGION TUESDAY. GFS PROGGING VERY STRONG
WAA WITH WINDS FROM AROUND 925-800 MB AT 50 TO 65 KNOTS AND 70-80
KNOTS AT 500 MB. PW FORECAST TO RISE TO >1.65" WITH K INDICES ON
THE HIGH SIDE OF 35. 0-3KM HELICITIES OF OF 400-530 EARLY TUESDAY
MORNING TAPER DOWN TO AROUND 230 BY EARLY AFTERNOON AS FRONT
APPROACHES. CAPE MAY BE THE ISSUE BUT EVEN WITH MOIST WARM NOSE
THE UNMODIFIED GUIDANCE SHOWS CAPE OF 500-1100 ACROSS THE REGION.WOULD ANTICIPATE MODERATE TO HIGH RISK SHOULD CURRENT MODEL PROGS
WIN OUT. STAY TUNED IT IS GOING TO GET INTERESTING.

[Ed Mahmoud]

We may not be so fortunate the next week as we have missed the severe weather outbreaks in SE TX. Here is an excerpt from this mornings Hou-Gal AFD. Rather ominous.

A
VIGOROUS UPPER LEVEL TROUGH WILL SWING THROUGH NRN CA SATURDAY AND
INTO ARIZONA SUNDAY AFTERNOON. THIS SHOULD BRING A STIFF EAST WIND
INTO THE COASTAL AREA ALONG WITH INCREASING MOISTURE. THIS STORM
SYSTEM BEGINS TO BEAR DOWN ON TX MONDAY AND SHOULD BRING A ROUND
OF SEVERE WEATHER TO THE REGION TUESDAY. GFS PROGGING VERY STRONG
WAA WITH WINDS FROM AROUND 925-800 MB AT 50 TO 65 KNOTS AND 70-80
KNOTS AT 500 MB. PW FORECAST TO RISE TO >1.65" WITH K INDICES ON
THE HIGH SIDE OF 35. 0-3KM HELICITIES OF OF 400-530 EARLY TUESDAY
MORNING TAPER DOWN TO AROUND 230 BY EARLY AFTERNOON AS FRONT
APPROACHES. CAPE MAY BE THE ISSUE BUT EVEN WITH MOIST WARM NOSE
THE UNMODIFIED GUIDANCE SHOWS CAPE OF 500-1100 ACROSS THE REGION.WOULD ANTICIPATE MODERATE TO HIGH RISK SHOULD CURRENT MODEL PROGS
WIN OUT. STAY TUNED IT IS GOING TO GET INTERESTING.

I discuss the late Monday through Tuesday possibly big deal severe outbreak on this thread

[jasons2k]

Update from Jeff Lindner:

Near record to record highs forecast today.

Massive storm system early next week with high end severe probabilities possible.

Discussion:

Low clouds slow to burn off this morning under capping inversion. Dryline extends roughly from SW OK to near Del Rio and will mix eastward this afternoon reaching our western counties. Position of short wave over the southern plains will result in strong WSW to SW winds off the Sierra Madre of NE Mexico which is a hot wind for the state of TX. Will go with 100-105 Rio Grande plains and taper down to mid to upper 80’s across SE TX…although these numbers may be a tad high if the low clouds hang tough. Anyhow we will be nearing the record for the date at KIAH.

Weak front crosses the area Saturday swing winds to the N and then around to the E on Sunday under clear skies and mild temps. It will be a very nice weekend outside besides the pollen.

Early Next Week:

Will pay much attention to next storm system digging into the W coast and will drop into N Mexico this weekend. Powerful jet core develops and begins its assault on the state Monday of next week. Upper low becomes pinched off from the main low…but does not appear to completely cut-off. Regardless a very active weather period with severe weather highly likely across the southern plains given a very favorable set up. Models are progging tremendous wind energy at 850 and 925mb with low level jet howling at 50-70kts (ouch!). 500mb flow comes crashing in at 80-100kts with wind veering to the WSW atop of strong SSE winds at the surface….directional speed shear with height. Cold pool comes into the state along with strong lift and will combine with PWS at or above 1.60”…it all spells a rough go of things Monday night through Tuesday night. Surface low track is across C and N TX where tornado potential will be greatest and SE TX should be entirely warm sectored with surface boundaries to our N and E limiting the tornado threat. However given the model forecasted shear values and low level helicity values any storm that forms in the warm sector will be rotating in its updraft. An intense squall line looks likely Tuesday as surface cold front crosses the area. Given model guidance and decent agreement on the intensity of this system at least a moderate risk from SPC seems likely. Timing is still debatable given potential closing off even more of the upper low and this may spread rain chances into Wednesday. This system bears very close watch.

[jasons2k]

I wouldn't get too worried yet on this system until we get closer to it. It does look potent but the timing is suspect. Also, remember the last one was supposed to be the best setup "in years" -- the mother of all outbreaks -- and all we got was a few rain drops and a tree fell down halfway between here and Shreveport.

[jinftl]

right...each thunderstorm is probably not going to be part of one of the biggest severe weather outbreak in years...and it is not likely that every few weeks the set-up for such an event will take place....that said, weather can get nasty without making the record books!

I wouldn't get too worried yet on this system until we get closer to it. It does look potent but the timing is suspect. Also, remember the last one was supposed to be the best setup "in years" -- the mother of all outbreaks -- and all we got was a few rain drops and a tree fell down halfway between here and Shreveport.

[Ed Mahmoud]

right...each thunderstorm is probably not going to be part of one of the biggest severe weather outbreak in years...and it is not likely that every few weeks the set-up for such an event will take place....that said, weather can get nasty without making the record books!

I wouldn't get too worried yet on this system until we get closer to it. It does look potent but the timing is suspect. Also, remember the last one was supposed to be the best setup "in years" -- the mother of all outbreaks -- and all we got was a few rain drops and a tree fell down halfway between here and Shreveport.

I remember that. Forecast soundings in SE Texas had helicity values over 500 J/Kg and decent CAPE, all the models predicted action, TWC sent someone to College Station, then nothing much happened.

[jinftl]

I don't recall TWC sending crews to cover severe weather events like that one too often...they always have the winter storms and tropical events covered, but was this one of the first times they sent crews to cover a potential severe storms event?

right...each thunderstorm is probably not going to be part of one of the biggest severe weather outbreak in years...and it is not likely that every few weeks the set-up for such an event will take place....that said, weather can get nasty without making the record books!

I wouldn't get too worried yet on this system until we get closer to it. It does look potent but the timing is suspect. Also, remember the last one was supposed to be the best setup "in years" -- the mother of all outbreaks -- and all we got was a few rain drops and a tree fell down halfway between here and Shreveport.

I remember that. Forecast soundings in SE Texas had helicity values over 500 J/Kg and decent CAPE, all the models predicted action, TWC sent someone to College Station, then nothing much happened.

[Ed Mahmoud]

Mike Seidl was in College Station, and the cap never broke in the warm sector. I remember it well...

[KatDaddy]

TUESDAY...SEVERE WEATHER. THE MAIN ACTION SHOULD BE EARLY TUESDAY
MORNING THROUGH THE EARLY EVENING HOURS. ON TUESDAY 130 KNOT SSW
UPPER JET WILL CONTINUE TO DRAG IN LL MOISTURE WITH NEAR RECORD
SETTING PW CURRENTLY BEING FORECAST BY BOTH GFS/NAM AT 1.95" FOR
MARCH. THE BIG ISSUE WILL BE THE SEVERE WEATHER THREAT AS THE
EXTREME LL WINDS THAT VEER WITH HEIGHT YIELD UP HELICITY VALUES
500-700M2/S2!!! INSTABILITY WILL BE PRESENT WITH CAPE RUNNING 500
TO 1800 J/KG AND NO CAP. THIS LOOKS LIKE AN OUTBREAK AND HAVE
ALREADY BEGUN THE MENTION OF SEVERE TUESDAY 06Z THROUGH TUESDAY
EVENING. I DONT THINK I AM GOING OUT ON LIMB TO SAY THIS MAY BE
SIGNIFICANT TORNADO OUTBREAK FOR TX...SETX...AND POINTS EAST. WILL
TRY TO DO A SPECIAL WEBCAST BRIEFING LATER THIS MORNING THAT WILL
RUN ON THE HGX WEB FRONT PAGE.

[KatDaddy]

Hou-Galv NWS Briefing

http://www.srh.noaa.gov/hgx/briefing/HGXbriefing.php

[Ed Mahmoud]

TUESDAY...SEVERE WEATHER. THE MAIN ACTION SHOULD BE EARLY TUESDAY
MORNING THROUGH THE EARLY EVENING HOURS. ON TUESDAY 130 KNOT SSW
UPPER JET WILL CONTINUE TO DRAG IN LL MOISTURE WITH NEAR RECORD
SETTING PW CURRENTLY BEING FORECAST BY BOTH GFS/NAM AT 1.95" FOR
MARCH. THE BIG ISSUE WILL BE THE SEVERE WEATHER THREAT AS THE
EXTREME LL WINDS THAT VEER WITH HEIGHT YIELD UP HELICITY VALUES
500-700M2/S2!!! INSTABILITY WILL BE PRESENT WITH CAPE RUNNING 500
TO 1800 J/KG AND NO CAP. THIS LOOKS LIKE AN OUTBREAK AND HAVE
ALREADY BEGUN THE MENTION OF SEVERE TUESDAY 06Z THROUGH TUESDAY
EVENING. I DONT THINK I AM GOING OUT ON LIMB TO SAY THIS MAY BE
SIGNIFICANT TORNADO OUTBREAK FOR TX...SETX...AND POINTS EAST. WILL
TRY TO DO A SPECIAL WEBCAST BRIEFING LATER THIS MORNING THAT WILL
RUN ON THE HGX WEB FRONT PAGE.

I call a discussion like that 'Weather Pr0n'.

[KatDaddy]

What a wonderful day! Setting at 90F with a dewpoint of 46F. A perfect day in my book. WXman57 would agree.

[JenBayles]

I hear ya KD. I took the time to heat up the pool on Friday, so yesterday was Splash Day. Absolutely fabulous weather. Now I'm wondering how badly my gardening efforts will get blown away on Tuesday...