SE Texas weather thread - Strong storms Sun/Mon

[gboudx]

JB is saying that a low will develop east of Brownsville and ride up the TX coast bringing high winds (to gale force) and heavy 4-8" rainfall to much of the NW Gulf coast. He said it may be similar to the situation back in May. Sounds like an interesting situation may be setting up for the end of the weekend.

This weekend? Man, I hope not. That would put a damper on the moisture flow into NTX from the GOM and limit our rainfall potential.

BTW, the DFW NWS gave this scenario a casual mention this morning, but completely blew it off due to the GFS being the only model showing it. They chalked it up to convective feedback issues. This afternoon's AFD makes no mention of this scenario and only mentions that we are expecting a lot of rain Sat night into Monday.

You guys need to keep the GOM door open for us.

[Ptarmigan]

JB is saying that a low will develop east of Brownsville and ride up the TX coast bringing high winds (to gale force) and heavy 4-8" rainfall to much of the NW Gulf coast. He said it may be similar to the situation back in May. Sounds like an interesting situation may be setting up for the end of the weekend.

Never heard of it. Nothing is mentioned of it at the local NWS office in Houston. It is suppose to rain though.

[Extremeweatherguy]

JB is saying that a low will develop east of Brownsville and ride up the TX coast bringing high winds (to gale force) and heavy 4-8" rainfall to much of the NW Gulf coast. He said it may be similar to the situation back in May. Sounds like an interesting situation may be setting up for the end of the weekend.

Never heard of it. Nothing is mentioned of it at the local NWS office in Houston. It is suppose to rain though.

It is discussed in the latest AFD:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
304 PM CDT FRI OCT 13 2006

.DISCUSSION...
LOW CLOUD COVER HAS ERODED OVER CENTRAL ZONES AND TO A LESSER
EXTENT OVER SE ZONES. DEWPOINTS RUNNING IN THE LOWER TO MID 40S
NORTHERN 2/3 OF CWFA AND MID 50S TO NEAR 60 ELSEWHERE. WARM FRONT
EXPECTED TO PUSH NORTH ACROSS CWFA SATURDAY NIGHT AND SUNDAY. PW
VALUES INDICATED BY BOTH GFS AND NAM TO INCREASE SIGNIFICANTLY ON
SUNDAY WITH VALUES AROUND 2.2 TO 2.4 INCHES. GFS IS NOW CLOSER TO
NAM`S SOLUTION BUT DIFFER ON TIMING OF UPPER LEVEL IMPULSES.
NONETHELESS...WE SHOULD HAVE A GOOD CHANCE OF RAIN SUNDAY WITH
WARM FRONT PUSHING THROUGH ALONG WITH INCREASING UPPER LEVEL LIFT.
IF GFS IS CORRECT...DEVELOPING SURFACE LOW OVER DEEP SOUTH TEXAS
WILL DEEPEN WHILE MOVING TO OUR REGION ON SUNDAY. THIS SCENARIO
MAY GIVE REGION HEAVY RAIN CHANCES. WE SHALL SEE WHAT LATER GFS
RUNS WILL INDICATE. NAM BRINGS UPPER LEVEL IMPULSE ON MONDAY
PROVIDING STRONG MID/UPPER LEVEL LIFT OVER CWFA. ON THING THE
MODELS AGREE ON IS THE HIGH PW VALUES FOR SUNDAY AND MONDAY.
ANYWAY...SATURDAY WILL BE A TRANSITION PERIOD WITH INCREASING
CLOUD COVER AS THE DAY PROGRESSES. GOOD RAIN CHANCES IN STORE
SUNDAY AND MONDAY. GFS INDICATE SOME DRYING NORTHERN ZONES TUESDAY
BUT STILL QUITE MOIST AT LOWER LEVELS SOUTHERN ZONES. OUR
CONFIDENCE IS ON THE LOW SIDE AFTER MONDAY DUE TO TIMING OF WEAK
UPPER LEVEL IMPULSES MOVING ACROSS WSW FLOW. NEXT COLD FRONT AS
PER GFS WILL BE ON THURSDAY. UPPER HIGH OVER GULF WILL FLATTEN
SOMEWHAT LATER NEXT WEEK. 37

[Extremeweatherguy]

Interesting things from the 18Z GFS:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_slp_048s.gif
^^The GFS shows a 1004mb low approaching Galveston next Sunday! looks impressive, and a windy and rainy time could be on the horizon!^^

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_slp_060s.gif
^^Low moves over Houston and then heads NE on Sunday evening.^^

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_slp_072s.gif
^^More rain and possible MCS on Monday!^^

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/fp0_144.shtml
^^Strongest front of the season could be on tap for next Thursday! ... first 40s (finally)?^^

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/fp0_168.shtml
^^Next Friday looks chilly.^^

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/fp0_264.shtml
^^Another strong front/rain event could be on the way for October 24th.^^

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/fp0_336.shtml
^^Things settle down, but still look nice by the end of the month.^^

Looks like an interesting 2 weeks of weather are ahead!

[Johnny]

^^The GFS shows a 1004mb low approaching Galveston next Sunday! looks impressive, and a windy and rainy time could be on the horizon!^^

You mean this Sunday?

[KatDaddy]

Yep

Even the TWC forecast for Houston-Galveston shows ESE 20-30MPH winds and 80% chance of thunderstorms Sunday..............We shall see.

[JenBayles]

Hey Jen,

Several things. The front is going to back-up on us as a warm front overnight and Saturday, allowing the gulf to open-up again. Also, the subtropical jet will be overhead pumping in moisture from the Pacific. Several disturbances in the jet will cause storms to form as they pass overhead. On top of that, moisture from two Pacific cyclones will get entrained in the jet overhead, just adding more fuel to the fire. Finally, mid or late next week another front approaches, continuing the chances for rain. So we basically have a succession of events that will keep us wet for awhile.

Hope this helps...

Yes! OK, now it's making some sense. I picked up on the front backing up but that was about it. Sounding more and more like I need to pull out the old canoe again for Sunday's recreation.

[JonathanBelles]

what do u mean by a Rouge Low?

[Extremeweatherguy]

what do u mean by a Rouge Low?

a strong low pressure system that can produce heavy rains and gusty winds but is not a tropical system (though they can at times become one). This one does not look like it will become tropical...but flooding rains, gusty winds, and strong storms are all possible if the scenario plays out for Sunday.

The system that was just off the mid Atlantic coast would also be considered a rouge low, as well as the system off the TX coast back in May.

[Extremeweatherguy]

It is already down to 59.9F on my thermometer and with mostly clear skies and light winds..I would expect to reach well below this afternoon's forecast low of 59F...probably down to 52-56F by tomorrow morning.

[double D]

It is already down to 59.9F on my thermometer and with mostly clear skies and light winds..I would expect to reach well below this afternoon's forecast low of 59F...probably down to 52-56F by tomorrow morning.

Enjoy while you can. It is 71 here in Fredericksburg with a dew point of 64. The NWS is forecasting a low of 57, but I doubt it will get below 63. The atmosphere continues to moisten up which is making our dewpoints rise.
It is kind of unusual that Houston would be cooler than the hill country, but I guess ya'll got more of the cool air than we did.

[Extremeweatherguy]

It is already down to 59.9F on my thermometer and with mostly clear skies and light winds..I would expect to reach well below this afternoon's forecast low of 59F...probably down to 52-56F by tomorrow morning.

Enjoy while you can. It is 71 here in Fredericksburg with a dew point of 64. The NWS is forecasting a low of 57, but I doubt it will get below 63. The atmosphere continues to moisten up which is making our dewpoints rise.
It is kind of unusual that Houston would be cooler than the hill country, but I guess ya'll got more of the cool air than we did.

yeah, I'm now down into the 57-58F range on my thermometer with Hooks airport down to 60F and Bush Intercontinental down to 61F.

Since the NWS is still calling for 59F, I have a feeling they will be busting big time tonight. They already have busted where I am, and it is only a matter of time before Bush and Hooks bust too (the forecast for Bush is 60F). Dewpoints in the area are still in the lower 50s as well, and with calm winds I see no reason why temps. should not still fall another 3-6F.

It is strange to see this area cooler than the Hill country though. That is not something you see very often. This will all change tomorrow though when we get back into the same temperature range again with increasing moisture like your seeing now.

[Extremeweatherguy]

latest 00Z GFS run continues to show a strong 1004mb low pressure system moving up the coast on Sunday:



Also, the 00Z run continues to bring a strong front through on Thursday:

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

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

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _162.shtml
^^Fri. afternoon^^

http://www.nco.ncep.noaa.gov/pmb/nwprod ... _174.shtml
^^Sat. morning^^

BTW, if this verifies, then that means some areas seeing lows in the 40s next Friday morning and then widespread lows in the 40s next Saturday morning.

[KatDaddy]

This mornings Houston-Galveston AFD



..HEAVY RAIN EVENT POSSIBLE SUNDAY THROUGH MONDAY...

YESTERDAY`S COLD FRONT HAS STALLED OVER THE CENTRAL GULF. THIS
BOUNDARY WILL RETURN NORTH AS A WARM FRONT LATER TODAY AND SERVE
AS A FOCUS FOR SHOWERS AND THUNDERSTORMS. GFS/NAM ARE IN BETTER
AGREEMENT WITH THE LARGE SCALE FEATURES BUT DIFFER IN THE MANY OF
THE DETAILS. BOTH MODELS PROG PW`S TO REACH 2.6 INCHES BY SUNDAY
AFTERNOON AND FOR THOSE OF YOU KEEPING SCORE AT HOME...THESE ARE
MAX VALUES FOR MID-OCTOBER. UPPER LEVEL WINDS WILL BECOME
INCREASINGLY DIVERGENT SUNDAY AFTERNOON. TOSS IN THE APPROACHING
WARM FRONT AND ALL THE INGREDIENTS ARE IN PLACE FOR HEAVY RAIN.
SPEAKING OF THE WARM FRONT...THERE SHOULD BE SIGNIFICANT SHEAR
AVAILABLE CLOSE TO THE FRONTAL BOUNDARY. HELICITIES ARE PROGGED TO
RANGE BETWEEN 200-400...SO SOME OF THE STORMS WILL PRODUCE WIND
DAMAGE AND TORNADOES. WILL MENTION SOME POSSIBLY SEVERE ON SUNDAY
AND ALSO LOCALLY HEAVY RAIN. THE ONE CAVEAT THAT COULD LIMIT
RAINFALL POTENTIAL WILL BE THE STORM MOTION OF 25 KNOTS. WILL NEED
TO HAVE PROLONGED TRAINING OF STORMS FOR HEAVY RAIN.

850 WINDS ARE PROGGED TO INCREASE TO BETWEEN 50-60 KNOTS ON SUNDAY
AFTERNOON. INFLOW REMAINS STRONG SUNDAY NIGHT AND WILL MAINTAIN
HIGH POPS. THE GFS DEVELOPS AN AREA OF LOW PRESSURE AND MOVES THIS
FEATURE UP THE COAST. THE NAM AND OTHER MODELS DO NOT SHOW THIS
FEATURE. THE GFS THEN FOCUSES THE PRECIP CLOSE TO THE LOW CENTER.
PREFER THE MORE WIDESPREAD PRECIP SHIELD PRODUCED BY THE NAM. THE
ECMWF/UKMET AND CAN ARE ALL IN GOOD AGREEMENT IN PRODUCING HEAVY
RAIN ACROSS SE TX ON SUNDAY. WIDESPREAD RAINFALL TOTALS OF 2 TO 4
INCHES LOOKS LIKELY ON SUN/SUN NITE WITH SOME ISOLATED TOTALS
BETWEEN 7 AND 9 INCHES. A FLOOD WATCH WILL LIKELY BE REQUIRED FOR
SUNDAY AFTERNOON AND SUNDAY NIGHT.

BY MONDAY...THE UPPER LEVEL TROUGH OVER CALIFORNIA WILL MOVE EAST.
GLOBAL MODELS NOW A LITTLE DEEPER WITH THE TROUGH AS IT IS EJECTED
EAST. PW`S AGAIN APPROACH 2.7 INCHES BY MONDAY AFTERNOON. EXPECT
MORE STORMS TO DEVELOP IN ADVANCE OF THE TROUGH. HELICITY VALUES
ARE LOWER BUT OTHER INSTABILITY PARAMETERS IMPROVE AND THINK
SEVERE THREAT WILL AGAIN BE POSSIBLE ON MONDAY. WILL NOT MENTION
HEAVY RAIN/SEVERE THREAT SINCE IT IS STILL A FEW DAYS OFF.

[Portastorm]

Y'all in SE Texas better keep an eye on that developing low south of Brownsville ... before it's said and done, that's going to be a major player in your (and my) weather.

Tropical development or lack thereof is going to dramatically affect Gulf inflow and subsequent PWS over our areas. Wow, this is going to be a real interesting weekend!

Even the venerable Wxman57 is forecasting tropical development of this system!!!

http://www.storm2k.org/phpbb2/viewtopic.php?t=90585

[KatDaddy]

First VIS images show a very interesting system in the W/SW GOM.

[double D]

I just watched Dr. Lyons on the TWC and he said this might develop into a tropical depression. Either way he said it will dump a lot of rain in southeast Texas.

The GFS did a good job on showing this feature develop.

[Portastorm]

I just watched Dr. Lyons on the TWC and he said this might develop into a tropical depression. Either way he said it will dump a lot of rain in southeast Texas.

The GFS did a good job on showing this feature develop.

Indeed it did, double D! The GFS has been very good with this system thus far and has been forecasting development for several consecutive runs.

[Extremeweatherguy]

very intresting. That would really make for an interesting weekend wouldn't it? The weirdest thing is that it will likely be impacting us around the anniversary of Jerry.

Even if this is not tropical, it will still be quite a weather maker with high winds and heavy rains/storms all likely.

[KatDaddy]

Updated Hou-Gal AFD:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1025 AM CDT SAT OCT 14 2006

.UPDATE...
CLOUD COVER INCREASING OVER CWFA AS EXPECTED. QUITE DRY OVER MUCH
OF REGION EXCEPT FOR SW ZONES DUE TO INCREASING LOW LEVEL CONVERGENCE
COASTAL BEND SOUTHWARD. HAVE ADJUSTED POPS SLIGHTLY DOWNWARD OVER
NORTHEAST HALF OF CWFA FOR THIS AFTERNOON AND EVENING. MODELS AND
CURRENT TRENDS INDICATE INCREASING POPS OVERNIGHT FROM SW
EXPANDING TO REST OF CWFA TOWARD MORNING. QPFERD (914 AM CDT)
MENTIONED THAT GFS MAY BE HAVING GRIDSCALE FEEDBACK PROBLEMS CONCERNING
CIRCULATION DEVELOPING AND MOVING NE UP THE TEXAS COAST. BUT WITH
(STILL) HIGH PW VALUES INDICATED BY NAM AND GFS...BELIEVE ZFPHGX
ON TRACK. WE HAVE NOTICED THAT THE UK...ECMWF AND NAM ARE IN
CLOSER AGREEMENT THE NEXT TWO DAYS. WE SHALL MONITOR DEVELOPING
SITUATION VERY CLOSELY. 37