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

[Ptarmigan]

I heard on the local weather that it could be stormy tonight.

[KatDaddy]

Joe B mentioned a decent coastal low will development in the WGOM off the middle TX Coast following the frontal system. He mentioned Jerry being the last October storm to form in the WGOM.

[PTrackerLA]

It is so muggy and oppressive this morning, feels like mid-July and not early October. Something has got to give soon!

[jasons2k]

Believe it or not, I'm getting tired of all the rain now. Spending WAY too much on chlorine these past few weeks. Already some storms firing to the SW.

[srainhoutx]

Believe it or not, I'm getting tired of all the rain now. Spending WAY too much on chlorine these past few weeks. Already some storms firing to the SW.

Let alone a battle with green algae for the first time since building the pool. 00Z ECMWF continued with another Baja system idea and a suspious little surface low off Tampico. Friday into Saturday looks wet, but hopefully cooler. The last couple of days have been down right Summerish.

[srainhoutx]

Getting rather dark to my SW. Looks like a batch of thundershowers head this way.

[vbhoutex]

Getting rather dark to my SW. Looks like a batch of thundershowers head this way.

You should get the heaviest part of it. I was out doing errands when I saw it. Drove out Katy to intercept due to some suspicious clouds which were nothing in the end. Torrential downpours were bad enough to almost stop traffic on the freeway. Got a quick 0.27" here at the house.

edit@2:06pm-Here it comes again. Another thunderstorm coming from the SW right over our area. Not sure what is setting this off, but the rain is still needed so I won't complain much.

[srainhoutx]

Getting rather dark to my SW. Looks like a batch of thundershowers head this way.

You should get the heaviest part of it. I was out doing errands when I saw it. Drove out Katy to intercept due to some suspicious clouds which were nothing in the end. Torrential downpours were bad enough to almost stop traffic on the freeway. Got a quick 0.27" here at the house.

edit@2:06pm-Here it comes again. Another thunderstorm coming from the SW right over our area. Not sure what is setting this off, but the rain is still needed so I won't complain much.

First round was just light to moderate rain with lots of lightning. I see the next mess headed this way. Boy was it muggy after the first batch.

Edit @ 2:41 PM just a little light rain and some thunder.

[southerngale]

Not a drop over here, but man is it ever hot & humid!

[Diva]

Not a drop over here, but man is it ever hot & humid!

You got that right! It's miserable here!!!!

[lrak]

Our low last night was like 80 with a heat index of 84...ACK.

I'm ready, around Jan 2010 I'll be wishing for the new hurricane season to start up...

[srainhoutx]

Jeff's e-mail this morning...

Relief on the way from this oppressive heat and humidity.

Upper level storm system over the Rockies will move into the plains today and Friday sending a strong cold front through SE TX on Friday afternoon/evening. For today moist southerly flow will increase at the surface as low pressure develops in the lee of the Rockies. Expect wind speeds to increase into the 20-25mph range this afternoon with gust to near 40mph around Matagorda Bay. Past hourly profiler data from Ledbetter, TX showed 45kts at 1,600 ft and CRP 88D showed 35-45kts in gate 1 so once heating commences this energy will begin to mix to the surface. Extremely moist air mass with dewpoints in the upper 70’s/lower 80’s is allowing for streamers to move inland off the Gulf over Matagorda County this morning. Mid level warm layer should keep most activity shallow and scattered today and mainly confined to streamer type showers moving inland under the towering cumulus cloud streets flowing northward out of the NW Gulf.

Potent storm system and cold front arrive into the mix over NW TX tonight and combine with the incredible moisture to produce a round of heavy rains and strong thunderstorms. Models are in good agreement that a squall line will develop along the front over SW TX through NE TX and move across the state on Friday. GFS seems to be the fastest with the frontal timing with the boundary near the coast by around 600pm Friday evening…while the other guidance is slower. With the mid level ridge shifting eastward, approaching lift ahead of the front, and daytime heating…I suspect we will not be able to hold thunderstorms down too long on Friday. Will probably start to see development at least by noon and then downhill during the afternoon as the front/squall line approaches. There will be a modest severe threat with the storms…mainly a wind threat. However will need to watch for discrete cells out ahead of the main line that could pose a tornadic risk given a low degree of low level wind shear.

Heavy rainfall threat remains the greatest concern with this event as PWS remain in the 2.2-2.4 inch range which is nearly insane for early October. As mentioned by the morning FWD forecaster…it is rare to have such high PWS air mass in early October and not have flash flooding. Feel the best threat for flash flooding will be north and west of SE TX, although our western and southwestern zones are of some concern…given these areas were hit hardest this past weekend with creeks and rivers near or above flood stage or on their recession limbs. This system should be progressive enough to limit the rainfall mainly to along the squall line however any period of cell training of slowing of the line could bring rapid flash flooding given the extremely moist air mass and great potential for 4 in+ per hour rainfall rates. Flash flood guidance is lowest over Wharton, Jackson, Victoria, Calhoun, and Colorado Counties with watersheds in this area still responding to the rains this past weekend especially the Guadalupe and Lavaca/Navidad river basins. Flash flood guidance is around 3.0-4.0 inches per 3-hours…problem is that this air mass is capable of producing 3-4 inches in an hour… and 1-hr guidance is around 2.5 inches…so run-off seems fairly likely.

Refreshing cold air advection will onset with the frontal passage and dewpoints will easily fall from near 80 into the 60’s and then the 50’s with gusty NW winds…it will feel much different Saturday morning. Clouds will be slower to clear the area and with cold air advection in place expect highs only to reach the low to mid 70’s on Saturday…about 20 degrees colder than today. Front stalls over the NW Gulf and transforms into a coastal trough. Not sure how far south the front pushes and if the coastal trough formation will be close enough to the coast to keep clouds in place. Isentropic lift creep into the picture by Sunday as dirty SW flow aloft develops over the cold dome at the surface. Models quickly fall out of agreement for early next week with potential secondary push of cold air and development of EPAC tropical cyclone around Baja with good moisture tap over TX. Will not commit to either wet or dry for now and see how things play out over the weekend…but the pattern of late seems to support the wetter solution and we could have Olaf part two play out at some point next week.

Hydro:

Guadalupe River:

River is in minor to moderate flood from above Victoria to below Bloomington. The river is in recession however additional heavy rainfall on Friday will likely produce a new rise and keep the river above flood stage.

Lavaca River:

The river crest Wednesday near moderate flood stage at Edna and is quickly falling.

Navidad River:

The river has crested and is falling below flood stage at all forecast points.

Additional heavy rains Friday may slow recessions and likely result in new rises on these watersheds as well as Mustang and East Mustang Creeks in Jackson County.

[JenBayles]

Man is it getting windy outside. It just blew my back door open.

[srainhoutx]

Latest SPC Day 2 Update put SE TX/SW LA in a Slight Risk for now. I wouldn't be surprised to see that increased to a Moderate Risk tomorrow...

http://www.spc.noaa.gov/products/outlook/day2otlk.html

[jasons2k]

Latest SPC Day 2 Update put SE TX/SW LA in a Slight Risk for now. I wouldn't be surprised to see that increased to a Moderate Risk tomorrow...

http://www.spc.noaa.gov/products/outlook/day2otlk.html

I was wondering when/if that flag would be raised. IMO there are just too many dynamics at play, esp. if this front comes thru in the afternoon hours. It's like April or May outside right now with the winds screaming from the south...something's got to give, right?

[srainhoutx]

Also noticed that NHC has the modeled EPAC disturbance listed as a Code Yellow S of the Baja. You have to wonder what issues we may have from the moisture associated with it as the front stalls just offshore. The "hints" we're getting of a possible trough/surface low along the Lower/Middle TX Coast after fropa sound a lot like last weekend.

[southerngale]

snippet from the Lake Charles AFD this morning... I hear ya, guys.


FOR OUR REGION TODAY...WE WILL CONTINUE TO BASK IN UNSEASONABLE
WARM TEMPS AND DEWPTS. EXPECT HIGHS TO REACH THE LOWER 90S. WITH
DEWPTS ONLY EXPECTED TO DROP TO THE MID 70S...HEAT INDICES WILL
AVERAGE NEAR TO THE LOWER 100S! YES...I DO HAVE TO CHECK THE
DATE...REALIZING IT`S OCTOBER 8TH AND NOT AUGUST 8TH. WITH MOST OF
THE UPPER LEVEL LIFT STILL NW OF THE REGION...ONLY EXPECT ISO
SHRA/TSRA TODAY.

[vbhoutex]

Latest SPC Day 2 Update put SE TX/SW LA in a Slight Risk for now. I wouldn't be surprised to see that increased to a Moderate Risk tomorrow...

http://www.spc.noaa.gov/products/outlook/day2otlk.html

I was wondering when/if that flag would be raised. IMO there are just too many dynamics at play, esp. if this front comes thru in the afternoon hours. It's like April or May outside right now with the winds screaming from the south...something's got to give, right?

You had to put it that way didn't you? Almost the entire weekend here in SE TX depends on where the front sets up residence. Further offshore is probably better for us worse for those East of us. Along the coast or near the coast more of "problem" for us. The rest of the equation is cut off low or trough? Either way it appears that there probably will be a moisture feed from the EPAC. IMO, not an easy forecasting situation.

[jasons2k]

From Jeff at 5:30:

Significant weather changes in the next 24 hours.

Powerful cold front blasting southward through NW TX has now passed Amarillo. Temperature is now 47 with N winds gusting to over 30mph compared to 82 at Lubbock and 100 at Laredo with S winds gusting to over 30mph.

Front will make progress tonight into central TX while gradually slowing as widespread showers and thunderstorms develop.

Should see the boundary enter our NW zones around 800am and progress slowly across the area with numerous thunderstorms. Highs temperatures will be prior to the frontal passage with temperatures falling at least 15-20 degrees post front under strong NW winds. This will be a shock due to our warm and very humid weather of late.

Lows Saturday even with clouds linger will fall to the coolest levels this fall...the mid 50's.

Still looking for a widespread 1-2 inches of rainfall with isolated amounts to up 3 inches Friday-Friday evening.

May need to ramp up rain chances on Sunday as the coastal trough evolves, but still not sure how far north the moisture gets...dare I say if it does move northward some areas could stay in the 60's on Sunday under cool NE winds, cloudy skies, and rain.

[srainhoutx]

Wash, rinse, and repeat of last weekend.