Texas/New Mexico/Louisiana/Mexico Obs And Discussion Thread Part 4

[Ed Lizard]

Oops Hunstville is out of commission

https://twitter.com/...9593217/photo/1

Kamikaze glider attack?

[Srain]

After a 'teaser event' last evening, things are coming together for an active 36-48 hours. The Euro & GFS have slowed the progression of the mid level low a bit and rainfall chances increase today with the frontal boundary draped across the area. Heavy rainfall with a potential Flash Flood Watch is being mentioned now by HGX and the HPC for tonight into tomorrow as night time rains are possible across areas along and N of the I-10 Corridor from Austin, College Station and points E extending near or just N of Metro Houston as this system is behaving like a decaying tropical system or warm cored low where heavy rains develop closer the center at night and train. Nocturnal showers/storms that ongoing along and S of the I-20 Corridor (Brownwood) and near Waco. These rains and the mid level low look to sag SSE today. Daytime heating and sea breeze activity should fire off rounds of storms later today and continue tonight into Friday. The fly in the ointment will be some potential further development along the Coast Friday into Saturday as the boundary and mid level low/trough linger across SE TX and may well extend into Sunday. The potential is there for just about everyone to see plentiful rains and even pulse severe storms with gusty winds and small hail possible. We may dry a bit on Sunday across the Northern zones, but rain chance may well increase again early next week as another front makes its approach from N TX.

[Srain]

Morning e-mail from Jeff:

Ingredients coming together for widespread rainfall today-Friday with some heavy.

Slow moving upper level low over NC TX this morning is slowly progressing SE toward the area with a large shield of rainfall extending from NW of Austin to near Dallas. Locally the weak frontal boundary over W LA yesterday has pushed westward mainly due to last evenings thunderstorms outflow and currently extends along a lien from near College Station to Katy to Galveston. Within the last hour thunderstorms have developed over the NW Gulf from offshore of Galveston inland across southern Brazoria and Matagorda counties. Expect numerous outflow boundaries to be produced by the convection to our NW and S/SW this morning and with surface heating over the next few hours, expect decent development likely late this morning across the region. Frontal boundary and other low level boundaries will help to focus storms today into the evening hours.

Tonight-Friday:

Very slow moving upper low moves into the area from the NW. Moisture levels will increase and the threat for sustained heavy rainfall will develop. Current thinking is that our NW/N counties are at greatest risk for some excessive rainfall tonight as convection develop near the low center (this low as taken on some warm core features). Slow storm motions and potential for training near the southern flank of the system along with modest southerly inflow all point to the threat for heavy rainfall tonight. This threat will expand slowly SE on the day Friday to include much of the area. We could see some fairly hefty totals, but where and how much is the question. For now will go with widespread 1-2 inches across the region with isolated 3-4 inches possible.

Upper low tries to exit the area on Saturday, but models have slowed down this progression so decent rainfall coverage may occur again on Saturday especially over the eastern areas. Should start to see less coverage on Sunday as ridging to the SW starts to build into the area.

Will need to closely watch radar trends and rainfall amounts over the next 24 hours. While grounds are fairly dry a flash flood watch may be needed for some portions of the area later tonight or on Friday.

[DoctorMu]

Two sets of storms converging on H-town

http://radar.weather.gov/radar.php?rid=HGX&product=N0R&overlay=11101111&loop=yes

[Srain]

Nice core rain event unfolding across SE TX. 4-6 inches have fallen since midnight just to my NW.

[Srain]

Morning e-mail from Jeff:

Activity was slightly more widespread on Thursday with much more of the area getting much needed rainfall.

Amounts averaged 1-2 inches in many areas, especially over the western and southwestern counties and this included a reported 4.1 inches by Jonathan Krenek in Egypt in Wharton County. Storms went well into the night with outflow boundaries galore crashing into each other. I had 6 separate outflow boundaries pass my house in Richmond last night between 400pm and 1000pm.

Upper level low partly responsible for the active weather is spinning directly over the western counties of SE TX this morning with light to moderate rainfall still in progress in the corridor from College Station to Matagorda Bay. East of this feature cloud cover is starting to break up allowing surface heating to begin and with the air mass extremely moist and the lift from the low overhead, do not think it will take much to get things going by early afternoon. Will favor the areas along and east of a line from College Station to Sugar Land to Galveston where the air mass will likely see the most heating and air flow is southerly off the Gulf. Suspect there are numerous boundaries across the area from any number of thunderstorm outflows and the seabreeze will begin its daily northward march by late morning. Hard to pin point where and when the storms will pop and on what boundary. Wind fields remain weak and motions have been highly meso scale driven by surging outflow boundaries especially yesterday evening.

Once again today as the past two days, some locations will see very heavy rainfall and some locations will see none. Hopefully today will wet those areas that have not seen any this week. A quick 1-2 inches is likely under the stronger cells. Upper low will begin to push eastward into LA on Saturday with rain chances falling to 30% across the region. Upper ridge builds back into the region for Sunday and Monday, but weak disturbances moving around this ridge may provide rain chances (currently slight) by Tuesday of next week.

Note:

Dry period of late has put much of the region back into moderate to now severe drought after much of the area was nearly drought free in early April after the incredibly wet late winter and early Spring. Wetting rains the last two days have been scattered and the impact on the local KBDI values has been marginal at best. Vegetation health is starting to suffer, especially over our north and eastern counties. Hopefully today will provide those counties their best shot at widespread wetting rainfall. Water supplies of SE TX remain good, with only Lake Conroe continuing to show a below normal pool elevation.

[DoctorMu]

That ULL is now throwing paddlewheels' full of moisture and convection up the Gulf Coast E 'round Miss and Bama shores. Dry slotting working in here and we are...shutting...down. isolated 3-4 in in locales. 1.39 in in CLL

[Srain]

The 00z Euro/Canadian/WRF suggest that a couple of short waves will traverse the area Tuesday/Wednesday as a weak frontal boundary stalls near the Red River. The GFS is dry, but something to watch I suppose. Guidance continues to advertise the monsoonal trough will lift N from Central America in the longer range perhaps increasing deep tropical moisture near the 20th, +/- a couple of days. With a more favorable MJO pulse and chi forecasts suggesting greater lift and lowering pressures for the W Caribbean and Gulf of Mexico. We will see.

HPC:

...SRN HIGH PLAINS...

A FRONT STALLING OUT ACRS THE SRN HIGH PLAINS REGION WILL HAVE A

POOL OF DEEP MSTR/PWATS ALONG IT WHICH ALONG WITH DIURNAL

HEATING/INSTABILITY AND SOME AID FROM OROGRAPHICS SHOULD HELP

FOSTER SOME BKN CLUSTERS OF SHWRS/TSTMS BEGINNING LATE TUES. MAY

WELL SEE A STRONGER MCS EVOLVING OUT OF THIS TUES NIGHT FROM ERN

NM SEWD INTO W CNTRL TX WITH THE AID OF A NOCTURNALLY ENHANCED LOW

LVL JET...WHICH THE 00Z NAM...00Z GFS AND 00Z ECMWF ALL SUPPORT.

WILL FAVOR SOME STRONGER CONVECTION WITH LOCALLY HVY RAINFALL ACRS

THIS REGION...BUT WILL ALLOW THE AXIS TO SET UP AND PROPAGATE A

LITTLE FARTHER SOUTH THAN THESE MDLS PROG ATTM.

[PottercountyWXobserver]

Hi Guys! You probably don't know me, but let me introduce myself. I'm from Pennsylvania and my name is Brandon, and I will be moving to Houston by July 9th for a job. I'm sure I will be posting quite often on this part of the forum come that time! This opportunity is a happy medium for me. I finally get to put my degree to good use, but I hate. and I mean hate heat lol. So tell me, when do temperatures get below 80F, I'm assuming October.

[Srain]

Hi Guys! You probably don't know me, but let me introduce myself. I'm from Pennsylvania and my name is Brandon, and I will be moving to Houston by July 9th for a job. I'm sure I will be posting quite often on this part of the forum come that time! This opportunity is a happy medium for me. I finally get to put my degree to good use, but I hate. and I mean hate heat lol. So tell me, when do temperatures get below 80F, I'm assuming October.

Welcome to Houston. It's actually a neat city with a bad rap. I may be a bit bias because this is where I was born and raised, but compared to many large Metro areas, you won't find a greater economic environment and a lower cost of living. There are many interesting and fascinating things to do here and Houston is truly a very International Cosmopolitan Area. Generally we start seeing cooler weather in October, but it depends on the year. Our weather does seem to be boring to some, but most that relocate here quickly fall in love with the area and many locations within a few hours drive such as the Hill Country, Padre Island and for the more adventurous, Big Bend National Park. Don't laugh when we get a snow/ice threat and city shuts down. You'll quickly come to understand the real weather events down here are Tropical in nature...

[PottercountyWXobserver]

Welcome to Houston. It's actually a neat city with a bad rap. I may be a bit bias because this is where I was born and raised, but compared to many large Metro areas, you won't find a greater economic environment and a lower cost of living. There are many interesting and fascinating things to do here and Houston is truly a very International Cosmopolitan Area. Generally we start seeing cooler weather in October, but it depends on the year. Our weather does seem to be boring to some, but most that relocate here quickly fall in love with the area and many locations within a few hours drive such as the Hill Country, Padre Island and for the more adventurous, Big Bend National Park. Don't laugh when we get a snow/ice threat and city shuts down. You'll quickly come to understand the real weather events down here are Tropical in nature...

Thanks for the welcome Steve! What is this bad rap you speak of?, when I was in Houston in the middle of May for my interview, all I heard was great things about the city. Once I arrive in Houston, you guys will have to tell me all about the city and the multiple facets. I think the only thing I'm going to despise about the city of Houston will be the unrelenting heat that is July and August. Eventhough Houston doesn't receive much snow, at least the weather will be perfect from NOV-FEB, because this time period resembles my hometown fall weather of 60-70s and that would be a great constellation prize since I won't be seeing much "winter" . MAR-APR should be interesting for me also because of severe wx action. If I can just get through JUN-SEP, I think I won't mind living in Houston wx wise. If I get depressed in the winter time, It will probably be from my withdrawls from my average of 70-80" of snow a year so I apologize in adavance! I tell you guys what, I will perform my PA snow magic, and Houston will have one BIG accumulating snow event this year of 4", thats right I said it!! I have never witnessed a tornado before and I would LOVE to at some point while I'm near the area, hopefully someone can show me the ropes and allow me to join in on a chase. I also can't wait for hurricane season to get in full gear. Here is hoping for another Ike, or dare I say Alicia

[Srain]

Guidance is advertising a couple of potent short wave crossing the region late Tuesday and again on Wednesday. While storms appear to be likely N of the I-10 Corridor, all will depend on just how far S the MCS pushes SE. A stalling frontal boundary to our N with storm complexes developing during the afternoon hours to our NW seem likely. The SPC has introduce a rather large area of Slight Risk extending from NE New Mexico and on SE very near our northern zones for Tuesday. The short term meso models are suggesting a rather robust MCS will approach the area Tuesday night. We'll need to monitor these trends today as see if the threat continues. Additional storm chances may be likely Wednesday as a second upper air disturbance swings by.

Meanwhile it will be very warm today with temps in the middle to upper 90's and very high heat index near or just above 100F. Those with outdoor plans need to drink plenty of water. Very high dew points will make 'feel' extremely hot. Stay safe out there today.

Looking ahead to next weekend in the longer range, a broad area of low pressure is suggested across the W Caribbean and possibly the Bay of Campeche as heights fall and lowering pressures increase from the EPAC on E into the Western North Atlantic Basin. The monsoonal trough looks to start lifting N from Central America and these features were noted the HPC this morning.

ACROSS THE TROPICS...MID-LEVEL HEIGHTS BECOME LOW ENOUGH BETWEEN

BERMUDA AND THE SOUTHEAST COAST TO INDUCE A BROAD SURFACE LOW/AREA

OF DISTURBED WEATHER IN THE WESTERN CARIBBEAN FROM THIS WEEKEND

ONWARD. RIDGING ACROSS NORTHERN MEXICO BRINGS THE PROMISE OF

RENEWED TROPICAL ACTIVITY SOUTH OF MEXICO ACROSS THE TROPICAL

PACIFIC OVER THE NEXT WEEK...WITH THE 12Z GLOBAL ENSEMBLE MEMBERS

INDICATING THREE PROSPECTS FOR DEVELOPMENT. SEE NATIONAL

HURRICANE CENTER /NHC/ TROPICAL WEATHER OUTLOOKS CONCERNING THE

FIRST OF THESE AREAS CURRENTLY WELL SOUTH OF BAJA CALIFORNIA.

[Srain]

Morning e-mail from Jeff:

SE TX will lie in the divide between an active/wet pattern over extreme east TX and LA and a hot and dry pattern over central and south TX.

Upper level trough that was over the area last week has moved well east of the area with high pressure having built overhead on Sunday. Smoke from a wildfire in Chambers County (sparked by lightening Friday evening) has plagued the areas around Galveston Bay over the weekend. High altitude smoke arrived in the area from the WNW last evening from the big wildfires burning in New Mexico and Arizona…so there will be a hazy/smokey look to the sky today.

Strong ridge of high pressure is over the area today, but the air mass just north of the area will become extremely unstable by late afternoon and expect a large complex of thunderstorms to develop over NE TX, SE OK at that time and move SSE to S overnight. Position of the eastern flank of the ridge over SW TX will guide this storm complex, and the current thinking is that the high pressure will be strong enough to shunt move of the activity into east TX and LA although would not rule out our NE and E counties from getting a storm (along and east of a line from Livingston to Liberty to High Island). What happens tonight will have at least some affect on the forecast for Tuesday, but boundaries likely pushing into the area from thunderstorm complexes just to our NE and E. Feel the ridge will remain strong for areas west of I-45, but eastern areas will at least stand a shot at some late day strong storms…and this area does need additional rainfall.

Ridging then builds slightly for the rest of the week, but active weather/unsettled pattern will remain just to our east over LA and will have to watch for any outflow boundaries or activity that may try and sneak westward in the late afternoon and early evening hours…especially if the ridge gives just a little ground.

Other item will be heat index values pushing into the 105-107 range during peak heating with highs topping out in the 94-98 range…may even see a couple of 100’s in the College Station to Huntsville corridor. We are just below advisory criteria of two days with heat index at or above 108 and/or overnight lows above 80. We will be close for much of the early to mid part of the week, but likely not fully meet the required criteria for a heat advisory.

Fire Weather:

While many locations did get wetting rainfall late last week, the areas that needed it the most were largely missed. Severe drought conditions have re-developed over San Jacinto, Polk, and Trinity counties. KBDI values range from 500-600+ over Liberty, San Jacinto, Polk, Trinity, and Houston counties indicating that vegetation health is drying and the formation and spread of wildfires is increasing. As noted with the lightening induced wildfire over Chambers County this weekend. Southerly winds today will range from 15-20mph by the afternoon, but surface RH will remain in the 30-40% range during the afternoon hours. This is not an overly high wildfire threat, but with a lot of dead fuel from the drought of 2011 and gusty winds, along with drying of fine fuels the threat is there for fire development and spread.

[Quixotic1]

2000+ CAPE values widespread already in DFW with dewpoints in the mid-70s (73 at DFW) and vertically developed CU field off to the north. Methinks 3-4000+ CAPE values later this afternoon. Whoever gets storms, will get some big uns.

[PottercountyWXobserver]

I was joking about the snow!, but lets hope we at least see some flakes this winter.

Srain, I was looking at the dew points this morning and all I can say is oppressive! How do you guys bare that kind of torcher. I was looking at some of the longer range, it looks like the winds may start coming out of the SE more regularly. Is that me or would a SE wind this time of year promote "cooler" weather, ie 85-90F rather than the 95+ variety. I would assume so as you pretty much get a direct flow off the Gulf temps near Houston hovering around 85F you would think that would be the case. Obviously a N wind would be the best cooling wind in winter/fall/spring. I would also assume a S to SW wind would be the kiss of death in the dead of summer as the air comes directly from Mexico, or is there a worse setup?

[Srain]

I was joking about the snow!, but lets hope we at least see some flakes this winter.

Srain, I was looking at the dew points this morning and all I can say is oppressive! How do you guys bare that kind of torcher. I was looking at some of the longer range, it looks like the winds may start coming out of the SE more regularly. Is that me or would a SE wind this time of year promote "cooler" weather, ie 85-90F rather than the 95+ variety. I would assume so as you pretty much get a direct flow off the Gulf temps near Houston hovering around 85F you would think that would be the case. Obviously a N wind would be the best cooling wind in winter/fall/spring. I would also assume a S to SW wind would be the kiss of death in the dead of summer as the air comes directly from Mexico, or is there a worse setup?

A NW to W flow aloft is our hottest during the summer months. Heat ridges can be frequent over Old Mexico, but daily sea breeze showers and storms are a welcome relief when we get a sustained SE flow off the Gulf. We'll see what that pattern offers this year, but I suspect we will not see the massive heat wave of last summer and the tropics could be a bit more active for the Western Gulf as we move further into summer.

[wxmx]

108F yesterday and 105F forecasted for today...and hovering around 100F for the next 7 days, at least.

Hopefully this heat moves to my NE

[Srain]

108F yesterday and 105F forecasted for today...and hovering around 100F for the next 7 days, at least.

Hopefully this heat moves to my NE

Monsoonal slopgyre ftw... At least the WRF/NMM is liking a MCS for N TX and point SE into LA. I'm not holding my breath for my backyard...

[bubba hotep]

2000+ CAPE values widespread already in DFW with dewpoints in the mid-70s (73 at DFW) and vertically developed CU field off to the north. Methinks 3-4000+ CAPE values later this afternoon. Whoever gets storms, will get some big uns.

This afternoon and evening could be very interesting. We could really see some explosive development later on.

[DoctorMu]

A NW to W flow aloft is our hottest during the summer months. Heat ridges can be frequent over Old Mexico, but daily sea breeze showers and storms are a welcome relief when we get a sustained SE flow off the Gulf. We'll see what that pattern offers this year, but I suspect we will not see the massive heat wave of last summer and the tropics could be a bit more active for the Western Gulf as we move further into summer.

Today's going to be a scorcher with DP about 74° and temps already hitting 90°. Close to the century mark with heat index near 108° in CLL. Got some Monterrey breeze kicking in.

Hoping for some T-storm action tomorrow and Wed.

Yeah, after a month we're lighting candles and praying for some tropical action...and it continues.

I sometimes miss NC weather this time of year. 89°-91° most days; chance of a T-storm...always with an eye on the tropics. Every once in a while a backdoor front.

[DoctorMu]

This afternoon and evening could be very interesting. We could really see some explosive development later on.

Denton and NW should see some action

[Quixotic1]

This afternoon and evening could be very interesting. We could really see some explosive development later on.

Agreed. Boom goes the dynamite. 4000 CAPEs showing up now.

And.......the NWS area radar is down for repair. Supposed to be back up before storms initiate.

[bubba hotep]

AFDFWD

AREA FORECAST DISCUSSION...UPDATED

NATIONAL WEATHER SERVICE FORT WORTH TX

1116 AM CDT MON JUN 11 2012

.UPDATE...

WE WILL LET THE CURRENT FORECAST PACKAGE RIDE THROUGH MIDDAY AS IT

SEEMS TO BE ON TRACK WITH REGARDS TO EXPECTED HIGH TEMPS AND

POTENTIAL FOR STRONG TO SEVERE CONVECTION LATE AFTERNOON AND THIS

EVENING.

LARGE CAPES VALUES /4000+ J/KG / WOULD RESULT IN INTENSE UPDRAFTS

THAT COULD PRODUCE VERY LARGE HAIL. ALTHOUGH THE LCL IS ABOVE 6000

FEET ACROSS MUCH OF NORTH TEXAS...ANY POOLING OF LOW LEVEL MOISTURE

ALONG THE COLD FRONT WOULD LOWER THE LOCAL LCL AND COULD RESULT IN

HORIZONTAL VORTICITY TUBES BEING DRAWN UP INTO THE UPDRAFT. THUS

WE THINK THERE IS A WINDOW OF OPPORTUNITY FOR ISOLATED TORNADOES

WHERE THIS OCCURS ALONG THE COLD FRONT. ALSO...OUR FWD MORNING SOUNDING

INDICATES VERTICAL VELOCITY POTENTIAL UP TO 75 M/S OR 168 MPH!! 75

[Srain]

MESOSCALE DISCUSSION 1125

NWS STORM PREDICTION CENTER NORMAN OK

0332 PM CDT MON JUN 11 2012

AREAS AFFECTED...W-CNTRL AND NW TX

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 112032Z - 112130Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE THREAT FOR LARGE HAIL AND DMGG WIND GUSTS IS

INCREASING OVER PARTS OF W-CNTRL AND NW TX. A WW WILL LIKELY BE

NEEDED WITHIN THE NEXT HR.

DISCUSSION...SFC ANALYSIS FROM 20Z PLACES A DEEPENING SFC LOW NEAR

SPS...WITH A SLOW-MOVING COLD FRONT ORIENTED SW-NE ACROSS N TX.

RECENT VISIBLE SATELLITE IMAGES SHOW INDICATIONS OF A DEVELOPING

SFC-BASED CU FIELD 40 NW MWL OCCURRING ALONG WIND SHIFT...AND

ADDITIONAL TOWERING CU DEVELOPING APPROXIMATELY 30 N SJT. VERY

STRONG BOUNDARY LAYER HEATING...WITH TEMPERATURES REACHING NEAR 100

F...HAS BEEN SUFFICIENT TO OVERCOME A WARM LAYER NEAR 850 MB

OBSERVED IN 12Z SOUNDINGS. FORCING FOR ASCENT IS EXPECTED TO BE

WEAK...BUT GIVEN THE STRONG HEATING AND CONTINUED WEAK CONVERGENCE

ALONG/NEAR WIND SHIFT AND ATTENDANT DRYLINE...INITIATION OF AT LEAST

ISOLATED STORMS APPEARS INCREASINGLY LIKELY. WITH MLCAPE VALUES NOW

EXCEEDING 4000 J/KG IN SOME AREAS...STORMS WILL LIKELY BE CAPABLE OF

PRODUCING VERY LARGE HAIL AND ISOLATED DMGG WIND GUSTS...BUT STORM

ORGANIZATION SHOULD BE SOMEWHAT LIMITED BY WEAK EFFECTIVE SHEAR

/NEAR 20 KTS/.

..ROGERS/MEAD.. 06/11/2012

ATTN...WFO...FWD...OUN...SJT...LUB...MAF...

[Srain]

[wxmx]

When MMIO (Saltillo) at 5800ft is 99F, you know things are bad...

[Ed Lizard]

Storms around Big Springs, temps over 100ºF, dews in the 40s, I'm hoping for some good dust storm video. Believe the term is haboobie.

[wxmx]

Storms around Big Springs, temps over 100ºF, dews in the 40s, I'm hoping for some good dust storm video. Believe the term is haboobie.

Haboob. I know, freudian slip.

[DoctorMu]

Storms around Big Springs, temps over 100ºF, dews in the 40s, I'm hoping for some good dust storm video. Believe the term is haboobie.

Thar she blows

...photo from '97

Connect the dots for a merge near DFW

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE FORT WORTH TX

300 PM CDT MON JUN 11 2012

.DISCUSSION...

THE COLD FRONT CURRENTLY EXTENDS FROM NEAR MCALESTER OKLAHOMA TO

HOBBS NEW MEXICO AND HAS ALREADY ENTERED NORTHWESTERN YOUNG

COUNTY. WE STILL FEEL THAT LATE AFTERNOON AND EVENING CONVECTION

WILL FAVOR AREAS ALONG AND AHEAD OF THE COLD FRONT...ESPECIALLY

FROM EAST OKLAHOMA TO THE TEXAS HILL COUNTRY. WITH SUCH AN UNSTABLE

AIR MASS IN PLACE OVER NORTH TEXAS...THUNDERSTORM DEVELOPMENT WILL

BE RAPID WITH LARGE HAIL POSSIBLY RESULTING WITHIN 30 MINUTES

AFTER THE FIRST ECHOES APPEAR. EXPECT DEVELOPMENT TO BEGIN IN

OKLAHOMA AND OVER THE TEXAS HILL COUNTRY WHERE INHIBITION IS THE LEAST

AND BUILD ALONG THE COLD FRONT INTO OUR NORTH AND WEST COUNTIES

THIS EVENING THEN OVER THE NORTHWEST THIRD BY MIDNIGHT AND

NORTHEAST LATE TONIGHT. SPC/S SLIGHT RISK OVER THE NORTHWEST TWO-

THIRDS OF NORTH TEXAS IS WARRANTED. ISOLATED DISCRETE CELLS WILL

HAVE TO BE WATCHED CLOSELY FOR MESO CYCLONE DEVELOPMENT 23-03Z

AND VERY LARGE HAIL POTENTIAL THROUGH 04Z.

[Srain]

Morning e-mail from Jeff:

What to do…Oh…what to do with the chances for thunderstorms today.

Large convective complex is currently roaring through central and western LA this morning with a westward moving gravity wave having kicked off local showers and thunderstorms in the favored streamer belts this morning from Galveston Bay to Chambers and Liberty Counties…this activity has weakened. Upstream outflow boundary along/ahead of the LA complex with no doubt get into the region from the NE/E at some point late this morning or early afternoon. Meso scale short term models are showing any number of solutions from a full blown line of thunderstorms moving across the entire area (WRF-NNM) to isolated storms along an outflow boundary (HRRR) to a new line of storms developing over NE TX and moving into the area this evening (TT WRF). Likely that none of the models are fully correct or incorrect and will side mostly with the less aggressive HRRR and blend in some of the TT WRF with the feeling that the WRF-NNM is way too aggressive with activity.

Air mass over the region will be hot, humid and very unstable by early to mid afternoon, but capped especially south of I-10 where the influences of high pressure over MX and S TX is in place. Forecast soundings north of I-10 suggest that when inputted with the forecast high temperatures the mid level inversion is weakened and is breakable. Additionally suspect there will be any number of outflow boundaries moving into the region from late morning through early afternoon which will/could help in forcing surface parcels through any remaining capping aloft. Boundaries will likely initiate storms and with good low level instability expect that some storms will be strong to locally severe with large hail and damaging winds the main threats. Best location for thunderstorms will be along and NE of a line from College Station to Conroe to High Island…in the region where capping is weakest and low level boundaries will reach during peak heating. Storms will then track S to SW into the region, but how far they make it is the big question. Suspect a few will make it to I-10 and possibly deeper into the area driven by strong outflow boundaries and a very unstable and super-heated late day air mass. It is not out of the possibility that storms could make it into the metro Houston area and even as far S and W as Waller, Fort Bend, and Galveston Counties. If the HRRR model is correct then the entire area will see activity…but this seems excessive given the capping south of I-10.

Wet pattern will continue just to our east into Wednesday and once again large storm complexes rolling down the eastern flank of the S TX ridge will just clip our area and sending their outflow boundaries into the region. Could once again see isolated to scattered storms on Wednesday north of I-10. Central US ridge builds a little into the late week and weekend while the S TX high pressure cell moves westward into Mexico. This dries out east TX and LA and allows a surge of tropical moisture to arrive into coastal south and central TX by Sunday. Models are showing the potential for some seabreeze thunderstorms this weekend especially from about Galveston Bay SW along the TX coast.

Early to mid next week a weakness develops in the ridge over the central US Gulf coast and moves westward along the southern flank of the central US high. This should increase tropical moisture transport northward into the area and provide a better shot at daily seabreeze thunderstorms.

Tropics:

Lots of uncertainty going into next week as several global models have been bouncing around with the idea of some sort of tropical cyclone formation anywhere from the western Caribbean to the southern Gulf of Mexico to the eastern Pacific. There is nothing there now, but models are showing a significant increase in moisture over the western Caribbean and southern Gulf likely in response to the lifting northward of the monsoon trough over central America and Mexico. Favorable global teleconnection patterns also appear to be aligning at the same time with a favorable wet phase of the MJO affecting the E PAC and Gulf of Mexico by mid to late next week. For now will need to watch the period from Friday-Monday for an increase in the moisture in this area (if this does occur) then it is likely that the models may be on to something and at some point next week a tropical system could attempt to spin up in the highlighted region.