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

[srainhoutx]

Morning e-mail from Jeff Lindner is to say the least worrisome and informative in many aspects...

Highly moist air mass remains over the region with PWS in excess of 2.0 inches at most locations. Morning radar and first few visible satellite images show scattered showers and thunderstorms over the nearshore waters with some activity as far inland as Needville in Fort Bend County. Deep southerly flow remains in progress and once trigger temps in the mid 80’s are reached expected numerous showers and thunderstorms to focus across the central and western portions of the region in the area of deepest moisture. Not sure upper ridging has built enough yet the limit rain chances and I suspect we will see as much coverage today as on Sunday…then a pronounce drying trend into mid week.

Upper ridge will build over the area Tuesday-Thursday with high temperatures returning to the upper 90’s/low 100’s. KCLL has now seen 41-100 degree days this summer! Ridge does not gain a strong foothold…nor did it last week and rain chances return starting Friday into next weekend as the ridge moves westward opening the door for an upper trough to cut off over the NW Gulf. This feature actually intensifying as it moves inland over S TX with deep tropical moisture surging back into SE TX late Friday. Will likely see a return of active seabreeze convection Friday into next weekend. Additionally, tropical wave near 45W this morning will be entering into the SE Gulf of Mexico by late next weekend. GFS has been hinting at some development with this wave as it reaches the Gulf with synoptic scale features showing downstream upper level high pressure positioned over the central and eastern Gulf supporting a favorable upper air environment.

99L:

Atlantic tropics heading toward a significant increase in activity per forecast models and favorable wet phase of MJO pattern….ie note upswing in EPAC and CPAC (TS Felicia heading for Hawaii) Additionally, ITCZ has crept northward of late and easterly trades from Africa toward the Lesser Antilles Islands in the Mean Development Region have greatly weakened along with significant moistening of the air mass off the coast of Africa and well west into the tropical Atlantic.

A strong tropical wave with an associated area of elongated low pressure is currently passing just south of the Cape Verde Islands. Visible and IR images show a fairly well defined system with broad surface low pressure and modest convection near and surrounding the broad circulation. The convection is not well organized and there is little banding features noted. Morning Quickscat satellite overpass showed impressive 40-45kt unflagged vectors on the southern side of the circulation however the overall rotation is broad and not well defined. There also appears to be a slight hint at SW wind shear as upper level moisture is streaming NE away from the system. Given all this, there still is decent potential for TD #2 to come within the next 48 hours as supported by nearly all of the global model guidance. General track guidance maintains a modest sub-tropical ridge north of the system allowing a WNW track for the next several days. This will allow the system to gain some latitude over time increasing the chances for a recurve out to sea.

FWIW, the global models especially the GFS develop the next 2 waves coming off of Africa with the next wave coming off at a very low latitude and tracking almost due west and growing into a strong tropical cyclone as it approaches the Leeward Islands in 9-13 days. We shall see…this is the most guidance action to date for the 2009 season. While we are in an El Nino period…such periods have been very unkind to the Gulf coast and there is growing evidence that El Nino does not as greatly affect Gulf of Mexico activity as much as the deep eastern Atlantic.

[jasons2k]

I got nothing yesterday except some sprinkles....maybe today will be better ?

[Ed Mahmoud]

Just heard thunder at the Galleria...

[Yankeegirl]

Its thrundering here in Cypress.... I love it!!! Why cant it do this every day?????

[srainhoutx]

Pouring rain and thunder in NW Harris County.

[jasons2k]

Storm just *barely* to my NW. It is quite a storm too...

[srainhoutx]

Storm just *barely* to my NW. It is quite a storm too...

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
408 PM CDT MON AUG 10 2009

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
NORTHERN HARRIS COUNTY IN SOUTHEAST TEXAS...
EASTERN MONTGOMERY COUNTY IN SOUTHEAST TEXAS...

* UNTIL 445 PM CDT

* AT 407 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL. THIS
STORM WAS LOCATED NEAR THE WOODLANDS...AND MOVING NORTHEAST AT 11
MPH.

* LOCATIONS IN THE SEVERE THUNDERSTORM WARNING INCLUDE BUT ARE NOT
LIMITED TO SPLASHTOWN...HOOKS AIRPORT...WILLIS...TOMBALL...
SPRING...SHENANDOAH...PORTER HEIGHTS...PANORAMA VILLAGE...OAK RIDGE
NORTH...CUT AND SHOOT AND CONROE.

[vbhoutex]

I got plenty of thunder and lightning nearby, but not one drop!! Sprinklers are out!

[srainhoutx]

E-mail from Jeff Lindner this morning deals with TD 2, but some nuggets concerning the upcoming pattern locally as well...

Second Tropical Depression of the 2009 Hurricane Season forms in the far eastern Atlantic.

Visible satellite images along with Quickscat overpass confirm that the strong tropical wave 280 miles WSW of the Cape Verde Islands has developed a well defined closed surface circulation and deep convection near/over the center to be upgraded to a tropical depression in a special 600am advisory package from NHC. A large convective explosion near/over the center early this morning has since waned some revealing a well defined low pressure center. The depression is moving westward toward the open Atlantic Ocean.

Track:

Model track guidance is split into two camps…but largely in decent agreement. A modest sub-tropical ridge to the north of TD # 2 will impart a general W to WNW motion for the next 48-72 hours before a weakness in the ridge around 50W results in a more WNW to NW motion. The tropical BAMS and HWRF model show a deeper system and resultant faster turn toward the NW prior to 50W while the GFDL, GFS, and CMC all show a weaker system and further westward track. Current NHC forecast track splits the difference and heads down nearly the middle of the guidance clustering with a slightly higher edge toward the more west/shallower solution. This is to the left of the HWRF and slightly right of the model clustering consensus.

Intensity:

The depression is located within fairly favorable conditions for slow development. Wind shear is light and the air surrounding the system moist. The only limiting factor is that the system is fairly far north in latitude and near the northern edge of warmer SST’s over the eastern Atl. SST’s warm toward the west and the depression will be crossing into warming waters as it moves westward. It should be noted that besides the HWRF, none of the respected global models really develop the system…which opens the door for a more westward track. It should also be noted that nearly all of the models greatly develop the wave moving off the African coast and plow this system due west toward the Caribbean Sea.

Local Weather:

Another afternoon of scattered showers and thunderstorms today as air mass remains moist and unstable. With trigger temps. in the lower 90’s expect the seabreeze to get stuff going around or shortly after noon. Radar is fairly dry this morning…so coverage will likely be less than Sunday and Monday as 500mb ridge builds over the area.

Large scale pattern change looks even more pronounced today than yesterday to support an even better chance of rain starting as earlier as Thursday and on into the weekend. Upper trough will drop southward and cut-off over the north-central Gulf coast and then move west as upper ridge builds into northern Mexico and the southern Rockies. Models remain at odds if the upper trough remains open or closes off into an upper low. Either way favorable air column cooling and increasing moisture point toward increased daily seabreeze events. Additionally, a frontal boundary will approach from the N and NE with large convective complex to our north sending outflow boundaries our way during the afternoon/evening hours. Will go with 40% on Thursday and this may be on the low side and then 30-40% into the weekend.

Sub-tropical ridge builds across FL into the eastern Gulf next week with central and western Gulf of Mexico open to tropical wave train influx in an increasingly tropically active Atlantic.

[vbhoutex]

Well, not a drop any where near me today. Managed 102ºF here at the house. I didn't see what the official was at IAH today. Isure hope they are right about our rain chances going up by the end of the week!

[Yankeegirl]

No rain here either.... and Im with ya, I hope it gets rainy for the weekend!

[jasons2k]

Email from Jeff Lindner:

TD#2
Morning satellite images including visible, IR, and WV show the deep convective burst waning on the western side of the center. Visible images suggest the center may be exposed on the far eastern edge of the deeper convection. Water vapor images show significant amounts of dry and stable air surrounding 02 on the W and N sides and from time to time being ingested into the circulation weakening the convection. The system also shows limited convective banding.

Track:

Guidance has trended westward since yesterday morning with the NHC track now right (east and north) of most of the model runs. HWRF and BAMD continue to indicate a sharp NW turn toward Day 4-5 as the system reaches a weakness in the sub-tropical ridge over the central Atlantic…since the system has failed to intensify much and the thermodynamic environment is not all that favorable…with only slow intensification expected…a more shallow west track seems more likely at this moment.

Intensity:

02 will continue to fight dry air intrusions into the circulation. While shear is light and SST’s are modest the dry air will inhibit rapid formation in the near term. A few models take the system to hurricane intensity in the next 48 hours…but will disregard and follow NHC thinking of only a modest 50kt TS at maximum for the moment.

Tropics:

Global models continue to pound away at the tropical wave moving off the African coast with nearly all models extremely aggressive in developing this feature into a significant hurricane. This system is forecast to be at a dangerously low latitude and track more westward than TD 2 supporting a threat to the Caribbean Islands.

Latest runs of the CMC and EURO also show the tropical wave in the eastern Caribbean Sea developing into a tropical system over the Florida Straits this weekend and tracking WNW toward the Sabine River. CMC is very aggressive in taking a tropical cyclone toward SE TX/ SW LA early next week while the EURO maintains the feature as an open wave. GFS has little to do with this feature.

Local Weather:

Weak low level boundary is nearly stationary over the northeastern part of SE TX this morning with showers and thunderstorms already developing in a moist and unstable air mass. PWS remain in the 1.8-2.0 inch range with trigger temps in the lower 90’s. Expect to see another day of scattered development especially along and E of I-45. Inverted V sounding profile supports strong microburst/downburst and gusty outflow winds.

Will see the same pattern on Thursday shift more SW so more of the area may get wet.

Pattern change is ushered in this weekend as sub-tropical ridge builds westward from the Atlantic into the Gulf of Mexico as powerful trough moves into the Pacific NW. This will open up the Gulf of Mexico and west/central Gulf to deep tropical moisture and a more typical summer pattern for SE TX as deep SE flow bring copious moisture. Expect more robust seabreeze storms starting Sunday. This also opens the door for Atlantic basin tropical cyclones to move W or WNW toward the Gulf of Mexico and the Atlantic looks to be in full swing by next week.

For now will maintain the TW over the eastern Caribbean Sea as an open wave and toss out the CMC as it has limited support from the other global models. However, last few runs of the GFDL on TD 2 has also shown closed isobars in the FL Straits this weekend in the same location the CMC develops this feature. For now will go with an uptick on the winds and seas Sunday out over the open Gulf waters as this feature open wave/or something else approaches the central Gulf of Mexico. Early next week will depend heavily on potential development of this feature and ultimate track. Forecast upper air pattern suggest a general WNW track toward the TX/LA coast early next week…big question is this a wave axis or something much stronger.

Long Range:

Global models in decent agreement on significant tropical cyclone (possibly major hurricane) moving into the Caribbean Sea from the Atlantic around the middle of next week. Intensity of mid and upper level ridging over the Atlantic suggest a general W to WNW track with the EURO showing the system just N of Cuba and the GFS S of Cuba toward the end of their runs by late next week into the weekend of the 22.

Now is the time to review your hurricane preparation plans and make sure your Hurricane Ike supplies are fully re-stocked.

[jasons2k]

Nice looking storms in Montgomery County Maybe finally

[Flyinman]

Had a quick shower a my house and I mean quick. My wife called to let me know it was raining and by the time she looked into the backyard it was no longer raining in the front yard. Oh well, I will take what I an get.

[srainhoutx]

Getting a lot of thunder now in NW Harris County. Storms in S Montgomery/N Harris Counties look strong. Seabreeze showing up nicely on radar as well.

[srainhoutx]

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
415 PM CDT WED AUG 12 2009

TXZ199-213-122215-
HARRIS-MONTGOMERY-
415 PM CDT WED AUG 12 2009

...SPECIAL WEATHER STATEMENT...

AT 413 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR SPRING...MOVING SOUTHWEST AT 10 MPH.

WINDS GREATER THAN 40 MPH...ARE POSSIBLE WITH THIS STORM.

LOCATIONS IN THE PATH OF THIS STORM INCLUDE...SPLASHTOWN...
MEMORIAL...HOOKS AIRPORT...THE GALLERIA...BUSH-INTERCONTINENTAL
AIRPORT...ADDICKS...TOMBALL...SPRING VALLEY...SPRING...PINEY POINT
VILLAGE...JERSEY VILLAGE...HUNTERS CREEK VILLAGE...HUMBLE...
HOUSTON...HILSHIRE VILLAGE...HEDWIG VILLAGE...BUNKER HILL VILLAGE AND
ALDINE.

[Flyinman]

Ok, this is not funny any more. I am in a total dead zone. Again have been watching storms move from the North, dissapate, then reform South of here....It will rain good here again one day.

[srainhoutx]

I feel your pain Flyinman...

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
434 PM CDT WED AUG 12 2009

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
CENTRAL HARRIS COUNTY IN SOUTHEAST TEXAS...

* UNTIL 515 PM CDT

* AT 433 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
OF 60 MPH. THIS STORM WAS LOCATED NEAR ALDINE...AND MOVING
SOUTH AT 15 MPH. BUSH INTERCONTINENTAL AIRPORT REPORTED A WIND
GUST OF 70 MPH.

* LOCATIONS IN THE SEVERE THUNDERSTORM WARNING INCLUDE BUT ARE NOT
LIMITED TO SPLASHTOWN...RELIANT PARK...HERMAN PARK...THE
GALLERIA...BUSH-INTERCONTINENTAL AIRPORT...WEST UNIVERSITY PLACE...
SPRING VALLEY...SPRING...SOUTHSIDE PLACE...PINEY POINT VILLAGE...
JERSEY VILLAGE...HUNTERS CREEK VILLAGE...HOUSTON...HEDWIG
VILLAGE...BUNKER HILL VILLAGE AND BELLAIRE

[srainhoutx]

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
442 PM CDT WED AUG 12 2009

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
NORTHWESTERN MONTGOMERY COUNTY IN SOUTHEAST TEXAS...
WESTERN SAN JACINTO COUNTY IN SOUTHEAST TEXAS...
SOUTHERN WALKER COUNTY IN SOUTHEAST TEXAS...

* UNTIL 530 PM CDT

* AT 441 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
OF 60 MPH. THIS STORM WAS LOCATED NEAR HUNTSVILLE...AND MOVING
SOUTH AT 20 MPH.

* LOCATIONS IN THE SEVERE THUNDERSTORM WARNING INCLUDE BUT ARE NOT
LIMITED TO HUNTSVILLE STATE PARK...WILLIS AND NEW WAVERLY.

[Flyinman]

I was in that storm near IAH and it was like being in the Hurricane again. Tree limbs and pine cones were blowing down the street and the drops were so big it was like hail. I know I complain about lack of rain, but I will take it anyday over getting one of the severe storms.