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

[Garnetcat5]

About to volunteer for after school meeting on Thurs. how bad could it get in Houston ...SW Houston Thurs. afternoon....any thoughts before I volunteer? LOL ok maybe I'm looking for a way out of the meeting...LOL

[Extremeweatherguy]

Has anyone else noticed that our current dewpoints are MUCH lower than what the models had predicted? As of 6pm the dewpoint at Hooks airport is down to 22F and at IAH the dewpoint is 27F. These numbers are a good 5-15 degrees lower than what the 12z and 18z model runs had predicted during this same time period (which is quite significant).

Because of these much lower dewpoints, I am beginning to wonder if our lows tonight will need to be adjusted downward. With a 6pm dewpoint of just 22F at Hooks, there is a good chance that the forecast low of 37F in northern Harris county could bust by at least a couple of degrees. In fact, I wouldn't even be surprised to see some freezing or below freezing readings come tomorrow morning.

Definitely something to watch..

update - 8pm dewpoints are now down to 19F at Hooks and 21F at IAH. None of the models even came close to these numbers for the 8pm hour! Most of them still show us having dewpoints in the 30s right now. lol.

[Extremeweatherguy]

Latest from the NWS: Winds are now expected to decouple overnight and good radiational cooling will ensue. A freeze is expected over the northern 1/2 of SE Texas...

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
811 PM CST TUE JAN 29 2008

.DISCUSSION...
AT 02Z...SURFACE DEW POINTS WERE IN THE UPPER TEENS OVER THE
NORTHWEST TO THE MID 30S ALONG THE COAST. THE PRESSURE GRADIENT IS
SHOWING SIGNS OF RELAXING AS A CENTER OF HIGH PRESSURE SETTLES
OVER SOUTHEAST TEXAS BY SUNRISE. SKIES CONTINUE TO CLEAR FROM THE
WEST AND AM EXPECTING MAINLY CLEAR SKIES AFTER MIDNIGHT. MIN TEMPS
ARE TRICKY. CURRENT THINKING IS THAT WINDS WILL DECOUPLE AFTER
MIDNIGHT OVER THE NORTHERN TWO-THIRDS OF THE CWA. IDEAL
RADIATIONAL CONDITIONS WILL ENSUE AND ALLOW TEMPS TO FALL NEAR OR
SLIGHTLY BELOW FREEZING OVER THE NORTH HALF. WINDS WILL PROVIDE A
BIT OF MIXING TOWARD THE COAST SO SLIGHTLY WARMER TEMPS TOWARD THE
WATER. THE AIR MASS IS SO DRY THAT IF WINDS DECOUPLE SOONER...SOME
SLIGHTLY COLDER VALUES WILL BE POSSIBLE. WILL BE MAKING MINOR
CHANGES TO THE GRIDS/ZFP.

THURSDAY MORNING IS LOOKING INTERESTING. TREMENDOUS SHEAR COUPLED
WITH MARGINAL INSTABILITY AND INCREASING MOISTURE SHOULD YIELD A
ROUND OF STRONG STORMS MAINLY BETWEEN 09Z AND 18Z. 43

[Extremeweatherguy]

Good thing light winds stayed up overnight. I am sitting at 32.2F right now, and will likely still drop another 0.5F or so, but overall this is not as cold as it could have been if we would have seen calm winds. It is, however, still colder than originally forecast yesterday afternoon.

[jasons2k]

I hit 33F this morning, definitely colder than expected.

[jasons2k]

From Jeff Lindner:

Moisture well underway with rapid increase in Gulf moisture expected in the next 6-10 hours.

Already 50 degree dewpoints are surging northward into the coastal bend compared with 10’s and 20’s over the majority of SE TX. Will continue to see moisture rapidly increase as low pressure builds into W TX and moves eastward while deepening. Cloud deck is rapidly advancing northward and overspreading the region at this time.

Will begin to see showers and thunderstorms develop after midnight as forcing from main upper trough moves across the state. Main linear forcing along strong frontal boundary will arrive around sunrise Thursday AM with expected linear MCS/squall line developing. Impressive wind fields at both the low and mid levels continue to foreshadow a damaging wind threat along with a hail threat with freezing levels falling to sub-10K feet.

Will go with the highest severe threat along and N of I-10 and E of I-45 while less of a threat around the Matagorda Bay region where capping will be the strongest and forcing the weakest. Still feel the bigger threat will lie just E of SE TX from the Sabine River E along the Gulf coast where surface based supercells may form producing a tornado threat.

Still looking at high winds Thursday post frontal passage and likely Red Flag conditions NW and W counties where wetting rains do not fall tonight and early Thursday. May need wind advisory all counties on Thursday PM as models continue to prog 40-50kts just off the surface.

[Ed Mahmoud]

About to volunteer for after school meeting on Thurs. how bad could it get in Houston ...SW Houston Thurs. afternoon....any thoughts before I volunteer? LOL ok maybe I'm looking for a way out of the meeting...LOL

The bad stuff should clear HOU area by lunch time.

[Ed Mahmoud]

About to volunteer for after school meeting on Thurs. how bad could it get in Houston ...SW Houston Thurs. afternoon....any thoughts before I volunteer? LOL ok maybe I'm looking for a way out of the meeting...LOL

The bad stuff should clear HOU area by lunch time.

Morning drive time, however...

[Extremeweatherguy]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
846 PM CST WED JAN 30 2008

.DISCUSSION...
PRECIP WAS A LITTLE MORE ROBUST (LIGHTNING SOUTH OF UTS) THIS
EVENING THAN PREVIOUSLY THOUGHT. AFTER MUCH CONSTERNATION...
DECIDED TO ADD SOME POSSIBLY SEVERE AFTER MIDNIGHT. AT 00Z...A
STRONG UPPER LEVEL TROUGH WAS LOCATED BETWEEN AMA AND OKC. THE
TROUGH WILL CONTINUE TO DEEPEN AS IT PUSHES EAST. THIS SYSTEM HAS
A GREAT DEAL OF WIND SHEAR AND WET BULB ZERO TEMPS ARE AROUND 8000
FT. IT WON`T TAKE MUCH LIFT TO GET SOME HAIL OUT OF THESE STORMS...
PARTICULARLY OVER THE NORTHERN HALF OF THE REGION. CLOSER TO THE
COAST...HELICITY VALUES ARE VERY HIGH AND IF ANY OF THE STORMS
BECOME SURFACE BASED...ISOLATED TORNADOES WILL BE POSSIBLE. THE
00Z NAM 12 HAS DEW POINTS IN THE LOWER 60S ALONG THE COAST AROUND
12Z THURSDAY. THINK THIS WILL PROVIDE THE INSTABILITY NEEDED FOR
SURFACE BASED STORMS. THE TORNADO THREAT AREA WILL BE ALONG AND
EAST OF A BAY CITY TO LIVINGSTON LINE. THE WINDOW FOR HAZARDOUS
WEATHER IS SMALL AND THIS IS A TOUGH CALL. CONFIDENCE IS LOW.

TEMPS WILL LIKELY REMAIN STEADY OR SLOWLY WARM OVERNIGHT. TWEAKED
HOURLY GRIDS TO REFLECT WARMING TREND. WINDS TOMORROW WILL BE
ANOTHER ISSUE AS GUIDANCE SUPPORTS WIND SPEEDS AOA 25 MPH. A WIND
ADVISORY WILL LIKELY BE REQUIRED FOR MUCH OF THE AREA BY THURSDAY
AFTERNOON. WILL LET THE NEXT SHIFT EVALUATE THAT PROBLEM.

WILL UPDATE THE HWO AND HAVE NEW ZONES OUT BY 930 PM.

[Ed Mahmoud]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
846 PM CST WED JAN 30 2008

.DISCUSSION...
PRECIP WAS A LITTLE MORE ROBUST (LIGHTNING SOUTH OF UTS) THIS
EVENING THAN PREVIOUSLY THOUGHT. AFTER MUCH CONSTERNATION...
DECIDED TO ADD SOME POSSIBLY SEVERE AFTER MIDNIGHT. AT 00Z...A
STRONG UPPER LEVEL TROUGH WAS LOCATED BETWEEN AMA AND OKC. THE
TROUGH WILL CONTINUE TO DEEPEN AS IT PUSHES EAST. THIS SYSTEM HAS
A GREAT DEAL OF WIND SHEAR AND WET BULB ZERO TEMPS ARE AROUND 8000
FT. IT WON`T TAKE MUCH LIFT TO GET SOME HAIL OUT OF THESE STORMS...
PARTICULARLY OVER THE NORTHERN HALF OF THE REGION. CLOSER TO THE
COAST...HELICITY VALUES ARE VERY HIGH AND IF ANY OF THE STORMS
BECOME SURFACE BASED...ISOLATED TORNADOES WILL BE POSSIBLE. THE
00Z NAM 12 HAS DEW POINTS IN THE LOWER 60S ALONG THE COAST AROUND
12Z THURSDAY. THINK THIS WILL PROVIDE THE INSTABILITY NEEDED FOR
SURFACE BASED STORMS. THE TORNADO THREAT AREA WILL BE ALONG AND
EAST OF A BAY CITY TO LIVINGSTON LINE. THE WINDOW FOR HAZARDOUS
WEATHER IS SMALL AND THIS IS A TOUGH CALL. CONFIDENCE IS LOW.

TEMPS WILL LIKELY REMAIN STEADY OR SLOWLY WARM OVERNIGHT. TWEAKED
HOURLY GRIDS TO REFLECT WARMING TREND. WINDS TOMORROW WILL BE
ANOTHER ISSUE AS GUIDANCE SUPPORTS WIND SPEEDS AOA 25 MPH. A WIND
ADVISORY WILL LIKELY BE REQUIRED FOR MUCH OF THE AREA BY THURSDAY
AFTERNOON. WILL LET THE NEXT SHIFT EVALUATE THAT PROBLEM.

WILL UPDATE THE HWO AND HAVE NEW ZONES OUT BY 930 PM.

Interesting Morning Commute Watch now in effect.

[jasons2k]

And that it is...

http://www.spc.noaa.gov/products/watch/ww0029.html

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 29
NWS STORM PREDICTION CENTER NORMAN OK
550 AM CST THU JAN 31 2008

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

SOUTHWEST AND SOUTH CENTRAL LOUISIANA
SOUTHEAST TEXAS
COASTAL WATERS

EFFECTIVE THIS THURSDAY MORNING AND AFTERNOON FROM 550 AM UNTIL
100 PM CST.

TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 115 STATUTE
MILES EAST AND WEST OF A LINE FROM 65 MILES NORTH NORTHEAST OF
LAKE CHARLES LOUISIANA TO 35 MILES SOUTHEAST OF GALVESTON TEXAS.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU9).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

DISCUSSION...TSTMS EXPECTED TO INCREASE IN NUMBER AND STRENGTH IN
WAA ZONE INVOF NW GULF OF MEXICO SFC WAVE. OTHER STORMS EXPECTED TO
INTENSIFY FARTHER NW ALONG LEADING EDGE OF ASCENT ASSOCIATED WITH
STRONG TX PANHANDLE UPR VORT. VERY SHALLOW LAYER OF POLAR AIR NOW
OVER WW REGION EXPECTED TO ERODE STEADILY NWD THROUGH
MIDDAY...INCREASING CHANCES THAT STORMS IN THE NW GULF AND SE TX
WILL BECOME MORE NEARLY SFC-BASED AS THEY MOVE/DEVELOP NE INTO LA.
GIVEN STRENGTH OF WIND FIELD AND CONSIDERABLE SPEED/DIRECTIONAL
SHEAR...RESULTING SUPERCELLS COULD PRODUCE TORNADOES IN ADDITION TO
HIGH WIND AND HAIL.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
400. MEAN STORM MOTION VECTOR 22040.

[Ed Mahmoud]

Well, foggy in Galleria, and waiting on storms to arrive.

But what is this? An interesting snippet from the NWS SJT AFD!

WEATHER-CLIMATE DIAGNOSTIC TOOLS FROM THE ESRL-PSD WEBSITE
INDICATE THAT SOME CHANGES ARE IN STORE DURING THE EARLY PART OF
WEEK 2 IN THE FORM OF SOME COLDER WEATHER. A STEADY RISE IN GLOBAL
RELATIVE AAM (ATMOSPHERIC ANGULAR MOMENTUM) AND RELATIVE AAM
TENDENCY HAS BEEN NOTED RECENTLY. THE AAM TENDENCY PEAKED ABOUT 4
DAYS AGO AND IS NOW HEADED DOWN. SO WHAT DOES THIS ALL MEAN? IT
MEANS THAT A TRANSITION TO A GSDM (GLOBAL SYNOPTIC DYNAMIC MODEL,
WEICKMANN-BERRY FEB 2007 MWR) PHASE 5/OLD STAGE 2 IS LIKELY DURING
WEEK 2. A STAGE 2 REGIME GENERALLY MEANS BELOW NORMAL TEMPS FOR
MUCH OF THE CENTRAL CONUS WITH LOWER UPPER HEIGHTS OVER THE
CENTRAL CONUS AND GREAT LAKES REGIONS WHILE RIDGING IS DOMINANT
ALONG OR JUST OFF THE WEST COAST. IRONICALLY, THE 240HR ECMWF
SHOWS AN ARCTIC BLAST PUNCHING INTO WESTERN TEXAS ON DAY 10 (SAT
FEB 10). WHILE ONE OBVIOUSLY CAN`T RELY ON THE EXACT TIMING OF
FEATURES THAT FAR OUT, THE GENERAL IDEA SEEMS PLAUSIBLE. STAY TUNED.

LACY

[Crostorm]

Nice Animation

[JenBayles]

I didn't need to look at the radar to know this storm is a biggun'. I can hardly move this morning for the arthritis in my hips flaring up. Best weather indicator I've got!

[jasons2k]

Pretty Impressive:

[jasons2k]

Maybe some rotation with the Montgomery County cell:

[jasons2k]

I would expect a warning for Harris at any time as the cell along 45-North has some large hail...

[jasons2k]

Voila!

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
854 AM CST THU JAN 31 2008

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
HARRIS COUNTY IN SOUTHEAST TEXAS
LIBERTY COUNTY IN SOUTHEAST TEXAS
MONTGOMERY COUNTY IN SOUTHEAST TEXAS
SAN JACINTO COUNTY IN SOUTHEAST TEXAS
POLK COUNTY IN SOUTHEAST TEXAS

* UNTIL 945 AM CST

* AT 848 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS FROM NEAR CLEVELAND TO SPLENDORA TO
SPRING TO JERSEY VILLAGE TO ADDICKS. THIS LINE WAS MOVING EAST
AT 50 MPH. STRONG WINDS AND LARGE HAIL ARE POSSIBLE IN THIS LINE.

* LOCATIONS IMPACTED INCLUDE...
HUMBLE...
HOUSTON...
LIBERTY...
KINGWOOD...
SHEPHERD...

THIS IS A DANGEROUS LINE OF STORMS. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 100 PM CST THURSDAY AFTERNOON
FOR SOUTHEAST TEXAS.

PLEASE REPORT SEVERE WEATHER TO THE COUNTY SHERIFF...LOCAL POLICE...
OR DEPARTMENT OF PUBLIC SAFETY. THEY WILL RELAY YOUR REPORT TO THE
NATIONAL WEATHER SERVICE.

[Ed Mahmoud]

Got very, very dark at Galleria, but seems now like a garden variety t-storm.

[Ed Mahmoud]

Montgomery County doing better than just a garden variety t-storm

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
908 AM CST THU JAN 31 2008

..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..

0838 AM HAIL 2 S WOODLOCH 30.19N 95.41W
01/31/2008 E1.00 INCH MONTGOMERY TX LAW ENFORCEMENT

QUARTER SIZED HAIL AT I45 AND RESEARCH FOREST.

0838 AM HAIL 2 W WOODBRANCH 30.18N 95.22W
01/31/2008 E0.75 INCH MONTGOMERY TX LAW ENFORCEMENT

MARBLE AND PENNY HAIL AT FM242 AND SOMERSET.

0902 AM HAIL KINGWOOD 30.06N 95.19W
01/31/2008 E0.25 INCH HARRIS TX AMATEUR RADIO

HIGHWAY 59 AND NORTHPARK.