August 2014 - Showers/Storms Possible To End The Month

[Rip76]

Is there just high pressure sitting over Houston?

[Texaspirate11]

Got 3 inches of rain near the bay. I am NOT complaining.

[tireman4]

The rain is coming. Yes, it is coming.

The morning AFD from HGX:

00
FXUS64 KHGX 291132
AFDHGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
632 AM CDT FRI AUG 29 2014

.DISCUSSION...
SEE AVIATION FOR 12Z TAF DISCUSSION.

&&

.AVIATION...
CHALLENGING FORECAST THIS MORNING WITH REGARD TO COVERAGE AND
DURATION OF CONVECTION. SHOULD SEE MORE ACTIVITY ACROSS INLAND
AREAS TODAY AS TROPICAL MOISTURE CONTINUES TO STREAM ONSHORE AND A
REMNANT BOUNDARY FROM THUNDERSTORMS ACROSS NORTH TEXAS MOVES INTO
THE REGION. THINK WE WILL SEE A BIT OF A BREAK FOR THE EVENING
HOURS BEFORE ACTIVITY REDEVELOPS ACROSS THE SOUTHERN HALF OF THE
REGION. 38

&&

.PREV DISCUSSION... /ISSUED 457 AM CDT FRI AUG 29 2014/

DISCUSSION...
ATMOSPHERIC CONDITIONS ARE LOOKING MORE FAVORABLE FOR HEAVY
RAINFALL TONIGHT INTO SATURDAY MAINLY FOR E AND SE TX. UPPER LEVEL
ANALYSIS SHOWS AN UPPER LEVEL TROUGH OVER THE C PLAINS AND A WEAK
UPPER LOW OVER S TX WHICH HAS REMAINED QUASI-STATIONARY THE LAST
DAY OR TWO. UPPER LEVEL TROUGH SHOULD PROVIDE SOME STEERING
CURRENTS FOR THE UPPER LOW AND EXPECT IT TO MOVE TOWARDS THE UPPER
TX COAST TONIGHT. THIS UPPER LOW IS ALSO PROVIDING FLOW FOR
TROPICAL MOISTURE TO ADVECT TOWARDS THE NW GULF FOR TONIGHT. IR
IMAGERY ALREADY SHOWS VERY DEEP CONVECTION ASSOCIATED WITH THIS
TROPICAL MOISTURE OVER THE C GULF. THERE IS ALSO A LINE OF STORMS
OVER N TX ASSOCIATED WITH THE UPPER TROUGH OVER THE PLAINS WHICH
SHOULD CONTINUE TO WEAKEN. THE 00Z CRP/LCH SOUNDINGS SHOW 2-2.2
INCHES OF PRECIP WATER. MOISTURE IN THE GULF HAS PW VALUES
APPROACHING 2.5 SO THERE WILL BE CERTAINLY PLENTY OF MOISTURE FOR
THUNDERSTORM ACTIVITY. THERE ARE ALREADY SOME STORMS PUSHING
INLAND WITH DEEPER MOISTURE IN PLACE.

GIVEN THAT THERE WILL BE PLENTY OF MOISTURE/INSTABILITY/LIFT IN
THE ATMOSPHERE...THINK 50/60 POPS LOOK GOOD FOR RAIN CHANCES TODAY
AND THEN INCREASING TO 70/80 PERCENT FOR SAT MORNING. THE
GFS/ECMWF STILL KEEP A GOOD AMOUNT OF MOISTURE AND RESULTING
PRECIP OVER E TX INTO SW LA. THE NAM HOWEVER REMAINS CONSISTENT
SHOWING HIGH PRECIP AMOUNTS OVER PORTIONS OF SE TX FOR SAT
MORNING. THIS STILL RAISES THE CONCERN FOR HEAVY RAINFALL AND
POSSIBILITY OF FLOODING. THINK THE HIGHEST RAIN CHANCES WILL BE
MAINLY EAST OF I-45 AND ALONG THE COAST. THESE AREAS COULD PICK UP
1-3 INCHES OF RAIN VERY EASILY WITH THAT MUCH MOISTURE OVER THE
REGION. HOURLY RAIN RATES COULD REACH THOSE LEVELS ALONE. POSSIBLE
THERE COULD BE POCKETS OF 2-4 INCHES OF RAIN WHICH WOULD THEN
APPROACH FLASH FLOOD GUIDANCE NUMBERS. RIGHT NOW WILL HOLD OFF ON
A FLOOD WATCH BUT IF THERE ARE GOOD RAINFALL AMOUNTS DURING THE
DAY TODAY... MAY NEED A WATCH FOR THE SATURDAY MORNING PERIOD.
THIS WILL NEED TO BE MONITORED CLOSELY.

THUNDERSTORM CHANCES DO TAPER OFF SAT NIGHT INTO SUN. PRECIP WATER
VALUES WILL STILL BE AROUND 2 INCHES AND COULD SUPPORT SCT
THUNDERSTORM ACTIVITY. FORECAST LOOKS GOOD WITH 40/50 POPS AND
LOCALLY HEAVY RAINFALL COULD BE POSSIBLE AGAIN. THE MODELS ALSO
HAVE THE UPPER LEVEL TROUGH PUSHING EAST WITH ANY TROUGH AXIS
SHEARING OUT. UPPER LEVEL RIDGING SHOULD TAKE OVER MON INTO TUE
AND INCREASE SUBSIDENCE OVER THE REGION. THERE SHOULD HOWEVER BE
JUST ENOUGH DEEP MOISTURE TO WARRANT KEEPING AT LEAST SOME MENTION
OF THUNDERSTORM CHANCES. THERE MAY BE A TROPICAL CONNECTION FOR
DEEP MOISTURE REMAINING OVER THE AREA AS A TROPICAL WAVE MOVES
INTO THE S GULF FROM THE YUCATAN ON MON/TUE TIME FRAME. GFS/ECMWF
KEEP THIS TROPICAL SYSTEM DISORGANIZED WHICH THE CANADIAN MAKES
IT A HURRICANE. REGARDLESS THE SYSTEM MOVES INTO MEXICO WITH
REALLY ONLY TROPICAL MOISTURE AFFECTING SE TX. AS SUCH THE FORECAST
WILL KEEP MENTION OF 20 POPS THROUGH THE MIDDLE OF THE WEEK WITH
THE THOUGHT THERE COULD BE A DAY OR TWO WITH BETTER THUNDERSTORM
CHANCES DEPENDING ON AMOUNT OF MOISTURE AND SUBSIDENCE FROM THE
RIDGE.

TEMPERATURE FORECAST WILL BE TOUGH THE NEXT COUPLE OF DAYS WITH
CONVECTION EXPECTED. FARTHER INLAND EXPECT HIGH TEMPS TO REACH THE
MID 90S ESPECIALLY NEXT WEEK. TEMPS MAY REMAIN IN THE 80S FOR MUCH
OF THE DAY TOMORROW DEPENDING ON CONVECTION. MIN TEMPS IN THE
MID/UPPER 70S LOOKS ON TRACK WITH RAIN COOLED TEMPS IN THE LOW 70S
POSSIBLE WITH THUNDERSTORMS MOVING THROUGH THE AREA.

39

MARINE...
MODERATE EAST SOUTHEAST WINDS MAY WEAKEN BRIEFLY AROUND MIDDAY
BEFORE PICKING UP AGAIN FOR THE EVENING AND OVERNIGHT HOURS. HAVE
EXTENDED SCEC THROUGH THE REMAINDER OF THE MORNING AND IT WILL
LIKELY BE REQUIRED FOR TONIGHT INTO EARLY SATURDAY. AN UPPER LEVEL
DISTURBANCE ACROSS THE WESTERN GULF OF MEXICO WILL KEEP ONSHORE
WINDS IN PLACE THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS THE COASTAL WATERS. 38

&&

[tireman4]

Rainfall Outlook This Weekend:

[jasons2k]

So far, a repeat of yesterday. All the bands fall apart as they advance inland...

[BlueJay]

Hook up the soaker hose!

[Rip76]

I've been watering for almost an hour now.

[mckinne63]

Nice shower in SW Houston earlier this morning, than the sun came out and saw a beautiful rainbow. Nothing more yet, it is starting to get cloudy. Keeping my fingers crossed for some rain!

[TexasBreeze]

Hook up the soaker hose!

Right! It hasn't rained one drop at the house since I don't know when. The mass offshore will probably dissipate and tonight's rain most likely in LCH forecast area.

[JamieP]

Nice thunderstorm just passed downtown. It was pouring!

[mckinne63]

Raining here in Stafford now, some rumbles of thunder too! No wind though. Will take the glorious wetness from the sky!

[BlueJay]

Cloudy with rain!!!!!!!!!!!!!!

[davidiowx]

Been raining here in Sugar Land area for a good 30-45 min! Loving it.

[cperk]

It's pouring here in Richmond.

[Rip76]

Slight spin noticed in the Gulf below Houston.

A little too close to the coast though.

[srainhoutx]

For what its worth the 12Z GFS brings that mess N of the Yucatan NNW and develops a 850 vort max that pushes inland between Matagorda and Galveston. It also looks like a good surge of deep tropical moisture surges into the Western Gulf with a tropical wave nearing the Yucatan in the NW Caribbean. Further E in the Caribbean SSW of Greater Antilles, another sheared tropical wave is moving W and pressures are beginning to fall across the Western Caribbean.

08282014 12Z GFS gfs_wnatl_030_850_vort_ht.gif

Remember the GFS yesterday suggested a mid level vort max developing somewhere S between Matagorda and Galveston. Looks like that has verified...

[unome]

tropical stuff? well then color me happy ! we've had about 1/10" in the last week & I am tired of mowing & watering in these temps/heat index

at least it's been cloudy most of today, still waiting on precip though

[srainhoutx]

The WPC/HPC is still monitoring the potential for very heavy rainfall nearing a Slight Risk for Excessive Rainfall across SE Texas with their afternoon Update.

TEXAS GULF COAST

AT LEAST TWO SLOW MOVING LOW TO MID LEVEL CIRCULATION OVER THE
WESTERN GULF OF MEXICO WILL KEEP CONVECTION ACTIVE ACROSS THIS
AREA THIS PERIOD. THERE SEEMS TO BE GENERAL AGREEMENT THAT ONE
CENTER MAY BE LIFTED NORTHEASTWARD INTO THE LOWER MS VALLEY---ON
THE SOUTHEAST SIDE OF THE UPPER MS VALLEY TROF---WHILE THE
CIRCULATION OFF THE SOUTH TX COAST MOVES LITTLE. WITH PW VALUES
1.5-2+ STANDARD DEVIATIONS ABOVE THE MEAN OVER THE WESTERN GULF IN
THE VICINITY OF THESE CIRCULATIONS---HEAVY PRECIPITATION POTENTIAL
WILL PERSIST. THAT SAID---CONFIDENCE STILL IS NOT GREAT WITH QPF
DETAILS WITH BOTH SYSTEMS AS THERE ARE DIFFERENCES IN HOW QUICKLY
ONE VORT IS PICKED UP TO THE NORTHEAST AND DIFFERENCES WITH THE
CONVECTIVE DETAILS NEAR THE SLOW MOVING VORT OFF THE SOUTH TX
COAST---THAT WILL LIKELY REMAIN POORLY DEPICTED IN THE MODELS.
VERY HEAVY RAINFALL AMOUNTS POSSIBLE WITH BOTH VORTS---WITH
POTENTIAL FOR ISOLATED VERY HEAVY TO EXCESSIVE RAINFALL AMOUNTS.
GIVEN THE HIGH FFG VALUES ACROSS THESE REGIONS---A RISK AREA WAS
NOT DEPICTED. IN AREAS THAT CONVECTION DOES ENHANCE---VERY HEAVY
RAINFALL TOTALS POSSIBLE WITH ISOLATED 1-2"+ AMOUNTS IN AN HOUR OR
TWO AND ISOLATED TOTALS OF 3-5"+.

[davidiowx]

Are they considering flood watches?

[srainhoutx]

Not at this time David. HGX is monitoring closely and should conditions change, they have stated the may issue a Flash Flood Watch later this evening for portions of SE Texas.