April 2016 Recap: Regional Flood/Severe Weather

[Texashawk]

WPC discussion update - sounds very ominous for our western side.


MADE ADJUSTMENTS TO THE HIGH RISK AND MODERATE RISK AREAS BASED ON
TRENDS. AN MCS OVER THE EASTERN PART OF THE HILL COUNTRY WAS BEST
SUPPORTED BY THE SYNOPTIC PATTERN / DEEP LAYER ASCENT...AND WILL
CONTINUE TO DRIVE A FLASH FLOOD THREAT AS IT SLIDES SLOWLY EAST
OVERNIGHT. OF GROWING CONCERN...HOWEVER...THE CLUSTER OF
THUNDERSTORMS THAT FORMED NEAR/NORTH OF HOUSTON HAS TAKEN ROOT
WITH A DEVELOPING COLD POOL. THIS WILL ANCHOR THAT SMALL MCS
AGAINST THE VERY MOIST AND MODERATELY UNSTABLE INFLOW OFF THE
GULF. THE HRRR AND ESRL EXPERIMENTAL HRRR HAVE SHOWN IN
CONSECUTIVE RUNS...A VERY PRONOUNCED RAINFALL MAXIMUM OVERNIGHT IN
THE VICINITY OF HOUSTON AND ESPECIALLY AREAS JUST NORTH AND WEST
OF THE CITY...INCLUDING HUNTSVILLE...COLLEGE STATION...AND OVER TO
NEAR I-35 / AUSTIN. WITH MODERATE INSTABILITY...STRONG INFLOW OF
SEASONABLY RICH MOISTURE...AND LITTLE NET MOVEMENT...EXPECT
EXTREME RAINFALL RATES. THE HRRR RUNS MENTIONED ARE PRODUCING NEAR
10 INCHES OF RAIN IN A 6 HOUR PERIOD. THE EVENT APPEARS TO BE
DEVELOPING IN A FOCUSED AND POTENTIALLY LIFE THREATENING WAY. SEE
MESOSCALE PRECIPITATION DISCUSSIONS FOR FURTHER DETAILS.

[djjordan]

Reports of over 7.5" of rainfall in Waller along with small hail and lightning. Rough night thus far.

[srainhoutx]

Update from Jeff:

Extremely dangerous and life threatening flash flood event unfolding over Austin, Waller and NW Harris Counties.

Slow moving and at times stationary tremendous rainfall of 3-5 inches per hour ongoing. HCFCD gage on upper Cypress Creek pushing 3.92 inches in the last hour with storm total over 6.5 inches. This is a very dangerous situation. Extensive flooding is rapidly developing. Storm cluster is edging very slowly toward the ESE and will move over more of western Harris County in the next hour.

Dangerous situation in the highlighted pink area.

[DoctorMu]

Meso is beginning to fill in the space between CLL and HOU. Ominous.

[unome]

ULLETIN - IMMEDIATE BROADCAST REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON, TX
1111 PM CDT SUN APR 17 2016

...The National Weather Service in Houston/Galveston has issued a flood warning for the following rivers...

Cypress Creek Near Katy-Hockley Road affecting the following counties in Texas... Harris... Waller


For Cypress Creek at Mathis Road... Sharp Road... Katy-Hockley Road, Minor flooding is forecasted.

Intense rainfall of 2-7 inches has fallen across the headwaters of Cypress Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Persons with interests along these streams should keep alert to rising water and take all precautions to protect their property. Do not drive or walk into flooded areas the depth and water velocity could be too great for you to cross safely. Motorists should avoid any water covered roads and find an alternate route. Livestock and equipment should be removed from the flood plain immediately.

Stay tuned to NOAA Weather radio or other news sources for further updates.

&&

1111 PM CDT SUN APR 17 2016

Forecast information for
Little Mound Creek Near Mathis Road
* At 1227 PM Sunday the stage was 197.2 feet.
* The creek should rise above flood stage.
* Flood stage is 205.3 feet.

[Texashawk]

Sounds like TranStar will be a very busy place tonight. Get some nutrients and caffeine in you Jeff and team!

[DoctorMu]

Update from Jeff:

Extremely dangerous and life threatening flash flood event unfolding over Austin, Waller and NW Harris Counties.

Slow moving and at times stationary tremendous rainfall of 3-5 inches per hour ongoing. HCFCD gage on upper Cypress Creek pushing 3.92 inches in the last hour with storm total over 6.5 inches. This is a very dangerous situation. Extensive flooding is rapidly developing. Storm cluster is edging very slowly toward the ESE and will move over more of western Harris County in the next hour.

Dangerous situation in the highlighted pink area.

Worse than that - expanding north and south. Incredibly dangerous situation appears to be developing.

[unome]

unome: that outflow boundary and border between the cold pool and warm air is creating a heck of a lot of lift.

The meso in Waller and Austin Cos. is being fed by a QPF firehose. Note that incoming moisture from the Gulf is expanding the southern border retrograde back to I-10 and south while the northern border continues to lift north. We have an expanding, extreme situation.

I'm about ready to get our son's car off the street & into our driveway, which is higher up... we're off Little Cypress Creek - would rather not take a chance

[srainhoutx]

Heading out to move two vehicles off the street into the driveway. Getting marble sized hail here at the house.

[djjordan]

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1117 PM CDT SUN APR 17 2016

TXZ198-199-211>213-180500-
GRIMES TX-AUSTIN TX-WALLER TX-HARRIS TX-MONTGOMERY TX-
1117 PM CDT SUN APR 17 2016

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL WALLER...SOUTHEASTERN
GRIMES...SOUTHWESTERN MONTGOMERY...NORTHWESTERN HARRIS AND
SOUTHEASTERN AUSTIN COUNTIES UNTIL MIDNIGHT CDT...

AT 1116 PM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM OVER
WALLER...OR NEAR PRAIRIE VIEW...MOVING NORTH AT 30 MPH.

HALF INCH HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM. PUBLIC HAS REPORTED SMALL HAIL WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
PRAIRIE VIEW...PINEHURST...HOCKLEY...WALLER...MAGNOLIA...PINE ISLAND...SAN
FELIPE...MONTGOMERY...STAGECOACH...PATTISON...TODD MISSION...DOBBIN...
MONAVILLE...DACUS AND PLANTERSVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 10 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO
STATIONS AND AVAILABLE TELEVISION STATIONS FOR ADDITIONAL INFORMATION
AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

[Texaspirate11]

While we aren't getting any rain, we are providing an amazing amount of wind energy down here by the bay.
Gusting like a Cat 1.
Be safe everyone!

[djjordan]

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1122 PM CDT SUN APR 17 2016

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* FLASH FLOOD WARNING FOR...
NORTHERN WALLER COUNTY IN SOUTHEASTERN TEXAS...
SOUTHEASTERN GRIMES COUNTY IN SOUTHEASTERN TEXAS...
SOUTHWESTERN MONTGOMERY COUNTY IN SOUTHEASTERN TEXAS...
NORTHWESTERN HARRIS COUNTY IN SOUTHEASTERN TEXAS...

* UNTIL 215 AM CDT

* AT 1121 PM CDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING
HEAVY RAIN ACROSS THE WARNED AREA. 2 TO 5 INCHES OF RAIN HAVE
FALLEN. FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
HEMPSTEAD...PRAIRIE VIEW...PINEHURST...HOCKLEY...WALLER...MAGNOLIA...
STAGECOACH...TODD MISSION...DOBBIN AND PLANTERSVILLE.

[DoctorMu]

Looks like some convergence in W and NW Harris Co, and another feeder line of entraining.

[unome]

that's a quick rise

http://www.harriscountyfws.org/GageDetail/Index/1230 (over banks)

http://www.harriscountyfws.org/GageDetail/Index/1090 (over banks)

http://www.harriscountyfws.org/GageDetail/Index/1190 (over banks)

adding south mayde, now also over banks
http://www.harriscountyfws.org/GageDetail/Index/2150

[unome]

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1129 PM CDT SUN APR 17 2016

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
SOUTHWESTERN MONTGOMERY COUNTY IN SOUTHEASTERN TEXAS...
NORTH CENTRAL HARRIS COUNTY IN SOUTHEASTERN TEXAS...

* UNTIL MIDNIGHT CDT

* AT 1128 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR JERSEY
VILLAGE...MOVING NORTH AT 30 MPH.

HAZARD...60 MPH WIND GUSTS AND QUARTER SIZE HAIL.

SOURCE...RADAR INDICATED.

IMPACT...HAIL DAMAGE TO VEHICLES IS EXPECTED. EXPECT WIND DAMAGE
TO ROOFS...SIDING...AND TREES.

* LOCATIONS IMPACTED INCLUDE...
TOMBALL...JERSEY VILLAGE...PINEHURST...SPRING BRANCH NORTH...THE
WOODLANDS...NORTHERN ADDICKS PARK TEN...SPRING BRANCH WEST...SPRING...
OAK RIDGE NORTH...SHENANDOAH...STAGECOACH...CYPRESS...SPLASHTOWN...
WILLOWBROOK...CARVERDALE...FAIRBANKS / NORTHWEST CROSSING...GREATER
INWOOD...WESTBRANCH...HOOKS AIRPORT AND SPRING BRANCH CENTRAL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

THIS STORM IS PRODUCING LARGE HAIL. SEEK SHELTER NOW INSIDE A STURDY
STRUCTURE AND STAY AWAY FROM WINDOWS!

LARGE HAIL AND DAMAGING WINDS AND CONTINUOUS CLOUD TO GROUND
LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS IMMEDIATELY.
LIGHTNING IS ONE OF NATURE'S LEADING KILLERS. REMEMBER...IF YOU CAN
HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING.

TORRENTIAL RAINFALL IS OCCURRING WITH THIS STORM...AND MAY LEAD TO
FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS.

&&

LAT...LON 2981 9549 2983 9570 3024 9571 3021 9540
TIME...MOT...LOC 0428Z 185DEG 25KT 2993 9559

HAIL...1.00IN
WIND...60MPH

[srainhoutx]

Definitely a meso scale vortex (MCV) wrapping up in Waller, NW Harris and Montgomery counties. Looks to be almost stationary. More hail again as well.

[unome]

Definitely a meso scale vortex (MCV) wrapping up in Waller, NW Harris and Montgomery counties. Looks to be almost stationary. More hail again as well.

funktop was popping green in Waller Co - looks like tropical season started early ?

[djjordan]

Well I'll keep monitoring .... gotta get a few hours of sleep or at least try to. I'll report back in if something major happens here in Ft. Bend/SGR.... although I am a bit worried about some of the radar trends I am seeing developing here.

[unome]

extreme lightning/thunder here

[DoctorMu]

Definitely a meso scale vortex (MCV) wrapping up in Waller, NW Harris and Montgomery counties. Looks to be almost stationary. More hail again as well.

funktop was popping green in Waller Co - looks like tropical season started early ?

http://www.thorntonweather.com/satellit ... unktop.php