Flash Flood Warning 45, NWS Houston/Galveston, TX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
127 PM CDT FRI MAY 27 2016

.AVIATION...
Storms continuing to develop and sag slowly south along a surface
boundary that was previously stalled E-W across northern parts of
the area this morning. A strong low-level inflow into these TSRAs
noted with downstream obs (with gusts approaching 30kts with some
sites) along with daytime heating and high PWs all indicating the
strong possibility that this line of storms will move all the way
to the coast. As such, have tried to time the TEMPO groups for TS
onset based on current movements. Behind the line kept with a gen-
eral VCTS for the rest of the afternoon. Went with a more blanket
BKN015 (MVFR CIGS) for the overnight hours for all sites. 41

&&

.PREV DISCUSSION...

Surface analysis late this morning had a stalled front draped E/W
across SE Texas with weak surface low pressure over the Hill
Country. Strong inflow was noted with 30-35kt southerly winds on
the KHGX VAD wind profile. Elevated storms have formed behind the
frontal boundary as deep moisture continues to stream northward
riding over the boundary. Convective trends have been for more
activity to develop and with daytime heating, there could be
isolated strong/severe storm that produces heavy rainfall. It is
challenging to pinpoint the evolution of this convection since it
is not well organized. HRRR has had a tough time resolving
convection and depicting its evolution as a result. Given the
moist inflow normal to the boundary and favorable jet structure,
there is no reason to think that more convection will not develop.
Moderate ML CAPE exists south of the boundary so again more reason
to support convection with severe/heavy rain threat. Tried to
updated the forecast with these thoughts which was to increase
thunderstorm chances again. The next 6-9 hours will need to be
watch carefully for deep convection.

Overpeck

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      81  71  88  72  86 /  80  40  30  10  30
Houston (IAH)              82  74  88  73  87 /  70  40  30  10  30
Galveston (GLS)            82  77  83  78  82 /  60  20  20  10  20

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Flash Flood Watch until 10 PM CDT this evening FOR THE FOLLOWING
     ZONES: Austin...Brazos...Burleson...Chambers...Colorado...
     Fort Bend...Grimes...Harris...Houston...Liberty...Madison...
     Montgomery...Polk...San Jacinto...Trinity...Walker...
     Waller...Washington...Wharton.

     High Rip Current Risk until 10 PM CDT this evening FOR THE
     FOLLOWING ZONES: Brazoria...Chambers...Galveston...
     Matagorda.

GM...Small Craft Advisory until 6 PM CDT this evening FOR THE
     FOLLOWING ZONES: Coastal waters from Freeport to the
     Matagorda Ship Channel out 20 NM...Coastal waters from High
     Island to Freeport out 20 NM...Galveston Bay...Matagorda
     Bay.

     SMALL CRAFT SHOULD EXERCISE CAUTION from 6 PM CDT this evening
     through late tonight FOR THE FOLLOWING ZONES: Galveston
     Bay...Matagorda Bay.

     SMALL CRAFT SHOULD EXERCISE CAUTION from 6 PM CDT this evening
     through Saturday morning FOR THE FOLLOWING ZONES: Coastal
     waters from Freeport to the Matagorda Ship Channel out 20
     NM...Coastal waters from High Island to Freeport out 20 NM.

     Small Craft Advisory until 10 PM CDT this evening FOR THE
     FOLLOWING ZONES: Waters from Freeport to the Matagorda Ship
     Channel from 20 to 60 NM...Waters from High Island to
     Freeport from 20 to 60 NM.

     SMALL CRAFT SHOULD EXERCISE CAUTION from 10 PM CDT this evening
     through Saturday morning FOR THE FOLLOWING ZONES: Waters
     from Freeport to the Matagorda Ship Channel from 20 to 60
     NM...Waters from High Island to Freeport from 20 to 60 NM.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
424 AM CDT FRI MAY 27 2016

GMZ330-335-350-355-370-375-TXZ163-164-176>179-195>200-210>214-226-
227-235>238-281300-
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-
COASTAL WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM-COASTAL WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM-
COLORADO-FORT BEND-GALVESTON-GALVESTON BAY-GRIMES-HARRIS-HOUSTON-
JACKSON-LIBERTY-MADISON-MATAGORDA-MATAGORDA BAY-MONTGOMERY-POLK-
SAN JACINTO-TRINITY-WALKER-WALLER-WASHINGTON-
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL FROM 20 TO
60 NM-WATERS FROM HIGH ISLAND TO FREEPORT FROM 20 TO 60 NM-
WHARTON-
424 AM CDT FRI MAY 27 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

LOOK FOR PERIODS OF SHOWERS AND THUNDERSTORMS AS A SERIES OF DISTURBANCES
MOVE ACROSS THE AREA. SOME OF THE THUNDERSTORMS WILL HAVE THE POTENTIAL
TO BECOME STRONG OR SEVERE. LOCALLY HEAVY RAINFALL, STRONG WINDS, FREQUENT
LIGHTNING AND HAIL WILL ALL BE POSSIBLE WITH THIS ACTIVITY.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

WHILE SHOWER AND THUNDERSTORM COVERAGE IS EXPECTED TO DECREASE ON SATURDAY,
SOME OF THE ACTIVITY MIGHT BE ABLE TO BECOME STRONG OR SEVERE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NEEDED TODAY AND MIGHT BE NEEDED ON SATURDAY.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
134 PM CDT FRI MAY 27 2016

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

0330 PM     TSTM WND DMG     6 SSE NAVASOTA          30.31N  96.04W
05/26/2016                   GRIMES             TX   NEWSPAPER

            GLOBAL VACUUM SYSTEMS BUILDING DAMAGED ON HIGHWAY 6. NO
            EMPLYEE INJURIES REPORTED.

&&

EVENT NUMBER HGX1600201

DCH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
226 PM CDT FRI MAY 27 2016

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

0608 PM     TSTM WND DMG     3 SSE CUT AND SHOOT     30.30N  95.34W
05/26/2016                   MONTGOMERY         TX   PUBLIC

            10 TREES DOWN INCLUDING 100 YEAR OLD OAK AT 25 ACRE
            RESIDENCE.

&&

EVENT NUMBER HGX1600202

DCH