Alert archive / Texas / Flash Flood Watches in 2015

Flash Flood Watch 9, NWS Houston/Galveston, TX

May 24, 201523 counties in Texas

NWS Houston/Galveston, TX issued this flash flood watch at May 24, 2015, 3:01 PM CDT for 23 counties in Texas. It took effect at May 25, 2015, 11:00 AM CDT. It was in force for 31 hr.

The area

The counties it named.

The facts

Issued: May 24, 2015, 3:01 PM CDT (20:01 UTC)
In effect from: May 25, 2015, 11:00 AM CDT
Expired: May 26, 2015, 6:00 PM CDT
In force: 31 hr
Issued by: NWS Houston/Galveston, TX
Flood severity: None

All 23 counties

Austin County, TX, Brazoria County, TX, Brazos County, TX, Burleson County, TX, Chambers County, TX, Colorado County, TX, Fort Bend County, TX, Galveston County, TX, Grimes County, TX, Harris County, TX, Houston County, TX, Jackson County, TX, Liberty County, TX, Madison County, TX, Matagorda County, TX, Montgomery County, TX, Polk County, TX, San Jacinto County, TX, Trinity County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 91 km from the middle of the area, began a volume at 20:01 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 8.0 hours before the alert went out and 242 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1371 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 795 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 198 m²/s²
0-3 km storm-relative helicity: 238 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 8.2

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Houston/Galveston, TX wrote its last area forecast discussion before this flash flood watch went out at May 24, 1:04 PM CDT, 1 hour 57 minutes earlier.

Area forecast discussion, May 24, 1:04 PM CDT, 1 hour 57 minutes before

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Hazardous weather outlook, May 24, 4:28 AM CDT, 10 hours 33 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
428 AM CDT SUN MAY 24 2015

TXZ163-164-176>179-195>200-210>213-226-227-250930-
AUSTIN-BRAZOS-BURLESON-COLORADO-FORT BEND-GRIMES-HARRIS-HOUSTON-
LIBERTY-MADISON-MONTGOMERY-POLK-SAN JACINTO-TRINITY-WALKER-WALLER-
WASHINGTON-WHARTON-
428 AM CDT SUN MAY 24 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

A LARGE AREA OF SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE
REGION FROM WEST TO EAST TODAY. TRAINING HEAVY RAIN...FLASH
FLOODING AND ISOLATED SEVERE STORMS CAPABLE OF GUSTY WINDS ARE
POSSIBLE. PLEASE SEE THE FLASH FLOOD WATCH FOR MORE DETAILED
INFORMATION.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

A CONTINUED FLASH FLOOD THREAT WILL EXIST INTO EARLY TUESDAY AS
ANOTHER ROUND OF WIDESPREAD HEAVY RAIN MOVES ACROSS THE AREA
MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUESTED THROUGH TUESDAY. REPORTS OF
FLASH FLOODING ARE ENCOURAGED AS WELL.

GMZ330-335-350-355-370-375-250930-
GALVESTON BAY-MATAGORDA BAY-
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM-
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM-
WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM-
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM-
428 AM CDT SUN MAY 24 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

A SMALL CRAFT ADVISORY IS IN EFFECT FOR INCREASING WINDS AND SEAS.
THREAT OF THUNDERSTORMS AFTER MIDNIGHT. WINDS AND SEAS HIGHER NEAR
STORMS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT UNTIL EARLY NEXT WEEK.
WINDS AND SEAS HIGHER NEAR STORMS INTO EARLY NEXT WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

TXZ214-235>238-250930-
BRAZORIA-CHAMBERS-GALVESTON-JACKSON-MATAGORDA-
428 AM CDT SUN MAY 24 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

A WIND ADVISORY IS IN EFFECT THROUGH THIS EVENING... AND STRONG
ONSHORE WINDS WILL CONTINUE THE THREAT OF STRONG RIP CURRENTS
AS SURF BUILDS ACROSS AREA BEACHES.

A LARGE AREA OF SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE
REGION FROM WEST TO EAST TODAY. TRAINING HEAVY RAIN...FLASH
FLOODING AND ISOLATED SEVERE STORMS CAPABLE OF GUSTY WINDS ARE
POSSIBLE. PLEASE SEE THE FLASH FLOOD WATCH FOR MORE DETAILED
INFORMATION.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

A CONTINUED FLASH FLOOD THREAT WILL EXIST INTO EARLY TUESDAY AS
ANOTHER ROUND OF WIDESPREAD HEAVY RAIN MOVES ACROSS THE AREA
MONDAY.

A HIGHER THAN NORMAL RISK OF RIP CURRENTS IS EXPECTED THROUGH EARLY
THIS WEEK. IF GOING TO THE BEACH...SWIM NEAR A LIFEGUARD AND WELL
AWAY FROM JETTIES...GROINS...AND PIERS. SWIM NEAR A LIFEGUARD.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUESTED THROUGH TUESDAY. REPORTS OF
FLASH FLOODING ARE ENCOURAGED AS WELL.

In the hours before

Local storm report, May 24, 9:50 AM CDT, 5 hours 11 minutes before

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Local storm report, May 24, 12:57 PM CDT, 2 hours 4 minutes before

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Local storm report, May 24, 1:08 PM CDT, 1 hour 53 minutes before

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The office that day

Everything else NWS Houston/Galveston, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 23, 10:33 PM CDT	Severe Thunderstorm Warning	HGX	Burleson	27 min
May 23, 11:01 PM CDT	Severe Thunderstorm Warning	HGX	Brazos, Burleson	44 min
May 23, 11:59 PM CDT	Special Weather Statement	HGX	Madison	46 min
May 24, 12:33 AM CDT	Areal Flood Advisory	HGX	Brazos, Grimes, Madison, Washington	57 min
May 24, 2:41 AM CDT	Special Marine Warning	HGX		64 min
May 24, 2:53 AM CDT	Severe Thunderstorm Warning	HGX	Jackson	52 min
May 24, 3:39 AM CDT	Severe Thunderstorm Warning	HGX	Austin, Colorado, Jackson, Matagorda, Wharton	36 min
May 24, 3:42 AM CDT	Special Marine Warning	HGX		63 min
May 24, 3:56 AM CDT	Wind Advisory	HGX	Brazoria, Chambers, Galveston, Jackson, Matagorda	14 hr
May 24, 4:20 AM CDT	Severe Thunderstorm Warning	HGX	Austin, Brazoria, Colorado, Fort Bend, Jackson, Matagorda and 3 more	55 min
May 24, 4:44 AM CDT	Special Marine Warning	HGX		91 min
May 24, 5:16 AM CDT	Severe Thunderstorm Warning	HGX	Austin, Brazoria, Fort Bend, Harris, Matagorda, Montgomery and 2 more	59 min
May 24, 5:52 AM CDT	Special Marine Warning	HGX		113 min
May 24, 6:02 AM CDT	Tornado Warning	HGX	Fort Bend, Harris	43 min
May 24, 6:08 AM CDT	Severe Thunderstorm Warning	HGX	Brazoria, Fort Bend, Galveston, Harris	67 min
May 24, 6:31 AM CDT	Tornado Warning	HGX	Harris	18 min
May 24, 6:53 AM CDT	Special Weather Statement	HGX	Montgomery	67 min
May 24, 7:18 AM CDT	Special Weather Statement	HGX	Chambers, Liberty	72 min
May 24, 8:18 AM CDT	Special Marine Warning	HGX		87 min
May 24, 8:37 AM CDT	Special Weather Statement	HGX	Houston, Polk, Trinity	53 min
May 24, 8:55 AM CDT	River Flood Warning	HGX	Burleson, Lee	6 days

Nearby

Flash Flood Watches in Texas, 2015 Every flash flood watch in 2015

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.