Alert archive / Texas / Flash Flood Warnings in 2015

Flash Flood Warning 14, NWS Houston/Galveston, TX

April 17, 2015Harris County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Apr 17, 2015, 12:00 AM CDT for Harris County, Texas. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Apr 17, 2015, 12:00 AM CDT (05:00 UTC)
Expired: Apr 17, 2015, 2:00 AM CDT
In force: 2 hr
Issued by: NWS Houston/Galveston, TX
Area: Storm-based polygon
Flood severity: None

County Harris County, TX

The radar

The Houston radar (KHGX), 52 km from the middle of the area, began a volume at 05:02 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

Corpus Christi, TX (KCRP), launched 00:00Z, 5.0 hours before the alert went out and 303 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: 2661 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 705 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 126 m²/s²
0-3 km storm-relative helicity: 152 m²/s²
Significant tornado parameter: 2.6
Supercell composite: 13.3

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning 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 warning went out at Apr 16, 9:53 PM CDT, 2 hours 7 minutes earlier.

Area forecast discussion, Apr 16, 9:53 PM CDT, 2 hours 7 minutes before

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Hazardous weather outlook, Apr 16, 6:59 AM CDT, 17 hours 1 minute before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
659 AM CDT THU APR 16 2015

GMZ330-335-350-355-370-375-TXZ163-164-176>179-195>200-210>214-226-
227-235>238-171200-
AUSTIN-BRAZORIA-BRAZOS-BURLESON-CHAMBERS-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 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-WHARTON-
659 AM CDT THU APR 16 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST TEXAS.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS ACROSS SOUTHEAST
TEXAS TODAY. AS UPPER LEVEL DISTURBANCES CONTINUE TO MOVE INTO THE
AREA FROM THE WEST...THE APPROACH AND PASSAGE OF THE WARM FRONT
FROM THE GULF WILL HELP TO FOCUS THUNDERSTORM DEVELOPMENT BY THIS
AFTERNOON. THE UNSTABLE AND VERY MOIST AIRMASS OVER SOUTHEAST
TEXAS COULD SUPPORT THE FORMATION OF STRONG TO SEVERE
THUNDERSTORMS. LARGE HAIL AND DAMAGING WINDS APPEAR TO BE THE MAIN
THREATS.

IN ADDITION TO THE THREAT OF SEVERE WEATHER...THERE ARE CONCERNS
WITH THE POSSIBILITY OF FLASH FLOODING TODAY AND TONIGHT. THE VERY
WET GROUNDS FROM RAINS THIS PAST WEEK MAY NOT BE ABLE TO HANDLE
THE HEAVY RAINS THAT DEVELOP TODAY. RAINFALL TOTALS SHOULD
AVERAGE FROM ONE HALF TO ONE INCH WITH ISOLATED TOTALS OF 3 TO 4
INCHES POSSIBLE TODAY. A FLASH FLOOD WATCH MAY BE NEEDED LATE
TODAY OR TONIGHT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE SLIGHT RISK OF SEVERE THUNDERSTORMS FOR SOUTHEAST TEXAS WILL
CONTINUE INTO FRIDAY. THE LINGERING WARM FRONT COMBINED WITH THE
STILL VERY MOIST AND VERY UNSTABLE AIRMASS...ALONG WITH EVEN MORE
FAVORABLE JET DYNAMICS ALOFT WILL SUPPORT THE DEVELOPMENT OF
STRONG TO SEVERE THUNDERSTORMS ONCE AGAIN. SUPERCELLS WITH
DAMAGING WINDS AND LARGE HAIL ARE POSSIBLE.

THE THREAT OF FLASH FLOODING AND FLOODING WILL ALSO CONTINUE INTO
FRIDAY. THE STRONG TO SEVERE STORMS THAT ARE EXPECTED TO FORM WILL
BE SLOW MOVING AND LIKELY TO PRODUCE HEAVY RAIN. RAINFALL TOTALS
FOR FRIDAY SHOULD AVERAGE AROUND ONE INCH WITH ISOLATED TOTALS
FROM 3 TO 6 INCHES. A FLOOD WATCH WILL LIKELY BE NECESSARY IF IT
HAS NOT ALREADY BEEN ISSUED.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL MAY BE NEEDED TODAY AND FRIDAY.

In the hours before

Local storm report, Apr 16, 10:28 PM CDT, 1 hour 32 minutes before

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Local storm report, Apr 16, 10:34 PM CDT, 1 hour 26 minutes before

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Local storm report, Apr 16, 10:38 PM CDT, 1 hour 22 minutes before

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Local storm report, Apr 16, 10:42 PM CDT, 1 hour 18 minutes before

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Local storm report, Apr 16, 10:54 PM CDT, 1 hour 6 minutes before

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Local storm report, Apr 16, 11:02 PM CDT, 58 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
Apr 16, 7:08 PM CDT	Areal Flood Advisory	HGX	Chambers, Harris, Liberty	112 min
Apr 16, 7:10 PM CDT	Areal Flood Advisory	HGX	Chambers, Harris, Liberty	2 hr
Apr 16, 7:20 PM CDT	Flash Flood Warning	HGX	Polk, San Jacinto, Walker	115 min
Apr 16, 7:27 PM CDT	Special Weather Statement	HGX	Wharton	33 min
Apr 16, 7:36 PM CDT	Severe Thunderstorm Warning	HGX	Matagorda, Wharton	39 min
Apr 16, 8:06 PM CDT	Flash Flood Warning	HGX	Chambers, Harris, Liberty	114 min
Apr 16, 8:14 PM CDT	Severe Thunderstorm Warning	HGX	Brazoria, Fort Bend, Matagorda, Wharton	46 min
Apr 16, 8:22 PM CDT	Severe Thunderstorm Warning	HGX	Austin, Colorado, Wharton	38 min
Apr 16, 8:57 PM CDT	Severe Thunderstorm Warning	HGX	Austin, Colorado, Fort Bend, Waller, Wharton	48 min
Apr 16, 9:03 PM CDT	Flash Flood Warning	HGX	Chambers, Harris, Liberty	117 min
Apr 16, 9:39 PM CDT	Areal Flood Advisory	HGX	Harris, Montgomery	2 hr
Apr 16, 9:45 PM CDT	Severe Thunderstorm Warning	HGX	Fort Bend	30 min
Apr 16, 10:14 PM CDT	Severe Thunderstorm Warning	HGX	Brazoria, Fort Bend	46 min
Apr 16, 10:25 PM CDT	Small Craft Advisory	HGX		9 hr
Apr 16, 10:41 PM CDT	Special Marine Warning	HGX		49 min
Apr 16, 10:54 PM CDT	Flash Flood Warning	HGX	Chambers, Harris, Liberty	3 hr
Apr 16, 11:04 PM CDT	Areal Flood Advisory	HGX	Harris	3 hr
Apr 16, 11:48 PM CDT	Areal Flood Advisory	HGX	Brazos, Burleson, Washington	117 min
Apr 17, 4:09 AM CDT	Special Marine Warning	HGX		36 min
Apr 17, 4:20 AM CDT	Special Marine Warning	HGX		40 min
Apr 17, 4:44 AM CDT	Special Marine Warning	HGX		46 min
Apr 17, 5:07 AM CDT	Special Marine Warning	HGX		38 min
Apr 17, 5:21 AM CDT	Special Marine Warning	HGX		84 min
Apr 17, 3:53 PM CDT	Special Marine Warning	HGX		67 min
Apr 17, 4:26 PM CDT	Special Weather Statement	HGX	Matagorda	49 min
Apr 17, 4:49 PM CDT	Severe Thunderstorm Warning	HGX	Jackson	41 min
Apr 17, 5:03 PM CDT	Areal Flood Advisory	HGX	Jackson	3 hr
Apr 17, 5:39 PM CDT	Areal Flood Advisory	HGX	Colorado, Wharton	3 hr
Apr 17, 5:45 PM CDT	Severe Thunderstorm Warning	HGX	Colorado, Jackson, Matagorda, Wharton	45 min
Apr 17, 6:10 PM CDT	Special Weather Statement	HGX	Waller	35 min
Apr 17, 6:14 PM CDT	Flash Flood Warning	HGX	Colorado, Jackson, Wharton	2 hr
Apr 17, 6:21 PM CDT	Severe Thunderstorm Warning	HGX	Austin, Brazoria, Colorado, Fort Bend, Jackson, Matagorda and 2 more	39 min
Apr 17, 6:32 PM CDT	Areal Flood Advisory	HGX	Austin, Colorado, Fort Bend, Harris, Waller, Wharton	118 min
Apr 17, 6:56 PM CDT	Areal Flood Advisory	HGX	Brazoria, Fort Bend, Jackson, Matagorda, Wharton	3 hr
Apr 17, 6:56 PM CDT	Severe Thunderstorm Warning	HGX	Austin, Brazoria, Fort Bend, Galveston, Harris, Matagorda and 2 more	49 min

Nearby

Flash Flood Warnings in Texas, 2015 Every flash flood warning 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.