Alert archive / Texas / Flash Flood Warnings in 2014

Flash Flood Warning 21, NWS Houston/Galveston, TX

July 17, 2014Trinity County, Texas

NWS Houston/Galveston, TX issued this flash flood warning at Jul 17, 2014, 11:41 PM CDT for Trinity County, Texas. It was in force for 79 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 17, 2014, 11:41 PM CDT (04:41 UTC)
Expired: Jul 18, 2014, 1:00 AM CDT
In force: 79 min
Issued by: NWS Houston/Galveston, TX
Area: Storm-based polygon
Flood severity: None

County Trinity County, TX

The radar

The Shreveport radar (KSHV), 170 km from the middle of the area, began a volume at 04:43 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 00:00Z, 4.7 hours before the alert went out and 209 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: 1236 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 761 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 145 m²/s²
0-3 km storm-relative helicity: 225 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 5.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

347 
WGUS54 KHGX 180441
FFWHGX
TXC455-180600-
/O.NEW.KHGX.FF.W.0021.140718T0441Z-140718T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
1141 PM CDT THU JUL 17 2014

THE NATIONAL WEATHER SERVICE IN LEAGUE CITY  HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN TRINITY COUNTY IN SOUTHEAST TEXAS...

* UNTIL 100 AM CDT
    
* AT 1136 PM CDT...DOPPLER RADAR INDICATED ADDITIONAL SHOWERS 
  AND THUNDERSTORMS APPROACHING TRINITY COUNTY FROM THE WEST. RADAR 
  ESTIMATES INDICATE THAT 3 TO 8 INCHES OF RAIN HAS FALLEN 
  ACROSS NORTHERN TRINITY COUNTY AND FLASH FLOODING IS EXPECTED 
  TO CONTINUE. FLOODING HAS BEEN REPORTED IN APPLE SPRINGS.   

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  APPLE SPRINGS AND CENTRALIA. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.

TURN AROUND...DONT DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

&&

LAT...LON 3134 9495 3133 9490 3129 9490 3129 9488
      3126 9490 3123 9486 3115 9485 3115 9484
      3109 9490 3110 9531 3123 9518 3138 9496

$$

LW

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 7:37 PM CDT	Areal Flood Advisory	HGX	Grimes, Waller, Washington	53 min
Jul 17, 8:37 PM CDT	Flash Flood Watch	HGX	Austin, Brazoria, Brazos, Burleson, Chambers, Fort Bend and 13 more	8 hr
Jul 17, 9:04 PM CDT	Areal Flood Advisory	HGX	Brazos, Burleson, Grimes, Montgomery, Walker	116 min
Jul 17, 9:27 PM CDT	Flash Flood Warning	HGX	Brazos, Burleson	2 hr
Jul 17, 9:32 PM CDT	Flash Flood Warning	HGX	Grimes, Montgomery, Walker	118 min
Jul 17, 9:37 PM CDT	Areal Flood Advisory	HGX	Trinity	53 min
Jul 17, 9:42 PM CDT	Flash Flood Warning	HGX	Trinity	2 hr
Jul 18, 12:52 AM CDT	Areal Flood Advisory	HGX	Brazos, Burleson, Washington	113 min
Jul 18, 1:04 AM CDT	Areal Flood Advisory	HGX	Houston, Trinity	3 hr
Jul 18, 5:30 AM CDT	Areal Flood Advisory	HGX	Liberty	2 hr
Jul 18, 5:40 AM CDT	Areal Flood Advisory	HGX	Colorado	65 min
Jul 18, 8:36 AM CDT	Special Marine Warning	HGX		24 min

Nearby

Flash Flood Warnings in Texas, 2014 Every flash flood warning in 2014

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.