Alert archive / Texas / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 105, NWS Houston/Galveston, TX

May 20, 2017Houston County, Trinity County, Texas

NWS Houston/Galveston, TX issued this severe thunderstorm warning at May 20, 2017, 7:44 PM CDT for Houston County, Trinity County, Texas. It was in force for 31 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 20, 2017, 7:44 PM CDT (00:44 UTC)
Expired: May 20, 2017, 8:15 PM CDT
In force: 31 min
Issued by: NWS Houston/Galveston, TX
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Houston County, TX, Trinity County, TX

The radar

The Houston radar (KHGX), 193 km from the middle of the area, began a volume at 00:46 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

Shreveport, LA (KBAD), launched 00:00Z, 0.7 hours before the alert went out and 202 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: 1368 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 1148 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 42 m²/s²
0-3 km storm-relative helicity: 115 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at May 20, 6:56 PM CDT, 48 minutes earlier.

Area forecast discussion, May 20, 6:56 PM CDT, 48 minutes before

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Hazardous weather outlook, May 20, 4:04 PM CDT, 3 hours 40 minutes before

Hazardous Weather Outlook
National Weather Service Houston/Galveston TX
404 PM CDT Sat May 20 2017

TXZ163-164-176>179-195>200-210>214-226-227-235>238-212115-
Austin-Brazoria-Brazos-Burleson-Chambers-Colorado-Fort Bend-
Galveston-Grimes-Harris-Houston-Jackson-Liberty-Madison-Matagorda-
Montgomery-Polk-San Jacinto-Trinity-Walker-Waller-Washington-
Wharton-
404 PM CDT Sat May 20 2017

This hazardous weather outlook is for portions of Southeast Texas..

.DAY ONE...This Afternoon and Tonight
Showers and thunderstorms capable of producing locally heavy
rainfall will be possible this afternoon and tonight generally
north of Interstate 10. Isolated amounts in excess of 2-4 inches
may be possible. Additionally, stronger thunderstorms this
afternoon may be capable of gusty winds and small hail.

.DAYS TWO THROUGH SEVEN...Sunday through Friday
Periods of showers and thunderstorms capable of producing locally
heavy rainfall will be possible Sunday through Thursday across
Southeast Texas. Some of this rainfall may be able to cause minor
or flash flooding Monday and Tuesday. Some of these thunderstorms
may also be capable of gusty winds or hail.

.SPOTTER INFORMATION STATEMENT...
Spotter activation is not anticipated at this time.

GMZ330-335-350-355-370-375-212115-
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-
Waters from Freeport to the Matagorda Ship Channel from 20 to
60 NM-Waters from High Island to Freeport from 20 to 60 NM-
404 PM CDT Sat May 20 2017

This hazardous weather outlook is for portions of Southeast Texas..

.DAY ONE...This Afternoon and Tonight
No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Sunday through Friday
Periods of showers and thunderstorms will be possible Sunday
through Tuesday ahead of a cold front. Small Craft Advisories may
be needed in the wake of the front Tuesday night or Wednesday
morning.

.SPOTTER INFORMATION STATEMENT...
Spotter activation is not anticipated at this time.

In the hours before

Special weather statement, May 20, 6:06 PM CDT, 1 hour 38 minutes before

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Special weather statement, May 20, 6:38 PM CDT, 1 hour 6 minutes before

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Special weather statement, May 20, 6:42 PM CDT, 1 hour 2 minutes before

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Local storm report, May 20, 7:03 PM CDT, 41 minutes before

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Special weather statement, May 20, 7:29 PM CDT, 15 minutes before

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Special weather statement, May 20, 7:34 PM CDT, 10 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 20, 7:29 PM CDT	Special Weather Statement	HGX	San Jacinto	46 min
May 20, 7:34 PM CDT	Special Weather Statement	HGX	Trinity	41 min
May 20, 8:41 PM CDT	Special Weather Statement	HGX	Houston	19 min
May 20, 11:42 PM CDT	Special Weather Statement	HGX	Burleson	48 min
May 20, 11:53 PM CDT	Severe Thunderstorm Warning	HGX	Brazos, Burleson	37 min
May 21, 12:27 AM CDT	Severe Thunderstorm Warning	HGX	Brazos, Burleson	33 min
May 21, 1:00 AM CDT	Special Weather Statement	HGX	Brazos, Grimes	30 min
May 21, 1:16 AM CDT	Severe Thunderstorm Warning	HGX	Brazos, Burleson, Grimes, Washington	29 min
May 21, 1:42 AM CDT	Severe Thunderstorm Warning	HGX	Brazos, Grimes, Montgomery, Walker	63 min
May 21, 2:43 AM CDT	Severe Thunderstorm Warning	HGX	Montgomery, Walker	47 min
May 21, 3:18 AM CDT	Special Weather Statement	HGX	Madison	42 min
May 21, 3:25 AM CDT	Severe Thunderstorm Warning	HGX	Brazos, Madison	50 min
May 21, 4:14 AM CDT	Severe Thunderstorm Warning	HGX	Houston, Madison, Walker	45 min
May 21, 5:04 AM CDT	Special Weather Statement	HGX	Houston, Trinity	56 min
May 21, 5:27 AM CDT	Severe Thunderstorm Warning	HGX	Houston	48 min
May 21, 9:14 AM CDT	Special Marine Warning	HGX		91 min
May 21, 9:45 AM CDT	Areal Flood Advisory	HGX	Harris	60 min
May 21, 9:57 AM CDT	Special Marine Warning	HGX		48 min
May 21, 10:44 AM CDT	Special Marine Warning	HGX		61 min
May 21, 10:45 AM CDT	Special Marine Warning	HGX		60 min
May 21, 10:49 AM CDT	Special Weather Statement	HGX	Galveston	41 min
May 21, 11:36 AM CDT	Special Weather Statement	HGX	Galveston	39 min
May 21, 11:55 AM CDT	Special Marine Warning	HGX		2 hr
May 21, 12:11 PM CDT	Special Weather Statement	HGX	Chambers	64 min
May 21, 3:05 PM CDT	Tornado Warning	HGX	Waller	25 min

Nearby

Severe Thunderstorm Warnings in Texas, 2017 Every severe thunderstorm warning in 2017

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.