Alert archive / Texas / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 169, NWS Fort Worth, TX

July 12, 2018Grayson County, Texas

NWS Fort Worth, TX issued this severe thunderstorm warning at Jul 12, 2018, 2:39 PM CDT for Grayson County, Texas. It was in force for 34 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: Jul 12, 2018, 2:39 PM CDT (19:39 UTC)
Expired: Jul 12, 2018, 3:13 PM CDT
In force: 34 min
Issued by: NWS Fort Worth, TX
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Grayson County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 131 km from the middle of the area, began a volume at 19:42 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

Fort Worth, TX (KFWD), launched 12:00Z, 7.7 hours before the alert went out and 105 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: 522 J/kg
Mixed-layer CIN: -125 J/kg
Mixed-layer LCL: 1509 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: -29 m²/s²
0-3 km storm-relative helicity: -17 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 Fort Worth, TX wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 12, 12:55 PM CDT, 1 hour 44 minutes earlier.

Area forecast discussion, Jul 12, 12:55 PM CDT, 1 hour 44 minutes before

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Hazardous weather outlook, Jul 12, 5:20 AM CDT, 9 hours 19 minutes before

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In the hours before

Special weather statement, Jul 12, 12:42 PM CDT, 1 hour 57 minutes before

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Special weather statement, Jul 12, 2:23 PM CDT, 16 minutes before

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Special weather statement, Jul 12, 2:32 PM CDT, 7 minutes before

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The office that day

Everything else NWS Fort Worth, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 12, 12:42 PM CDT	Special Weather Statement	FWD	Denton	33 min
Jul 12, 1:03 PM CDT	Areal Flood Advisory	FWD	Denton	57 min
Jul 12, 2:23 PM CDT	Special Weather Statement	FWD	Tarrant	37 min
Jul 12, 2:32 PM CDT	Special Weather Statement	FWD	Grayson	28 min
Jul 12, 2:53 PM CDT	Special Weather Statement	FWD	Tarrant	37 min
Jul 12, 3:24 PM CDT	Special Weather Statement	FWD	Tarrant	36 min
Jul 12, 3:28 PM CDT	Special Weather Statement	FWD	Tarrant	32 min
Jul 12, 3:39 PM CDT	Severe Thunderstorm Warning	FWD	Tarrant	51 min
Jul 12, 4:19 PM CDT	Special Weather Statement	FWD	Leon	26 min
Jul 12, 4:24 PM CDT	Special Weather Statement	FWD	Ellis	36 min
Jul 12, 4:26 PM CDT	Special Weather Statement	FWD	Dallas	34 min
Jul 12, 4:37 PM CDT	Special Weather Statement	FWD	Rockwall	23 min
Jul 12, 4:43 PM CDT	Areal Flood Advisory	FWD	Collin, Dallas, Rockwall	2 hr
Jul 12, 5:16 PM CDT	Areal Flood Advisory	FWD	Dallas	119 min
Jul 12, 5:37 PM CDT	Special Weather Statement	FWD	Kaufman	53 min
Jul 12, 5:40 PM CDT	Areal Flood Advisory	FWD	Delta, Hopkins	2 hr
Jul 12, 5:55 PM CDT	Areal Flood Advisory	FWD	Dallas, Ellis, Kaufman, Rockwall	2 hr
Jul 12, 6:17 PM CDT	Flash Flood Warning	FWD	Ellis	118 min
Jul 12, 6:41 PM CDT	Areal Flood Advisory	FWD	Hunt, Kaufman, Van Zandt	2 hr
Jul 12, 6:52 PM CDT	Special Weather Statement	FWD	Jack	23 min

Nearby

Severe Thunderstorm Warnings in Texas, 2018 Every severe thunderstorm warning in 2018

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.