Alert archive / Louisiana / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 235, NWS Shreveport, LA

July 31, 20205 parishes in Louisiana

NWS Shreveport, LA issued this severe thunderstorm warning at Jul 31, 2020, 4:21 PM CDT for 5 parishes in Louisiana. It was in force for 54 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 31, 2020, 4:21 PM CDT (21:21 UTC)
Expired: Jul 31, 2020, 5:15 PM CDT
In force: 54 min
Issued by: NWS Shreveport, LA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Caldwell Parish, LA, Grant Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Winn Parish, LA

The radar

The Ft Polk radar (KPOE), 85 km from the middle of the area, began a volume at 21:19 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 31, 1:21 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 9.4 hours before the alert went out and 236 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: 937 J/kg
Mixed-layer CIN: -72 J/kg
Mixed-layer LCL: 784 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 108 m²/s²
0-3 km storm-relative helicity: 74 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 Shreveport, LA wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 31, 2:57 PM CDT, 1 hour 24 minutes earlier.

Area forecast discussion, Jul 31, 2:57 PM CDT, 1 hour 24 minutes before

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Hazardous weather outlook, Jul 31, 11:52 AM CDT, 4 hours 29 minutes before

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In the hours before

Special weather statement, Jul 31, 1:14 PM CDT, 3 hours 7 minutes before

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Special weather statement, Jul 31, 2:59 PM CDT, 1 hour 22 minutes before

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Special weather statement, Jul 31, 3:02 PM CDT, 1 hour 19 minutes before

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Special weather statement, Jul 31, 3:43 PM CDT, 38 minutes before

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The office that day

Everything else NWS Shreveport, LA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 30, 9:04 PM CDT	Severe Thunderstorm Warning	SHV	Red River	56 min
Jul 30, 9:55 PM CDT	Severe Thunderstorm Warning	SHV	Bowie, Red River	65 min
Jul 30, 10:16 PM CDT	Special Weather Statement	SHV	Bowie, Camp, Cass, Morris, Titus, Upshur and 1 more	44 min
Jul 30, 10:49 PM CDT	Special Weather Statement	SHV	Cass, Gregg, Marion, Smith, Upshur, Wood	41 min
Jul 30, 11:26 PM CDT	Special Weather Statement	SHV	Cass, Marion	34 min
Jul 31, 6:50 AM CDT	Special Weather Statement	SHV	Franklin, Titus	25 min
Jul 31, 3:02 PM CDT	Special Weather Statement	SHV	Sabine, San Augustine	58 min
Jul 31, 1:14 PM CDT	Special Weather Statement	SHV	Lincoln, Union	46 min
Jul 31, 2:59 PM CDT	Special Weather Statement	SHV	Jackson, Natchitoches, Sabine, Winn	61 min
Jul 31, 3:43 PM CDT	Special Weather Statement	SHV	Caldwell, Grant, LaSalle, Natchitoches, Winn	62 min
Jul 30, 10:37 PM CDT	Special Weather Statement	SHV	Hempstead, Howard	38 min
Jul 30, 11:14 PM CDT	Special Weather Statement	SHV	Nevada	46 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 2020 Every severe thunderstorm warning in 2020

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.