Alert archive / Texas / Flash Flood Watches in 2009

Flash Flood Watch 4, NWS Shreveport, LA

May 2, 200921 counties in Texas; 17 parishes in Louisiana; 9 counties in Arkansas

NWS Shreveport, LA issued this flash flood watch at May 2, 2009, 5:27 AM CDT for 21 counties in Texas; 17 parishes in Louisiana; 9 counties in Arkansas. It took effect at May 2, 2009, 1:00 PM CDT. It was in force for 26 hr.

The area

The counties it named.

The facts

Issued: May 2, 2009, 5:27 AM CDT (10:27 UTC)
In effect from: May 2, 2009, 1:00 PM CDT
Expired: May 3, 2009, 3:27 PM CDT
In force: 26 hr
Issued by: NWS Shreveport, LA
Flood severity: None

All 47 counties

Columbia County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Sevier County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Webster Parish, LA, Winn Parish, LA, Angelina County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Morris County, TX, Nacogdoches County, TX, Panola County, TX, Red River County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 16 km from the middle of the area, began a volume at 10:27 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 00:00Z, 10.5 hours before the alert went out and 323 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: 3417 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 667 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 105 m²/s²
0-3 km storm-relative helicity: 145 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 7.4

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch 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 flash flood watch went out at May 1, 10:17 PM CDT, 7 hours 10 minutes earlier.

Area forecast discussion, May 1, 10:17 PM CDT, 7 hours 10 minutes before

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Hazardous weather outlook, May 1, 11:45 AM CDT, 17 hours 42 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
May 2, 4:41 PM CDT	Tornado Warning	SHV	Bowie	64 min
May 2, 4:57 PM CDT	Severe Thunderstorm Warning	SHV	Camp, Franklin, Red River, Titus, Upshur, Wood	48 min
May 2, 5:12 PM CDT	Severe Thunderstorm Warning	SHV	Bowie, Cass, Morris	48 min
May 2, 5:21 PM CDT	Tornado Warning	SHV	Red River	54 min
May 2, 5:23 PM CDT	Severe Thunderstorm Warning	SHV	Bowie, Camp, Cass, Franklin, Gregg, Harrison and 6 more	67 min
May 2, 5:42 PM CDT	Tornado Warning	SHV	Bowie, Cass	63 min
May 2, 5:59 PM CDT	Severe Thunderstorm Warning	SHV	Cass, Marion	46 min
May 2, 6:03 PM CDT	Flash Flood Warning	SHV	Bowie, Red River	117 min
May 2, 6:08 PM CDT	Tornado Warning	SHV	Cass	67 min
May 2, 6:10 PM CDT	Severe Thunderstorm Warning	SHV	Bowie	65 min
May 2, 6:42 PM CDT	Flash Flood Warning	SHV	Bowie	14 hr
May 2, 6:57 PM CDT	Flash Flood Warning	SHV	Bowie, Cass, Morris, Red River	14 hr
May 2, 6:16 PM CDT	Severe Thunderstorm Warning	SHV	Bossier, Caddo, Webster	59 min
May 2, 6:58 PM CDT	Severe Thunderstorm Warning	SHV	Bossier, Claiborne, Webster	62 min
May 2, 12:28 PM CDT	Severe Thunderstorm Warning	SHV	Howard	32 min
May 2, 4:00 PM CDT	Severe Thunderstorm Warning	SHV	Columbia, Hempstead, Lafayette, Nevada	45 min

Nearby

Flash Flood Watches in Texas, 2009 Flash Flood Watches in Louisiana, 2009 Flash Flood Watches in Arkansas, 2009 Every flash flood watch in 2009

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.