Alert archive / Texas / Flash Flood Watches in 2016

Flash Flood Watch 4, NWS Shreveport, LA

April 20, 201621 counties in Texas; 17 parishes in Louisiana; 9 counties in Arkansas

NWS Shreveport, LA issued this flash flood watch at Apr 20, 2016, 2:18 AM CDT for 21 counties in Texas; 17 parishes in Louisiana; 9 counties in Arkansas. It was in force for 34 hr.

The area

The counties it named.

The facts

Issued: Apr 20, 2016, 2:18 AM CDT (07:18 UTC)
Expired: Apr 21, 2016, 12:08 PM CDT
In force: 34 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 07:21 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, 7.3 hours before the alert went out and 282 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: 345 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 729 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: -3 m²/s²
0-3 km storm-relative helicity: 56 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 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 Apr 20, 12:01 AM CDT, 2 hours 17 minutes earlier.

Area forecast discussion, Apr 20, 12:01 AM CDT, 2 hours 17 minutes before

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Hazardous weather outlook, Apr 19, 12:44 PM CDT, 13 hours 34 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SHREVEPORT LA
1244 PM CDT TUE APR 19 2016

ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077-
TXZ096-097-108>112-124>126-136>138-149>153-165>167-201100-
SEVIER-HOWARD-LITTLE RIVER-HEMPSTEAD-NEVADA-MILLER-LAFAYETTE-
COLUMBIA-UNION-CADDO-BOSSIER-WEBSTER-CLAIBORNE-LINCOLN-DE SOTO-
RED RIVER-BIENVILLE-JACKSON-OUACHITA-SABINE-NATCHITOCHES-WINN-
GRANT-CALDWELL-LA SALLE-MCCURTAIN-BOWIE-FRANKLIN-TITUS-CAMP-
MORRIS-CASS-WOOD-UPSHUR-MARION-SMITH-GREGG-HARRISON-CHEROKEE-RUSK-
PANOLA-NACOGDOCHES-SHELBY-ANGELINA-SAN AUGUSTINE-
1244 PM CDT TUE APR 19 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
AND SOUTHWEST ARKANSAS...NORTH CENTRAL AND NORTHWEST
LOUISIANA...SOUTHEAST OKLAHOMA...AND EAST NORTHEAST TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

PERIODS OF MODERATE TO HEAVY RAINFALL WILL BE POSSIBLE FOR PARTS
OF SOUTHERN ARKANSAS AND NORTH LOUISIANA. PRECIPITATION TOTALS OF
AN INCH OR TWO CAN BE EXPECTED. ADDITIONALLY...EMBEDDED
THUNDERSTORMS CAPABLE OF PRODUCING GUSTY WINDS MAY BE POSSIBLE
THIS AFTERNOON AND EVENING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY...

ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ON WEDNESDAY AND
THURSDAY COULD PRODUCE LOCALLY HEAVY RAINFALL AND THE POTENTIAL
FOR FLASH FLOODING. ISOLATED SEVERE THUNDERSTORMS PRODUCING HAIL
AND DAMAGING WINDS ARE ALSO POSSIBLE ON WEDNESDAY AND THURSDAY.
PRECIPITATION WILL DIMINISH THURSDAY AFTERNOON WITH THE PASSAGE OF
A WEAK COLD FRONT THAT WILL MOVE THROUGH THE REGION.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF EMERGENCY MANAGERS...SKYWARN NETWORKS...AND AMATEUR
RADIO OPERATORS...IS NOT EXPECTED THIS AFTERNOON AND EVENING.

06

In the hours before

Local storm report, Apr 19, 9:08 PM CDT, 5 hours 10 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
Apr 19, 7:24 PM CDT	Special Weather Statement	SHV	Harrison	51 min
Apr 19, 8:12 PM CDT	Special Weather Statement	SHV	Harrison	48 min
Apr 19, 8:37 PM CDT	River Flood Warning	SHV	Nacogdoches, Rusk	52 hr
Apr 20, 3:34 AM CDT	Special Weather Statement	SHV	Red River	56 min
Apr 20, 4:23 AM CDT	Special Weather Statement	SHV	Franklin, Titus	52 min
Apr 20, 4:54 AM CDT	Special Weather Statement	SHV	Camp, Upshur, Wood	51 min
Apr 20, 5:42 AM CDT	Special Weather Statement	SHV	Camp, Morris	48 min
Apr 20, 12:14 PM CDT	Areal Flood Advisory	SHV	Sabine	3 hr
Apr 19, 7:00 PM CDT	Areal Flood Advisory	SHV	Bossier, Caddo	3 hr
Apr 19, 8:00 PM CDT	Areal Flood Advisory	SHV	Claiborne	3 hr
Apr 19, 8:37 PM CDT	River Flood Warning	SHV	Bossier	3 days
Apr 20, 10:04 AM CDT	River Flood Warning	SHV	Bienville, Bossier, Webster	8 days
Apr 20, 10:04 AM CDT	River Flood Warning	SHV	Bienville, Bossier, Red River, Webster	8 days

Nearby

Flash Flood Watches in Texas, 2016 Flash Flood Watches in Louisiana, 2016 Flash Flood Watches in Arkansas, 2016 Every flash flood watch in 2016

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.