Alert archive / Texas / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 108, NWS Shreveport, LA

April 27, 2009Harrison County, Marion County, Texas; Caddo Parish, Louisiana

NWS Shreveport, LA issued this severe thunderstorm warning at Apr 27, 2009, 2:58 PM CDT for Harrison County, Marion County, Texas; Caddo Parish, Louisiana. It was in force for 32 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
Apr 27, 2009, 2:58 PM CDT (19:58 UTC)
Expired
Apr 27, 2009, 3:30 PM CDT
In force
32 min
Issued by
NWS Shreveport, LA
Area
Storm-based polygon

Counties Caddo Parish, LA, Harrison County, TX, Marion County, TX

The radar

The Shreveport radar (KSHV), 40 km from the middle of the area, began a volume at 19:59 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.

IssuedProductOfficeLasted
Apr 27, 9:28 AM CDTSevere Thunderstorm WatchSPC12 hr
Apr 27, 2:57 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 8.0 hours before the alert went out and 290 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-pSkew-T log-p diagram, Fort Worth, TX at 12:00Z on 2009-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2160 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 12:00Z on 2009-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 79 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
2160 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
513 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
79 m²/s²
0-3 km storm-relative helicity
315 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.5

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 Apr 27, 10:10 AM CDT, 4 hours 48 minutes earlier.

Area forecast discussion, Apr 27, 10:10 AM CDT, 4 hours 48 minutes before
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Hazardous weather outlook, Apr 27, 11:48 AM CDT, 3 hours 10 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SHREVEPORT LA
1148 AM CDT MON APR 27 2009

ARZ050-051-059>061-070>072-LAZ001>004-010>012-OKZ077-TXZ096-097-
108>112-124>126-136>138-149>153-281700-
SEVIER-HOWARD-LITTLE RIVER-HEMPSTEAD-NEVADA-MILLER-LAFAYETTE-
COLUMBIA-CADDO-BOSSIER-WEBSTER-CLAIBORNE-DE SOTO-RED RIVER-
BIENVILLE-MCCURTAIN-BOWIE-FRANKLIN-TITUS-CAMP-MORRIS-CASS-WOOD-
UPSHUR-MARION-SMITH-GREGG-HARRISON-CHEROKEE-RUSK-PANOLA-
NACOGDOCHES-SHELBY-
1148 AM CDT MON APR 27 2009

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

.DAY ONE...THIS AFTERNOON AND TONIGHT...
A COLD FRONT WILL BE MOVING INTO NORTH CENTRAL TEXAS... SOUTHEAST
OKLAHOMA...AND WESTERN ARKANSAS THIS EVENING. STRONG TO SEVERE
THUNDERSTORMS WILL DEVELOP AND SPREAD NORTHEAST AHEAD OF THE
SYSTEM AS UPPER DISTURBANCES MOVE OVERHEAD IN A MOIST AND UNSTABLE
ATMOSPHERE. STORMS ARE EXPECTED TO PRODUCE LARGE HAIL...HIGH AND
DAMAGING WINDS...LOCALLY HEAVY RAINFALL AND ISOLATED TORNADOES.
RAINFALL AMOUNTS THROUGH TONIGHT WILL RANGE FROM ONE TO TWO INCHES
WITH ISOLATED AMOUNTS TO FOUR INCHES POSSIBLE.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...
A COLD FRONT WILL BECOME NEARLY STATIONARY ACROSS NORTHEAST TEXAS
INTO SOUTHWEST ARKANSAS ON TUESDAY...THEN LIFT BACK NORTH INTO
WEDNESDAY. STRONG TO SEVERE THUNDERSTORMS WILL CONTINUE TO DEVELOP
AND SPREAD EAST AND NORTHEAST ACROSS THE AREA THROUGH THE WEEKEND.
STORMS ARE EXPECTED TO PRODUCE LARGE HAIL...HIGH AND DAMAGING
WINDS...LOCALLY HEAVY RAINFALL AND ISOLATED TORNADOES. RAINFALL
MAY BE HEAVY AT TIMES...WITH FLASH FLOODING POSSIBLE.

.SPOTTER INFORMATION STATEMENT...
ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND EMERGENCY
MANAGERS EXPECTED THROUGH THE AFTERNOON AND OVERNIGHT.

ARZ073-LAZ005-006-013-014-017>022-TXZ165>167-281700-
UNION AR-LINCOLN-UNION LA-JACKSON-OUACHITA-SABINE LA-NATCHITOCHES-
WINN-GRANT-CALDWELL-LA SALLE-ANGELINA-SAN AUGUSTINE-SABINE TX-
1148 AM CDT MON APR 27 2009

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

.DAY ONE...TODAY AND TONIGHT...

A COLD FRONT WILL BE MOVING INTO NORTH CENTRAL TEXAS... SOUTHEAST
OKLAHOMA...AND WESTERN ARKANSAS THIS EVENING. STRONG TO SEVERE
THUNDERSTORMS WILL DEVELOP AND SPREAD NORTHEAST AHEAD OF THE SYSTEM
AS UPPER DISTURBANCES MOVE OVERHEAD IN A MOIST AND UNSTABLE ATMOSPHERE.
STORMS ARE EXPECTED TO PRODUCE LARGE HAIL...HIGH AND DAMAGING WINDS...
LOCALLY HEAVY RAINFALL AND ISOLATED TORNADOES.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

A COLD FRONT WILL BECOME NEARLY STATIONARY ACROSS NORTHEAST TEXAS
INTO SOUTHWEST ARKANSAS ON TUESDAY...THEN LIFT BACK NORTH INTO
WEDNESDAY. STRONG TO SEVERE THUNDERSTORMS WILL CONTINUE TO DEVELOP
AND SPREAD EAST AND NORTHEAST ACROSS THE AREA THROUGH THE WEEKEND.
STORMS ARE EXPECTED TO PRODUCE LARGE HAIL...HIGH AND DAMAGING
WINDS...LOCALLY HEAVY RAINFALL AND ISOLATED TORNADOES. RAINFALL
MAY BE HEAVY AT TIMES...WITH FLASH FLOODING POSSIBLE.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND EMERGENCY
MANAGERS MAY BE NEEDED TONIGHT.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 27, 2:29 PM CDTSevere Thunderstorm WarningSHVHarrison, Panola31 min

Nearby

Severe Thunderstorm Warnings in Texas, 2009Severe Thunderstorm Warnings in Louisiana, 2009Every severe thunderstorm warning 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.