Alert archive / Louisiana / Severe Thunderstorm Warnings in 2009
Severe Thunderstorm Warning 261, NWS Shreveport, LA
NWS Shreveport, LA issued this severe thunderstorm warning at Jul 20, 2009, 5:10 PM CDT for 4 parishes in Louisiana. It was in force for 35 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 20, 2009, 5:10 PM CDT (22:10 UTC)
- Expired
- Jul 20, 2009, 5:45 PM CDT
- In force
- 35 min
- Issued by
- NWS Shreveport, LA
- Area
- Storm-based polygon
Counties Jackson Parish, LA, Lincoln Parish, LA, Ouachita Parish, LA, Union Parish, LA
The radar
The Shreveport radar (KSHV), 132 km from the middle of the area, began a volume at 22:12 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
Shreveport, LA (KSHV), launched 12:00Z, 10.2 hours before the alert went out and 123 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.
- Mixed-layer CAPE
- 1178 J/kg
- Mixed-layer CIN
- -75 J/kg
- Mixed-layer LCL
- 995 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 60 m²/s²
- 0-3 km storm-relative helicity
- 75 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 2.3
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 20, 3:33 PM CDT, 1 hour 37 minutes earlier.
Area forecast discussion, Jul 20, 3:33 PM CDT, 1 hour 37 minutes before
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</html>Hazardous weather outlook, Jul 20, 11:38 AM CDT, 5 hours 32 minutes before
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SHREVEPORT LA 1138 AM CDT MON JUL 20 2009 ARZ050-051-059>061-OKZ077-211645- SEVIER-HOWARD-LITTLE RIVER-HEMPSTEAD-NEVADA-MCCURTAIN- 1138 AM CDT MON JUL 20 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST ARKANSAS AND SOUTHEAST OKLAHOMA. .DAY ONE...THIS AFTERNOON AND TONIGHT... SCATTERED THUNDERSTORMS WILL BE POSSIBLE TODAY ALONG AND NORTH OF THE INTERSTATE 30 CORRIDOR...AS UPPER LEVEL DISTURBANCES CONTINUE MOVING THROUGH THE REGION. WHILE NO SEVERE STORMS ARE EXPECTED... THE STRONGER STORMS WILL BE CAPABLE OF PRODUCING WIND GUSTS AROUND 35 MILES AN HOUR AND HAIL SMALLER THAN THREE QUARTERS OF AN INCH. STRONG THUNDERSTORMS WILL BE POSSIBLE BETWEEN MIDNIGHT TONIGHT AND SUNRISE TUESDAY...AS A COMPLEX OF THUNDERSTORMS APPROACHES THE REGION. THESE STORMS COULD PRODUCE WIND GUSTS AROUND 50 MILES AN HOUR AND HAIL SMALLER THAN THREE QUARTERS OF AN INCH. AN ISOLATED SEVERE STORM CANNOT BE RULED OUT. HOWEVER...A LACK OF STRONG INSTABILITY SHOULD LIMIT THE SEVERE WEATHER RISK. IF SEVERE STORMS OCCUR...THE MAIN SEVERE WEATHER RISK WILL LIKELY BE DAMAGING WINDS IN EXCESS OF 60 MILES AN HOUR. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY... STRONG THUNDERSTORMS WILL BE POSSIBLE INTO TUESDAY...AS A COMPLEX OF STORMS CONTINUES MOVING THROUGH THE FOUR STATE REGION. LOCALIZED HEAVY RAIN AND GUSTY WINDS WILL BE POSSIBLE. OVERALL...THOUGH...THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER APPEARS LOW THROUGH SUNDAY. .SPOTTER INFORMATION STATEMENT... ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND EMERGENCY MANAGEMENT PERSONNEL COULD BE NEEDED BETWEEN MIDNIGHT AND 7 AM WEDNESDAY IF SEVERE WEATHER DEVELOPS. OTHERWISE...ACTIVATION SHOULD NOT BE REQUIRED. ARZ070-LAZ001-002-010-011-017-018-TXZ096-097-108>112-124>126- 136>138-149>153-165>167-211645- MILLER-CADDO-BOSSIER-DE SOTO-RED RIVER-SABINE LA-NATCHITOCHES- BOWIE-FRANKLIN-TITUS-CAMP-MORRIS-CASS-WOOD-UPSHUR-MARION-SMITH- GREGG-HARRISON-CHEROKEE-RUSK-PANOLA-NACOGDOCHES-SHELBY-ANGELINA- SAN AUGUSTINE-SABINE TX- 1138 AM CDT MON JUL 20 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST ARKANSAS...NORTHWEST LOUISIANA...EAST TEXAS AND NORTHEAST TEXAS. .DAY ONE...THIS AFTERNOON AND TONIGHT... SCATTERED THUNDERSTORMS WILL BE POSSIBLE THROUGH TONIGHT ACROSS EAST TEXAS AND NORTHWEST LOUISIANA...GENERALLY ALONG AND WEST OF THE INTERSTATE 49 CORRIDOR. WHILE NO SEVERE STORMS ARE EXPECTED... THE STRONGER STORMS WILL BE CAPABLE OF PRODUCING WIND GUSTS AROUND 35 MILES AN HOUR AND HAIL SMALLER THAN THREE QUARTERS OF AN INCH. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY... STRONG THUNDERSTORMS WILL BE POSSIBLE INTO TUESDAY...AS A COMPLEX OF STORMS CONTINUES MOVING THROUGH THE FOUR STATE REGION BRINGING HEAVY RAIN AND GUSTY WINDS. OVERALL...THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER APPEARS LOW THROUGH SUNDAY. .SPOTTER INFORMATION STATEMENT... ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND EMERGENCY MANAGEMENT PERSONNEL COULD BE NEEDED BETWEEN MIDNIGHT AND 7 AM WEDNESDAY IF SEVERE WEATHER DEVELOPS. OTHERWISE...ACTIVATION SHOULD NOT BE REQUIRED. ARZ071>073-LAZ003>006-012>014-019>022-211645- LAFAYETTE-COLUMBIA-UNION AR-WEBSTER-CLAIBORNE-LINCOLN-UNION LA- BIENVILLE-JACKSON-OUACHITA-WINN-GRANT-CALDWELL-LA SALLE- 1138 AM CDT MON JUL 20 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL ARKANSAS...SOUTHWEST ARKANSAS...NORTH CENTRAL LOUISIANA AND NORTHWEST LOUISIANA. .DAY ONE...THIS AFTERNOON AND TONIGHT... ISOLATED THUNDERSTORMS WILL BE POSSIBLE TODAY ACROSS SOUTH CENTRAL ARKANSAS AND NORTH LOUISIANA...GENERALLY ALONG AND EAST OF THE INTERSTATE 49 CORRIDOR. THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE TONIGHT AS A SERIES OF DISTURBANCES MOVE THROUGH THE REGION. WHILE NO SEVERE STORMS ARE EXPECTED...THE STRONGER STORMS WILL BE CAPABLE OF PRODUCING WIND GUSTS AROUND 35 MILES AN HOUR AND HAIL SMALLER THAN THREE QUARTERS OF AN INCH. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY... STRONG THUNDERSTORMS WILL BE POSSIBLE INTO TUESDAY...AS A COMPLEX OF STORMS CONTINUES MOVING THROUGH THE FOUR STATE REGION. OVERALL...THOUGH...THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER APPEARS LOW THROUGH SUNDAY. .SPOTTER INFORMATION STATEMENT... ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS...AND EMERGENCY MANAGEMENT PERSONNEL WILL NOT BE NEEDED THROUGH TONIGHT. 04
In the hours before
Special weather statement, Jul 20, 2:02 PM CDT, 3 hours 8 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
202 PM CDT MON JUL 20 2009
TXZ138-202000-
HARRISON-
202 PM CDT MON JUL 20 2009
...SIGNIFICANT WEATHER ALERT...
THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A SIGNIFICANT
WEATHER ALERT...EFFECTIVE UNTIL 300 PM CDT...FOR THE FOLLOWING
COUNTY...
IN NORTHEAST TEXAS...
HARRISON...
INCLUDING THE FOLLOWING LOCATIONS...
ELYSIAN FIELDS...KARNACK...MARSHALL...WASKOM AND WOODLAWN...
AT 202 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS ARE TRACKING
A STRONG THUNDERSTORM 6 MILES EAST OF MARSHALL...MOVING EAST AT 10
MPH.
PEA SIZE HAIL...AND WINDS 40 TO 50 MPH ARE EXPECTED WITH THIS STORM.Local storm report, Jul 20, 2:12 PM CDT, 2 hours 58 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
212 PM CDT MON JUL 20 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0137 PM TSTM WND GST DE QUEEN 34.04N 94.34W
07/20/2009 M0 MPH SEVIER AR ASOS
66 MPH WIND GUST REPORTED BY ASOS
&&
04Local storm report, Jul 20, 3:09 PM CDT, 2 hours 1 minute before
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</html>Local storm report, Jul 20, 3:19 PM CDT, 1 hour 51 minutes before
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</html>Special weather statement, Jul 20, 4:59 PM CDT, 11 minutes before
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</html>The office that day
Everything else NWS Shreveport, LA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 2:37 PM CDT | Severe Thunderstorm Warning | SHV | Bossier, Caddo | 38 min |
| Jul 20, 4:22 PM CDT | Severe Thunderstorm Warning | SHV | Claiborne | 38 min |
| Jul 20, 2:02 PM CDT | Severe Thunderstorm Warning | SHV | Howard, Little River, Sevier | 43 min |
Nearby
Severe 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.