Alert archive / Texas / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 249, NWS Shreveport, LA

July 16, 2009Cass County, Texas; Caddo Parish, Louisiana; Miller County, Arkansas

NWS Shreveport, LA issued this severe thunderstorm warning at Jul 16, 2009, 7:41 PM CDT for Cass County, Texas; Caddo Parish, Louisiana; Miller County, Arkansas. It was in force for 49 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 16, 2009, 7:41 PM CDT (00:41 UTC)
Expired: Jul 16, 2009, 8:30 PM CDT
In force: 49 min
Issued by: NWS Shreveport, LA
Area: Storm-based polygon

Counties Miller County, AR, Caddo Parish, LA, Cass County, TX

The radar

The Shreveport radar (KSHV), 63 km from the middle of the area, began a volume at 00:44 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 16, 3:33 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Shreveport, LA (KSHV), launched 00:00Z, 0.7 hours before the alert went out and 63 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: 1155 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 2275 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: -21 m²/s²
0-3 km storm-relative helicity: 11 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 16, 6:49 PM CDT, 52 minutes earlier.

Area forecast discussion, Jul 16, 6:49 PM CDT, 52 minutes before

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Hazardous weather outlook, Jul 16, 12:00 PM CDT, 7 hours 41 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SHREVEPORT LA
1200 PM CDT THU JUL 16 2009

ARZ050-051-059>061-070>073-OKZ077-TXZ096-097-108-109-111-112-171100-
BOWIE-CASS-COLUMBIA-FRANKLIN-HEMPSTEAD-HOWARD-LAFAYETTE-LITTLE RIVER-
MCCURTAIN-MILLER-MORRIS-NEVADA-RED RIVER TX-SEVIER-TITUS-UNION AR-
1200 PM CDT THU JUL 16 2009

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

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

ISOLATED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON...MAINLY NORTH
AND EAST OF A BROKEN BOW OKLAHOMA TO MAGNOLIA ARKANSAS LINE.
THESE STORMS SHOULD NOT BE SEVERE...HOWEVER STRONGER STORMS WILL
BE CAPABLE OF PRODUCING WIND GUSTS UP TO 40 MILES AN HOUR AND
BRIEF HEAVY RAIN.

TONIGHT...A COLD FRONT WILL MOVE SOUTH ACROSS OKLAHOMA AND
ARKANSAS. SCATTERED THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT
AND MOVE INTO SOUTHEAST OKLAHOMA...SOUTHWEST ARKANSAS...AND
EVENTUALLY NORTHEAST TEXAS. SOME OF THESE STORMS MAY BE
SEVERE...WITH DAMAGING WINDS THE MAIN THREAT. LARGE HAIL IS ALSO
POSSIBLE IN ISOLATED STORMS.

OTHERWISE...A HEAT ADVISORY REMAINS IN EFFECT TODAY WITH HEAT
INDICES BETWEEN 105 AND 109 DEGREES.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY...
A FEW THUNDERSTORMS MAY LINGER INTO THE FIRST PART OF THE WEEKEND.
HOWEVER...A COLD FRONT WILL BRING SLIGHTLY COOLER AND DRIER
CONDITIONS ACROSS THE REGION.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NECESSARY LATER TONIGHT ACROSS SOUTHEAST
OKLAHOMA...NORTHEAST TEXAS AND SOUTHWEST ARKANSAS, .

LAZ001>006-010>014-017>022-TXZ110-124>126-136>138-149>153-165>167-
171100-
ANGELINA-BIENVILLE-BOSSIER-CADDO-CALDWELL-CAMP-CHEROKEE-CLAIBORNE-
DE SOTO-GRANT-GREGG-HARRISON-JACKSON-LA SALLE-LINCOLN-MARION-
NACOGDOCHES-NATCHITOCHES-OUACHITA-PANOLA-RED RIVER LA-RUSK-SABINE LA-
SABINE TX-SAN AUGUSTINE-SHELBY-SMITH-UNION LA-UPSHUR-WEBSTER-WINN-
WOOD-
1200 PM CDT THU JUL 16 2009

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

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

ISOLATED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON...SOUTHEAST OF
A HOMER LOUISIANA TO SAN AUGUSTINE TEXAS LINE. STORMS SHOULD NOT
BE SEVERE...HOWEVER STRONGER STORMS WILL BE CAPABLE OF PRODUCING
WIND GUSTS UP TO 40 MILES AN HOUR AND BRIEF HEAVY RAIN. WIDELY
SCATTERED THUNDERSTORMS MAY DEVELOP AREA WIDE TONIGHT AHEAD OF A
COLD FRONT MOVING ACROSS OKLAHOMA AND ARKANSAS. THESE STORMS
SHOULD REMAIN BELOW SEVERE LIMITS.

OTHERWISE...A HEAT ADVISORY REMAINS IN EFFECT TODAY WITH HEAT
INDICES BETWEEN 105 AND 109 DEGREES.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY...
A FEW THUNDERSTORMS MAY LINGER INTO THE FIRST PART OF THE WEEKEND.
HOWEVER...A COLD FRONT WILL BRING SLIGHTLY COOLER AND DRIER
CONDITIONS ACROSS THE REGION.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

DUE TO THE VERY ISOLATED NATURE OF ANY POSSIBLE SEVERE
WEATHER...SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.

In the hours before

Local storm report, Jul 16, 6:35 PM CDT, 1 hour 6 minutes before

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Special weather statement, Jul 16, 6:47 PM CDT, 54 minutes before

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Special weather statement, Jul 16, 6:58 PM CDT, 43 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
658 PM CDT THU JUL 16 2009

ARZ070-170045-
MILLER-
658 PM CDT THU JUL 16 2009

...SIGNIFICANT WEATHER ALERT...

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A SIGNIFICANT
WEATHER ALERT...EFFECTIVE UNTIL 745 PM CDT...FOR THE FOLLOWING
COUNTY...

IN SOUTHWEST ARKANSAS...
     MILLER...

INCLUDING THE FOLLOWING LOCATIONS...
     BRIGHTSTAR AND DODDRIDGE...

AT 656 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS ARE TRACKING
A STRONG THUNDERSTORM JUST NORTH OF BRIGHTSTAR...OR 12 MILES EAST OF
ATLANTA...MOVING EAST AT 10 MPH.

SMALL HAIL...AND WINDS 40 TO 50 MPH ARE EXPECTED WITH THIS STORM.
SHOULD THIS STORM INTENSIFY...A SEVERE THUNDERSTORM WARNING WILL BE
NEEDED.

15

Local storm report, Jul 16, 7:20 PM CDT, 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
720 PM CDT THU JUL 16 2009

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0704 PM     NON-TSTM WND GST EL DORADO               33.22N 92.66W
07/16/2009  M59 MPH          UNION              AR   ASOS

&&

18

Local storm report, Jul 16, 7:26 PM CDT, 15 minutes before

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Special weather statement, Jul 16, 7:34 PM CDT, 7 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SHREVEPORT LA
734 PM CDT THU JUL 16 2009

ARZ070-LAZ001-TXZ112-170115-
CADDO-CASS-MILLER-
734 PM CDT THU JUL 16 2009

...SIGNIFICANT WEATHER ALERT...

THE NATIONAL WEATHER SERVICE IN SHREVEPORT HAS ISSUED A SIGNIFICANT
WEATHER ALERT...EFFECTIVE UNTIL 815 PM CDT...FOR THE FOLLOWING
COUNTIES AND PARISHES...

IN SOUTHWEST ARKANSAS...
     MILLER...
IN NORTHWEST LOUISIANA...
     CADDO...
IN NORTHEAST TEXAS...
     CASS...

INCLUDING THE FOLLOWING LOCATIONS...
     DODDRIDGE AND MCLEOD...

AT 734 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS ARE TRACKING
A STRONG THUNDERSTORM NEAR RAVANNA...OR 9 MILES SOUTHEAST OF
ATLANTA...MOVING SOUTHEAST AT 15 MPH.

SMALL HAIL...AND WINDS 40 TO 50 MPH ARE EXPECTED WITH THIS STORM.
SHOULD THIS STORM INTENSIFY...A SEVERE THUNDERSTORM WARNING WILL BE
NEEDED.

15

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 16, 8:14 PM CDT	Severe Thunderstorm Warning	SHV	Harrison, Marion, Panola	46 min
Jul 16, 8:50 PM CDT	Flash Flood Warning	SHV	Harrison, Marion	3 hr
Jul 16, 9:00 PM CDT	Severe Thunderstorm Warning	SHV	Harrison, Marion, Panola	60 min
Jul 17, 5:42 AM CDT	Severe Thunderstorm Warning	SHV	Gregg, Harrison, Rusk, Smith, Upshur	38 min
Jul 17, 6:00 AM CDT	Severe Thunderstorm Warning	SHV	Gregg, Harrison, Marion, Panola, Rusk	45 min
Jul 17, 6:38 AM CDT	Areal Flood Advisory	SHV	Gregg, Harrison, Rusk, Upshur	3 hr
Jul 16, 7:19 PM CDT	Severe Thunderstorm Warning	SHV	Claiborne, Union	41 min
Jul 16, 7:56 PM CDT	Severe Thunderstorm Warning	SHV	Bienville, Claiborne, Jackson, Lincoln, Ouachita, Union and 1 more	64 min
Jul 16, 9:04 PM CDT	Severe Thunderstorm Warning	SHV	Caldwell, Jackson, Lincoln, Ouachita, Union	56 min

Nearby

Severe Thunderstorm Warnings in Texas, 2009 Severe Thunderstorm Warnings in Louisiana, 2009 Severe Thunderstorm Warnings in Arkansas, 2009 Every 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.