Alert archive / Louisiana / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 64, NWS Lake Charles, LA

May 10, 1999Jefferson Davis Parish, Louisiana

NWS Lake Charles, LA issued this severe thunderstorm warning at May 10, 1999, 9:18 AM CDT for Jefferson Davis Parish, Louisiana. It was in force for 57 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: May 10, 1999, 9:18 AM CDT (14:18 UTC)
Expired: May 10, 1999, 10:15 AM CDT
In force: 57 min
Issued by: NWS Lake Charles, LA
Area: Whole counties

County Jefferson Davis Parish, LA

The radar

The Lake Charles radar (KLCH), 42 km from the middle of the area, began a volume at 14:22 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.

What was reported inside it

Time	Report	Where	Remark
May 10, 9:30 AM CDT	Thunderstorm Wind	Hathaway, LA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 10, 7:45 AM CDT	Severe Thunderstorm Watch	SPC	5 hr
May 10, 8:30 AM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 2.3 hours before the alert went out and 41 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: 1626 J/kg
Mixed-layer CIN: -38 J/kg
Mixed-layer LCL: 624 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 40 m²/s²
0-3 km storm-relative helicity: 129 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 3.8

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 Lake Charles, LA wrote its last area forecast discussion before this severe thunderstorm warning went out at May 10, 1:48 AM CDT, 7 hours 30 minutes earlier.

Area forecast discussion, May 10, 1:48 AM CDT, 7 hours 30 minutes before

SOUTHWEST...CENTRAL LOUISIANA AND SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
148 AM CDT MON MAY 10 1999

ETA / NGM /AVN PROGS ARE SIMILAR IN MOVING SHORT-WAVE TROUGH AXIS TO
EAST TEXAS THIS MORNING...INTO WESTERN LOUISIANA THIS EVENING TO
EASTERN EXTREMES OF THE FORECAST AREA BY MIDNIGHT TONIGHT. THEY ALSO
PROG ANOTHER SHORT-WAVE AXIS TO DEVELOP IN SOUTHEAST TEXAS BY MID-DAY
TUESDAY. AVN SHOWING WEAKER SHORT-WAVE TODAY DISSIPATING NEAR RIDGE
AXIS. AVN SHOWS 250 MB DIVERGENT PATTERN DEVELOPING OVER THE AREA
BY MID DAY TODAY AND SHIFTING OVER MAINLY CENTRAL AND EAST PARTS OF
THE AREA MID NIGHT TONIGHT.

MODELS ARE IN REASONABLY GOOD AGREEMENT SHOWING MODERATE TO HIGH
MOISTURE SPREADING NORTHEAST OVER THE AREA TODAY INTO EVENING DRYING
FROM THE SOUTHWEST BY MIDNIGHT TONIGHT TO MODERATE LEVEL TUE. ETA
SHOWS A RESURGENCE IN MOISTURE FROM THE WEST TUESDAY WHILE ETA / NGM
ARE SIMILAR THROUGH THAT PERIOD IN THEIR DISTRIBUTION OF MEAN
RELATIVE HUMIDITIES.

GIVEN SIMILARITY OF NGM TO OTHER MODELS EXCEPT FOR ETA/S MOISTURE
DISTRIBUTION TUESDAY IT LOOKS AS THOUGH NGM MOS POPS / TEMPS SHOULD
BE PRETTY GOOD AND WILL USE THEM WITH ONLY MINOR CHANGES.

20-SPARKS

LCH CB 082/069 085/071 522
LFT CB 085/069 085/069 422
AEX CB 083/068 083/070 632
BPT CB 083/069 086/072 522

The office that day

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

Issued	Product	Office	Counties	Lasted
May 10, 8:11 AM CDT	Severe Thunderstorm Warning	LCH		59 min
May 10, 8:35 AM CDT	Severe Thunderstorm Warning	LCH	Beauregard, Vernon	50 min
May 10, 8:35 AM CDT	Severe Thunderstorm Warning	LCH	Calcasieu, Cameron	50 min
May 10, 9:18 AM CDT	Severe Thunderstorm Warning	LCH	Allen, Rapides	57 min
May 10, 9:27 AM CDT	Severe Thunderstorm Warning	LCH	Beauregard, Calcasieu, Vernon	48 min
May 10, 9:27 AM CDT	Severe Thunderstorm Warning	LCH	Cameron	48 min
May 10, 10:47 AM CDT	Tornado Warning	LCH	Evangeline	48 min
May 10, 10:59 AM CDT	Tornado Warning	LCH	Avoyelles	51 min
May 10, 11:28 AM CDT	Severe Thunderstorm Warning	LCH	Iberia, Lafayette, Saint Martin	77 min
May 10, 11:28 AM CDT	Severe Thunderstorm Warning	LCH	Saint Landry	77 min
May 10, 11:45 AM CDT	Severe Thunderstorm Warning	LCH	Saint Martin, St. Mary	60 min
May 10, 12:03 PM CDT	Tornado Warning	LCH	Saint Martin	47 min
May 10, 12:57 PM CDT	Severe Thunderstorm Warning	LCH	Saint Martin, St. Mary	63 min
May 10, 7:15 AM CDT	Severe Thunderstorm Warning	LCH	Hardin, Jefferson	60 min
May 10, 7:15 AM CDT	Severe Thunderstorm Warning	LCH	Tyler	60 min
May 10, 7:46 AM CDT	Tornado Warning	LCH	Tyler	49 min
May 10, 7:50 AM CDT	Tornado Warning	LCH	Hardin	50 min
May 10, 8:04 AM CDT	Tornado Warning	LCH	Jasper	61 min
May 10, 8:11 AM CDT	Severe Thunderstorm Warning	LCH	Jefferson, Newton, Orange	59 min
May 10, 8:15 AM CDT	Tornado Warning	LCH	Orange	65 min
May 10, 8:31 AM CDT	Tornado Warning	LCH	Newton	49 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 1999 Every severe thunderstorm warning in 1999

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.