Alert archive / Texas / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 77, NWS Midland/Odessa, TX

May 1, 1999Dawson County, Texas

NWS Midland/Odessa, TX issued this severe thunderstorm warning at May 1, 1999, 9:47 PM CDT for Dawson County, Texas. It was in force for 58 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 1, 1999, 9:47 PM CDT (02:47 UTC)
Expired: May 1, 1999, 10:45 PM CDT
In force: 58 min
Issued by: NWS Midland/Odessa, TX
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Dawson County, TX

The radar

The Midland/Odessa radar (KMAF), 92 km from the middle of the area, began a volume at 02:46 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 1, 10:25 PM CDT	Hail 0.75	Lamesa, TX

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 1, 5:00 PM CDT	Tornado Watch	SPC	5 hr
May 1, 8:30 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Midland Regional, TX (KMAF), launched 00:00Z, 2.8 hours before the alert went out and 91 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: 844 J/kg
Mixed-layer CIN: -88 J/kg
Mixed-layer LCL: 804 m above ground
0-6 km bulk shear: 52 kt
0-1 km storm-relative helicity: 143 m²/s²
0-3 km storm-relative helicity: 232 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 5.8

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 Midland/Odessa, TX wrote its last area forecast discussion before this severe thunderstorm warning went out at May 1, 9:20 PM CDT, 27 minutes earlier.

Area forecast discussion, May 1, 9:20 PM CDT, 27 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND TX
920 PM CDT SAT MAY 1 1999

01Z SURFACE MAP SHOWS DRY LINE ALONG NM BORDER...STATIONARY BOUNDARY
FROM A NORTH OF SJT TO S OF CVS LINE AND APPARENT PAC FRONT E OF ROW
AND CNM.  WATER VAPOR IMAGERY SHOWS JET STREAK IS FARTHER S THAN
MODELS HAD PREDICTED.  MAF 00Z SOUNDING SHOWS SUBSTANTIAL INVERSION
ABOVE SURFACE KEEPING CONVECTION FROM FIRING FARTHER SOUTH ALONG
DRYLINE.

PAC FRONT SHOULD CATCH DRYLINE BY 06Z AND BACK EDGE OF CONVECTION
SHOULD BEGIN EASTWARD MOVEMENT IN FOR SURE.  COOLING ALOFT AND
SYNOPTIC LIFT SHOULD WIPE OUT MUCH OF INVERSION FARTHER AND FARTHER
SOUTH ALLOWING CONVECTION TO DEVELOP SOUTHWARD.  BELIEVE PRESENT
TRENDS OF FORMING A LINE WILL CONTINUE...ESPECIALLY AFTER FRONTAL
BOUNDARY GETS INVOLVED.  LINEAR STRUCTURE SHOULD LIMIT ABUNDANCE OF
ROTATING UPDRAFTS.

MATHEWS

In the hours before

Local storm report, May 1, 7:25 PM CDT, 2 hours 22 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MIDLAND TX
725 PM CDT SAT MAY 01 1999

TIME(CDT)  .....CITY LOCATION.....   STATE...EVENT/REMARKS...
           ....COUNTY LOCATION....

345 PM     SEMINOLE                  TX   FLOODING
05/01/99   GAINES                         F.M. ROAD 303 NEAR HWY 180
                                          IMPASSIBLE

438 PM     15 SE SEMINOLE            TX   TORNADO
05/01/99   GAINES                         SPOTTER REPORTED TORNADO
                                          NEAR HWYS 1429 AND 422

450 PM     15 W LAMESA               TX   TORNADO
05/01/99   DAWSON                         SHERIFF OFFICE REPORTED
                                          TORNADO NEAR SAND

515 PM     10 S WELCH                TX   TORNADO
05/01/99   DAWSON                         SHERIFF OFFICE REPORTED
                                          TORNADO ON GROUND

536 PM     10 W TARZAN               TX   TORNADO
05/01/99   MARTIN                         SPOTTER REPORTED
                                          TORNADO AT INTERSECTION
                                          HWYS 349 AND 176

629 PM     TARZAN                    TX   TORNADO
05/01/99   MARTIN                         PUBLIC REPORTED TORNADO

01

The office that day

Everything else NWS Midland/Odessa, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 1, 8:42 PM CDT	Flash Flood Warning	MAF	Gaines	3 hr
May 1, 9:17 PM CDT	Severe Thunderstorm Warning	MAF	Gaines	28 min
May 1, 9:41 PM CDT	Severe Thunderstorm Warning	MAF	Andrews, Gaines	34 min
May 1, 11:14 PM CDT	Flash Flood Warning	MAF	Borden, Dawson	61 min
May 1, 11:41 PM CDT	Severe Thunderstorm Warning	MAF	Scurry	64 min

Nearby

Severe Thunderstorm Warnings in Texas, 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.