Alert archive / Texas / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 49, NWS Midland/Odessa, TX

April 28, 1999Andrews County, Texas

NWS Midland/Odessa, TX issued this severe thunderstorm warning at Apr 28, 1999, 7:31 PM CDT for Andrews County, Texas. It was in force for 44 min. 1 report came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued: Apr 28, 1999, 7:31 PM CDT (00:31 UTC)
Expired: Apr 28, 1999, 8:15 PM CDT
In force: 44 min
Issued by: NWS Midland/Odessa, TX
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Andrews County, TX

The radar

The Midland/Odessa radar (KMAF), 41 km from the middle of the area, began a volume at 00:34 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
Apr 28, 7:53 PM CDT	Hail 0.75	Andrews, TX	This small single cell storm was briefly severe.

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
Apr 28, 6:30 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Midland Regional, TX (KMAF), launched 00:00Z, 0.5 hours before the alert went out and 40 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: 1227 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 2480 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 56 m²/s²
0-3 km storm-relative helicity: 103 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

999 
WUUS1 KMAF 290033 RRA
SVRMAF
TXC003-290115-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MIDLAND-ODESSA TX
731 PM CDT WED APR 28 1999

THE MIDLAND-ODESSA NATIONAL WEATHER SERVICE OFFICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN ANDREWS COUNTY IN TEXAS

* UNTIL 815 PM CDT

* AT 724 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR DETECTED A
  SEVERE THUNDERSTORM OVER SOUTH CENTRAL ANDREWS COUNTY...OR ABOUT 11
  MILES SOUTH OF ANDREWS...MOVING NORTHEAST AT 20 MPH.

LAT...LON 3210 10263 3210 10242 3221 10221 3252 10220
          3251 10242

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 Apr 28, 3:30 PM CDT, 4 hours 1 minute earlier.

Area forecast discussion, Apr 28, 3:30 PM CDT, 4 hours 1 minute before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIDLAND TX
330 PM CDT WED APR 28 1999

19Z SFC ANLYS INDCS WARM FNT W TCC-S LBB-SE ABI LINE AND CDFNT ALG
RED RIVER-W CDS-DHT LINE. CNVTN DVLPG ATTM ALG ANALYZED WARM FNTL
BNDRY MOVG NEWD JUST N OF MAF CWA. OTRW GENLY SELY LOW LVL FLOW PVLG
E OF MTNS WITH LGT SWLY FLOW ACR FAR WRN SECTIONS. DRY LINE ANALYZED
ALG E SLPS MTNS WITH DWPNTS LOW 40S-LOW 50S E OF MTNS. MID/HI LVL
MSTR MOVG E ACR NM SPREADING INTO W TX. STLT DERIVED LI/S APCHG
MINUS 6 CNTRL SECTIONS AND MINUS 10 ACR EXTREME NRN FA. STLT DERIVED
CAPES BTWN 800-1300 J/KG. MODELS IN GOOD AGREEMENT THIS FCST PD.
SHRTWV ROTATING AROUND BROAD WRN U.S. TROF ALG WITH AFOREMENTIONED
SFC BNDRYS TO PROVIDE SUF LIFT LATE THIS AFTN/EVE FOR WDLY SCT TSTMS.

SOME TSTMS MAY BE SEVERE TNGT ACR NRN AND ERN ZONES WHERE DEEPER LOW
LVL MSTR IS LOCATED.  IN WRN AREAS...EVEN THOUGH GOOD LARGE SCALE
LIFT IS ENTERING SCENE...EXPECTED CAPES/LOW LVL MSTR PROBABLY TOO LOW
FOR SVR. MITIGATING FACTOR FOR WIDESPREAD CNVTN ATTM IS NEGLIGIBLE
LOW LVL MSTR AND ADAP CAP 5 DEG C AT MAF. IF CNVTN DVLPS NEXT FEW
HRS...BELIEVE IT WILL DO SO WRN SECTIONS VCNTY MTNS/DRY LINE AND
SYNOPTIC LIFT AND MOVE NE PER MODEL HODOGRAPHS.

MODEL SOUNDINGS FOR MAF SUG INITIALLY SPLITTING STORMS WITH BETTER
CHCS OF ISOLD SUPERCELLS LATER TNGT AS LLJ DEVELOPS AND HODOGRAPH
BECOMES MORE IMPRESSIVE. SHRTWV XPCD TO ROTATE ACR AREA BY SUNRISE.
PSG OF SHRTWV SUGS MORE INSOLATION THUR VS TDA DUE TO ASSOCD MID LVL
SUBSIDENCE. THEREFORE BELIEVE INCRD CHC CNVTN APPRS TO BE LATE
THURS/FRI AS NEXT SHRTWV EJECTS ACR AREA FROM GREAT BASIN SYS. AS
LOW LVL FLOW BACKS TO MORE ELY COMPONENT...GRADUALLY COOLER
CONDITIONS XPCD INTO FRIDAY. MED RANGE MODELS INDC PCPN CHCS DECR
LATE IN WEEKEND.

BF

MAF   59/86/60/82   30/20/40/40
CNM   56/88/55/81   30/20/30/30
MRF   46/82/46/73   20/20/30/40
PO7   62/84/60/81   30/20/30/30

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 28, 7:19 PM CDT	Severe Thunderstorm Warning	MAF	Dawson, Gaines	26 min
Apr 28, 7:38 PM CDT	Severe Thunderstorm Warning	MAF	Winkler	52 min
Apr 28, 8:13 PM CDT	Severe Thunderstorm Warning	MAF	Ward	32 min
Apr 28, 8:15 PM CDT	Severe Thunderstorm Warning	MAF	Andrews	45 min
Apr 28, 8:47 PM CDT	Severe Thunderstorm Warning	MAF	Gaines	43 min
Apr 28, 9:35 PM CDT	Severe Thunderstorm Warning	MAF	Andrews	25 min
Apr 28, 9:58 PM CDT	Tornado Warning	MAF	Andrews, Gaines	47 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.