Alert archive / Texas / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 14, NWS Brownsville, TX

May 20, 2001Jim Hogg County, Zapata County, Texas

NWS Brownsville, TX issued this severe thunderstorm warning at May 20, 2001, 6:37 PM CDT for Jim Hogg County, Zapata County, Texas. It was in force for 53 min. 2 reports 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
May 20, 2001, 6:37 PM CDT (23:37 UTC)
Expired
May 20, 2001, 7:30 PM CDT
In force
53 min
Issued by
NWS Brownsville, TX
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties Jim Hogg County, TX, Zapata County, TX

The radar

The Corpus Christi radar (KCRP), 160 km from the middle of the area, began a volume at 23:41 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

TimeReportWhereRemark
May 20, 7:00 PM CDTHail 0.75Zapata, TXDime size hail was reported by the public along Highway 2687.
May 20, 7:15 PM CDTHail 0.75Randado, TXDime size hail was reported by a Border Patrol Agent along Highway 16.

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 nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 11.6 hours before the alert went out and 172 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-pSkew-T log-p diagram, Corpus Christi, TX at 12:00Z on 2001-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 195 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Corpus Christi, TX at 12:00Z on 2001-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 108 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
195 J/kg
Mixed-layer CIN
-489 J/kg
Mixed-layer LCL
1288 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
108 m²/s²
0-3 km storm-relative helicity
168 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
WUUS54 KBRO 202337
SVRBRO
TXC247-505-210030-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BROWNSVILLE TX
637 PM CDT SUN MAY 20 2001

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN ZAPATA COUNTY IN DEEP SOUTH TEXAS
  JIM HOGG COUNTY IN DEEP SOUTH TEXAS

* UNTIL 730 PM CDT

* AT 631 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 19 MILES EAST OF ZAPATA...MOVING NORTHEAST AT
  25 MPH. THIS SEVERE THUNDERSTORM WILL LIKELY PRODUCE HAIL TO THE   
  SIZE OF NICKLE TO QUARTER...AND WINDS IN EXCESS OF 60 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
   GUERRA BY 710 PM CDT.7

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE OFFICE.

LAT...LON 2690 9912 2678 9897 2719 9853 2734 9868

CASTILLO

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 Brownsville, TX wrote its last area forecast discussion before this severe thunderstorm warning went out at May 20, 4:02 PM CDT, 2 hours 35 minutes earlier.

Area forecast discussion, May 20, 4:02 PM CDT, 2 hours 35 minutes before
DEEP SOUTH TEXAS FORECAST DISCUSSION...CORRECTION FOR SCA WORDING
NATIONAL WEATHER SERVICE BROWNSVILLE TX
230 PM CDT SUN MAY 20 2001

WATER VAPOR IMAGERY CLEARLY SHOWS A LARGE UPPER-LOW OVER SOUTHERN
SASKATCHEWAN...NOW MOVING SOUTH INTO THE NORTHERN PLAINS.  AS THIS
NORTHERN STREAM WAVE PHASES WITH A SOUTHERN STREAM WAVE MOVING
ACROSS OKLAHOMA AT THIS TIME...A LARGE LONGWAVE TROUGH WILL DEVELOP
OVER THE CENTRAL PLAINS...AND ALLOW AN UNSEASONABLY COLD CANADIAN
AIRMASS TO MOVE SOUTH AND EAST.  A COLD FRONT WILL MOVE RAPIDLY
THROUGH THE LOWER VALLEY ON MONDAY EVENING...CLEARING THE RIO GRANDE
RIVER SHORTLY AFTER MIDNIGHT.

SHOWERS AND THUNDERSTORMS ARE A GOOD POSSIBILITY AREA-WIDE BEGINNING
MONDAY EVENING.  STRENGTH OF LOW-LEVEL CONVERGENCE ALONG THE COLD
FRONT...AND SOMEWHAT FAVORABLE TIMING OF FRONTAL PASSAGE IN THE
EARLY EVENING ACROSS THE NORTH WILL ENHANCE THE CHANCES FOR
CONVECTION THERE.  HOWEVER...WEAK FORECASTED WIND
PROFILES...SLIGHTLY CONFLUENT UPPER-FLOW...AND LACK OF UPPER SUPPORT
IN THE FORM OF CYCLONIC VORTICITY ADVECTION WILL LIKELY INHIBIT
SEVERE THREAT.  FOR NOW...WILL INCREASE POPS TO 20 PERCENT ON
MONDAY...AND MAINTAIN 40 PERCENT POPS FOR MONDAY NIGHT AND TUESDAY.
SEVERE THREAT WILL BE HIGHEST IN NORTHERN COUNTIES OF THE CWA...AND
WILL LIKELY COME IN THE FORM OF LARGE HAIL.  CURRENT FORECAST
NUMBERS FOR TEMPS LOOK GOOD...AND WILL STICK WITH THEM.  COLDEST
TEMPERATURES ON TUESDAY WILL BE CLOSER TO SURFACE RIDGE AXIS IN THE
WEST.

UPPER NORTHWEST FLOW WILL PERSIST THROUGH NEXT WEEKEND...AS AN
UNSEASONABLY COLD UPPER CYCLONE REMAINS OVER THE EASTERN U.S.  A FEW
WEAK SHORTWAVE TROUGHS EMBEDDED IN THE UPPER NORTHWEST FLOW WILL
BRING CHANCES OF RAIN TO THE AREA FOR FRIDAY AND SATURDAY.  SKIES
SHOULD BEGIN TO CLEAR ON SUNDAY...AS UPPER RIDGE DEVELOPS OVER THE
SOUTHERN PLAINS.

MARINE...SOUTHEAST WINDS AT 16 KNOTS AND 4 FOOT SEAS CURRENTLY
REPORTED OFFSHORE.  SCA MAY BE NEEDED FOR THE BAY AGAIN TOMORROW...
AND WILL LIKELY BE NEEDED ACROSS ALL COASTAL WATERS AFTER PASSAGE OF
A STRONG COLD FRONT ON MONDAY EVENING.  SCATTERED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE ON MONDAY EVENING AND TUESDAY.

PRELIMINARY NUMBERS:
BRO BB 077/093 070/078 065  00/20/40/40/00
HRL BB 076/095 069/078 064  00/20/40/40/00
MFE BB 076/097 070/076 063  00/20/40/40/00
RGC BB 075/101 068/074 060  00/20/40/40/00
SPI BB 077/085 073/079 067  00/20/40/40/00

SYNOPTIC...DD (65) / AVIATION-MARINE...60 / MESO...SM

INTERNET ADDRESS...WWW.SRH.NOAA.GOV/BRO

.BRO...SCA TONIGHT FOR GMZ130.

The office that day

Everything else NWS Brownsville, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 5:44 PM CDTSevere Thunderstorm WarningBROZapata46 min

Nearby

Severe Thunderstorm Warnings in Texas, 2001Every severe thunderstorm warning in 2001

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.