Alert archive / Texas / Tornado Watches in 2005

Tornado Watch 648

July 20, 20057 counties in Texas

The Storm Prediction Center issued this tornado watch at Jul 20, 2005, 12:55 AM CDT for 7 counties in Texas. It was in force for 9 hr.

The area

The outline as issued.

The facts

Issued
Jul 20, 2005, 12:55 AM CDT (05:55 UTC)
Expired
Jul 20, 2005, 9:38 AM CDT
In force
9 hr
Issued by
the Storm Prediction Center

Counties Brooks County, TX, Cameron County, TX, Hidalgo County, TX, Kenedy County, TX, Starr County, TX, Willacy County, TX, Zapata County, TX

The radar

The Brownsville radar (KBRO), 120 km from the middle of the area, began a volume at 05:56 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.

Warnings issued inside it

4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jul 20, 4:32 AM CDTTornado WarningBROWillacy43 min
Jul 20, 5:24 AM CDTFlash Flood WarningBROHidalgo96 min
Jul 20, 7:02 AM CDTTornado WarningBROCameron43 min
Jul 20, 8:09 AM CDTTornado WarningBROHidalgo41 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Brownsville Intl, TX (KBRO), launched 00:00Z, 5.9 hours before the alert went out and 123 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, Brownsville Intl, TX at 00:00Z on 2005-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1109 joules per kilogram.LCLEL10008507005003002001001 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, Brownsville Intl, TX at 00:00Z on 2005-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 172 square meters per square second.193958Sfc1 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
1109 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
594 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
172 m²/s²
0-3 km storm-relative helicity
162 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 200551
SEL8  
SPC WW 200551
TXZ000-CWZ000-201500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 648
NWS STORM PREDICTION CENTER NORMAN OK
1255 AM CDT WED JUL 20 2005

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       DEEP SOUTH TEXAS
       COASTAL WATERS

EFFECTIVE THIS WEDNESDAY MORNING FROM 1255 AM UNTIL 1000 AM CDT.

TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 60 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE MILES
EAST AND WEST OF A LINE FROM 60 MILES NORTH OF MCALLEN TEXAS TO 25
MILES SOUTH SOUTHEAST OF MCALLEN TEXAS.  FOR A COMPLETE DEPICTION
OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS
WOU8).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA.
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 646. WATCH NUMBER 646 WILL NOT BE IN EFFECT AFTER
1255 AM CDT. CONTINUE...WW 647...

DISCUSSION...THREAT FOR ISOLATED TORNADOES MAY INCREASE LATER THIS
MORNING AS EMILY MOVES ASHORE IN NE MEXICO...INCREASING LOW LEVEL
DIRECTIONAL COMPONENT TO STRONGLY-SHEARED WIND FIELD ALREADY PRESENT
OVER REGION.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 50 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 12035.


...CORFIDI

270,0970 255,0970 255,0990 270,0991

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 19, 10:01 PM CDTMesoscale DiscussionSPCBrooks, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells and 6 more89 min
Jul 20, 9:24 AM CDTMesoscale DiscussionSPCBrooks, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells and 5 more96 min
Jul 20, 9:40 AM CDTTornado WatchSPCBrooks, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells and 7 more9 hr
Jul 20, 12:42 PM CDTMesoscale DiscussionSPCBrooks, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells and 7 more2 hr
Jul 20, 5:08 PM CDTMesoscale DiscussionSPCBee, Brooks, Duval, Hidalgo, Jim Hogg, Jim Wells and 9 more2 hr

Nearby

Tornado Watches in Texas, 2005Every tornado watch in 2005

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.