Alert archive / Texas / Mesoscale Discussions in 2008

Mesoscale Discussion 749

April 27, 200865 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2008, 7:45 AM CDT for 65 counties in Texas. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
Apr 27, 2008, 7:45 AM CDT (12:45 UTC)
Expired
Apr 27, 2008, 8:45 AM CDT
In force
60 min
Issued by
the Storm Prediction Center
All 65 counties

Atascosa County, TX, Austin County, TX, Bandera County, TX, Bastrop County, TX, Bell County, TX, Bexar County, TX, Blanco County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Colorado County, TX, Comal County, TX, Concho County, TX, Coryell County, TX, Crockett County, TX, DeWitt County, TX, Dimmit County, TX, Edwards County, TX, Falls County, TX, Fayette County, TX, Fort Bend County, TX, Frio County, TX, Gillespie County, TX, Goliad County, TX, Gonzales County, TX, Grimes County, TX, Guadalupe County, TX, Hays County, TX, Irion County, TX, Jackson County, TX, Karnes County, TX, Kendall County, TX, Kerr County, TX, Kimble County, TX, Kinney County, TX, Lampasas County, TX, Lavaca County, TX, Lee County, TX, Llano County, TX, Mason County, TX, Matagorda County, TX, Maverick County, TX, McCulloch County, TX, Medina County, TX, Menard County, TX, Milam County, TX, Mills County, TX, Reagan County, TX, Real County, TX, Robertson County, TX, San Saba County, TX, Schleicher County, TX, Sutton County, TX, Tom Green County, TX, Travis County, TX, Uvalde County, TX, Val Verde County, TX, Victoria County, TX, Waller County, TX, Washington County, TX, Wharton County, TX, Williamson County, TX, Wilson County, TX, Zavala County, TX

The radar

The Austin/San Antonio radar (KEWX), 101 km from the middle of the area, began a volume at 12:47 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.

The nearest sounding before it

Del Rio, TX (KDRT), launched 12:00Z, 0.8 hours before the alert went out and 191 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, Del Rio, TX at 12:00Z on 2008-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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, Del Rio, TX at 12:00Z on 2008-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 50 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
2 J/kg
Mixed-layer CIN
-554 J/kg
Mixed-layer LCL
1766 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
50 m²/s²
0-3 km storm-relative helicity
215 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 
ACUS11 KWNS 271246
SWOMCD
SPC MCD 271245 
TXZ000-271345-

MESOSCALE DISCUSSION 0749
NWS STORM PREDICTION CENTER NORMAN OK
0745 AM CDT SUN APR 27 2008

AREAS AFFECTED...MUCH OF CENTRAL AND SRN TX

CONCERNING...SEVERE THUNDERSTORM WATCH 241...

VALID 271245Z - 271345Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 241
CONTINUES.

ISOLATED SEVERE STORMS REMAIN POSSIBLE IN THE SHORT TERM /NEXT 1-3
HOURS/ ACROSS MAINLY ERN PARTS OF WW 241.

12Z SURFACE ANALYSIS SHOWED THE COLD FRONT CONTINUED TO PROGRESS
SSEWD AND EXTENDED FROM THE LOWER OH VALLEY SWWD THROUGH THE
ARKLATEX TO CENTRAL AND SW TX.  A WEAKER BOUNDARY S OF THE FRONT
EXTENDED FROM SE OF DRT EWD TO NEAR HOU TO OFFSHORE OF LA...WHILE AN
OLD FRONT EXTENDED NEWD THROUGH E TX...CENTRAL LA TO NRN AL.  A
MOIST/MODERATELY UNSTABLE AIR MASS RESIDES S OF THE COLD FRONT. 
EFFECTIVE BULK SHEAR VALUES AROUND 30 KT SHOULD SUPPORT AN ISOLATED
SEVERE TSTM ACROSS MAINLY THE ERN HALF OF WW 241 THROUGH 14-15Z AS
ADDITIONAL TSTMS DEVELOP CLOSER TO AND TRACK EWD THROUGH THE
STRONGER INSTABILITY.  HOWEVER...OVERALL WARMING CLOUD TOP
TEMPERATURES AND DIMINISHING TREND IN STORM INTENSITIES WOULD
SUGGEST THAT THE SEVERE THREAT FOR THE NEXT SEVERAL HOURS WILL
CONTINUE TO DECREASE.

MEANWHILE...REGIONAL RADARS/LIGHTNING DATA INDICATED RECENT ELEVATED
TSTM DEVELOPMENT ACROSS WEST CENTRAL TX WHERE WSR-88D VWPS AND WIND
PROFILERS SHOWED THE POST-FRONTAL COLD BOUNDARY LAYER WAS ABOUT 2 KM
DEEP.  HEIGHT FALLS WITH SHORT WAVE TROUGH TRACKING SEWD THROUGH THE
SRN HIGH PLAINS SHOULD SUPPORT ADDITIONAL TSTM DEVELOPMENT THIS
MORNING...BUT WEAK INSTABILITY IS EXPECTED TO LIMIT THE SEVERE
WEATHER THREAT.

..PETERS.. 04/27/2008

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...HGX...FWD...CRP...EWX...SJT...MAF...

28769557 28769558 28429682 28519819 28439943 28370016
29110092 29570120 29840161 30480174 31090236 31250169
31690119 31790016 31559871 31489801 31349636 31109596

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 26, 9:33 PM CDTMesoscale DiscussionSPCCoke, Concho, Crockett, Glasscock, Irion, Menard and 6 more87 min
Apr 26, 11:34 PM CDTSevere Thunderstorm WatchSPCBandera, Bastrop, Bell, Blanco, Brown, Burnet and 33 more5 hr
Apr 27, 1:46 AM CDTMesoscale DiscussionSPCAnderson, Bandera, Bastrop, Bell, Blanco, Bosque and 75 more29 min
Apr 27, 3:39 AM CDTMesoscale DiscussionSPCAnderson, Bandera, Bastrop, Bell, Bexar, Blanco and 45 more36 min
Apr 27, 4:34 AM CDTSevere Thunderstorm WatchSPCAtascosa, Austin, Bandera, Bastrop, Bell, Bexar and 54 more7 hr

Nearby

Mesoscale Discussions in Texas, 2008Every mesoscale discussion in 2008

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.