Alert archive / Texas / Mesoscale Discussions in 2005

Mesoscale Discussion 321

March 21, 200533 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 21, 2005, 10:57 AM CST for 33 counties in Texas. It was in force for 33 min.

The area

The outline as issued.

The facts

Issued
Mar 21, 2005, 10:57 AM CST (16:57 UTC)
Expired
Mar 21, 2005, 11:30 AM CST
In force
33 min
Issued by
the Storm Prediction Center
All 33 counties

Atascosa County, TX, Austin County, TX, Bastrop County, TX, Bexar County, TX, Brazoria County, TX, Caldwell County, TX, Chambers County, TX, Colorado County, TX, Comal County, TX, DeWitt County, TX, Fayette County, TX, Fort Bend County, TX, Galveston County, TX, Goliad County, TX, Gonzales County, TX, Guadalupe County, TX, Harris County, TX, Hays County, TX, Jackson County, TX, Karnes County, TX, Kendall County, TX, Lavaca County, TX, Lee County, TX, Liberty County, TX, Matagorda County, TX, Montgomery County, TX, San Jacinto County, TX, Travis County, TX, Victoria County, TX, Waller County, TX, Washington County, TX, Wharton County, TX, Wilson County, TX

The radar

The Austin/San Antonio radar (KEWX), 136 km from the middle of the area, began a volume at 16:57 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

Corpus Christi, TX (KCRP), launched 12:00Z, 5.0 hours before the alert went out and 215 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 2005-03-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 167 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 2005-03-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 152 square meters per square second.1939587897117Sfc1 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
167 J/kg
Mixed-layer CIN
-316 J/kg
Mixed-layer LCL
622 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
152 m²/s²
0-3 km storm-relative helicity
263 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
ACUS11 KWNS 211658
SWOMCD
SPC MCD 211657 
TXZ000-211730-

MESOSCALE DISCUSSION 0321
NWS STORM PREDICTION CENTER NORMAN OK
1057 AM CST MON MAR 21 2005

AREAS AFFECTED...PORTIONS OF CENTRAL TX TO THE UPPER TX COAST

CONCERNING...SEVERE THUNDERSTORM WATCH 55...

VALID 211657Z - 211730Z

WW MAY BE REQUIRED SOON FOR PORTIONS OF CENTRAL TX EWD INTO SE TX. 

VIS IMAGERY THIS MORNING HAS INDICATED MAINLY CLEAR SKIES BETWEEN
VCT AND THE HOU AREA...ALLOWING FOR SURFACE HEATING WITHIN AN AXIS
OF RICH MOISTURE.  THUNDERSTORMS...CURRENTLY OVER THE SERN PORTION
OF WW 055 /IN HAYS COUNTY/ HAVE SHOWN SOME INCREASE IN INTENSITY PER
LIGHTNING DATA SUGGESTING THEY HAVE BECOME MORE ROOTED TOWARD THE
SURFACE.  THIS TREND IS EXPECTED TO CONTINUE INTO THE AFTERNOON FROM
AROUND SAT EWD INTO SE TX...WITH ADDITIONAL DESTABILIZATION AND DEEP
LAYER SHEAR MORE THAN SUFFICIENT FOR SUPERCELLS.

..PETERS.. 03/21/2005

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

ATTN...WFO...LCH...HGX...CRP...EWX...

28639883 30149888 30329795 30519610 30779474 30629451
29599434 28829533 28509617 28669722

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 21, 3:39 AM CSTMesoscale DiscussionSPCBosque, Clay, Collin, Comanche, Cooke, Dallas and 26 more3 hr
Mar 21, 6:05 AM CSTSevere Thunderstorm WatchSPCBastrop, Bell, Blanco, Bosque, Brown, Burnet and 59 more6 hr
Mar 21, 7:43 AM CSTMesoscale DiscussionSPCBastrop, Bell, Blanco, Bosque, Brown, Burleson and 60 more92 min
Mar 21, 9:26 AM CSTMesoscale DiscussionSPCAnderson, Bastrop, Bell, Blanco, Bosque, Burleson and 57 more34 min
Mar 21, 2:59 PM CSTMesoscale DiscussionSPCAnderson, Camp, Cherokee, Delta, Falls, Fannin and 18 more3 hr
Mar 21, 5:10 PM CSTMesoscale DiscussionSPCAnderson, Angelina, Austin, Bowie, Brazoria, Brazos and 55 more95 min
Mar 21, 5:40 PM CSTTornado WatchSPCAnderson, Angelina, Austin, Bowie, Brazos, Camp and 40 more7 hr

Nearby

Mesoscale Discussions in Texas, 2005Every mesoscale discussion 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.