Alert archive / Texas / Mesoscale Discussions in 2015

Mesoscale Discussion 430

April 24, 20155 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2015, 2:36 AM CDT for 5 counties in Texas. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Apr 24, 2015, 2:36 AM CDT (07:36 UTC)
Expired
Apr 24, 2015, 4:00 AM CDT
In force
84 min
Issued by
the Storm Prediction Center
Chance of a watch
60%

Counties Dimmit County, TX, La Salle County, TX, McMullen County, TX, Webb County, TX, Zavala County, TX

The radar

The Laughlin AFB radar (KDFX), 113 km from the middle of the area, began a volume at 07:36 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Del Rio, TX (KDLF), launched 00:00Z, 7.6 hours before the alert went out and 156 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 00:00Z on 2015-04-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1325 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Del Rio, TX at 00:00Z on 2015-04-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.1939587897Sfc1 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
1325 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
1694 m above ground
0-6 km bulk shear
67 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
214 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.8

Open this sounding in Storm Lab

The text

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

629 
ACUS11 KWNS 240736
SWOMCD
SPC MCD 240736 
TXZ000-240900-

MESOSCALE DISCUSSION 0430
NWS STORM PREDICTION CENTER NORMAN OK
0236 AM CDT FRI APR 24 2015

AREAS AFFECTED...MIDDLE RIO GRANDE VALLEY/SOUTH-CENTRAL TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 240736Z - 240900Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...A SUPERCELL OR TWO MAY MAY POSE MOSTLY A LARGE HAIL AND
POSSIBLY SOME TORNADO/DAMAGING WIND RISK ACROSS PARTS OF THE MIDDLE
RIO GRANDE VALLEY AND POSSIBLY ADDITIONAL PARTS OF SOUTH-CENTRAL TX
OVERNIGHT. A WATCH MAY BE NEEDED.

DISCUSSION...A SUPERCELL IS CURRENTLY CROSSING THE MIDDLE RIO GRANDE
RIVER INTO SOUTHERN MAVERICK COUNTY TX. THE REGION APPEARS TO BE AT
LEAST SOMEWHAT INFLUENCED BY WEAK HEIGHT FALLS VIA AN UPSTREAM
TROUGH OVER NORTHERN MEXICO. THE ENVIRONMENT ACROSS THE MIDDLE RIO
GRANDE VALLEY/SOUTH-CENTRAL TX IS VERY MOIST/MODERATELY UNSTABLE IN
THE PRESENCE OF LOWER 70S F SURFACE DEWPOINTS AND PRECIPITABLE WATER
VALUES THAT ARE LIKELY IN EXCESS OF 1.5 INCHES. ACCENTUATED BY LIGHT
EASTERLY WINDS IN THE BOUNDARY LAYER...STRONG DEEP-LAYER/LOW-LEVEL
SHEAR WILL BE SUPPORTIVE OF SUPERCELLS CAPABLE OF LARGE HAIL ALONG
WITH SOME TORNADO/DAMAGING WIND RISK.

..GUYER/CORFIDI.. 04/24/2015

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

ATTN...WFO...CRP...EWX...

LAT...LON   28620046 29029957 28309844 27449949 28620046

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 23, 9:34 PM CDTMesoscale DiscussionSPCBandera, Dimmit, Edwards, Frio, Jim Hogg, Kinney and 10 more56 min
Apr 24, 3:01 AM CDTSevere Thunderstorm WatchSPCAtascosa, Dimmit, Frio, La Salle, Live Oak, McMullen and 5 more4 hr
Apr 24, 5:41 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Dimmit, Duval, Edwards, Frio and 10 more94 min
Apr 24, 10:29 AM CDTMesoscale DiscussionSPCHardin, Jasper, Liberty, Newton, Orange, Tyler91 min
Apr 24, 11:12 AM CDTMesoscale DiscussionSPCBosque, Brown, Callahan, Coke, Coleman, Collin and 43 more2 hr
Apr 24, 11:53 AM CDTMesoscale DiscussionSPCHardin, Jefferson, Newton, Orange97 min
Apr 24, 12:18 PM CDTTornado WatchSPCJasper, Newton, Orange5 hr
Apr 24, 12:56 PM CDTMesoscale DiscussionSPCChildress, Collingsworth, Cottle, Crosby, Dickens, Foard and 3 more94 min
Apr 24, 2:10 PM CDTTornado WatchSPCAnderson, Bell, Bosque, Brown, Callahan, Coke and 52 more8 hr
Apr 24, 3:58 PM CDTMesoscale DiscussionSPCAngelina, Camp, Cass, Cherokee, Gregg, Harrison and 16 more92 min
Apr 24, 4:45 PM CDTTornado WatchSPCAngelina, Bowie, Camp, Cass, Cherokee, Franklin and 20 more5 hr
Apr 24, 4:56 PM CDTMesoscale DiscussionSPCAtascosa, Dimmit, Duval, Frio, Jim Hogg, Kinney and 9 more94 min
Apr 24, 6:01 PM CDTMesoscale DiscussionSPCDallas, Ellis, Erath, Hood, Johnson, Kaufman and 3 more59 min
Apr 24, 6:53 PM CDTSevere Thunderstorm WatchSPCAtascosa, Bee, Brooks, Cameron, DeWitt, Dimmit and 19 more6 hr

Nearby

Mesoscale Discussions in Texas, 2015Every mesoscale discussion in 2015

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.