Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 756

May 8, 201219 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 8, 2012, 1:42 AM CDT for 19 counties in Texas. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
May 8, 2012, 1:42 AM CDT (06:42 UTC)
Expired
May 8, 2012, 3:15 AM CDT
In force
93 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Atascosa County, TX, Bandera County, TX, Bexar County, TX, Comal County, TX, Dimmit County, TX, Edwards County, TX, Frio County, TX, Kendall County, TX, Kerr County, TX, Kinney County, TX, La Salle County, TX, Maverick County, TX, McMullen County, TX, Medina County, TX, Real County, TX, Uvalde County, TX, Val Verde County, TX, Wilson County, TX, Zavala County, TX

The radar

The Laughlin AFB radar (KDFX), 70 km from the middle of the area, began a volume at 06:43 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 00:00Z, 6.7 hours before the alert went out and 125 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 2012-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1281 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 00:00Z on 2012-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 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
1281 J/kg
Mixed-layer CIN
-57 J/kg
Mixed-layer LCL
2316 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
-15 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.

633 
ACUS11 KWNS 080642
SWOMCD
SPC MCD 080642 
TXZ000-080815-

MESOSCALE DISCUSSION 0756
NWS STORM PREDICTION CENTER NORMAN OK
0142 AM CDT TUE MAY 08 2012

AREAS AFFECTED...SWRN TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 080642Z - 080815Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN INCREASE IN STORM COVERAGE IS EXPECTED OVER MUCH OF
SWRN TX WITH MARGINAL HAIL LIKELY. A FEW WIND GUSTS CANNOT BE RULED
IF STORMS EVOLVE JUST RIGHT.

DISCUSSION...A BAND OF ELEVATED STORMS HAS FORMED FROM JUST S OF
MIDLAND SEWD ACROSS THE HILL COUNTRY WITH STEEP MIDLEVEL LAPSE RATES
ALOFT...BUT THE CORES WERE FAIRLY WEAK. HOWEVER...WITH SUCH COOL
TEMPERATURES ALOFT...STORMS WILL CONTINUE TO FORM WITH INCREASING
UPPER DIVERGENCE AND SUFFICIENT DEEP SHEAR FOR SOME SUSTAINED
UPDRAFTS.

SURFACE OBSERVATIONS AS WELL AS FORECAST SOUNDINGS FROM MULTIPLE
MODELS INDICATE A RATHER POOR LAPSE RATE IN THE LOWEST SEVERAL
KM...IN PART DUE TO COOL ELY SURFACE WINDS AND TEMPERATURES ONLY IN
THE MID TO UPPER 60S F. THEREFORE...MARGINAL HAIL APPEARS TO BE THE
MAIN THREAT FOR NOW WITH EFFECTIVELY SHORTENED HODOGRAPHS.
HOWEVER...AS STORMS EXPAND ACROSS THE REGION...TRENDS WILL NEED TO
BE MONITORED FOR SIGNS OF UPSCALE GROWTH SUGGESTING THE LOWER
PORTIONS OF THE HODOGRAPHS ARE BEING MADE EFFECTIVE. MUCH GREATER
PRECIPITABLE WATER EXISTS SE OF DEL RIO NEAR LAREDO.

..JEWELL.. 05/08/2012

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

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

LAT...LON   28160025 28920067 29610144 30150152 30450011 30279883
            29819799 29149808 28659809 28159851 27869936 27899996
            28160025

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 7, 7:39 PM CDTSevere Thunderstorm WatchSPCCamp, Gregg, Harrison, Marion, Morris, Panola and 5 more4 hr
May 7, 7:54 PM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bastrop, Bee, Bexar, Brazos and 40 more66 min
May 7, 9:15 PM CDTMesoscale DiscussionSPCCamp, Cass, Gregg, Harrison, Marion, Morris and 6 more60 min
May 7, 9:46 PM CDTMesoscale DiscussionSPCAndrews, Borden, Crane, Crockett, Dawson, Ector and 15 more89 min
May 8, 10:44 AM CDTMesoscale DiscussionSPCBee, Brooks, Duval, Frio, Goliad, Jim Hogg and 11 more61 min
May 8, 10:58 AM CDTSevere Thunderstorm WatchSPCAransas, Atascosa, Bee, Brooks, Calhoun, Cameron and 28 more8 hr
May 8, 1:37 PM CDTMesoscale DiscussionSPCBrewster, Culberson, El Paso, Hudspeth, Jeff Davis, Presidio and 1 more113 min
May 8, 2:07 PM CDTSevere Thunderstorm WatchSPCBrewster, Culberson, El Paso, Hudspeth, Jeff Davis, Presidio7 hr
May 8, 3:03 PM CDTMesoscale DiscussionSPCCameron, Hidalgo, Starr, Willacy87 min
May 8, 4:53 PM CDTMesoscale DiscussionSPCBrewster, Culberson, El Paso, Hudspeth, Jeff Davis, Presidio67 min
May 8, 5:47 PM CDTMesoscale DiscussionSPCCameron, Hidalgo, Kenedy, Willacy58 min

Nearby

Mesoscale Discussions in Texas, 2012Every mesoscale discussion in 2012

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.