Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 759

May 8, 20124 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 8, 2012, 3:03 PM CDT for 4 counties in Texas. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
May 8, 2012, 3:03 PM CDT (20:03 UTC)
Expired
May 8, 2012, 4:30 PM CDT
In force
87 min
Issued by
the Storm Prediction Center

Counties Cameron County, TX, Hidalgo County, TX, Starr County, TX, Willacy County, TX

The radar

The Brownsville radar (KBRO), 105 km from the middle of the area, began a volume at 20:05 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

Brownsville Intl, TX (KBRO), launched 12:00Z, 8.1 hours before the alert went out and 108 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 12:00Z on 2012-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1588 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, Brownsville Intl, TX at 12:00Z on 2012-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
1588 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
637 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

051 
ACUS11 KWNS 082004
SWOMCD
SPC MCD 082003
TXZ000-082130-

MESOSCALE DISCUSSION 0759
NWS STORM PREDICTION CENTER NORMAN OK
0303 PM CDT TUE MAY 08 2012

AREAS AFFECTED...DEEP SOUTH TEXAS

CONCERNING...SEVERE THUNDERSTORM WATCH 267...

VALID 082003Z - 082130Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 267
CONTINUES.

SUMMARY...RISK FOR SUPERCELLS CONTINUES AND MAY INCREASE A BIT
THROUGH 22-00Z...ACROSS STARR/HIDALGO/CAMERON AND WILLACY COUNTIES.

DISCUSSION...ALTHOUGH THE INITIAL INTENSE SUPERCELL DISSIPATED EAST
OF ZAPATA COUNTY...NEW CONVECTION CONTINUES TO DEVELOP TO THE
WEST...ABOVE ITS OUTFLOW...AND WITHIN MOIST UPSLOPE FLOW TO THE WEST
OF THE RIO GRANDE RIVER.  AS WEAK TO MODERATE WESTERLY DEEP LAYER
MEAN FLOW ADVECTS THIS ACTIVITY EASTWARD...POTENTIAL EXISTS FOR
INTENSIFICATION NEAR/NORTHWEST OF MCALLEN INTO THE BROWNSVILLE AREA
BETWEEN NOW AND 22-00Z.  ALONG AND JUST SOUTH OF A SOUTHWARD
ADVANCING COLD FRONT...LOW-LEVEL CONVERGENCE HAS BEEN STRENGTHENING
ACROSS THIS REGION...IN THE PRESENCE OF STEEPENING LOW-LEVEL LAPSE
RATES AND MODERATELY LARGE CAPE.  AS A 30-40 KT WESTERLY 500 MB JET
GRADUALLY SHIFTS THROUGH THE LOWER GRANDE VALLEY...VERTICAL SHEAR
PROFILES ARE BECOMING INCREASINGLY FAVORABLE FOR SUPERCELLS.

..KERR.. 05/08/2012

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

ATTN...WFO...BRO...

LAT...LON   26379943 26759923 26889869 26769808 26889767 26479738
            26059729 25599753 25529791 25999938 26379943

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, 1:42 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bexar, Comal, Dimmit, Edwards and 13 more93 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, 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.