Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 941

May 28, 20126 counties in Oklahoma; 36 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 28, 2012, 2:54 PM CDT for 6 counties in Oklahoma; 36 counties in Texas. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
May 28, 2012, 2:54 PM CDT (19:54 UTC)
Expired
May 28, 2012, 4:30 PM CDT
In force
96 min
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 42 counties

Comanche County, OK, Cotton County, OK, Jackson County, OK, Jefferson County, OK, Stephens County, OK, Tillman County, OK, Andrews County, TX, Archer County, TX, Baylor County, TX, Borden County, TX, Cottle County, TX, Crane County, TX, Crosby County, TX, Dawson County, TX, Dickens County, TX, Ector County, TX, Fisher County, TX, Foard County, TX, Garza County, TX, Glasscock County, TX, Hardeman County, TX, Haskell County, TX, Howard County, TX, Jones County, TX, Kent County, TX, King County, TX, Knox County, TX, Lynn County, TX, Martin County, TX, Midland County, TX, Mitchell County, TX, Nolan County, TX, Pecos County, TX, Reagan County, TX, Scurry County, TX, Sterling County, TX, Stonewall County, TX, Throckmorton County, TX, Upton County, TX, Ward County, TX, Wichita County, TX, Wilbarger County, TX

The radar

The Dyess AFB radar (KDYX), 116 km from the middle of the area, began a volume at 19:54 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

Midland Regional, TX (KMAF), launched 12:00Z, 7.9 hours before the alert went out and 187 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, Midland Regional, TX at 12:00Z on 2012-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1975 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, Midland Regional, TX at 12:00Z on 2012-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 117 square meters per square second.193958Sfc1 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
1975 J/kg
Mixed-layer CIN
-143 J/kg
Mixed-layer LCL
1079 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
117 m²/s²
0-3 km storm-relative helicity
126 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

817 
ACUS11 KWNS 281955
SWOMCD
SPC MCD 281954
OKZ000-TXZ000-282130-

MESOSCALE DISCUSSION 0941
NWS STORM PREDICTION CENTER NORMAN OK
0254 PM CDT MON MAY 28 2012

AREAS AFFECTED...WEST AND NORTHWEST TX

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 281954Z - 282130Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...A SEVERE THREAT IS EXPECTED TO DEVELOP ACROSS WEST TX LATE
THIS AFTERNOON. LARGE HAIL AND WIND DAMAGE WILL BE THE MAIN THREATS
WITH THE STORMS. WW ISSUANCE WILL LIKELY BE NEEDED ONCE CELLS BEGIN
TO INITIATE ACROSS WEST TX LATE THIS AFTERNOON.

DISCUSSION...THE LATEST SFC ANALYSIS SHOWS A DIFFUSE FRONTAL
BOUNDARY FROM NEAR CHILDRESS EXTENDING SWWD INTO FAR SE NM. TO THE
SOUTHEAST OF THE BOUNDARY...MODERATE TO STRONG INSTABILITY IS IN
PLACE WITH MLCAPE ESTIMATED IN THE 2000 TO 3000 J/KG RANGE. THE
CAPPING INVERSION IS NOW GONE AND A FIELD OF CUMULUS IS GROWING ON
THE NWRN EDGE OF INSTABILITY IMMEDIATELY SOUTHEAST OF THE FRONT.
SHORT-TERM MODEL FORECASTS ARE IN FAIRLY GOOD AGREEMENT...INITIATING
STORMS IN THE 2030Z TO 2130Z TIMEFRAME BETWEEN MIDLAND AND LUBBOCK
WITH CONVECTION EXPANDING NEWD INTO THE LOW ROLLING PLAINS OF NW TX
AND INTO SW OK. THE LATEST WSR-88D VWPS WCNTRL TX SHOW 30 TO 40 KT
OF DEEP LAYER SHEAR WHICH COMBINED WITH LAPSE RATES AROUND 8.0 C/KM
SHOULD BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL. DEEP LAYER SHEAR
IS FORECAST TO INCREASE TOWARD EARLY EVENING AS THE LOW-LEVEL JET
STRENGTHENS. THIS ALONG WITH THE PRISTINE THERMODYNAMIC ENVIRONMENT
MAY ENABLE THE MORE DOMINANT SUPERCELLS TO HAVE HAIL GREATER THAN 2
INCHES IN DIAMETER. AN ISOLATED WIND DAMAGE THREAT SHOULD ALSO
DEVELOP AS THE CELLS MATURE.

..BROYLES.. 05/28/2012

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

ATTN...WFO...FWD...OUN...SJT...LUB...MAF...

LAT...LON   34089778 34649768 34909799 34999844 34869893 34020066
            33340172 32560260 31660309 30700340 30260324 30220262
            30500213 30930170 31660119 32679998 33149922 33519863
            34089778

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 28, 3:48 PM CDTSevere Thunderstorm WatchSPCCanadian, Carter, Cleveland, Comanche, Cotton, Garvin and 13 more8 hr
May 28, 6:14 PM CDTMesoscale DiscussionSPCComanche, Cotton, Grady, Jefferson, Stephens, Tillman91 min
May 27, 7:37 PM CDTMesoscale DiscussionSPCTerrell53 min

Nearby

Mesoscale Discussions in Texas, 2012Mesoscale Discussions in Oklahoma, 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.