Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 1607

July 26, 2012Jefferson County, Oklahoma; 55 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jul 26, 2012, 2:23 PM CDT for Jefferson County, Oklahoma; 55 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 26, 2012, 2:23 PM CDT (19:23 UTC)
Expired
Jul 26, 2012, 4:30 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
5%
All 56 counties

Jefferson County, OK, Archer County, TX, Baylor County, TX, Borden County, TX, Brewster County, TX, Brown County, TX, Callahan County, TX, Clay County, TX, Coke County, TX, Coleman County, TX, Comanche County, TX, Concho County, TX, Crane County, TX, Crockett County, TX, Eastland County, TX, Ector County, TX, Erath County, TX, Fisher County, TX, Glasscock County, TX, Haskell County, TX, Howard County, TX, Irion County, TX, Jack County, TX, Jones County, TX, Kent County, TX, Knox County, TX, Martin County, TX, McCulloch County, TX, Menard County, TX, Midland County, TX, Mitchell County, TX, Montague County, TX, Nolan County, TX, Palo Pinto County, TX, Parker County, TX, Pecos County, TX, Presidio County, TX, Reagan County, TX, Runnels County, TX, Schleicher County, TX, Scurry County, TX, Shackelford County, TX, Stephens County, TX, Sterling County, TX, Stonewall County, TX, Sutton County, TX, Taylor County, TX, Terrell County, TX, Throckmorton County, TX, Tom Green County, TX, Upton County, TX, Val Verde County, TX, Ward County, TX, Wichita County, TX, Wise County, TX, Young County, TX

The radar

The San Angelo radar (KSJT), 71 km from the middle of the area, began a volume at 19:24 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

Midland Regional, TX (KMAF), launched 12:00Z, 7.4 hours before the alert went out and 137 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 2012-07-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 42 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 2012-07-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 square meters per square second.1939Sfc1 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
42 J/kg
Mixed-layer CIN
-237 J/kg
Mixed-layer LCL
1976 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
38 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.

762 
ACUS11 KWNS 261923
SWOMCD
SPC MCD 261923 
OKZ000-TXZ000-262130-

MESOSCALE DISCUSSION 1607
NWS STORM PREDICTION CENTER NORMAN OK
0223 PM CDT THU JUL 26 2012

AREAS AFFECTED...SWRN TX NEWD INTO N-CNTRL TX AND FAR SRN OK

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 261923Z - 262130Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...AN ISOLATED THREAT FOR SEVERE THUNDERSTORMS WILL EXIST
THROUGH THE LATE AFTERNOON HOURS. GIVEN THE ANTICIPATED SPORADIC
NATURE OF THE SVR THREAT...AND THE DISORGANIZED CHARACTERISTICS OF
THE CONVECTION...WW ISSUANCE IS UNLIKELY.

DISCUSSION...OVER THE WRN FRINGES OF A PLUME OF MODESTLY RICH DEEP
MOISTURE OVER THE SRN PLAINS -- PW OF 1.65-1.85 INCHES PER GPS 
DATA -- THE AIR MASS CONTINUES TO DESTABILIZE SE OF A DIFFERENTIAL
HEATING ZONE EXTENDING FROM ENE OF WICHITA FALLS TX TO NEAR MIDLAND
TX. MODIFIED 12Z RAOBS INDICATE 1500-2500 J/KG OF MLCAPE ACROSS THE
AREA. AND...WITH LOW-LEVEL ASCENT ASSOCIATED WITH A N/S-ORIENTED SFC
TROUGH/WIND-SHIFT AXIS LYING SOUTH OF A STALLED FRONT ACROSS NW
TX...AND WITH BAROCLINICITY ATTENDANT TO THE DIFFERENTIAL HEATING
ZONE...SCATTERED THUNDERSTORMS ARE EXPECTED THROUGH THE LATE
AFTERNOON. GIVEN THE AFOREMENTIONED MAGNITUDE OF BUOYANCY...INTENSE
UPDRAFTS/DOWNDRAFTS WILL BE POSSIBLE...AND SPORADIC INSTANCES OF
DMGG WIND GUSTS MAY OCCUR. HOWEVER...WITH WEAK TROPOSPHERIC FLOW
OVER THE AREA PER VWP/PROFILER DATA...CONVECTION IS EXPECTED TO
EXHIBIT PRIMARILY PULSE/DISORGANIZED CHARACTERISTICS.

..COHEN/HART.. 07/26/2012

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

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

LAT...LON   29570104 29710161 29720205 29570237 29290256 28950312
            29040364 29310419 29860463 31090388 32230257 32880151
            33899954 34229837 34169760 33819734 32849751 31799852
            30270017 29570104

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 26, 1:44 PM CDTMesoscale DiscussionSPCAdair, Atoka, Cherokee, Cleveland, Coal, Garvin and 17 more3 hr
Jul 26, 5:27 PM CDTMesoscale DiscussionSPCLatimer, LeFlore, McCurtain, Pushmataha33 min
Jul 26, 5:46 PM CDTSevere Thunderstorm WatchSPCChoctaw, Haskell, Latimer, LeFlore, McCurtain, McIntosh and 5 more6 hr

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.