Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 558

April 24, 2011Beaver County, Oklahoma; 11 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2011, 7:35 PM CDT for Beaver County, Oklahoma; 11 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Apr 24, 2011, 7:35 PM CDT (00:35 UTC)
Expired: Apr 24, 2011, 10:00 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Beaver County, OK, Carson County, TX, Gray County, TX, Hansford County, TX, Hemphill County, TX, Hutchinson County, TX, Lipscomb County, TX, Moore County, TX, Ochiltree County, TX, Roberts County, TX, Sherman County, TX, Wheeler County, TX

The radar

The Amarillo radar (KAMA), 104 km from the middle of the area, began a volume at 00:38 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

Amarillo Airport, TX (KAMA), launched 00:00Z, 0.6 hours before the alert went out and 103 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 282 J/kg
Mixed-layer CIN: -210 J/kg
Mixed-layer LCL: 1797 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 167 m²/s²
0-3 km storm-relative helicity: 294 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

525 
ACUS11 KWNS 250035
SWOMCD
SPC MCD 250035 
OKZ000-TXZ000-250300-

MESOSCALE DISCUSSION 0558
NWS STORM PREDICTION CENTER NORMAN OK
0735 PM CDT SUN APR 24 2011

AREAS AFFECTED...PORTIONS TX/OK PANHANDLES...EXTREME WRN/NWRN OK.

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 250035Z - 250300Z

THREAT IS INCREASING FOR LARGE HAIL OVER THIS REGION.  ISOLATED
STG-SVR TSTM HAS DEVELOPED ALONG ELEVATED FRONTAL ZONE OVER NRN
PANHANDLE...MOVING EWD OVER SHERMAN COUNTY TOWARD AREAS BETWEEN
GUY-GAG.  ADDITIONAL DEVELOPMENT ALSO IS POSSIBLE AS LARGE-SCALE
ASCENT AND LOW-LEVEL MOISTURE EACH INCREASE.

GIVEN ISOLATED COVERAGE AND MRGL NATURE OF NEAR-TERM HAIL
THREAT...WW IS NOT ANTICIPATED...AND 5% HAIL PROBABILITIES WILL BE
EXTENDED ACROSS ERN PANHANDLE IN UPCOMING SPC DAY-1 OUTLOOK.
HOWEVER...AS THIS REGIME SHIFTS EWD INTO WRN OK LATE TONIGHT...HAIL
THREAT MAY INCREASE SUBSTANTIALLY.

SFC MESOANALYSIS SHOWS LOW BETWEEN TCC-CAO...WITH FRONTAL ZONE SEWD
ACROSS SWISHER/KING COUNTIES TX.  LOW AND FRONT SHOULD BECOME
QUASISTATIONARY FOR SEVERAL HOURS...WHILE LOW-LEVEL WAA/MOIST
ADVECTION INCREASE TO ITS NE INVOF PARALLEL 850-MB FRONTAL ZONE. 
THIS REGIME WILL BE JUXTAPOSED WITH STRENGTHENING LARGE-SCALE
LIFT/COOLING IN MID-UPPER LEVELS...AHEAD OF APCHG SWRN CONUS
SYNOPTIC TROUGH.  COMPACT PLUME OF DEEP-LAYER ASCENT SHOULD RESULT
OVER PANHANDLES...MOVING EWD IN SUPPORT OF INCREASING CONVECTIVE
COVERAGE THROUGH REMAINDER EVENING/OVERNIGHT HOURS.  ISOLATED TSTM
OVER NRN PANHANDLE AND HIGH-BASED CONVECTION OVER NERN NM APPEAR TO
BE EARLIEST MANIFESTATION OF THIS PROCESS.  TSTMS WILL ENCOUNTER
PROGRESSIVELY GREATER MOISTURE AND ELEVATED BUOYANCY WITH EWD EXTENT
AS LLJ STRENGTHENS.  MUCAPE MAY INCREASE TO NEAR 1000 J/KG OVER ERN
PANHANDLES AND 1500 J/KG OVER EXTREME WRN OK THROUGH 04Z...AMIDST
40-50 KT EFFECTIVE SHEAR MAGNITUDES.

..EDWARDS.. 04/25/2011

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

ATTN...WFO...OUN...AMA...

LAT...LON   34990088 35220170 36030244 36510170 36760115 36950025
            36699984 35339985 34990088

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 24, 10:13 PM CDT	Mesoscale Discussion	SPC	McCurtain	2 hr
Apr 24, 11:43 PM CDT	Severe Thunderstorm Watch	SPC	McCurtain	5 hr
Apr 24, 11:58 PM CDT	Mesoscale Discussion	SPC	Alfalfa, Beaver, Blaine, Canadian, Custer, Dewey and 14 more	92 min
Apr 25, 4:41 AM CDT	Severe Thunderstorm Watch	SPC	Choctaw, Latimer, LeFlore, McCurtain, Pushmataha	7 hr
Apr 25, 10:46 AM CDT	Mesoscale Discussion	SPC	Atoka, Bryan, Choctaw, Coal, Johnston, Latimer and 4 more	59 min
Apr 25, 11:00 AM CDT	Tornado Watch	SPC	Atoka, Bryan, Carter, Choctaw, Coal, Haskell and 14 more	7 hr
Apr 25, 1:28 PM CDT	Mesoscale Discussion	SPC	Adair, Atoka, Bryan, Carter, Cherokee, Choctaw and 21 more	92 min
Apr 25, 3:22 PM CDT	Tornado Watch PDS	SPC	McCurtain	8 hr
Apr 25, 5:24 PM CDT	Mesoscale Discussion	SPC	Beckham, Caddo, Canadian, Cleveland, Comanche, Cotton and 13 more	66 min
Apr 24, 8:48 PM CDT	Mesoscale Discussion	SPC	Bosque, Brown, Callahan, Coleman, Collin, Comanche and 36 more	117 min
Apr 24, 11:25 PM CDT	Mesoscale Discussion	SPC	Bosque, Brown, Callahan, Camp, Coke, Coleman and 39 more	65 min
Apr 25, 3:29 AM CDT	Mesoscale Discussion	SPC	Bosque, Camp, Collin, Dallas, Delta, Denton and 24 more	61 min
Apr 25, 7:23 AM CDT	Mesoscale Discussion	SPC	Bowie, Camp, Cass, Gregg, Harrison, Marion and 3 more	97 min
Apr 25, 2:16 PM CDT	Mesoscale Discussion	SPC	Angelina, Bastrop, Bell, Blanco, Brazos, Burleson and 27 more	59 min
Apr 25, 2:41 PM CDT	Tornado Watch	SPC	Anderson, Angelina, Bastrop, Bell, Blanco, Bosque and 49 more	9 hr
Apr 25, 5:21 PM CDT	Mesoscale Discussion	SPC	Bosque, Delta, Ellis, Henderson, Hill, Hopkins and 7 more	54 min
Apr 25, 6:57 PM CDT	Mesoscale Discussion	SPC	Anderson, Angelina, Bell, Blanco, Brazos, Burleson and 22 more	2 hr

Nearby

Mesoscale Discussions in Texas, 2011 Mesoscale Discussions in Oklahoma, 2011 Every mesoscale discussion in 2011

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.