Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 982

May 30, 201214 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 30, 2012, 2:58 PM CDT for 14 counties in Texas. It was in force for 62 min.

The area

The outline as issued.

The facts

Issued: May 30, 2012, 2:58 PM CDT (19:58 UTC)
Expired: May 30, 2012, 4:00 PM CDT
In force: 62 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

Counties Briscoe County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Dickens County, TX, Donley County, TX, Foard County, TX, Hall County, TX, Haskell County, TX, Kent County, TX, King County, TX, Knox County, TX, Motley County, TX, Stonewall County, TX

The radar

The Altus AFB radar (KFDR), 135 km from the middle of the area, began a volume at 19:59 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

Amarillo Airport, TX (KAMA), launched 12:00Z, 8.0 hours before the alert went out and 166 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: 1219 J/kg
Mixed-layer CIN: -331 J/kg
Mixed-layer LCL: 2065 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 256 m²/s²
0-3 km storm-relative helicity: 299 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

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

103 
ACUS11 KWNS 301958
SWOMCD
SPC MCD 301958 
OKZ000-TXZ000-302100-

MESOSCALE DISCUSSION 0982
NWS STORM PREDICTION CENTER NORMAN OK
0258 PM CDT WED MAY 30 2012

AREAS AFFECTED...SE TX PANHANDLE...NORTHWEST TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 301958Z - 302100Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...A SEVERE THREAT IS EXPECTED TO DEVELOP ACROSS THE SERN TX
PANHANDLE AND IN NW TX LATE THIS AFTERNOON. LARGE HAIL AND ISOLATED
WIND DAMAGE WILL BE POSSIBLE AS STORMS INITIATE AND INCREASE IN
COVERAGE. WW ISSUANCE APPEARS LIKELY ACROSS THE MCD AREA.

DISCUSSION...THE LATEST VISIBLE SATELLITE IMAGERY SHOWS TOWERING
CUMULUS DEVELOPING JUST TO THE WEST OF CHILDRESS TX ALONG A DRYLINE
WHERE SFC DEWPOINTS TO THE EAST OF THE DRYLINE ARE IN THE MID 60S F.
AS SFC TEMPS HAVE WARMED...A NARROW CORRIDOR OF STRONG INSTABILITY
HAS DEVELOPED WITH MLCAPE ESTIMATED FROM 2500 TO 3500 J/KG. AS THE
CAP WEAKENS ALONG THE DRYLINE...THUNDERSTORMS SHOULD INITIATE OVER
THE NEXT HOUR. THE LATEST WSR-88D VWP AT FREDERICK OK SHOWS ABOUT 50
KT OF DEEP LAYER SHEAR AND FORECAST SOUNDINGS IN THAT SAME AREA SHOW
VERY STEEP LAPSE RATES EXCEEDING 8.0 C/KM. THIS ENVIRONMENT SHOULD
SUPPORT SUPERCELLS WITH LARGE HAIL AND WIND DAMAGE WILL ALSO BE
POSSIBLE. ON VISIBLE SATELLITE IMAGERY...WAVE CLOUDS ARE EVIDENT
ACROSS MUCH OF SW OK AND NW TX SUGGESTING THE AIRMASS IS MORE STABLE
FURTHER TO THE EAST. THIS SHOULD LIMIT THE EWD EXTENT OF THE SEVERE
THREAT WITH THE GREATEST SEVERE THREAT LOCATED JUST TO THE EAST OF
THE CAPROCK.

..BROYLES/WEISS.. 05/30/2012

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

ATTN...WFO...OUN...SJT...LUB...AMA...MAF...

LAT...LON   35400040 35390072 35180105 34550125 33260110 32910084
            32740028 32849985 33269954 33929975 35109993 35400040

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 29, 8:54 PM CDT	Mesoscale Discussion	SPC	Collin, Dallas, Denton, Hood, Jack, Johnson and 6 more	96 min
May 29, 11:28 PM CDT	Mesoscale Discussion	SPC	Cooke, Fannin, Grayson, Lamar, Montague	62 min
May 30, 12:43 AM CDT	Severe Thunderstorm Watch	SPC	Camp, Collin, Cooke, Dallas, Delta, Denton and 19 more	7 hr
May 30, 2:43 AM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Camp, Cass, Clay, Collin and 37 more	92 min
May 30, 5:07 AM CDT	Mesoscale Discussion	SPC	Anderson, Camp, Cherokee, Collin, Dallas, Denton and 28 more	83 min
May 30, 3:38 PM CDT	Tornado Watch	SPC	Baylor, Briscoe, Childress, Collingsworth, Cottle, Dickens and 15 more	5 hr
May 30, 4:52 PM CDT	Mesoscale Discussion	SPC	Brown, Callahan, Coke, Coleman, Concho, Eastland and 17 more	83 min
May 30, 5:11 PM CDT	Tornado Watch	SPC	Brown, Burnet, Callahan, Coke, Coleman, Comanche and 27 more	6 hr
May 30, 6:13 PM CDT	Severe Thunderstorm Watch	SPC	Archer, Baylor, Clay, Cooke, Denton, Jack and 5 more	8 hr

Nearby

Mesoscale Discussions in Texas, 2012 Every 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.