Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 745

May 7, 2012Chaves County, Eddy County, Lea County, New Mexico; 9 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 7, 2012, 1:24 PM MDT for Chaves County, Eddy County, Lea County, New Mexico; 9 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 7, 2012, 1:24 PM MDT (19:24 UTC)
Expired: May 7, 2012, 3:30 PM MDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 80%

Counties Chaves County, NM, Eddy County, NM, Lea County, NM, Andrews County, TX, Crane County, TX, Ector County, TX, Gaines County, TX, Loving County, TX, Midland County, TX, Reeves County, TX, Ward County, TX, Winkler County, TX

The radar

The Midland/Odessa radar (KMAF), 166 km from the middle of the area, began a volume at 19:23 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.

Severe Thunderstorm Watch 264May 7, 2:50 PM MDT

The nearest sounding before it

Midland Regional, TX (KMAF), launched 12:00Z, 7.4 hours before the alert went out and 165 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: 1136 J/kg
Mixed-layer CIN: -273 J/kg
Mixed-layer LCL: 1187 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 238 m²/s²
0-3 km storm-relative helicity: 220 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

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

746 
ACUS11 KWNS 071925
SWOMCD
SPC MCD 071924
TXZ000-NMZ000-072130-

MESOSCALE DISCUSSION 0745
NWS STORM PREDICTION CENTER NORMAN OK
0224 PM CDT MON MAY 07 2012

AREAS AFFECTED...PORTIONS OF W TX INTO SERN NM

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 071924Z - 072130Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...SEVERE THREAT IS INCREASING AND A WW WILL LIKELY BE NEEDED
BY 21Z. LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN THREAT ACROSS
THE SERN NEW MEXICO PLAINS INTO SW TX INTO THE EARLY EVENING.

DISCUSSION...A CUMULUS FIELD WAS INCREASING THIS AFTERNOON IN
EASTERLY UPSLOPE FLOW ACROSS SERN NM AND A FEW TCU WERE NOTED ALONG
THE HIGHER TERRAIN OF THE GUADALUPE AND SACRAMENTO MOUNTAINS.
TEMPERATURES HAVE WARMED INTO THE MID 70S TO NEAR 80...RESULTING IN
MODEST INSTABILITY AND DECREASING CIN. CAPPING SHOULD CONTINUE TO
ERODE WITH CONTINUED HEATING THIS AFTERNOON AND AS A VORTICITY MAX
APPROACHES FROM THE WEST /NOTED ON 19Z WV IMAGERY/...DEEP LAYER
FORCING FOR ASCENT WILL INCREASE. BULK LAYER SHEAR OF 45-55 KT WILL
FAVOR SUPERCELL STORM MODES AND STEEP MIDLEVEL LAPSE RATES/COOL
TEMPS ALOFT WILL AID IN LARGE HAIL PRODUCTION. STRONG WINDS WILL
ALSO BE POSSIBLE GIVEN STEEP LOW LEVEL LAPSE RATES AND LARGE
TEMPERATURE-DEWPOINT SPREADS. A SEVERE THUNDERSTORM WATCH WILL
LIKELY BE NEEDED BY 21Z FOR PORTIONS OF SE NM INTO SW TX.

..LEITMAN/MEAD.. 05/07/2012

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

ATTN...WFO...LUB...MAF...ABQ...EPZ...

LAT...LON   31900175 30510379 32700510 33000502 33500473 33660437
            33600376 33420324 31900175

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 7, 2:56 PM MDT	Severe Thunderstorm Watch	SPC	Chaves, Eddy, Lea	7 hr
May 7, 5:55 PM MDT	Mesoscale Discussion	SPC	Lea	95 min
May 7, 11:46 AM MDT	Severe Thunderstorm Watch	SPC	Brewster, Brown, Callahan, Coke, Coleman, Concho and 23 more	8 hr
May 7, 1:37 PM MDT	Mesoscale Discussion	SPC	Bandera, Blanco, Burnet, Concho, Gillespie, Kendall and 11 more	83 min
May 7, 2:27 PM MDT	Severe Thunderstorm Watch	SPC	Bandera, Bastrop, Bell, Bexar, Blanco, Bosque and 30 more	7 hr
May 7, 3:38 PM MDT	Mesoscale Discussion	SPC	Bowie, Camp, Cass, Franklin, Gregg, Harrison and 4 more	67 min
May 7, 4:21 PM MDT	Severe Thunderstorm Watch	SPC	Bowie, Cass	5 hr
May 7, 4:31 PM MDT	Mesoscale Discussion	SPC	Bandera, Bastrop, Bell, Blanco, Burnet, Comal and 28 more	89 min

Nearby

Mesoscale Discussions in Texas, 2012 Mesoscale Discussions in New Mexico, 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.