Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 491

April 11, 2012Eddy County, Otero County, New Mexico; 13 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2012, 1:53 PM MDT for Eddy County, Otero County, New Mexico; 13 counties in Texas. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: Apr 11, 2012, 1:53 PM MDT (19:53 UTC)
Expired: Apr 11, 2012, 3:30 PM MDT
In force: 97 min
Issued by: the Storm Prediction Center

Counties Eddy County, NM, Otero County, NM, Brewster County, TX, Crane County, TX, Culberson County, TX, El Paso County, TX, Hudspeth County, TX, Jeff Davis County, TX, Loving County, TX, Pecos County, TX, Presidio County, TX, Reeves County, TX, Terrell County, TX, Ward County, TX, Winkler County, TX

The radar

The Midland/Odessa radar (KMAF), 217 km from the middle of the area, began a volume at 19:55 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 156Apr 11, 2:45 PM MDT

The nearest sounding before it

Midland Regional, TX (KMAF), launched 12:00Z, 7.9 hours before the alert went out and 217 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: 60 J/kg
Mixed-layer CIN: -326 J/kg
Mixed-layer LCL: 1194 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 48 m²/s²
0-3 km storm-relative helicity: -11 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.

854 
ACUS11 KWNS 111954
SWOMCD
SPC MCD 111953
TXZ000-NMZ000-112130-

MESOSCALE DISCUSSION 0491
NWS STORM PREDICTION CENTER NORMAN OK
0253 PM CDT WED APR 11 2012

AREAS AFFECTED...SERN NM INTO FAR W TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 111953Z - 112130Z

INCREASING CONVECTION ACROSS FAR W TX AND INTO SRN NM MAY WARRANT WW
ISSUANCE.

LATEST SATELLITE/RADAR IMAGERY SHOWS CONVECTIVE DEVELOPMENT UNDERWAY
ACROSS PARTS OF SRN NM AND ADJACENT FAR W TX...FROM THE SACRAMENTO
MOUNTAINS OF NM SEWD INTO THE DAVIS MOUNTAINS OF TX.  HERE...DAYTIME
HEATING OF THE MODESTLY-MOIST BOUNDARY LAYER HAS RESULTED IN
SURFACE-BASED CAPE AROUND 1000 J/KG -- FUELING THE CONVECTIVE
ACTIVITY.

AS LARGE-SCALE ASCENT INCREASES WITH TIME ACROSS THIS REGION AHEAD
OF THE SLOWLY ADVANCING SWRN U.S. UPPER SYSTEM...INTENSITY AND
COVERAGE OF CONVECTION SHOULD LIKEWISE INCREASE.  SUPPORTED BY THE
SLOWLY STRENGTHENING DEEP-LAYER WIND FIELD...AN ISOLATED CELL IN SRN
REEVES CO TX IS SHOWING MID-LEVEL ROTATION.  WITH THIS UPWARD TREND
IN STORM COVERAGE/INTENSITY EXPECTED TO CONTINUE...WW ISSUANCE MAY
BE NEEDED.

..GOSS.. 04/11/2012

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

ATTN...WFO...SJT...MAF...ABQ...EPZ...

LAT...LON   28980290 29410410 31060580 32230656 33300653 33440539
            32800433 31480249 30140202 28980290

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 11, 1:05 PM MDT	Mesoscale Discussion	SPC	Chaves, Colfax, Curry, De Baca, Guadalupe, Harding and 9 more	115 min
Apr 11, 2:05 PM MDT	Mesoscale Discussion	SPC	Union	25 min
Apr 11, 2:11 PM MDT	Tornado Watch	SPC	Union	7 hr
Apr 11, 2:43 PM MDT	Severe Thunderstorm Watch	SPC	Chaves, Colfax, Curry, De Baca, Eddy, Guadalupe and 6 more	6 hr
Apr 11, 5:21 PM MDT	Mesoscale Discussion	SPC	Chaves, Curry, De Baca, Eddy, Guadalupe, Harding and 5 more	84 min
Apr 11, 5:08 PM MDT	Mesoscale Discussion	SPC	Armstrong, Carson, Dallam, Gray, Hansford, Hartley and 7 more	97 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.