Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 2083

October 22, 201221 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Oct 22, 2012, 10:37 AM CDT for 21 counties in Texas. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Oct 22, 2012, 10:37 AM CDT (15:37 UTC)
Expired
Oct 22, 2012, 11:30 AM CDT
In force
53 min
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 21 counties

Brown County, TX, Callahan County, TX, Coleman County, TX, Comanche County, TX, Cooke County, TX, Denton County, TX, Eastland County, TX, Erath County, TX, Hood County, TX, Jack County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Runnels County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Taylor County, TX, Wise County, TX, Young County, TX

The radar

The Dyess AFB radar (KDYX), 66 km from the middle of the area, began a volume at 15:37 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

Fort Worth, TX (KFWD), launched 12:00Z, 3.6 hours before the alert went out and 123 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, Fort Worth, TX at 12:00Z on 2012-10-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1026 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, Fort Worth, TX at 12:00Z on 2012-10-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 194 square meters per square second.19395878Sfc1 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
1026 J/kg
Mixed-layer CIN
-229 J/kg
Mixed-layer LCL
648 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
194 m²/s²
0-3 km storm-relative helicity
201 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.

729 
ACUS11 KWNS 221538
SWOMCD
SPC MCD 221537
TXZ000-221630-

MESOSCALE DISCUSSION 2083
NWS STORM PREDICTION CENTER NORMAN OK
1037 AM CDT MON OCT 22 2012

AREAS AFFECTED...PORTIONS OF N-CNTRL TX/LOW ROLLING PLAINS OF TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 221537Z - 221630Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN ISOLATED THREAT FOR MARGINALLY SVR STORMS WILL EXIST
THROUGH THE LATE MORNING HOURS. IN THE SHORT TERM...THE ISSUANCE OF
A WW IS UNLIKELY.

DISCUSSION...CAPPI DATA AT 9 KM INDICATE A MODEST UPTICK IN
CONVECTIVE INTENSITY AT THE LEADING EDGE OF A COLD POOL ACCOMPANYING
AN ONGOING CLUSTER OF CONVECTION CROSSING THE AREA. HAIL APPROACHING
MARGINALLY SVR THRESHOLDS MAY EXIST WITH THE STRONGEST STORMS OWING
TO THE STEEP MID-LEVEL LAPSE RATES ACCOMPANYING AN EML SAMPLED BY
THE 12Z FORT WORTH RAOB -- I.E. 700-500 MB LAPSE RATE OF 8 C/KM
SUPPORTING MUCAPE OVER 1500 J/KG. ALSO...STRONG WIND GUSTS MAY
BRIEFLY OCCUR WITH THIS ACTIVITY. HOWEVER...CONVECTION WILL HAVE A
TENDENCY TO BE UNDERCUT BY THE EWD-MOVING COLD POOL OWING TO ITS /1/
SPATIAL DISPLACEMENT FROM STRONGER FORCING FOR ASCENT AND STRONGER
DEEP SHEAR ATTENDANT TO A SHORTWAVE TROUGH FARTHER W/NW AND /2/ DEEP
SHEAR VECTORS THROUGH THE CLOUD-BEARING LAYER BEING NEARLY PARALLEL
TO THE LEADING EDGE OF THE COLD POOL. AS SUCH...ANY STRONG/SVR
STORMS SHOULD BE RATHER BRIEF/SPORADIC.

..COHEN/MEAD.. 10/22/2012

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

ATTN...WFO...FWD...OUN...SJT...

LAT...LON   33569697 32769706 31929811 31639921 31860052 32210048
            32480012 33009927 33659840 33769755 33569697

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 22, 1:27 PM CDTMesoscale DiscussionSPCBosque, Brown, Callahan, Coleman, Collin, Comanche and 17 more3 hr

Nearby

Mesoscale Discussions in Texas, 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.