Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 786

May 11, 201234 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 11, 2012, 1:22 PM CDT for 34 counties in Texas. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
May 11, 2012, 1:22 PM CDT (18:22 UTC)
Expired
May 11, 2012, 2:15 PM CDT
In force
53 min
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 34 counties

Anderson County, TX, Bosque County, TX, Camp County, TX, Cherokee County, TX, Collin County, TX, Cooke County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Ellis County, TX, Fannin County, TX, Freestone County, TX, Grayson County, TX, Gregg County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Limestone County, TX, Montague County, TX, Navarro County, TX, Parker County, TX, Rains County, TX, Rockwall County, TX, Smith County, TX, Somervell County, TX, Tarrant County, TX, Upshur County, TX, Van Zandt County, TX, Wise County, TX, Wood County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 82 km from the middle of the area, began a volume at 18:22 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, 6.4 hours before the alert went out and 78 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 2012-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 119 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 2012-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 60 square meters per square second.1939587897117Sfc1 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
119 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
617 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
60 m²/s²
0-3 km storm-relative helicity
128 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.

473 
ACUS11 KWNS 111823
SWOMCD
SPC MCD 111822
TXZ000-OKZ000-111915-

MESOSCALE DISCUSSION 0786
NWS STORM PREDICTION CENTER NORMAN OK
0122 PM CDT FRI MAY 11 2012

AREAS AFFECTED...NORTHEAST TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 111822Z - 111915Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...SHOWERS AND STORMS ARE INCREASING ACROSS PARTS OF N TX
NEAR AND N OF THE DFW METROPLEX...BUT OVERALL SEVERE POTENTIAL
SHOULD REMAIN LIMITED.

DISCUSSION...WHILE PERSISTENT CLOUD COVER IS OBSERVED...MODEST
HEATING/DESTABILIZATION IS UNDERWAY ACROSS PARTS OF N CENTRAL AND
NERN TX -- WHICH HAS ALLOWED A SLOW INCREASE IN CONVECTIVE COVERAGE
AND INTENSITY TO OCCUR OVER THE PAST HOUR AHEAD OF THE UPPER LOW
WHICH LINGERS ATTM OVER NWRN TX.

SOME ADDITIONAL DESTABILIZATION WILL SUPPORT FURTHER CONVECTIVE
DEVELOPMENT...BUT OVERALL LIMITED CAPE COMBINED WITH MODEST FLOW
ALOFT /DEPICTED BY MODEL FORECASTS AND CONFIRMED BY THE LATEST KFWS
/FORT WORTH/ WSR-88D VWP/ SHOULD MITIGATE SEVERE POTENTIAL IN
GENERAL.  WHILE A FEW STRONGER CELLS MAY BECOME CAPABLE OF MARGINAL
HAIL AND GUSTY WINDS...ATTM THREAT DOES NOT APPEAR TO WARRANT WW
CONSIDERATION.

..GOSS/HART.. 05/11/2012

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

ATTN...WFO...SHV...HGX...FWD...OUN...

LAT...LON   32899478 31579489 31529710 31889784 32799785 33709773
            33929718 33619598 32899478

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 10, 7:18 PM CDTMesoscale DiscussionSPCAransas, Atascosa, Austin, Bastrop, Bee, Bexar and 43 more57 min
May 10, 7:50 PM CDTTornado WatchSPCAransas, Atascosa, Austin, Bastrop, Bee, Bell and 48 more9 hr
May 10, 9:42 PM CDTMesoscale DiscussionSPCAransas, Atascosa, Austin, Bastrop, Bee, Bell and 36 more63 min
May 10, 11:36 PM CDTMesoscale DiscussionSPCAransas, Brooks, Calhoun, Cameron, Hidalgo, Jackson and 13 more84 min
May 11, 1:40 AM CDTMesoscale DiscussionSPCAransas, Austin, Bee, Brazoria, Brooks, Calhoun and 25 more65 min
May 11, 2:41 AM CDTMesoscale DiscussionSPCCameron, Chambers, Galveston, Hidalgo, Jefferson, Kenedy and 3 more34 min
May 11, 2:13 PM CDTMesoscale DiscussionSPCAtascosa, Austin, Bandera, Bastrop, Bell, Bexar and 41 more2 hr
May 11, 5:18 PM CDTMesoscale DiscussionSPCAnderson, Angelina, Austin, Bastrop, Bell, Blanco and 40 more87 min
May 11, 5:51 PM CDTMesoscale DiscussionSPCBee, Brooks, Duval, Goliad, Hidalgo, Jim Hogg and 7 more84 min

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.