Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 499

April 12, 20125 counties in Kansas; Beaver County, Texas County, Oklahoma; 8 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2012, 2:28 PM CDT for 5 counties in Kansas; Beaver County, Texas County, Oklahoma; 8 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 12, 2012, 2:28 PM CDT (19:28 UTC)
Expired
Apr 12, 2012, 4:30 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center

Counties Grant County, KS, Haskell County, KS, Meade County, KS, Seward County, KS, Stevens County, KS, Beaver County, OK, Texas County, OK, Carson County, TX, Gray County, TX, Hansford County, TX, Hemphill County, TX, Hutchinson County, TX, Lipscomb County, TX, Ochiltree County, TX, Roberts County, TX

The radar

The Dodge City radar (KDDC), 155 km from the middle of the area, began a volume at 19:32 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

Dodge City, (KDDC), launched 12:00Z, 7.5 hours before the alert went out and 159 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, Dodge City, at 12:00Z on 2012-04-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Dodge City, at 12:00Z on 2012-04-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 219 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
619 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
219 m²/s²
0-3 km storm-relative helicity
472 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.

456 
ACUS11 KWNS 121929
SWOMCD
SPC MCD 121928
OKZ000-KSZ000-TXZ000-122130-

MESOSCALE DISCUSSION 0499
NWS STORM PREDICTION CENTER NORMAN OK
0228 PM CDT THU APR 12 2012

AREAS AFFECTED...SWRN KS THROUGH THE ERN OK AND TX PANHANDLES

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 121928Z - 122130Z

SWRN KS THROUGH THE ERN TX AND OK PANHANDLES ARE BEING MONITORED FOR
THUNDERSTORM INITIATION. OVERALL THREAT IS CONDITIONAL GIVEN
UNCERTAINTY REGARDING INITIATION. SHOULD STORMS DEVELOP COVERAGE
SHOULD REMAIN SPARSE...BUT DISCRETE SUPERCELLS CAPABLE OF VERY LARGE
HAIL AND A WINDOW FOR ISOLATED TORNADOES WILL BE THE MAIN THREATS
INTO THE EARLY EVENING.

THE BOUNDARY LAYER IS MIXING OUT WITH A DECREASE IN STRATOCUMULUS
FROM THE WEST ACROSS SWRN KS THROUGH THE OK AND TX PANHANDLES TO THE
EAST OF A DRYLINE THAT EXTENDS FROM ERN CO SWD THROUGH WRN TX.
HOWEVER...THE BOUNDARY LAYER REMAINS CAPPED BY AN EML THAT HAS
ADVECTED THROUGH THE WARM SECTOR BENEATH AXIS OF UPPER 50S
DEWPOINTS...CONTRIBUTING TO 1500-2000 J/KG MLCAPE. THE DEEPER
FORCING ATTENDING SHORTWAVE TROUGH CURRENTLY EJECTING NEWD THROUGH
CO WILL REMAIN NORTH OF THIS REGION. HOWEVER...CONTINUED DIABATIC
WARMING AND DRYLINE CONVERGENCE MIGHT BE SUFFICIENT TO INITIATE AT
LEAST AN ISOLATED STORM OR TWO LATER THIS AFTERNOON OR EARLY
EVENING. SHOULD STORMS DEVELOP...EFFECTIVE BULK SHEAR OF 40-50 KT
WILL SUPPORT SUPERCELLS. THE 0-1 KM HODOGRAPH SIZE WILL ALSO
INCREASE AS THE LLJ STRENGTHENS TOWARD EVENING SUPPORTING A WINDOW
FOR ISOLATED TORNADOES BEFORE THE BOUNDARY LAYER DECOUPLES.

..DIAL.. 04/12/2012

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

ATTN...WFO...OUN...DDC...AMA...

LAT...LON   37600138 37590047 37069985 36099986 35340049 35070150
            35970163 37080184 37600138

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 12, 1:24 PM CDTMesoscale DiscussionSPCCheyenne, Decatur, Finney, Gove, Greeley, Kearny and 9 more2 hr
Apr 12, 1:47 PM CDTTornado WatchSPCCheyenne, Decatur, Greeley, Hamilton, Kearny, Logan and 7 more7 hr
Apr 12, 5:02 PM CDTMesoscale DiscussionSPCCheyenne, Greeley, Hamilton, Kearny, Logan, Rawlins and 4 more88 min
Apr 12, 3:34 PM CDTMesoscale DiscussionSPCBeckham, Caddo, Comanche, Custer, Dewey, Ellis and 7 more86 min
Apr 12, 6:06 PM CDTMesoscale DiscussionSPCBeckham, Greer, Harmon, Jackson, Kiowa, Roger Mills and 1 more114 min
Apr 11, 8:54 PM CDTMesoscale DiscussionSPCArmstrong, Carson, Donley, Gray, Hansford, Hartley and 8 more66 min
Apr 11, 9:12 PM CDTMesoscale DiscussionSPCAndrews, Cochran, Crane, Dawson, Ector, Gaines and 16 more93 min

Nearby

Mesoscale Discussions in Texas, 2012Mesoscale Discussions in Kansas, 2012Mesoscale Discussions in Oklahoma, 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.