Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 1898

September 5, 201222 counties in Oklahoma; 32 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Sep 5, 2012, 6:53 PM CDT for 22 counties in Oklahoma; 32 counties in Texas. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued
Sep 5, 2012, 6:53 PM CDT (23:53 UTC)
Expired
Sep 5, 2012, 8:00 PM CDT
In force
67 min
Issued by
the Storm Prediction Center
All 54 counties

Alfalfa County, OK, Beaver County, OK, Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Garfield County, OK, Grant County, OK, Greer County, OK, Harmon County, OK, Harper County, OK, Jackson County, OK, Kingfisher County, OK, Kiowa County, OK, Major County, OK, Roger Mills County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Armstrong County, TX, Bailey County, TX, Briscoe County, TX, Carson County, TX, Castro County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Deaf Smith County, TX, Donley County, TX, Floyd County, TX, Gray County, TX, Hale County, TX, Hall County, TX, Hansford County, TX, Hardeman County, TX, Hartley County, TX, Hemphill County, TX, Hutchinson County, TX, Lamb County, TX, Lipscomb County, TX, Moore County, TX, Motley County, TX, Ochiltree County, TX, Oldham County, TX, Parmer County, TX, Potter County, TX, Randall County, TX, Roberts County, TX, Sherman County, TX, Swisher County, TX, Wheeler County, TX

The radar

The Amarillo radar (KAMA), 96 km from the middle of the area, began a volume at 23:53 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

Amarillo Airport, TX (KAMA), launched 12:00Z, 11.9 hours before the alert went out and 95 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, Amarillo Airport, TX at 12:00Z on 2012-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1415 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, Amarillo Airport, TX at 12:00Z on 2012-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 49 square meters per square second.1939Sfc1 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
1415 J/kg
Mixed-layer CIN
-182 J/kg
Mixed-layer LCL
1651 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
49 m²/s²
0-3 km storm-relative helicity
66 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

251 
ACUS11 KWNS 052353
SWOMCD
SPC MCD 052353 
OKZ000-TXZ000-NMZ000-060100-

MESOSCALE DISCUSSION 1898
NWS STORM PREDICTION CENTER NORMAN OK
0653 PM CDT WED SEP 05 2012

AREAS AFFECTED...TX PANHANDLE INTO WRN OK/NW TX

CONCERNING...SEVERE THUNDERSTORM WATCH 622...623...

VALID 052353Z - 060100Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
622...623...CONTINUES.

SUMMARY...SEVERE WIND/HAIL THREAT WILL REMAIN LIMITED THROUGH THE
REMAINDER OF THE EVENING. STORM CLUSTERS ARE EXPECTED TO REMAIN
RATHER UNORGANIZED WITH ONLY BRIEF UPTICK IN STORM INTENSITY. SLOW
STORM MOTION WILL ALSO LEAD TO A THREAT OF HEAVY DOWNPOURS.

DISCUSSION...STORM CLUSTERS HAVE GENERALLY DECREASED IN INTENSITY
OVER THE LAST HOUR OR SO EXCEPT IN THE VICINITY OF I-40 IN THE TX
PANHANDLE. HERE...CONVERGENCE ALONG A WEAK FRONTAL BOUNDARY COUPLED
WITH SLIGHTLY INCREASING BULK SHEAR VALUES ARE LIKELY HELPING TO
GENERATE/SUSTAIN STRONGER UPDRAFTS. IT IS UNCLEAR HOW PERSISTENT
THIS AREA OF MORE ROBUST CONVECTION MAY BE DUE TO WEAK INSTABILITY.
EITHER WAY...STORMS WILL LIKELY CONTINUE ACROSS WW 622 AND 623 THE
NEXT FEW HOURS WITH SEVERE WIND/HAIL THREAT CONTINUING TO BE RATHER
SPORADIC THROUGH THE REMAINDER OF THE EVENING. THE LACK OF
ORGANIZATION AND AMORPHOUS/SLOW STORM MOTION WILL ALSO BRING A
THREAT OF HEAVY DOWNPOURS.

..LEITMAN.. 09/05/2012

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

ATTN...WFO...OUN...LUB...AMA...ABQ...

LAT...LON   33830303 36020300 36989997 36989772 35549773 33840008
            33830303

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 5, 2:49 PM CDTMesoscale DiscussionSPCBeckham, Custer, Dewey, Ellis, Greer, Harmon and 7 more56 min
Sep 5, 3:19 PM CDTSevere Thunderstorm WatchSPCBeaver, Texas8 hr
Sep 5, 3:56 PM CDTSevere Thunderstorm WatchSPCAlfalfa, Blaine, Custer, Dewey, Ellis, Garfield and 7 more7 hr

Nearby

Mesoscale Discussions in Texas, 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.