Alert archive / Missouri / Mesoscale Discussions in 2012

Mesoscale Discussion 1702

August 4, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Aug 4, 2012, 5:20 PM CDT for 4 states. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Aug 4, 2012, 5:20 PM CDT (22:20 UTC)
Expired
Aug 4, 2012, 6:45 PM CDT
In force
85 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 60 counties

Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Fulton County, AR, Marion County, AR, Cherokee County, KS, Crawford County, KS, Labette County, KS, Barry County, MO, Barton County, MO, Camden County, MO, Carter County, MO, Cedar County, MO, Christian County, MO, Cole County, MO, Crawford County, MO, Dade County, MO, Dallas County, MO, Dent County, MO, Douglas County, MO, Franklin County, MO, Gasconade County, MO, Greene County, MO, Hickory County, MO, Howell County, MO, Iron County, MO, Jasper County, MO, Jefferson County, MO, Laclede County, MO, Lawrence County, MO, Maries County, MO, McDonald County, MO, Miller County, MO, Morgan County, MO, Newton County, MO, Oregon County, MO, Osage County, MO, Ozark County, MO, Phelps County, MO, Polk County, MO, Pulaski County, MO, Reynolds County, MO, Saint Charles County, MO, Shannon County, MO, St. Clair County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Warren County, MO, Washington County, MO, Webster County, MO, Wright County, MO, Craig County, OK, Delaware County, OK, Mayes County, OK, Nowata County, OK, Ottawa County, OK, Rogers County, OK, Washington County, OK

The radar

The Springfield radar (KSGF), 12 km from the middle of the area, began a volume at 22:23 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.

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 10.3 hours before the alert went out and 39 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, Springfield, MO at 12:00Z on 2012-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 917 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, Springfield, MO at 12:00Z on 2012-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
917 J/kg
Mixed-layer CIN
-319 J/kg
Mixed-layer LCL
1875 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
41 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.

125 
ACUS11 KWNS 042220
SWOMCD
SPC MCD 042220 
MOZ000-ARZ000-OKZ000-KSZ000-042345-

MESOSCALE DISCUSSION 1702
NWS STORM PREDICTION CENTER NORMAN OK
0520 PM CDT SAT AUG 04 2012

AREAS AFFECTED...FAR NERN OK/SERN KS...SRN/CNTRL MO...FAR NRN AR

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 042220Z - 042345Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...SCATTERED THUNDERSTORMS ARE FORECAST TO DEVELOP THIS
EVENING ALONG AND AHEAD OF A COLD FRONT ACROSS PORTIONS OF FAR NERN
OK/SERN KS...SRN/CNTRL MO...AND FAR NRN AR. THREAT FOR DAMAGING
WINDS AND LARGE HAIL WILL EXIST...TRENDS WILL BE MONITORED FOR A
POSSIBLE WW.

DISCUSSION...MESOANALYSIS AT 22Z SHOWS A COLD FRONT EXTENDING SWWD
FROM CNTRL IL INTO SWRN MO AND NRN OK. TEMPERATURES HAVE WARMED TO
NEAR 110F ALONG THE OK PORTION OF THE FRONT...AND HAVE AIDED IN THE
DEVELOPMENT OF STEEP LOW-LEVEL LAPSE RATES AND STRONG BOUNDARY LAYER
DESTABILIZATION...WHICH HAS FAVORED THE DEVELOPMENT OF A
THUNDERSTORM CLUSTER DURING THE LAST HR OR TWO. FARTHER E OVER SRN
MO AND FAR NRN AR...VISIBLE SATELLITE IMAGERY SHOWS DEEPENING
CUMULUS OCCURRING BETWEEN THE HOTTER/DRIER AIRMASS TO THE W AND
SLIGHTLY COOLER/MORE MOIST AIRMASS TO THE E. SHORT-TERM MODEL
GUIDANCE INDICATES THIS CUMULUS WILL EVOLVE INTO THUNDERSTORM
CLUSTERS...AND THEN SPREAD EWD TOWARD THE MS RIVER DURING THE NIGHT.
GIVEN SURFACE CONDITIONS CHARACTERIZED BY TEMPERATURES FROM
90-100F...DEWPOINTS IN THE 60S TO LOW 70S...AND STEEP MIDLEVEL LAPSE
RATES...ESTIMATES OF MLCAPE EXCEED 2000 J/KG OVER THE ERN HALF OF
SRN/CNTRL MO. THE LARGE BUOYANCY COMBINED WITH 0-6 KM BULK SHEAR
NEAR 30 KT WILL FAVOR STRONG TO SVR MULTICELL THUNDERSTORMS POSING A
THREAT FOR DAMAGING WINDS AND LARGE HAIL. MEANWHILE...STORMS
OCCURRING OVER FAR NERN OK/SERN KS AND SWRN MO MAY POSE A THREAT FOR
ISOLATED DAMAGING WIND GUSTS GIVEN THE PRESENCE OF A HOT AND MORE
STRONGLY MIXED BOUNDARY LAYER.

..GARNER/HART.. 08/04/2012

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

ATTN...WFO...PAH...MEG...LSX...LZK...SGF...EAX...TSA...ICT...

LAT...LON   37009600 38729238 38869049 36909060 36129177 36129455
            36449607 37009600

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 4, 3:08 AM CDTMesoscale DiscussionSPCAudrain, Boone, Callaway, Cooper, Howard, Lincoln and 7 more2 hr
Aug 4, 10:26 AM CDTMesoscale DiscussionSPCAdair, Clark, Grundy, Knox, Lewis, Marion and 5 more49 min
Aug 4, 1:09 PM CDTMesoscale DiscussionSPCClark66 min
Aug 4, 6:12 PM CDTSevere Thunderstorm WatchSPCBarry, Barton, Camden, Cedar, Christian, Crawford and 39 more6 hr

Nearby

Mesoscale Discussions in Missouri, 2012Mesoscale Discussions in Oklahoma, 2012Mesoscale Discussions in Arkansas, 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.