Mesoscale Discussion 1744

Issued

Aug 12, 2012, 3:39 PM CDT (20:39 UTC)

Expired

Aug 12, 2012, 5:45 PM CDT

In force

2 hr

Issued by

the Storm Prediction Center

Chance of a watch

40%

The Pleasant Hill radar (KEAX), 59 km from the middle of the area, began a volume at 20:42 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.

883 
ACUS11 KWNS 122039
SWOMCD
SPC MCD 122039 
MOZ000-IAZ000-KSZ000-122245-

MESOSCALE DISCUSSION 1744
NWS STORM PREDICTION CENTER NORMAN OK
0339 PM CDT SUN AUG 12 2012

AREAS AFFECTED...FAR S-CNTRL IA...MUCH OF WRN MO...EXTREME ERN KS

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 122039Z - 122245Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED BY 00Z.
STRONGER STORMS MAY PRODUCE SPORADIC SEVERE WIND/HAIL AS
THUNDERSTORM LINE SEGMENTS TRACK EWD AHEAD OF SFC COLD FRONT. GIVEN
LIMITED INSTABILITY/MARGINAL MIDLEVEL LAPSE RATES...WW PROBABILITY
REMAINS IN QUESTION AT THIS TIME SO TRENDS WILL BE MONITORED.

DISCUSSION...ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO
DEVELOP BY 00Z. 20Z VIS SATELLITE IMAGERY SHOWS AN EXPANDING CU
FIELD FROM S-CNTRL IA ACROSS PARTS OF WRN MO/ERN KS. THIS CU FIELD
WAS DEVELOPING IN WARM/MOIST ENVIRONMENT AHEAD OF APPROACHING SFC
COLD FRONT AND UPPER SHORTWAVE IMPULSE. CONVERGENCE ALONG THE FRONT
IN ADDITION TO DEEP FORCING FOR ASCENT PROVIDED BY THE SHORTWAVE
SHOULD ALLOW FOR A FEW POTENTIALLY STRONG/SEVERE THUNDERSTORMS INTO
THE EVENING HOURS. WHILE THE AIRMASS IS NOT EXPECTED TO DESTABILIZE
TOO MUCH...500-1000 J/KG MLCAPE...STEEPENING LAPSE RATES AND COOLING
TEMPERATURES ALOFT MAY SUPPORT AN ISOLATED WIND/HAIL THREAT. WITH
DEEP LAYER SHEAR ON THE ORDER OF 40-45 KT...SEMI-DISCRETE CELLS MAY
OCCUR INITIALLY BEFORE TRANSITIONING INTO LINEAR SEGMENTS AHEAD OF
COLD FRONT. GIVEN LIMITED INSTABILITY/MODEST MIDLEVEL LAPSE
RATES...WW ISSUANCE REMAINS IN QUESTION. TRENDS WILL BE MONITORED
FOR POSSIBLE WW ISSUANCE BY EARLY EVENING.

..LEITMAN/CARBIN.. 08/12/2012

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

ATTN...WFO...SGF...DMX...EAX...OAX...TOP...ICT...

LAT...LON   40109502 40759495 41039478 41089435 40969382 40539342
            39909315 38669310 38039341 37619378 37489447 37599511
            37889543 38279543 39309511 40109502

Mesoscale Discussions in Missouri, 2012Mesoscale Discussions in Kansas, 2012Mesoscale Discussions in Iowa, 2012Every mesoscale discussion in 2012

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.