Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 221913
SWOMCD
SPC MCD 221913
WIZ000-MNZ000-IAZ000-NEZ000-SDZ000-222015-

MESOSCALE DISCUSSION 1731
NWS STORM PREDICTION CENTER NORMAN OK
0213 PM CDT SAT AUG 22 2015

AREAS AFFECTED...CNTRL/SRN MN...CNTRL/NRN IA...FAR ERN SD....FAR
NERN NEB

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 221913Z - 222015Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...TSTMS ARE EXPECTED TO RAPIDLY INCREASE IN COVERAGE THIS
AFTERNOON FROM CNTRL MN SWD INTO NWRN IA. LARGE HAIL...DMGG
WINDS...AND TORNADOES ARE POSSIBLE...AND A TORNADO WATCH WILL LIKELY
BE ISSUED.

DISCUSSION...LATEST OBSERVATIONAL TRENDS SHOW EROSION OF PERSISTENT
MORNING/EARLY AFTERNOON CLOUD COVER HAS OCCURRED FROM MSP
SWD...WHERE TEMPERATURES ARE CLIMBING INTO THE LOW 80S AMIDST
UPPER-60S TO LOWER-70S DEWPOINTS. WHILE PRIMARY MIDLEVEL TROUGH AND
ACCOMPANYING FORCING FOR ASCENT ARE STILL POSITIONED W OF THE
REGION...A SEPARATE PRE-FRONTAL BAND OF MOISTENING/ASCENT WAS NOTED
IN WATER VAPOR LOOPS...AND MAY SERVE AS A FOCUS FOR TSTM DEVELOPMENT
OVER THE NEXT COUPLE HRS. THE AIR MASS CONTINUES TO
DESTABILIZE...WITH MLCAPE VALUES APPROACHING 3000 J/KG...BUT IS
STILL CAPPED PER 19Z MPX SOUNDING. HOWEVER...WITH ADDITIONAL HEATING
AND LARGE-SCALE FORCING FOR ASCENT OVERSPREADING THE
AREA...CONVECTIVE INITIATION WILL BECOME INCREASINGLY LIKELY INTO
THE LATE AFTERNOON.

STRENGTHENING WIND LOW-MIDLEVEL WIND FIELDS AMIDST A 50 KT LLJ /PER
MSP VWP DATA/ WILL BE SUFFICIENT FOR ORGANIZED DISCRETE OR CLUSTER
SUPERCELL MODES...WITH THE POTENTIAL FOR LARGE HAIL...DMGG WIND
GUSTS...AND TORNADOES POSSIBLE. A TORNADO WATCH WILL LIKELY BE
ISSUED IN THE NEXT HOUR AS CONVECTIVE TRENDS CONTINUE TO BE CLOSELY
MONITORED.

..ROGERS/CORFIDI.. 08/22/2015

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

ATTN...WFO...ARX...MPX...DMX...FGF...FSD...OAX...ABR...

LAT...LON   45389252 45959372 45849709 43879751 42279714 41499564
            41639333 41869310 45389252



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