Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 101535
SWOMCD
SPC MCD 101534
OHZ000-INZ000-ILZ000-101730-

MESOSCALE DISCUSSION 1707
NWS STORM PREDICTION CENTER NORMAN OK
1034 AM CDT WED SEP 10 2014

AREAS AFFECTED...ERN IL..IND...WRN OH

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 101534Z - 101730Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...TRENDS ARE BEING MONITORED FOR ANY INCREASE IN
THUNDERSTORM ACTIVITY LATE THIS MORNING THROUGH EARLY AFTERNOON FOR
A CONDITIONAL TORNADO THREAT.

DISCUSSION...A LEADING SHORTWAVE TROUGH IS CURRENTLY MOVING ACROSS
NRN IL AND WILL CONTINUE RAPIDLY NEWD ACROSS INDIANA...NWRN OH AND
LOWER MI. WIND PROFILES ASSOCIATED WITH THIS FEATURE ARE RELATIVELY
STRONG...WITH AREA VWPS SHOWING 300-400 M2/S2 0-1 KM SRH.

AROUND 1430Z...A WEAK THUNDERSTORM SHOWED BRIEF SUPERCELL
CHARACTERISTICS OVER CNTRL IL...BUT IT APPEARS THE PRIMARY UPDRAFT
HAS SINCE DETACHED FROM THE BOUNDARY LAYER INFLOW AND HAS BECOME
ELEVATED...SHIFTING LEFTWARD. HOWEVER...THIS SUGGESTS THE
ENVIRONMENT IS CLOSE TO BEING FAVORABLE FOR AT LEAST BRIEF
TORNADOES...CONDITIONAL MAINLY ON SUFFICIENT BOUNDARY LAYER
DESTBILIZATION OCCURRING COINCIDENT WITH THE LEADING DISTURBANCE.

15Z SURFACE ANALYSIS SHOWS DEWPOINTS IN THE 70-71 F RANGE WIDESPREAD
NOW ACROSS THE WARM SECTOR AND GRADUALLY SPREADING NWD ACROSS
INDIANA AND WRN OH. UPPER 70S TO LOWER 80S TEMPERATURES WERE PRESENT
ACROSS SRN IL...AND THIS HIGHER THETA-E AIR SHOULD SPREAD NWD LATER
THIS MORNING ACROSS INDIANA. A LIMITING FACTOR IS EXTENSIVE CLOUD
COVER AHEAD OF THE LEADING BAND OF PRECIPITATION...BUT PARTIAL
HEATING IS OCCURRING ACROSS SWRN INDIANA.

IT IS UNCLEAR WHETHER DESTABILIZATION VIA LOW-LEVEL ADVECTION WILL
BE SUFFICIENT FOR FURTHER SUPERCELL DEVELOPMENT TODAY BEFORE THE
AFOREMENTIONED SHORTWAVE TROUGH MOVES THROUGH. ONCE THIS WAVE
PASSES...EARLY POTENTIAL SHOULD BE LARGELY OVER...WITH ANY
ADDITIONAL AND PRIMARILY WIND THREAT FOCUSING SWWD ALONG THE
TRAILING COLD FRONT.

..JEWELL/CORFIDI.. 09/10/2014

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

ATTN...WFO...CLE...ILN...IWX...IND...LOT...ILX...

LAT...LON   40448798 41008742 41458634 41618527 41528427 40888379
            40178393 39628533 39258655 39148749 39318829 39758843
            40448798



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