Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 282256
SWOMCD
SPC MCD 282256
ILZ000-MOZ000-IAZ000-290030-

MESOSCALE DISCUSSION 1224
NWS STORM PREDICTION CENTER NORMAN OK
0556 PM CDT SUN JUN 28 2015

AREAS AFFECTED...CNTRL AND NE MO THRU PARTS OF NW/W CNTRL IL

CONCERNING...TORNADO WATCH 367...

VALID 282256Z - 290030Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 367 CONTINUES.

SUMMARY...SCATTERED STRONG TO LOCALLY SEVERE THUNDERSTORM ACTIVITY
WILL GRADUALLY OVERSPREAD AREAS IN AND AROUND THE GREATER ST. LOUIS
METROPOLITAN REGION THROUGH 01-02Z.

DISCUSSION...NUMEROUS...SOMEWHAT SMALL...BUT
VIGOROUS...THUNDERSTORMS HAVE DEVELOPED DURING THE PAST FEW HOURS
ACROSS PARTS OF CENTRAL AND NORTHEAST MISSOURI...AND ADJACENT
PORTIONS OF THE MIDDLE MISSISSIPPI VALLEY.  THIS IS BEING AIDED BY
FORCING FOR ASCENT ACCOMPANYING ONE OF AT LEAST A COUPLE OF DIGGING
SHORT WAVE IMPULSES WITHIN CYCLONIC NORTHWESTERLY MID/UPPER FLOW.

ACTIVITY HAS INITIATED IN A MODERATELY UNSTABLE BOUNDARY LAYER THAT
APPEARS CHARACTERIZED BY CAPE ON THE ORDER OF 2000 J/KG... BUT AT
LEAST ACROSS THE ST. LOUIS METRO AND AREAS TO THE NORTHEAST...THE
TENDENCY WILL BE FOR ACTIVITY TO PROPAGATE INTO A SOMEWHAT COOLER
AND LESS UNSTABLE ENVIRONMENT.  INTERFERENCE FROM OTHER STORMS COULD
ALSO BE A LIMITING FACTOR TO OVERALL STORM SUSTENANCE.  IT REMAINS
UNCLEAR WHETHER FORCING ASSOCIATED WITH AN AN AREA OF WEAK LOW-LEVEL
WARM ADVECTION OVERSPREADING THE REGION WILL BE STRONG ENOUGH TO
SUPPORT CONSOLIDATION AND UPSCALE GROWTH OF CONVECTION.

DESPITE THESE POTENTIAL NEGATIVE FACTORS...THERE STILL APPEARS A
WINDOW OF OPPORTUNITY THROUGH AROUND 01-02Z...FOR AT LEAST A COUPLE
OF STORMS TO EMERGE WITH AT LEAST SOME INCREASE IN SEVERE WEATHER
POTENTIAL.  THIS WILL INCLUDE THE RISK FOR MARGINALLY SEVERE HAIL
AND LOCALIZED STRONG WIND GUSTS.  PERHAPS OF MORE CONCERN...20-30 KT
SOUTHWESTERLY 850 MB FLOW WILL CONTINUE TO CONTRIBUTE TO
SUFFICIENTLY LARGE LOW-LEVEL HODOGRAPHS TO SUPPORT THE RISK FOR AT
LEAST RELATIVELY SHORT-LIVED TORNADOES WITH ANY OF THE POTENTIALLY
STRONGER EMERGING STORMS THROUGH EARLY EVENING.

..KERR.. 06/28/2015

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

ATTN...WFO...PAH...ILX...LSX...DVN...SGF...DMX...

LAT...LON   39279208 40839227 39739053 39068895 38328931 37949009
            37879099 38059169 38489240 39279208



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