Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 290245
SWOMCD
SPC MCD 290244
MNZ000-NDZ000-290415-

MESOSCALE DISCUSSION 1607
NWS STORM PREDICTION CENTER NORMAN OK
0944 PM CDT SUN AUG 28 2016

AREAS AFFECTED...PORTIONS OF NORTHWEST MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 290244Z - 290415Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...AN ISOLATED SUPERCELL AND ATTENDANT DAMAGING WIND/TORNADO
THREAT MAY PERSIST ANOTHER 1-2 HOURS.

DISCUSSION...AN ISOLATED...DISCRETE AND NEARLY STATIONARY SUPERCELL
OVER POLK AND NORMAN COUNTIES IN NW MN PRODUCED A TORNADO IN THE
LAST 30 MINUTES OR SO. THIS STORM DEVELOPED NEAR A WARM FRONT IN LOW
LEVEL CONVERGENT FLOW. EFFECTIVE SHEAR NEAR 25-30 KT...WHILE ON THE
LOW END FOR SUPERCELLS...WILL BE SUFFICIENT TO SUSTAIN THIS CELL IN
A STRONGLY UNSTABLE ENVIRONMENT. EFFECTIVE SRH VALUES AROUND 200-300
M2/S2 PER 02Z MESOANALYSIS AND MVX VWP...COUPLED WITH CURVED LOW
LEVEL HODOGRAPHS IN THE VICINITY OF THE WARM FRONT...WILL CONTINUE
TO SUPPORT LOW LEVEL ROTATION. THAT BEING SAID...FAVORABLE TORNADO
THREAT APPEARS TO BE OVER A SMALL AREA...AND WILL LIKELY DIMINISH
WITH TIME AS BOUNDARY LAYER STABILIZATION ENSUES.
FURTHERMORE...GIVEN SLOW FORWARD MOTION OF CURRENT ISOLATED CELL
LEADING TO DEVELOPMENT OF SURGING OUTFLOW...AND ONLY MODEST LOW
LEVEL JET DEVELOPMENT...ADDITIONAL TORNADO THREAT SHOULD BE LIMITED
IN TIME AS WELL. CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED.

..LEITMAN/THOMPSON.. 08/29/2016

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

ATTN...WFO...FGF...

LAT...LON   47869695 48039664 47949597 47609533 47299519 47049523
            46939549 47009601 47159660 47259673 47589691 47869695




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