Severe Storm Outlook Narrative (AC)
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000
ACUS01 KWNS 290041
SWODY1
SPC AC 290040

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0740 PM CDT THU AUG 28 2014

VALID 290100Z - 291200Z

...NO SVR TSTM AREAS FORECAST...

...SUMMARY...
WIDELY SCATTERED STRONG THUNDERSTORMS CONTINUE POSSIBLE THIS EVENING
ACROSS THE CENTRAL PLAINS.  ADDITIONAL STRONG STORMS NOW DEVELOPING
ACROSS PARTS OF SOUTHERN ALBERTA AND SASKATCHEWAN MAY SPREAD ACROSS
THE INTERNATIONAL BORDER AREA INTO NORTHERN MONTANA...BEFORE
WEAKENING LATE TONIGHT.

...MONTANA...
WEAK TO MODERATE DESTABILIZATION APPEARS TO HAVE OCCURRED WITHIN A
CORRIDOR ALONG AND AHEAD OF A COLD FRONT ASSOCIATED WITH A SHORT
WAVE IMPULSE EMBEDDED WITHIN THE STRONGER MID-LEVEL WESTERLIES
ACROSS ALBERTA/SASKATCHEWAN.  LATEST OBJECTIVE ANALYSIS SUGGESTS
THAT THE AXIS OF INSTABILITY EXTENDS FROM NEAR THE MONTANA/ALBERTA
BORDER EAST NORTHEASTWARD THROUGH SOUTHERN SASKATCHEWAN.  THIS
FEATURE IS EXPECTED TO BECOME THE FOCUS FOR INCREASING VIGOROUS
CONVECTIVE DEVELOPMENT DURING THE NEXT COUPLE OF HOURS...AIDED BY
FAVORABLE LARGE-SCALE FORCING FOR UPWARD VERTICAL MOTION...IN THE
PRESENCE OF STRONG VERTICAL SHEAR BENEATH 40-50 KT WESTERLY 500 MB
FLOW.  A COUPLE OF STORMS ARE ALREADY APPROACHING THE INTERNATIONAL
BORDER...AND PROBABLY WILL CONTINUE SOUTHEASTWARD INTO PORTIONS OF
NORTHERN MONTANA THIS EVENING ACCOMPANIED BY AT LEAST LOW
PROBABILITIES FOR SEVERE HAIL AND WIND.

...PLAINS...
SCATTERED THUNDERSTORM ACTIVITY ALONG A WARM FRONTAL ZONE ACROSS THE
MID MISSOURI VALLEY...AND NEAR SURFACE TROUGHING EXTENDING FROM THE
FRONT SOUTHWARD INTO THE SOUTHERN HIGH PLAINS...MAY CONTINUE TO BE
ACCOMPANIED BY LOW SEVERE WEATHER PROBABILITIES ANOTHER COUPLE OF
HOURS.  IN GENERAL THOUGH...DUE IN PART TO THE PRESENCE OF RATHER
MODEST MID-LEVEL LAPSE RATES AND DEEP LAYER FLOW/SHEAR...THE
ENVIRONMENT AHEAD OF WEAK UPPER TROUGHING PROGRESSING EASTWARD INTO
THE PLAINS APPEARS ONLY MARGINALLY CONDUCIVE TO SEVERE WEATHER
POTENTIAL.  THIS THREAT PROBABLY WILL GRADUALLY DIMINISH WITH
BOUNDARY LAYER STABILIZATION ASSOCIATED WITH THE LOSS OF DAYTIME
HEATING.

..KERR.. 08/29/2014




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