Severe Storm Outlook Narrative (AC)
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ACUS02 KWNS 271731
SWODY2
SPC AC 271730

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM CDT THU AUG 27 2015

VALID 281200Z - 291200Z

...THERE IS A MRGL RISK OF SVR TSTMS OVER NERN ND INTO NWRN MN...

...SUMMARY...
THUNDERSTORMS ARE POSSIBLE FRIDAY OVER THE UPPER MIDWEST...PARTS OF
THE CORN BELT...PARTS OF THE SOUTHEAST...AND THE INTERIOR WEST.

...SYNOPSIS...

ERN U.S. SYNOPTIC UPPER TROUGH WILL CONTINUE TO DEAMPLIFY FRIDAY
WHILE A SLOW MOVING SHORTWAVE TROUGH ADVANCES THROUGH THE UPPER MS
VALLEY INTO THE GREAT LAKES REGION. A WEAK SFC LOW WILL ACCOMPANY
THIS FEATURE INTO THE UPPER MS VALLEY WITH TRAILING WEAK COLD FRONT
ADVANCING SEWD THROUGH THE CNTRL PLAINS. A WARM FRONT WILL EXTEND
EWD FROM THE LOW AND MOVE NWD INTO SRN PORTIONS OF THE GREAT LAKES.
A FASTER...LOW-AMPLITUDE SHORTWAVE TROUGH IS FORECAST TO MOVE ESEWD
ALONG THE INTERNATIONAL BORDER IN PROXIMITY NERN ND AND NWRN MN
DURING THE DAY. FARTHER WEST A SHORTWAVE TROUGH WILL MOVE THROUGH
BASE OF AN UPPER LOW AND INTO NRN CA AND WRN OREGON FRIDAY NIGHT.

...NERN ND THROUGH NWRN MN...

A PLUME OF STEEPER LAPSE RATES WILL DEVELOP EWD THROUGH ND INTO NRN
MN BENEATH GENERALLY LOW-60S F DEWPOINTS RESULTING IN 1500 J/KG
MLCAPE AS THE BOUNDARY LAYER WARMS FRIDAY AFTERNOON. WEAK FORCING
AND LIKELIHOOD OF AT LEAST A MODEST CAPPING INVERSION SHOULD LIMIT
SFC-BASED THUNDERSTORM DEVELOPMENT MUCH OF DAY. HOWEVER...DIABATIC
WARMING OF BOUNDARY LAYER AND MODEST ASCENT DUE TO GLANCING
INFLUENCE OF THE LOW-AMPLITUDE SHORTWAVE TROUGH MAY WEAKEN THE CAP
ENOUGH FOR A FEW STORMS TO DEVELOP OVER NERN ND OR NWRN MN BY LATE
AFTERNOON INTO EARLY EVENING. A FEW OF THESE STORMS MAY PRODUCE A
FEW INSTANCES OF LARGE HAIL AND STRONG WIND GUSTS.

...MID MS VALLEY REGION...

WIDESPREAD CLOUDS AND ONGOING PRECIPITATION ASSOCIATED WITH THE SLOW
MOVING SHORTWAVE TROUGH SHOULD RESULT IN AN UNFAVORABLE
THERMODYNAMIC ENVIRONMENT FOR SEVERE STORMS IN THIS REGION.

..DIAL.. 08/27/2015




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