Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 311723
SWODY2
SPC AC 311722

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1222 PM CDT FRI JUL 31 2015

VALID 011200Z - 021200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS NERN NEB...SERN
SD...IA...SRN MN...

...THERE IS A MRGL RISK OF SVR TSTMS FROM SD/NEB INTO WI AND IL...

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS NRN NEW ENGLAND...

...SUMMARY...
SEVERE STORMS CAPABLE OF HAIL AND WIND ARE EXPECTED MAINLY FROM
NEBRASKA INTO IOWA DURING THE LATE AFTERNOON AND EVENING...WITH MORE
ISOLATED ACTIVITY INTO SOUTH DAKOTA...MINNESOTA AND WISCONSIN. A FEW
SEVERE STORMS WITH HAIL MAY ALSO OCCUR OVER A PORTION OF NEW
ENGLAND.

...SYNOPSIS...
AN UPPER TROUGH WILL MOVE ACROSS THE NERN STATES DURING THE DAY WITH
A WEAK COLD FRONT SUPPORTING A FEW STRONG STORMS ACROSS NRN NEW
ENGLAND. TO THE W...A SECONDARY SHORTWAVE TROUGH WILL SINK SWD
ACROSS THE NRN PLAINS AND UPPER MS VALLEY LATER IN THE DAY...WITH
SFC LOW DEVELOPING ACROSS THE ERN DAKOTAS SEWD INTO WI. POCKETS OF
60S F DEWPOINTS AND HEATING WILL LEAD TO CLUSTER OF STORMS ACROSS
THE REGION FOCUSED NEAR THE COLD FRONT WITH HAIL AND WIND POSSIBLE.

...ERN NEB...IA...SERN SD...SRN MN...
A SURFACE HIGH TO THE S OF THE AREA AS WELL AS BOUNDARY LAYER MIXING
SHOULD LEAD TO ONLY LOWER TO MID 60S F DEWPOINTS ACROSS THE WARM
SECTOR BY AFTERNOON...BUT COOL TEMPERATURES ALOFT WILL AID
INSTABILITY LEVELS. SEVERE HAIL AND WIND IS EXPECTED TO INITIATE
ACROSS SRN SD INTO NEB DURING THE LATE AFTERNOON WHERE HEATING WILL
BE STRONGEST AND CLOSER TO THE SFC TROUGH/FRONT. ADDITIONAL STORMS
ARE EXPECTED FARTHER N ALONG THE FRONT INTO WRN MN AS WELL. THE NWLY
FLOW PATTERN AS RELATIVELY LARGE T/TD SPREADS SHOULD FAVOR SOME
UPSCALE GROWTH AS STORMS DEVELOP SEWD ACROSS MN AND IA...WITH SEVERE
WIND AND HAIL POSSIBLE. WITH TIME...THE LOW-LEVEL JET WILL VEER TO
WLY...AND WILL FOCUS LIFT EWD INTO WI POSSIBLY SUPPORTING A FEW
SEVERE STORMS. THERE IS SOME CONCERN ABOUT CAPPING ACROSS MN/WI AS
STORMS MOVE AWAY FROM THE LOW-LEVEL LAPSE RATE PLUME...AND SOME
MODELS DO NOT INDICATE VERY STRONG QPF SIGNALS INTO THESE
AREAS...THUS WILL MAINTAIN A MARGINAL THREAT AT THIS TIME.

...NRN NEW ENGLAND...
A SHORTWAVE TROUGH WILL SWING THROUGH THE AREA DURING THE DAY WITH
SCATTERED THUNDERSTORMS DEVELOPING NEAR A COLD FRONT/WIND SHIFT BY
EARLY AFTERNOON. COOL TEMPERATURES ALOFT ALONG WITH HEATING WILL
SUPPORT DEVELOPMENT WITH LONG/STRAIGHT HODOGRAPHS SUPPORTING
CELLULAR ACTIVITY CAPABLE OF LARGE HAIL. WIND THREAT IS EXPECTED TO
BE LARGELY MITIGATED BY CELLULAR STORM MODE.

..JEWELL.. 07/31/2015



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