Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS01 KWNS 121627
SWODY1
SPC AC 121625

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1125 AM CDT SAT JUL 12 2014

VALID 121630Z - 131200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM EASTERN NEB INTO PARTS OF
IND/LOWER MI...

...SUMMARY...
ISOLATED TO SCATTERED SEVERE STORMS ARE ANTICIPATED FROM PARTS OF
THE MID-MISSOURI VALLEY TO THE SOUTHERN LAKE MICHIGAN REGION DURING
THE LATE AFTERNOON INTO TONIGHT. DAMAGING WINDS SHOULD BE THE
PRIMARY HAZARD...BUT SEVERE HAIL AND A TORNADO OR TWO WILL BE
POSSIBLE.

...MIDWEST STATES...
WATER VAPOR LOOPS SHOW A SHORTWAVE TROUGH OVER SD/NEB.  THIS FEATURE
WILL TRACK EASTWARD AND HELP TO INITIATE SCATTERED THUNDERSTORMS
THIS AFTERNOON ALONG/NORTH OF A REMNANT OUTFLOW BOUNDARY OVER IA.
SURFACE DEWPOINTS IN THE 70S COUPLED WITH INCREASING DIURNAL HEATING
THROUGH THE AFTERNOON WILL YIELD MLCAPE VALUES OVER 2000
J/KG...WHILE CYCLONIC FLOW ALOFT AND STRENGTHENING MID LEVEL WINDS
CONTRIBUTE TO FAVORABLE EFFECTIVE SHEAR VALUES.

THUNDERSTORMS ARE EXPECTED TO DEVELOP INITIALLY OVER CENTRAL/EASTERN
IA BY LATE AFTERNOON.  THESE STORMS WILL PROBABLY BE SUPERCELLULAR
AND TRACK EASTWARD INTO PARTS OF NORTHERN IL/SOUTHERN WI AND
EVENTUALLY INTO NORTHERN IND.  MID LEVEL LAPSE RATES ARE NOT
PARTICULARLY STEEP...SUGGESTING THAT DAMAGING WINDS WILL BE THE MAIN
THREAT INSTEAD OF HAIL.  LOW LEVEL VERTICAL SHEAR WILL STRENGTHEN
DURING THE EVENING POSING SOME RISK OF A FEW TORNADOES.

DURING THE EVENING...STORMS ARE FORECAST TO BUILD WESTWARD FROM
CENTRAL IA INTO SOUTHEAST NEB AND NORTHERN KS.  WEAKER VERTICAL
SHEAR WILL PROVIDE MORE UNCERTAINTY REGARDING CONVECTIVE INTENSITY
AND OVERALL SEVERE THREAT.

...ND/MN...
A VIGOROUS SHORTWAVE TROUGH IS DIGGING SOUTHEASTWARD ACROSS MANITOBA
TOWARD ND/MN.  MOST MODEL SOLUTIONS SUGGEST ISOLATED THUNDERSTORM
DEVELOPMENT AHEAD OF THIS FEATURE THIS AFTERNOON AND EARLY EVENING.
WIND FIELDS IN THIS AREA WILL BE QUITE STRONG...BUT INSTABILITY WILL
BE MARGINAL.  A FEW OF THE THUNDERSTORMS MAY PRODUCE GUSTY WINDS AND
HAIL.

..HART/SMITH.. 07/12/2014



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