SPC AC 221727

   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1227 PM CDT FRI AUG 22 2014

   VALID 231200Z - 241200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS ERN SD...SERN ND AND WRN
   MN...

   ...SUMMARY...
   SCATTERED THUNDERSTORMS CAN BE EXPECTED ACROSS PARTS OF THE NORTHERN
   PLAINS AND THE UPPER MISSISSIPPI VALLEY ON SATURDAY. THE STRONGEST
   STORMS MAY PRODUCE SOME HAIL...GUSTY WINDS...AND A TORNADO THREAT.

   ...SYNOPSIS...
   A SHORTWAVE TROUGH MOVING INTO THE NRN INTERMOUNTAIN WEST...GREAT
   BASIN AND NRN ROCKIES TODAY WILL SHIFT EWD THEN NEWD DURING DAY 2
   WITH SOME DEEPENING OF THIS SYSTEM AS IT TAKES ON A NEGATIVE TILT
   TRACKING TOWARD THE NRN PLAINS.  A SPEED MAX ROUNDING THE BASE OF
   THE WRN TROUGH TODAY MAY PHASE WITH A SHORTWAVE TROUGH...CURRENTLY
   MOVING INTO THE FOUR CORNERS REGION...AS THESE FEATURES TRACK NNEWD
   ACROSS THE DAKOTAS SATURDAY AFTERNOON AND THROUGH THE NRN RED RIVER
   VALLEY TO SOUTH CENTRAL CANADA SATURDAY NIGHT.  

   CONCURRENT WITH THIS EVOLUTION...AN AREA OF LOW PRESSURE WILL TRACK
   FROM NWRN KS/SWRN NEB AT 23/12Z THROUGH THE NRN PLAINS TO IN
   VICINITY OF THE NERN ND/MANITOBA BORDER.  A WARM FRONT APPROACHING
   THE MID MO RIVER VALLEY EARLY SATURDAY MORNING WILL CONTINUE TO
   ADVANCE POLEWARD AND SHOULD EXTEND FROM CENTRAL-ERN SD INTO
   SWRN-SOUTH CENTRAL MN SATURDAY AFTERNOON.  STRONG LOW-LEVEL WAA
   EXPECTED THROUGH DAY 2 ALONG AND NORTH OF THE WARM FRONT AND UPWARD
   VERTICAL MOTION ATTENDANT TO MID-LEVEL IMPULSES TRACKING NWD THROUGH
   THE NRN PLAINS WILL SUPPORT AN EXTENDED PERIOD OF SHOWERS/TSTMS N
   AND NW OF THE WARM SECTOR.

   ...PORTIONS OF THE NRN PLAINS...
   GIVEN SOME UNCERTAINTY IN THE MOTION OF THE SURFACE LOW THROUGH SD
   SATURDAY AFTERNOON AND ITS AFFECT ON THE PLACEMENT OF THE WARM
   SECTOR THROUGH PEAK HEATING...THERE IS POTENTIAL THAT MORE OF ERN SD
   WILL NEED TO BE IN THE SLIGHT RISK.  DESPITE SOME DIFFERENCES IN THE
   LOCATION OF THE SURFACE LOW BY 24/00Z /00Z ECMWF BEING THE FARTHEST
   SOUTH ACROSS SOUTH CENTRAL SD/...MODELS TEND TO AGREE WITH NEW
   CONVECTIVE DEVELOPMENT IN ERN SD NEAR THE SRN PERIPHERY OF THE
   ONGOING AFOREMENTIONED AREA OF WAA SHOWERS/TSTMS.  AND...NEW
   DEVELOPMENT MAY OCCUR SWD INTO NORTH CENTRAL-NERN NEB LATE SATURDAY
   AFTERNOON...ESPECIALLY AS A COLD FRONT ADVANCES EWD TOWARD THIS
   REGION.  THESE FACTORS COMBINED WITH THE JUXTAPOSITION OF MODERATE
   INSTABILITY WITHIN THE WARM SECTOR AND EFFECTIVE BULK SHEAR OF 35-40
   KT SUGGEST THE SWD EXPANSION OF THE SLIGHT RISK IS WARRANTED TO
   INCLUDE...AT LEAST...MORE OF EAST CENTRAL SD.  GIVEN FAVORABLE DEEP
   LAYER SHEAR AND LOW-LEVEL SHEAR FOR ORGANIZED STORMS...INCLUDING
   SUPERCELLS...ALL SEVERE HAZARDS WILL BE POSSIBLE.  THE TRACK OF THE
   SHORTWAVE TROUGH AND SURFACE LOW INTO ERN ND SATURDAY NIGHT SUGGESTS
   STRONG-SEVERE STORMS WILL MOVE NNE TOWARD THE NRN RED RIVER VALLEY
   AND WEST-CENTRAL/NWRN MN.

   ..PETERS.. 08/22/2014

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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z