MESOSCALE DISCUSSION 1627
   NWS STORM PREDICTION CENTER NORMAN OK
   0610 PM CDT FRI JUL 15 2011
   
   AREAS AFFECTED...SERN ND/FAR NERN SD AND NWRN MN
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 152310Z - 160015Z
   
   A FEW STRONG TO SEVERE STORMS ARE POSSIBLE THIS EVENING INVOF A
   SW-NE ORIENTED LOW LEVEL CONVERGENCE ZONE EXTENDING FROM SERN ND/FAR
   NERN SD INTO NWRN MN.  PROBABILITY FOR WW ISSUANCE AT THIS TIME IS
   LESS THAN 40 PERCENT.
   
   A VERY MOIST AIR MASS EXISTS FROM ERN SD INTO SERN ND AND NWRN MN
   WHERE SURFACE DEWPOINTS ARE IN THE LOWER 70S.  THIS COMBINED WITH
   HEATING AND MODEST MIDLEVEL LAPSE RATES AROUND 7 C/KM ARE RESULTING
   IN MODERATE TO VERY STRONG INSTABILITY /MLCAPE 2000-4000 J PER KG/
   ALONG THE SURFACE WIND SHIFT.  DESPITE THESE FAVORABLE PARAMETERS
   THAT WOULD SUPPORT ORGANIZED SEVERE STORMS...A FEW LARGE SCALE
   FACTORS APPEAR TO BE NEGATING GREATER STORM DEVELOPMENT AT THIS
   TIME.  THE DISCUSSION AREA RESIDES BETWEEN TWO STRONGER SHORTWAVE
   TROUGHS...1/ MOVING EWD WITH AN MCS SERN MN/UPPER MS VALLEY AND 2/
   MOVING NEWD ACROSS CENTRAL CANADA...AND HEIGHTS ARE RISING ACROSS
   ERN ND/NWRN MN.  THESE FACTORS SUGGEST THE AREAL COVERAGE AND
   TEMPORAL EXTENT OF THE SEVERE WEATHER THREAT MAY BE LIMITED AS
   INDICATED BY THE 20Z WRF-HRRR AND 12Z WRF-NMM.
   
   ..PETERS.. 07/15/2011
   
   
   ATTN...WFO...DLH...MPX...FGF...ABR...BIS...
   
   LAT...LON   48399517 47949430 47399420 46679459 45919582 45629667
               45629790 45579895 46119934 47079846 48399517