MESOSCALE DISCUSSION 1561
   NWS STORM PREDICTION CENTER NORMAN OK
   0157 AM CDT TUE JUL 28 2015

   AREAS AFFECTED...ERN SD...WRN MN...SE ND...FAR NW IA

   CONCERNING...SEVERE THUNDERSTORM WATCH 458...

   VALID 280657Z - 280900Z

   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 458
   CONTINUES.

   SUMMARY...A POTENTIAL FOR ISOLATED WIND DAMAGE AND HAIL WILL LIKELY
   CONTINUE FOR SEVERAL MORE HOURS ACROSS SE ND...ERN SD AND MAY AFFECT
   WRN MN LATER THIS MORNING. ADDITIONAL WW ISSUANCE MAY BE NEEDED AS
   THE LINE OF STORMS MOVES TOWARD THE EDGE OF WW 458.

   DISCUSSION...LATEST RADAR IMAGERY SHOW A LINE OF STRONG
   THUNDERSTORMS EXTENDING ACROSS SERN ND SWD INTO ERN SD ALONG WHICH
   MULTIPLE BOWING LINE SEGMENTS ARE ONGOING. THE LINE IS LOCATED ALONG
   AN AXIS OF MODERATE INSTABILITY WHERE MLCAPE IS ESTIMATED FROM 1500
   TO 2000 J/KG AND SFC DEWPOINTS ARE IN THE LOWER TO MID 70S F. THE
   LINE OF STORMS IS BEING SUPPORTED BY LARGE-SCALE ASCENT ASSOCIATED
   WITH A MINOR SHORTWAVE TROUGH AND BY A STRENGTHENING 40 TO 55 KT
   LOW-LEVEL JET. THE LOW-LEVEL JET IS BEING SAMPLED BY THE FSD WSR-88D
   VWP WHICH SHOWS 50 KT AT 1 KM AGL WITH 35-40 KT OF 0-6 KM SHEAR.
   THIS ENVIRONMENT SHOULD CONTINUE TO SUPPORT AN ISOLATED SEVERE
   THREAT OVER THE NEXT FEW HOURS. WIND DAMAGE AND MARGINAL HAIL WILL
   BE THE PRIMARY THREATS. THE GREATEST SEVERE WEATHER THREAT MAY BE
   ACROSS SERN SD OVER THE NEXT 1 TO 3 HOURS AS THE SRN PART OF THE
   CONVECTIVE LINE INTERACTS WITH THE NOSE OF THE CNTRL PLAINS
   LOW-LEVEL JET. THIS IS CURRENTLY THE STRONGEST PART OF THE LINE WITH
   A 54 KT WIND GUST OBSERVED AT HURON. HOWEVER...THE SEVERE THREAT MAY
   BECOME MORE ISOLATED ONCE IT GETS TOWARD THE MN STATE LINE WHERE
   INSTABILITY IS MUCH WEAKER. FOR THIS REASON...WW ISSUANCE DOES NOT
   APPEAR LIKELY TO THE EAST OF WW 458 BUT STILL CANNOT BE RULED OUT.

   ..BROYLES/EDWARDS.. 07/28/2015


   ATTN...WFO...MPX...FGF...FSD...ABR...BIS...LBF...

   LAT...LON   45049508 46679533 47449620 47549703 47499799 47219868
               46689887 45899853 44239859 43539893 43239891 43009873
               42879763 43009623 43809528 45049508