

972 

WWUS20 KWNS 210607

SEL0

SPC WW 210607

MNZ000-211200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 470

NWS STORM PREDICTION CENTER NORMAN OK

105 AM CDT THU AUG 21 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  SOUTHERN MINNESOTA



* EFFECTIVE THIS THURSDAY MORNING FROM 105 AM UNTIL 700 AM CDT.



* PRIMARY THREATS INCLUDE...

  ISOLATED LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 60 MILES SOUTHWEST

OF ALEXANDRIA MINNESOTA TO 35 MILES NORTH NORTHEAST OF MANKATO

MINNESOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



&&



DISCUSSION...THUNDERSTORM DEVELOPMENT WAS UNDERWAY ACROSS WRN MN

LATE TONIGHT AHEAD OF A SHORTWAVE TROUGH AND ASSOCIATED SURFACE LOW

AND WARM FRONT SITUATED ACROSS THE NRN PLAINS. LIFT OCCURRING ACROSS

THE WARM FRONT SHOULD CONTINUE TO AID UPDRAFT DEVELOPMENT ON THE

EDGE OF STRONGER CAPPING INVERSION. MODEST INSTABILITY AND

INCREASING SHEAR SHOULD CONTRIBUTE TO HAIL PRODUCTION FROM SOME OF

THE STRONGER CELLS. DOWNWARD MOMENTUM TRANSFER MAY ALSO RESULT IN

GUSTY/STRONGER WINDS GIVEN RELATIVELY WEAK BOUNDARY LAYER

INHIBITION. EXPECT THIS CONVECTION TO SPREAD EAST ACROSS PARTS OF

SRN MN OVER THE NEXT SEVERAL HOURS SUSTAINED BY THE SHORTWAVE TROUGH

AND ENHANCED MASS TRANSPORT ON THE NOSE OF 40KT LOW LEVEL JET.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 50

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 27025.





...CARBIN



547 

WWUS20 KWNS 210607

SEL0

SPC WW 210607

MNZ000-211200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 470

NWS STORM PREDICTION CENTER NORMAN OK

105 AM CDT THU AUG 21 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  SOUTHERN MINNESOTA



* EFFECTIVE THIS THURSDAY MORNING FROM 105 AM UNTIL 700 AM CDT.



* PRIMARY THREATS INCLUDE...

  ISOLATED LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 60 MILES SOUTHWEST

OF ALEXANDRIA MINNESOTA TO 35 MILES NORTH NORTHEAST OF MANKATO

MINNESOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



&&



DISCUSSION...THUNDERSTORM DEVELOPMENT WAS UNDERWAY ACROSS WRN MN

LATE TONIGHT AHEAD OF A SHORTWAVE TROUGH AND ASSOCIATED SURFACE LOW

AND WARM FRONT SITUATED ACROSS THE NRN PLAINS. LIFT OCCURRING ACROSS

THE WARM FRONT SHOULD CONTINUE TO AID UPDRAFT DEVELOPMENT ON THE

EDGE OF STRONGER CAPPING INVERSION. MODEST INSTABILITY AND

INCREASING SHEAR SHOULD CONTRIBUTE TO HAIL PRODUCTION FROM SOME OF

THE STRONGER CELLS. DOWNWARD MOMENTUM TRANSFER MAY ALSO RESULT IN

GUSTY/STRONGER WINDS GIVEN RELATIVELY WEAK BOUNDARY LAYER

INHIBITION. EXPECT THIS CONVECTION TO SPREAD EAST ACROSS PARTS OF

SRN MN OVER THE NEXT SEVERAL HOURS SUSTAINED BY THE SHORTWAVE TROUGH

AND ENHANCED MASS TRANSPORT ON THE NOSE OF 40KT LOW LEVEL JET.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 50

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 27025.





...CARBIN

