Severe Thunderstorm Warning 267, NWS Grand Forks, ND

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
250 PM CDT MON AUG 26 2002

...NEW SVR WATCH JUST ISSUED FOR ERN ND PER SPC CONF CALL...

MAIN CHALLENGE IS SVR WX POTENTIAL TONIGHT.

SFC MAP SHOWS CONTINUED WEAK FLOW OVER THE AREA MAKING BOUNDARY
IDENTIFICATION DIFFICULT.  SFC LOW IN SE WYOMING WITH A TROUGH NORTH
INTO FAR WRN ND.  OTHERWISE ERN/CNTRL ND AND WRN MN IN SOUTHEASTLY
FLOW.  DEW PTS HAVE MADE GOOD RECOVERY WITH MOST SITES IN THE 65 TO
70 RANGE...ONCE AGAIN A GOOD 4-8 DEGREES HIGHER THAN PROGGED BY ANY
MODEL.  MSAS SHOWS SFC LI DOWN TO -9 OVER NE ND AND ERN SD.  VSBL
SATELLITE HAS SHOWN TENDENCY FOR CU TO FORM IN AREA FROM BISMARCK TO
JUST WEST OF GRAND FORKS...BUT NOT MUCH GROWTH SINCE 18Z.  RADARS
SHOW TSRA IN NRN SD BACKBUILDING WESTWARD INTO NW SD IN AREA OF
THICKNESS DIFFLUENCE.

.SHORT TERM...
MODIFIED MESO ETA SOUNDINGS FOR TEMPS IN THE MID 80S AND DEW PTS IN
THE UPR 60S SHOWS CAPES AT 00Z AROUND 3600 J/KG AND LI TO -10 AT
KGFK.  WATER VAPOR SHOWS SOME WEAK EMBEDDED SHORT WAVES MOVING SOUTH
OF UPR LOW THRU SD/ND....BUT REALLLY HARD TO DISCERN WHICH ONE WILL
SET OFF ACTIVITY.  85H JET/THETA-E VALUES INCREASE A BIT OVERNIGHT
MAXING AROUND 06Z.  BASED ON PAST DAYS WEATHER AND CURRENT
INSTABILITY VALUES WOULD EXPECT SCT TSRA TO FIRE LATE THIS AFTN
NORTHEAST OF BISMARCK WITH POTENTIAL FOR GROWTH INTO A LARGER AREA
DURING THE EVENING.  WILL CONTINUE MENTION OF SVR THIS EVENING FOR
NW MN AND ERN ND.  FZG LEVELS AROUND 11.5 KFT.  THICKNESS FIELDS AND
UPR FLOW ALOFT WOULD SUGGEST SLOW MOVES WITH POTENTIAL FOR
BACKBUILDING OF ANY COMPLEX WHICH MAY FORM.  THIS COULD GIVE LOCALLY
HEAVY RAIN POTENTIAL.

.LONGER TERM...
50H UPR LOW IN SRN SASK WILL DRIFT ENE VERY SLOWLY INTO SRN MANITOBA
TUE-WED TIME FRAME AND WEAKEN FURTHER.  50H TEMPS WARM A BIT BUT LOW
LEVEL MOISTURE REMAINS HIGH WITH DEW PTS HOLDING IN THE 60S.  WITH
CONTINUED SHORT WAVES MOVING THRU AREA IN BROAD SW FLOW WILL
CONTINUE MENTION OF TSRA THRU WED.  ETA BRINGS A TROUGH INTO ERN ND
LATE WED AVN BRINGS IT THROUGH LATE TUESDAY.  WILL LEAN TOWARD
SLOWER ETA SOLN. WILL KEEP THURSDAY DRY AWAITING NEXT IMPULSE.
WILL KEEP TEMPS NEARLY SAME THRU PD.

.EXTENDED...
LONG RANGE MODELS IN PRETTY GOOD AGREEMENT. 500MB TROF
DEEPENS ALONG W US COAST...AS ANOTHER UPPER LEVEL TROF MOVES THROUGH
THE REGION BY THE WEEKEND. THEN...UPPER LEVEL RIDGE STARTS BUILDING
INTO THE AREA. WITH GOOD CONTINUITY TO PRIOR FORECAST...ONLY MINIMAL
NEEDED TO BOTH PRECIPITATION AND TEMPERATURES.

.FGF...NONE.

RIDDLE/NG

.FGF...NONE
RIDDLE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS, ND
530 PM CDT MON AUG 26 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0500 PM    MINNEWAUKAN               ND   .88 INCH HAIL
08/26/02   BENSON                         HAIL FELL FOR HALF AN
                                          HOUR. REPORTED BY LAW
                                          ENFORCEMENT.

DPORTER

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS, ND
535 PM CDT MON AUG 26 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0512 PM    MADDOCK                   ND   .75 INCH HAIL
08/26/02   BENSON

DPORTER

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS, ND
542 PM CDT MON AUG 26 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0540 PM    PENN                      ND   1.00 INCH HAIL
08/26/02   RAMSEY

DPORTER

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS, ND
553 PM CDT MON AUG 26 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0545 PM    LEEDS                     ND   .88 INCH HAIL
08/26/02   BENSON                         REPORTED BY CO-OP
                                          OBSERVER.

DPORTER

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS, ND
602 PM CDT MON AUG 26 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0415 PM    6 W RED LAKE FALLS        MN   1.00 INCH HAIL
08/26/02   RED LAKE                       REPORTED BY PUBLIC.

DPORTER

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS, ND
621 PM CDT MON AUG 26 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0620 PM    CANDO                     ND   .75 INCH HAIL
08/26/02   TOWNER                         REPORTED BY CO-OP
                                          OBSERVER.

DPORTER