Severe Thunderstorm Warning 280, NWS Grand Forks, ND

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
202 PM CDT WED AUG 8 2001

...MAIN FORECAST CHALLENGE THIS PACKAGE IS CONVECTION WITH FROPA AND
THEN EXTENT OF COOLDOWN THEREAFTER...

.CURRENT OBSERVATIONAL OVERVIEW...
18Z MSAS ANALYSIS DEPICTED DOUBLE BARREL LOW STRUCTURE FROM EXTREME
SOUTHEAST MB PROVINCE TO NORTH CENTRAL SOUTH DAKOTA. SCATTERED
CONVECTION FIRING AHEAD OF FEATURE AND ASSOCIATED TROUGH FROM
EASTERN NORTH DAKOTA INTO MINNESOTA IN CONJUNCTION WITH STRONG
SURFACE-850MB WAA PUNCH...PER KMVX RADAR. FURTHER UPSTREAM PARENT
COLD FRONT WAS EVIDENT OVER NORTHWEST NORTH DAKOTA WITH GOOD
PRESSURE RISES NOTED IN WAKE OF BOUNDARY OVER MONTANA AND SASK
PROVINCE.

.FORECAST DETAILS...
THE GOOD NEWS IS MUCH WELCOME AND PROLONGED RELIEF ON THE WAY IN THE
FORM OF A STRONG COLD FRONT. HOWEVER...INITIALLY WE WILL HAVE TO THE
PAY THE PIPER IN THE PRICE OF SEVERE STORM THREAT THIS AFTN/EVE AS
INCREASING MOISTURE FLUX CONVERGENCE AND MID-LEVEL COOLING ENHANCES
CONVECTIVE POTENTIAL IN CONJUNCTION WITH FROPA. SEE SPC SWODY1 FOR
FURTHER DETAILS. EXPECT POP THREAT TO END FROM NW TO SE TONIGHT.
ALIGNED FLOW AND TIGHTENING PRESSURE GRADIENT SHOULD LEAD TO ACTIVE
NORTHWEST FLOW LATE TONIGHT AND THURSDAY AS MUCH COOLER AND LESS
HUMID AIR ADVECTS INTO THE REGION. LINGERING CYCLONIC FLOW COUPLED
WITH GOOD THICKNESS COOLING PROBABLY WILL LEAD TO DIURNAL DRIVEN
BROKEN CU DECK FORMATION ON THURSDAY. THESE FACTORS SHOULD RESULT IN
THE MERCURY STRUGGLING TO RISE MUCH OUT OF THE LOW TO MID 70S. WILL
MAKE GAME TIME DECISION ON WHETHER TO LINGER HEAT ADVISORY THIS
EVENING ACROSS SOUTHEAST ZONES.

.EXTENDED...UPPER LOW DROPS SOUTHEAST INTO LOWER HUDSON BAY BY EARLY
MONDAY WITH NORTHERN PLAINS UNDER NORTHWEST FLOW REGIME. PATTERN
SHIFTS A BIT TOWARD THE END OF THE PERIOD AS ANOTHER LOW PROGGED TO
DROP INTO THE PACIFIC NW WITH UPPER RIDGE STARTING TO REBUILD OVER
THE CENTRAL US. SEVERAL WEAK WAVES IN THE NORTHWEST FLOW SAT NIGHT
AND SUN MAY BRING A FEW SHOWERS. MRF HINTING AT OVERNIGHT CONVECTION
MON NIGHT/EARLY TUE...BUT THIS IS A BIG CHANGE FROM YESTERDAY AND
WILL LEAVE DRY FOR NOW. MEX/FMR NUMBERS SHOWING BELOW NORMAL TEMPS
EARLY TRENDING BACK TOWARD NORMAL LATE IN THE PERIOD WHICH LOOKS
REASONABLE.

.FGF...HEAT ADVISORY THIS EVENING ALONG AND SOUTH OF A FAR-PKD LINE.

BERG/GODON

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS
722 PM CDT WED AUG 08 2001

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

0245 PM    6 NW PONSFORD             MN   60 MPH TSTM GUST
08/08/01   BECKER

0339 PM    AKELEY                    MN   62 MPH TSTM GUST
08/08/01   HUBBARD                        MEASURED MN DOT
                                          ROADSIDE SITE

0340 PM    PARK RAPIDS               MN   WIND DAMAGE
08/08/01   HUBBARD                        NUMEROUS TREES DOWN

0600 PM    2 SW MADDOCK              ND   1 INCH HAIL
08/08/01   BENSON

0620 PM    4 SW ESMOND               ND   1 INCH HAIL
08/08/01   BENSON

0620 PM    9 NW MADDOCK              ND   .88 INCH HAIL
08/08/01   BENSON                         4 INCH DIAMETER TREE
                                          BRANCHES ALSO DOWN

0623 PM    5 NE MADDOCK              ND   .75 INCH HAIL
08/08/01   BENSON                         4 INCH DIAMETER TREE
                                          BRANCHES ALSO DOWN

0640 PM    4 NW OBERON               ND   WIND DAMAGE
08/08/01   BENSON                         2 TREES BLOWN DOWN

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