Severe Thunderstorm Warning 217, NWS Grand Forks, ND

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
225 PM MON AUG 14 2000

...MAIN FORECAST CHALLENGE CONCERNS CHC FOR SVR WX EARLY THIS
   EVENING...

ETA MODELS VERIFYING WELL AT 18Z...AND WAS ONLY MODEL WHICH HANDLED
TRACK OF SFC LOW FROM PREVIOUS 12Z RUN. THUS WILL STICK WITH IT THIS
PACKAGE.

.SHORT TERM...ONGOING SVR TSRA ACTIVITY GRADUALLY SHIFTING SE WITH
TIME AS AREA OF BEST SFC CONVERGENCE SLIDES EAST AS WELL AHEAD OF
SFC LOW. ETA TAKES SFC LOW INTO SW MN BY 0Z WHILE A COLD FRONT
PUSHES INTO THE WRN FA BY THEN. WARM FRONT EXTENDING EAST FROM THE
LOW TO SLIGHTLY LIFT N WITH TIME. INSTABILITY PARAMETERS STAY QUITE
HIGH...ESPECIALLY OVER THE SOUTH...WHERE LI/S HOLD AROUND -6 WITH
SHOWALTER INDEX DROPPING TO -6 AS WELL OVER THE SE FA. WITH LAPSE
RATES INCREASING THIS AFTERNOON...EXPECT THUNDERSTORMS TO FIRE UP IN
FAR SRN ZONES WHERE NO ACTIVITY HAS OCCURRED YET...WITH THESE STORMS
RAPIDLY BECOMING SEVERE. CLOUD COVER JUST NORTH OF THIS AREA HAS
HELPED KEEP TEMPERATURES DOWN THIS AFTERNOON SO LESS INSTABILITY
THERE FOR SVR CONVECTION. ACROSS THE NW FA...DRIER AIR PUNCHING IN
TO LIMIT TSRA DEVELOPMENT AND WILL LEAVE OUT...WITH ONLY A SLIGHT
CHC EXPECTED ACROSS THE NE FA.

TEMPERATURE FORECAST TO BE TRICKY WITH COLD FRONT MOVING THROUGH AND
HIGH PRESSURE RAPIDLY BUILDING IN...BUT WINDS SHOULD STAY UP ENOUGH
TO KEEP TEMPS FROM FALLING TOO FAR BELOW SEASONAL AVERAGES.

.LONG TERM...SFC HIGH CONTINUES TO BUILD IN AND WILL DOMINATE THE
REGION THROUGH 48 HRS. THEN 3H JET MOVES JUST SOUTH OF THE
INTERNATIONAL BORDER PLACING THE SRN FA UNDER RIGHT ENTRANCE REGION
BY AFTERNOON. WITH RETURN FLOW DEVELOPING OVER THE DAKOTAS THERE
WILL BE ENOUGH MOISTURE FOR CONVECTIVE ACTIVITY...BUT MOST TSRA
SHOULD BE WELL SOUTH OF THE FA CLOSER TO BEST SFC CONVERGENCE
ASSOCIATED WITH SFC LOW. WILL MENTION TSRA IN SRN FA ON WED.

TEMPS TO STAY NEAR OR BELOW SEASONAL AVERAGES THROUGH PD 4 WITH SFC
HIGH DOMINATING THE AREA.

.EXTENDED...MODELS IN FAIR AGREEMENT THRU MUCH OF PERIOD...WITH SOME
TIMING DIFFERENCES LATE. GOOD S/W SLIPS OVER NW MN THU AFTN...WITH
SFC LO AND CDFNT SWIPING NE ZONES AS COLD POOL (-16C) AT H5 DIPS
DOWN SOUTH OF BORDER. WILL TRIM BACK POPS ON THU TO MAINLY AREAS N/E
FROM KGFK AS REST OF CWA COMES UNDER INFLUENCE OF HI PRES. S/W
RIDGING AND SFC RETURN FLO FOR FRI SHUD MEAN DRY DAY. BY SAT/SUN
PATTERN AMPLIFIES WITH NRN PLAINS AGAIN UNDER SW FLO AND MAIN BELT
OF WESTERLIES NEARBY CWA. ANOTHER ROUND OF STRONG CONVECTION
POSSIBLE BY SAT NGT THRU MON WITH INITIALLY WMFNTL MCS ACTIVITY
AIDED BY U/L JET DIVERGENCE AND THEN CDFNT ARRIVING BY LATE SUN OR
MONDAY (DEPENDING ON MODEL TIMING). WL RIDE WITH TSRA CHANCES SAT
NGT THRU MON. TEMPS ON COOL SIDE THU WITH SOME WARMUP IN MAINLY SRN
SECTIONS TO NEAR SEASONAL BY WEEKEND AS BAROCLINIC ZONE HANGS NEAR
CWA.

.FGF...SVR TSRA WATCH CONTINUES UNTIL 0Z MN ZONES 15>17-22>24

DSS/RJT

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS
105 PM CDT MON AUG 14 2000

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

1150 PM    10 N CALVIN               ND   .75 INCH HAIL
08/13/00   CAVALIER

0420 AM    2 W VALLEY CITY           ND   .75 INCH HAIL
08/14/00   BARNES

0440 AM    4 NW HANNAFORD            ND   .75 INCH HAIL
08/14/00   GRIGGS

0610 AM    3 W DAVENPORT             ND   .75 INCH HAIL
08/14/00   CASS

0650 AM    3 NW ROTHSAY              MN   .75 INCH HAIL
08/14/00   WILKIN

0702 AM    PELICAN RAPIDS            MN   1.75 INCH HAIL
08/14/00   OTTER TAIL

0710 AM    3 N PELICAN RAPIDS        MN   .75 INCH HAIL
08/14/00   OTTER TAIL

0710 AM    5 E PELICAN RAPIDS        MN   .75 INCH HAIL
08/14/00   OTTER TAIL                     HAIL OCCURED ON
                                          SOUTHEAST SHORE OF
                                          LAKE LIDA

0720 AM    DENT                      MN   1 INCH HAIL
08/14/00   OTTER TAIL

0730 AM    4 NW HANNAFORD            ND   .75 INCH HAIL
08/14/00   GRIGGS

0731 AM    6 S COOPERSTOWN           ND   1.25 INCH HAIL
08/14/00   GRIGGS

1100 AM    4 SW EUCLID               MN   1.25 INCH HAIL
08/14/00   POLK

1202 PM    1 SE HILLVIEW             MN   1.75 INCH HAIL
08/14/00   OTTER TAIL

1210 PM    SEBEKA                    MN   1.75 INCH HAIL
08/14/00   WADENA

1225 PM    12 N LAKE GEORGE          MN   .75 INCH HAIL
08/14/00   HUBBARD

1234 PM    12 N LAKE GEORGE          MN   1 INCH HAIL
08/14/00   HUBBARD

NNNN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS
139 PM CDT MON AUG 14 2000

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

1256 PM    1 E LAKE ITASCA           MN   .75 INCH HAIL
08/14/00   HUBBARD

0120 PM    7 E LAKE GEORGE           MN   1.75 INCH HAIL
08/14/00   HUBBARD

NNNN

MNZ015>017-022>024-142140-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
338 PM CDT MON AUG 14 2000

...SEVERE THUNDERSTORM WATCH NUMBER 685 CANCELLED FOR PARTS OF
NORTHWEST MINNESOTA...

SEVERE THUNDERSTORMS ARE NO LONGER EXPECTED IN THESE PARTS OF
NORTHWEST MINNESOTA...THEREFORE THE WATCH HAS BEEN CANCELLED.

SOROKA

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