Severe Thunderstorm Warning 200, NWS Grand Forks, ND

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
215 PM CDT WED JUL 27 1999

FCST CHALLENGE: SVR THREAT IN NW FLOW REGIME...TNGT AND TMRW NGT.

MODEL SELECTION: ETA INCOMPLETE. NGM/ETA FAIR ON UPR FEATURES AND
INITIALIZING WELL ON WEAK VORT IN SERN SASK. LOW LEVEL MOISTURE
FIELDS ARE SOMEWHAT WEAK...12Z RUC WAS BETTER. WILL USE NGM
PRIMARILY.

NEAR TERM: MODELS WEAK ON HANDLING MOISTURE/INSTABILITY SURGE AHEAD
OF SFC TROF...NOW ENTERING ERN ND. 18Z ABR SOUNDING SHOWS CAPE
VALUES AROUND 4K WHILE ETA HAS AXIS OF 3-4K BAND BACK IN CNTRL SD.
SFC DEWPTS APCHG 70 IN SERN ND WITH CONVECTION FIRING NEAR JMS. LOW
LEVEL SHEAR PROFILES SHOW GOOD VEERING BLO H7. H5 ANALYSIS HAD
SEMBLANCE OF WEAK COUPLED JET OVR FGF CWFA BETWEEN NRN AND SRN
BRANCH FLOW. 50KTS AT H5 GENERALLY SUPPORTING GOOD DIVERGENCE ALOFT.
WILL COORD WITH SPC ON LATE AFTERNOON SVR TSTM WATCH AREA. FAN TEMPS
LOOK REASONABLE AS DEWPTS SHOULD STAY UP A BIT.

MID TERM: PATTERN REPEATS ON WEDNESDAY...WITH WEAK SFC BOUNDARY
PUSHING INTO ERN ND AT MAX HEATING AND WK UPR WAVE IN NW FLOW
PATTERN. WILL STICK WITH WDLY SCT AFTERNOON TSTMS ND ZONES. PM TSTMS
IN MN ZONES.

EXTENDED: LONG RANGE MODELS SIMILAR IN THEIR HANDLING OF THE
REDEVELOPMENT OF HIGH PRESSURE RIDGE OVER THE UPPER MIDWEST THROUGH
THE EXTENDED FORECAST PERIOD. IN GENERAL...UPPER LEVEL RIDGE REMAINS
OVER MT AND WRN ND AREA WITH UPPER LEVEL LOW MOVING SOUTH FROM
CANADA INTO GREAT LAKES AREA. ONLY CHANCE FOR PCPN APPEARS ON
SATURDAY NIGHT AS FRONT ASSOCIATED WITH LOW MOVES THROUGH THE CWFA.
CWFA THEN REMAINS BETWEEN THESE SYSTEMS FOR REST OF EXTENDED
FORECAST PERIOD. WITH THE MAJORITY OF CWFA ON COLD SIDE OF
RIDGE...EXPECT TEMPS TO HOLD AROUND NORMALS.

.FGF...TOR WATCH #591 UNTIL 7PM CDT...PORTIONS OF ERN ND AND NW MN.

GUST/GODON

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS
115 PM CDT MON JUL 26 1999...CORRECTION TO TIME AT ULEN

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

1100 AM    2 NE POLAND               ND   .75 INCH HAIL
07/25/99   WALSH

0210 PM    1 W ULEN                  MN   WIND DAMAGE
07/25/99   CLAY                           THREE INCH DIAMTER TREE
                                          BRANCHES DOWN

0212 PM    ULEN                      MN   WIND DAMAGE
07/25/99   CLAY                           SEVERAL TREES DOWN IN TOWN

AMD
MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052-053-271910-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
1248 PM CDT TUE JUL 27 1999

...SEVERE STORMS ARE EXPECTED ACROSS EXTREME EASTERN NORTH
DAKOTA...NORTHWEST AND WEST CENTRAL MINNESOTA THIS AFTERNOON AND
EVENING...

SYNOPSIS...WARM...MOIST AND UNSTABLE AIR WILL CONTINUE TO WORK
NORTHWARD   ACROSS EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA. AT
THE SAME TIME A STRONG UPPER-LEVEL JET STREAM AND SURFACE TROUGH
WILL WORK INTO EASTERN NORTH DAKOTA. ALL OF THESE COMBINED WILL
PRODUCE SUFFICIENT LIFT AND INSTABILITY TO PRODUCE AREAS OF SEVERE
THUNDERSTORMS LATER THIS AFTERNOON AND EVENING. THERE WILL ALSO BE
ENOUGH WIND SHEAR THAT A FEW TORNADOES ARE POSSIBLE WITH THE
STRONGER THUNDERSTORMS.

AREA OF CONCERN...A MODERATE RISK OF SEVERE WEATHER IS FORECAST
SOUTH AND EAST OF A LINE FROM FORT RANSOM TO GRANDIN AND EAST TO
BEMIDJI. A SLIGHT RISK IS EXPECTED EAST OF A LINE FROM COOPERSTOWN
TO HALLOCK MINNESOTA.

TIME...START AFTER 2 PM AND SHOULD MOVE OUT OF THE AREA TOWARDS
MIDNIGHT.

TYPE OF HAZARD...MAINLY LARGE HAIL AND DAMAGING WINDS. HOWEVER
A FEW TORNADOES ARE ALSO POSSIBLE.

PERSONS SHOULD STAY TUNED TO NOAA WEATHER RADIO...LOCAL RADIO AND
TELEVISION FOR FURTHER FORECASTS AND POSSIBLE WATCHES LATER THIS
AFTERNOON.