Severe Thunderstorm Warning 172, NWS Grand Forks, ND

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
330 AM CDT WED JUL 30 2003

SCATTERED SHOWERS MOVING SOUTHEAST IN SOUTHERN MANITOBA MAY LAST
TO CROSS OVER INTO EXTREME NORTHEAST ND/NORTHWEST MN THIS MORNING
SO WILL KEEP ITS MENTION THIS AREA. LOW CLOUDS DEVELOPING AND
SPREADING IN LAKE REGION OF NORTHWEST MN DUE TO MOISTURE LAID DOWN
DURING EVENING... A WEAK SUBSIDENCE INVERSION WHICH DEVELOPED OVER
THE TOP OF THE STRATUS LAYER...AND CONTINUED MOIST FLOW FROM
NORTHWEST. WILL GO FOR A LATE MORNING BURN OFF OF THIS LAYER.
PATCHY FOG IS LIKELY LATE TONIGHT IN LAKE REGION IF CLOUDS CAN
DISSIPATE SOON ENOUGH AS TEMPERATURES DIP A LITTLE MORE.

MINIMAL JET DYNAMICS OR THERMAL BOUNDARIES ARE AVAILABLE TO AID
CONVECTION TODAY. INITIATION OF THUNDER/SHOWERS IS MAINLY DEPENDENT
ON REACHING THE CONVECTIVE TEMPERATURE WHICH SHOULDN/T BE DIFFICULT
TO REACH TODAY OR THU EXCEPT POSSIBLY WEST AND SOUTH OF FARGO.
CONVECTION WILL BE PRETTY DISORGANIZED BUT THEIR LOCATION WILL
DEPEND MAINLY ON VORTICITY LOBES ROTATING AROUND PARENT UPPER LOW.
WATER VAPOR SHOWS MANY OF THE VORT CENTERS BUT THE STRONGEST THAT
BOTH ETA/GFS AGREE OVER IS CURRENTLY OVER WESTCENTRAL MANITOBA WHILE
MOVING OVER SLIGHTLY DEEPER MOISTURE THAN WE HAVE THIS FAR SOUTH.
THIS FEATURE WILL SWING SOUTHWARD LATE LATE AFTERNOON/EARLY EVE
TO NORTHERN RED RIVER VALLEY AND DEW POINTS WILL STAY RATHER HIGH
(UPPER 50S/NEAR 60) UNDERNEATH SUCH A COLD CORE LOW. BUT OTHER MINOR
VORTICITY MAXES WILL FIRE OTHER THUNDERSTORMS...ESPECIALLY FOR
NORTHWEST MN.

FREEZING LEVEL REMAINS JUST OVER 10 KFT BUT THIS WILL BE LOW
ENOUGH TO MAKE LARGE HAIL A PROBLEM IN SOME STORMS...PROBABLY NOT
WIDESPREAD BUT WILL INCLUDE MENTION OF HAIL IN NORTHERN AND MN
ZONES EAST OF THE VALLEY.

THE STRONG VORT MOVING NORTHWARD IN EXTREME WESTERN ONTARIO IS
EXPECTED BY MODELS TO ROTATE AROUND TO REVISIT VALLEY REGION AGAIN
LATE TONIGHT SO WILL KEEP SCATTERED SHOWERS GOING ALL NIGHT. EXPECT
THAT THERE WILL BE MORE OF THESE APPEARING AS SPOKES ON THE UPPER
LOW...PROBABLY ROTATING INTO AREA INTO SAT ALONG WITH RELATIVELY
HIGH MOISTURE. WILL MAINTAIN THE MENTION OF SHOWERS INTO SAT AS
CURRENTLY STATED. COLD AIR ALOFT WILL LIKELY SLIDE FAR ENOUGH
EASTWARD THAT THUNDER IS LESS LIKELY BY SAT.

.FGF...NONE.

GV

MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-301430-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
650 AM CDT WED JUL 30 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN NORTH DAKOTA...WEST
CENTRAL AND NORTHWEST MINNESOTA.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE PORTION
OF NORTHWEST AND WESTCENTRAL MINNESOTA JUST EAST OF THE RED RIVER
VALLEY BEGINNING IN EARLY AFTERNOON AND CONTINUING INTO EARLY
EVENING. ISOLATED SEVERE THUNDERSTORMS ARE ALSO EXPECTED OVER THE
NORTH PORTION OF THE RED RIVER VALLEY. ONE CAN EXPECT MAINLY LARGE
HAIL AND A FEW DOWNBURSTS CAUSING HIGH WIND IN THESE THUNDERSTORMS
DUE TO A COLD UPPER LEVEL LOW PRESSURE SYSTEM MOVING SOUTH FROM
MANITOBA.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A CONTINUED CHANCE OF THUNDERSTORMS THROUGHOUT THE
REGION...MAINLY ON THURSDAY AFTERNOON AND EVENING...AND THEY
MAY DEVELOP AGAIN OVER THE MINNESOTA PORTION ON FRIDAY. THE NEXT
CHANCE OF THUNDERSTORMS WILL BE IN AND WESTWARD FROM THE RED
RIVER VALLEY ON TUESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

GV

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS, ND
1016 AM CDT WED JUL 30 2003

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

0600 PM    10 S ZERKEL               MN   1.00 INCH HAIL
07/29/03   CLEARWATER

0629 PM    15 NW BEMIDJI             MN   .75 INCH HAIL
07/29/03   BELTRAMI                       LARGE HAIL FOR 3 MINUTES

0657 PM    BLACKDUCK                 MN   70 MPH WIND GUST
07/29/03   BELTRAMI                       REPORTED BY TRAINED
                                          SPOTTER.

0707 PM    BENEDICT                  MN   1.00 INCH HAIL
07/29/03   HUBBARD                        REPORTED BY TRAINED
                                          SPOTTER.

GJG