Severe Thunderstorm Warning 118, NWS Grand Forks, ND

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
330 PM CDT SUN JUL 13 2003

.SHORT TERM...
WATER VAPOR LOOP SHOWS SHORT WAVE OVER SOUTHERN MANITOBA WITH
CONVECTION THAT HAS MOVED OUT OF SOUTHEAST MANITOBA AND INTO THE
NORTHEAST ZONES. RIDGE AXIS WAS OVER SOUTHERN SASKATCHEWAN AND EASTERN
MT. SECONARY AXIS WAS OVER EASTERN DAKOTAS. SHORT WAVE TO THE NORTH
WAS KNOCKING RIDGE DOWN. SAME THEME WILL OCCUR TONIGHT WITH WAVE
OVER NORTHERN ID WILL MOVE INTO WESTERN ND BY 12Z MON. WAVE THEN
DIGS MONDAY AFTER MOVING TO OUR EAST. THETA-E RIDGE OVER THE WESTERN
DAKOTAS MOVES OVER THE CWFA BY MORNING. EXPECT THUNDERSTORMS ALONG
THE THETA-E RIDGE. PRECIPITABLE WATERS RISE TO 1.5 INCHES THIS
AFTERNOON AND TO 1.8 INCHES BY MORNING. 700 HPA TEMPERATURES
PROVIDING A REASONABLE CAP ACROSS THE REGION BUT LOWERS OVERNIGHT
FROM THE NORTHWEST. 88D SHOWING THUNDER NORTHWEST AND NORTH CENTRAL
ND MOVING EAST. 110 KT UPPER JET PUNCHES INTO THE REGION MONDAY
AFTERNOON. 850 HPA DEWPOINTS REMAIN AROUND 10-12C IN THE EASTERN
ZONES.  LOW LEVEL JET OVER EASTERN SD IN THE MORNING. ANOTHER WEAK
LOW LEVEL JET OVER THE WESTERN DAKOTAS IN RESPONSE TO APPROACHING
UPPER JET. WILL UP THREAT OF THUNDER TONIGHT AND MONDAY. LOCALLY
HEAVY WILL BE POSSIBLE HOWEVER THUNDERSTORMS ARE EXPECTED TO BE
PROGRESSIVE AT A MODEST SPEED.

EXTENDED...OPERATIONAL GFS IS DIFFERENT FROM OTHER MODELS AND FROM
ITS ENSEMBLE REGARDING THE UPPER LOW CENTERED OVER SASK ON THU. BUT
12Z GFS RUN DID SLOW IT DOWN AND PUSH FARTHER NORTHWARD...MORE IN
THE DIRECTION OF OTHER MODEL SOLUTIONS. GFS APPEARS TO BE HAVING A
TOUGH TIME ALLOWING THE WESTERN U.S. RIDGE TO BUILD ONTO CANADIAN
ROCKY MOUNTAINS IN SPITE OF PLACING RATHER STRONG TROUGHS OVER GULF
OF ALASKA AND OVER EASTERN N.A...SO KEPT TEMPERATURES A FEW DEGREES
HIGHER THAN MEX GUIDANCE THROUGH THE PERIOD. EUROPEAN MODEL MAY BE
HAVING A SIMILAR PROBLEM WITH THE SHORTWAVE IN B.C. BY 12Z SAT. GFS
PLACEMENT OF CONVECTIVE ACTIVITY LOOKS DECENT ANYWAY AND USED IT
THROUGH SUNDAY.

.FGF...NONE.

HOPPES/GV

MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-131430-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
632 AM CDT SUN JUL 13 2003

...SCATTERED SEVERE THUNDERSTORMS TO DEVELOP LATE TODAY AND
TONIGHT...

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

.DAY ONE...TODAY AND TONIGHT

ISOLATED SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP AFTER 4 PM
THIS AFTERNOON ACROSS THE DEVILS LAKE REGION AND THE FAR NORTHERN
PORTION OF THE RED RIVER VALLEY.  THUNDERSTORM COVERAGE IS EXPECTED
TO INCREASE AND SPREAD OVER THE REST OF THE REGION AFTER 7 PM.  THE
THREAT FOR SEVERE WEATHER WILL THEN CONTINUE INTO MUCH OF THE NIGHT.
DAMAGING WINDS AND LARGE HAIL ARE THE MAIN THREATS.

THE THUNDERSTORMS WILL FORM IN A VERY WARM AND UNSTABLE AIRMASS
TODAY AHEAD OF A WEAK COLD FRONT THAT WILL EXTEND FROM NEAR WINNIPEG
TO MINOT TO DICKINSON LATE THIS AFTERNOON.  THE FRONT WILL MOVE EAST
ACROSS THE REGION OVERNIGHT AND EARLY MONDAY.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY
A CHANCE OF THUNDERSTORMS WILL CONTINUE INTO MONDAY...BUT NO SEVERE
WEATHER IS EXPECTED.  THE NEXT CHANCE OF THUNDERSTORMS WILL COME
THURSDAY THROUGH SATURDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED AFTER 4 PM TODAY THROUGH TONIGHT.

RIDDLE