Severe Thunderstorm Warning 115, NWS Grand Forks, ND

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
310 AM CDT SUN JUL 7 2002

FORECAST CHALLENGE CONCERNS EARLY HEAVY RAIN THREAT AND
TEMPERATURES.

MODELS IN PRETTY CLOSE AGREEMENT WITH ONLY SLIGHT BOUNDARY LOCATION
AND TIMING DIFFERENCES. OVERALL MODELS IN AGREEMENT FOR POTENTIAL
HEAVY RAIN EVENT ACROSS SOUTH HALF OF FA FOR TODAY AND TONIGHT.

FAIRLY COMPLEX SFC PATTERN EARLY THIS AM WITH E-W ORIENTED
BOUNDARIES THROUGH CENTRAL NORTH DAKOTA INTO NW MN AND FROM SW SD
INTO CENTRAL MN. UPPER LOW OVER NE PANHANDLE DIPICTED BY 00Z UA
ANALYSIS HOWEVER TOUGH TO PICK OUT FROM WATER VAPOR. THIS FEATURE TO
LIFT SLOWLY NORTHEAST AND AS IT DOES ASSOCIATED SFC LOW BECOMES
BETTER DEFINED AND MAIN LOW LEVEL BOUNDARY BECOMES ORIENTED ALONG
ND/SD BORDER. REGIONAL RADARS INDICATING UPSTREAM PRECIPITAITON
ASSOCIATED WITH UPPER LOW LIFTING SLOWLY NORTH THROUGH CENTRAL
DAKOTAS. PWATS INCREASE TO AROUND 2 INCHES AND 850MB DEWPOINTS TO
14C. AS UPPER LOW LIFTS NORTHEAST ASSOCIATED SFC LOW TO RIDE ALONG
BOUNDARY PROVIDING ADDITIONAL LOW LEVEL CONVERGENCE. 850MB
CONVERGENCES ALSO INCREASES ACROSS SOUTHERN THIRD OF ND. ALL THIS
LEADS TO GOOD POTENTIAL FOR HEAVY RAIN EVENT WITH SLOW MOVEMENT OF
MID LEVEL LOW AND LOOSE THICKNESS GRADIENT. ORIENTATION OF BOUNDARY AND
INITIATION OF DEEP CONVECTION WILL BE KEY HOWEVER AT THIS TIME IT
LOOKS LIKE SOUTHERN THIRD OF FA UNDER THE GUN AND WILL HIGHLIGHT ON
WATCH. ALSO CANNOT RULE OUT POTENTIAL FOR SEVERE AS SFC LOW TRACKS
ALONG BORDER AND 850MB WARM ADVECTION INCREASE AHEAD OF WAVE
...HOWEVER THIS WILL HINGE ON DEGREE OF SOLAR. CLOUDS TO GRADUALLY
THICKEN HOWEVER WITH MILD START WILL NOT TAKE MUCH SOLAR TO REALIZE
NUMERICAL GUIDANCE VALUES WHICH ARE AGAIN IN CLOSE AGREEMENT. WILL
HOWEVER STAY ON LOW END.

MID LEVEL FEATURE MOVES ONLY SLOWLY EAST OVERNIGHT AND EXPECT HEAVY
RAIN THREAT TO CONTINUE WITH GRADUAL IMPROVEMENT FROM WEST TO EAST
OVERNIGHT. RICH LOW LEVEL MOISTURE WILL HOLD TEMPS UP.

CLOUDS TO LINGER MONDAY AS SYSTEM EXITS REGION. BEST POTENTIAL FOR
ADDITIONAL RAINFALL LOOKS TO BE CONFINED TO SE FORECAST AREA.
OTHERWISE EXPECT GRADUAL IMPROVEMENT FROM WEST TO EAST.

BREAK WILL BE SHORT LIVED AS CURRENT PAC NW UPPER LOW TRACKS ACROSS
SOUTH CANADIAN PROVINCES. ASSOCIATED SFC FEATURE WILL BRING CHANCE
OF PCPN BACK INTO FORECAST FOR TUESDAY AND WEDNESDAY.

.FGF...FLOOD WATCH FULL CWFA SUN AND MON.
VOELKER