Severe Thunderstorm Warning 77, NWS Grand Forks, ND

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
205 PM CDT WED JUN 20 2001

FORECAST CHALLENGE IS EVENING CONVECTIVE THREAT THEN SHIFTS TO LONG
AWAITED WARMUP. WATER VAPOR LOOP SHOWING ONE WAVE MOVING INTO
WESTERN NORTH DAKOTA AND A SECOND WAVE DROPPING SOUTH OVER WESTERN
ONTARIO. BOTH ETA AND AVN MATCHED THESE FEATURES WELL WITH LITTLE
DIFFERENCE SEEN EITHER AT THE SFC OR H5...SO BASICALLY FOLLOWED A
COMPROMISE FOR THE FORECAST DETAILS. CONVECTION CURRENTLY FIRING
AHEAD OF WAVE DROPPING INTO WESTERN ND ALONG WEAK SFC MOISTURE
CONVERGENCE AREA FROM KMOT TO KGFK TO KBIS. LOWEST LI'S ON MSAS
STILL SHIFTING INTO SOUTHEAST ND ALONG THIS MOISTURE CONVERGENCE
LINE...SO STILL EXPECTING THUNDERSTORMS TO FIRE ACROSS THIS AREA AS
WELL.

PREVIOUSLY MENTIONED H5 SHORT WAVE DROPS THROUGH THE AREA ON THE
NORTHWEST FLOW OVERNIGHT. H85-7 Q VECTOR CONVERGENCE AND H7 OMEGA
WHICH PEAKS ACROSS SOUTHERN AREAS BETWEEN 18Z AND 00Z DIMINISHES
QUICKLY AFTER 00Z. LI AND SHOWALTER INDICES ALSO PEAK DURING THE
AFTERNOON AND QUICKLY TAPER OFF WITH LOSS OF DAYTIME HEATING. SO AS
WAS THE CASE TUESDAY...CONVECTION SHOULD TAPER OFF BY SUNSET. H85-5
Q VECTOR DIVERGENCE AND SFC HIGH NOSING INTO WESTERN ND BY 12Z THU
WILL BRING A DECREASE IN CLOUD COVER FROM NW TO SE. WILL KEEP CLOUD
COVER IN LONGEST ACROSS WEST CENTRAL MN...WHICH WILL HELP TO KEEP
TEMPS WARMEST ACROSS THESE AREAS. WITH WIND SPEEDS FALLING OFF AND
CLEARING WORKING IN...MAY BE SOME PATCHY FOG. KTVF AND KCKN DIPPED
TO A QUARTER MILE THIS MORNING...BUT WERE THE ONLY SITES THAT
REPORTED FOG. AGAIN WOULD EXPECT ANY FOG TO BE MORE ISOLATED AND
WILL NOT MENTION AT THIS TIME.

BUILDING RIDGE ON THURSDAY WITH H5 COLD POOL FINALLY SHIFTING TO THE
EAST. EXPECT PLENTY OF SUNSHINE FOR MOST AREAS...WITH SOME AFTERNOON
CU DEVELOPMENT AGAIN OVER FAR EASTERN ZONES. MODEL SOUNDINGS GIVE
THIS AREA A CONVECTIVE TEMP IN THE MIDDLE 60S...WHICH WILL EASILY BE
REACHED. THICKNESSES AND H85 TEMPS BEGIN TO RISE SLIGHTLY DURING THE
DAY THU...SO RISING TREND ON TEMPS STILL LOOKS GOOD. BETTER H85 WAA
TAKES PLACE THU NIGHT INTO FRI. SFC HIGH SHIFTS INTO THE CENTRAL
PLAINS ON FRI...SETTING UP WEAK RETURN FLOW AND ANOTHER WARM DAY.

MODEL TRENDS CONTINUE TO BE VERY CONSISTENT IN THE EXTENDED PERIODS.
THE FINER DETAILS ARE ALSO BECOMING MORE CLEAR WITH POSSIBILITY OF
SEVERE WEATHER SUNDAY NIGHT AND MONDAY. UNTIL SATURDAY...REGION WILL
BE IN FINE SHAPE UNDER 50H RIDGING WITH A CONTINUED BREAK IN THE
PRECIPITATION AND WARMER TEMPERATURES. FIRST RIDGE RIDER WILL MOVE
INTO SOUTHERN CANADA ON SATURDAY. THIS WILL INITIATE CYCLOGENESIS
IN MONTANA DYNAMICS IN PLACE FOR A SLIGHT CHANCE OF A THUNDERSTORM
IN THE DVL AREA SATURDAY. WITH THE 850MB FLOW...WEAKENING COMPLEX
WILL ROLL INTO THE RED RIVER VALLEY SATURDAY NIGHT AND SUNDAY
MORNING. DURING THE AFTERNOON ON SUNDAY IS WHEN THINGS WILL REALLY
GET GOING OUT WEST. A PEEK AT THE 850MB TEMPS SHOW DECENT CAP WILL
BUILD INTO THE SOUTHERN RED RIVER VALLEY LEAVING THE AREA
PRECIPITATION FREE DURING THE DAY...WITH THE ONLY CHANCE OF
PRECIPITATION ON THE FRINGE OF THE CAP ACROSS THE DVL AREA AND
EXTREME NORTHERN RED RIVER VALLEY. THE MAIN SHOW WILL HOLD OFF UNTIL
LATE SUNDAY NIGHT INTO MONDAY...WHEN CAP FINALLY WEAKENS AND 60KT
MID-LEVEL FLOW WORKS INTO THE AREA. STIL2L COULD BE SOME SHOWERS LEFT
OVER ON TUESDAY...BUT WILL BE OPTIMISTIC FOR NOW.

.FGF...NONE.

GODON/BRAZZELL