Severe Thunderstorm Warning 72, NWS Grand Forks, ND

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
255 AM CDT TUE JUN 13 2000

FORECAST CHALLENGE CONCERNS SVR THREAT ALONG WITH ADDNL PCPN AND
HYDRO.

ONGOING CONVECTION CONTINUING TO POSE FLASH FLOOD THREAT OVR SMALL
PART OF NE ND WHERE FFW IN EFFECT TIL MORNING. CENTRAL NODAK MCS
MOVING INTO SE ND ATTM. THERE HAD BEEN A GENERAL DECREASE IN
INTENSITY HOWEVER WILL NEED TO MONITOR AS MCS MERGES WITH OUTFLOWS
OVER UNWORKED/UNSTABLE AIRMASS OVR SOUTHEAST NODAK. OTHER THAN THE
THREE COUNTIES COVERED IN THE FFW REMAINDER OF FA HAS NOT SEEN SIG
RAINFALL AND CONVECTIVE LINE FAIRLY NARROW AND PROGRESSIVE SO ATTM
NO ADDNL MAJOR FLOODING EXPECTED IN THE SHORT TERM.

NOT MUCH RELIEF THOUGH AS SHARP MID LEVEL TROUGH ENTERS FA AND
DEEPENING SFC LOW LIFTS NORTHEAST ACROSS FA THROUGH PERIOD. AS LOW
APPROACHES MAIN H8 THETA-E RIDGE/WAA SHIFTS EAST INTO MN WITH SPOKE
ACROSS NORTHERN NODAK. THIS AREA (N ND) ALSO IN DEEPER INTEGRATED RH
AND WILL LIKELY BE FOCUS FOR HEAVIEST RAINFALL IN DEFORMATION ZONE.
NORTHERN NODAK HAS HAD LITTLE RAINFALL SO FAR THIS SEASON AND DRY
GROUND SHOULD BE ABLE HOLD QUITE A BIT OF RAINFALL. AIRMASS REMAINS
SOMEWHAT UNSTABLE WITH LI'S BLO ZERO AND PWATS CONTINUE AROUND 1.5
INCH SO IMBEDDED TSRA WILL CONTINUE. AS A RESULT TSRA/RA TO CONTINUE
DURING DAY. CONCERNING SVR THREAT BY LATE AFTERNOON SFC LOW TO BE
OVR EAST CENTRAL NODAK WITH WARM FRONT ACROSS NORTHERN MN AND COLD FRONT
ALONG DAKOTAS MN BORDER. GREATEST INSTABILITIES AND CAPES FROM OUR
SOUTHEAST COUNTIES SOUTHWARD HOWEVER AGREE WITH SPC THAT SVR THREAT
WILL HINGE IN PART ON AMOUNT OF SFC HEATING DURING DAY. WITH
BOUNDARY AND TRIPLE POINT OVR FA WILL CONTINUE WITH SVR THREAT ON AM
HWO.

UPPER LOW CLOSES OFF OVR FA OVERNIGHT WITH SFC LOW LIFTING TO NEAR
INL BY 12Z. H8 THETA-E SPOKE AND BAND OF DEEP INTEGRATED RH ROTATES
SOUTHWARD THROUGH FA SO WRAP AROUND PCPN TO CONTINUE. OTHER THAN
ABOVE MENTIONED COUNTIES THAT HAVE BEEN DELUGED OVER NIGHT REMAINDER
OF REGION SHOULD BE ABLE TO HANDLE ADDNL PCPN WITH THIS EVENT SO NO
FLOODING HEADLINES ANTICIPATED.

WINDS TO REV UP FROM WEST TO EAST LATE TUESDAY NIGHT AND WEDNESDAY
IN TIGHT GRADIENT BEHIND SFC LOW. WITH UPPER FLOW BECOMING
UNIDIRECTIONAL AT 30 TO 40KTS AND CAA WIND ADVISORY CRITERIA WILL
LIKELY BE MET IF CURRENT SCENARIO PANS OUT. AS LOW LIFTS OUT -RA TO
END FROM WEST TO EAST HOWEVER ANY BREAKS IN CLOUD COVER TO BE
CONFINED TO FAR WESTERN ZONES. WITH CAA/CLOUDS MUCH COOLER READINGS
EXPECTED.

.FGF...FLASH FLOOD WARNING IN EFFECT FOR EDDY...NELSON AND GRAND
FORKS COUNTIES UNTIL 6 AM.

VOELKER