Severe Thunderstorm Warning 298, NWS Grand Forks, ND

FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
205 PM CDT TUE AUG 14 2001

AFTER FURTHER DISCUSSION...WILL GO WITH FLASH FLOOD WATCH INSTEAD OF
FLOOD WATCH AS PREV DISCUSSED IN COORD CALLS.
--------------------------
PREV AFD...

PCPN CHANCES HIGHLIGHT CHALLENGES THIS FCST.  AFTER INTER-OFFICE
COORDINATION AND COORD WITH DLH/BIS WILL ISSUE FLASH FLOOD WATCH FOR
FAR NE ND AND NW MN (GFK-BJI AND POINTS NORTH) FOR TONIGHT.

.CURRENT...
18Z SFC MAP SHOWS LOW NORTH OF WINNIPEG WITH TROUGH SOUTHWEST TO
NORTH OF MINOT TO ANOTHER WK LOW IN WCNTRL ND.  TSRA CONTINUES TO
DEVELOP ALONG THIS BOUNDARY AND MOVE EAST...MAINLY ACROSS SRN MB.
COLD FRONT LOCATED A BIT FARTHER NORTHWEST AND BEGINNING TO CATCH UP
TO BOUNDARY NORTH OF MINOT AND CAUSING INCREASED CONVECTION ON KMBX
RADAR.  00Z ETA GFK SOUNDING SHOWS FREEZING LEVEL AT 12.6 KFT.

12Z MODELS ARE IN FAIR AGREEMENT...AND LOOK AT UCAR MM5 AND WRF
SUPPORTS THEIR SOLNS OF BRINGING HEAVIEST PCPN DEVELOPING IN FAR NE
ND LATE THIS AFTN AND THEN OVER NW MN BTWN 00-06Z.

.SHORT TERM...
FRONT TO SAG SOUTHEAST ACROSS CWFA TONIGHT...REACHING FAR SE CWFA NR
12Z. EXPECT CONVECTION ALONG FRONT TONIGHT...ENDING NW ZONES BEFORE
MIDNIGHT.  HEAVIEST RAIN POTENTIAL PER DAY1 QPF AND MODEL QPF FROM
GFK-TVF-BJI-BDE ZONES...WHERE THEY HAVE HAD THE MOST RAINS THIS
SUMMER.  AFTER COORD WILL ISSUE AN FFA FOR TONIGHT FOR THAT AREA AS
THAT AREA STANDS THE BEST CHC OF WIDESPREAD 1+ INCH AMOUNTS.  SVR
POTENTIAL ALSO GOOD LATE THIS AFTN/EVE.  MSAS LI TO -10 IN CNTRL ND
WITH THETA E CONVERGENCE CONTINUING ALONG BOUNDARY TO OUR NORTHWEST.
GOOD SHEAR PROFILE AS WELL S-SW WINDS SFC-85H AND W-NW AT 70H SO
SUPERCELLS PSBL.

.LONGER TERM...
OVERNIGHT CONVECTION TO BE EXITING CWFA EARLY WED AM...THEN 50H
TROUGH TO DROP SOUTH THROUGH THE AREA 18-00Z WITH 50H TEMPS TO
-16C.  ETA SOUNDINGS SHOW CONVECTIVE TEMPS NR 70...WHICH WILL BE
REACHED. THUS WILL MAINTAIN POPS FOR TSRA WEDNESDAY PER CURRENT
ZONES.  TROUGH WILL PASS OUT OF AREA WED EVENING FOLLOWED BY HIGH
PRESSURE ON THURSDAY.

.EXTENDED...MODELS IN DECENT AGREEMENT THRU DAY 4 AND THEN SLOWLY
DIVERGE AFTER THEN. MRF SHOWING CONTINUITY WITH PREVIOUS RUN UNTIL
DAY 6 WITH LATEST RUNS DEPICTING A LESS AMPLIFIED PATTERN OVER THE
NRN TIER OF THE U.S. BY THEN. 5H LOW OVER THE NE PACIFIC MOVES ENE
INTO WRN CANADA AS TROF DROPS INTO THE ERN U.S. DAY 3 THRU 5. 5H RDG
MOVES E INTO THE NRN PLAINS BRINGING DRY AND MILD CONDITIONS FOR THE
WEEKEND. CHC FOR PCPN FRI INITIAL TROF PASSAGE AND AGAIN ON MON AS
SECOND SHRT WV MOVES THRU IN NEARLY ZONAL FLOW. BEST CHC FOR PCPN TO
BE OVER THE NE ZONES FRI AND WL BREAK UP EXTENDED TO REFLECT THIS.
NEAR NORMAL LOWS AND BLO NORMAL HIGHS TO PREVAIL THRU THE EXTENDED.

.FGF...FLASH FLOOD WATCH TONIGHT FOR EXTREME NORTHEAST NORTH DAKOTA
AND NORTHWEST MINNESOTA...FOR AREAS ALONG AND NORTH OF A GRAND FORKS
TO BEMIDJI LINE.

DR/RT