River Flood Warning 59, NWS Grand Forks, ND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
419 AM CDT SAT JUN 27 2009

.DISCUSSION...
MAIN FORECAST CHALLENGE IS PCPN. WHEN LOOKING AT THE LATEST SURFACE
ANALYSIS...AN AREA OF LOW PRESSURE IS CENTERED BETWEEN JMS AND FAR
WITH AN INVERTED TROF EXTENDING ALONG A GFK TO HCO LINE. WHEN
COMPARING THE MODELS...THE MODELS ARE IN PRETTY GOOD AGREEMENT FOR
THE SHORT TERM FORECAST ON THE PATTERN TRANSITIONS...SO ENDED UP
USING A MODEL BLEND FOR THE FORECAST. THE NAM IS DOING BETTER ON
PCPN PLACEMENT...SO PRIMARILY USED IT FOR POPS AND ENDED UP USING
EITHER FORECAST CONTINUITY OR THE ADJMAVBC GUIDANCE FOR TEMPS.

ALTHOUGH THE MAJORITY OF THE ACTUAL TSRA ACTIVITY IS NOW E OF THE
AREA...STILL LEFT WITH A LARGE RAIN AREA...WITH EMBEDDED HEAVY RAIN
SHOWERS...MOSTLY OVER THE MN SIDE. WITH THE LOW EXPECTED TO TRACK TO
THE NE TODAY...WILL STILL HAVE THE PCPN HANGING AROUND THROUGH MUCH
OF THE MORNING AND INTO THE AFTERNOON IN NW MN. THEN...A 500MB TROF
MOVES INTO ND FOR THIS AFTERNOON AND EVENING...WITH SURFACE HEATING
CREATING INSTABILITY IN CONJUNCTION WITH THE COLDER AIR ALOFT WHICH
COULD SET OFF ANOTHER ROUND OF TSRA FOR LATE THIS AFTERNOON INTO
TONIGHT ON THE ND SIDE. WITH THE COLDER TEMPS ALOFT...THESE STORMS
WILL NEED TO BE WATCHED FOR THE POTENTIAL OF HAIL AND SPC HAS
INCLUDED MUCH OF THE AREA IN A SLIGHT RISK. DID NOT PUT SVR WORDING
IN THE GRIDS OR ZONES AT THIS TIME. LATER SHIFTS WILL NEED TO
MONITOR CONVECTIVE DEVELOPMENT AND ADD SVR WORDING IF NEEDED.

FOR TONIGHT INTO SUN...THE SURFACE AND 500 MB LOW BECOME STACKED IN
S ONT...KEEPING PARTS OF NW MN IN CYCLONIC FLOW. THUS...KEPT A SCHC
FOR SHRA/TSRA IN FORECAST THROUGH SUN. SURFACE HIGH PRESSURE BUILDS
INTO THE N PLAINS AND DOMINATES THE WEATHER FOR SUN NIGHT INTO
WED...SO KEPT FORECAST DRY. THE NEXT LOW PRESSURE SYSTEM MOVES OUT
INTO THE CENTRAL PLAINS ON THU...BUT WITH BEST INSTABILITY REMAINING
S OF THE AREA AT THIS TIME...KEPT FORECAST DRY.

&&

.AVIATION...
IFR/MVFR CIGS AND VSBYS EXPECTED TO SLOWLY IMPROVE BY 18Z TODAY AS
PCPN MOVES OUT OF THE AREA. WINDS TO TURN NW AND INCREASE TO
AROUND 15 KTS...WITH GUSTS TO AROUND 25 KTS POSSIBLE.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

NG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND FORKS ND
652 AM CDT SAT JUN 27 2009

MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-281200-
WEST POLK-NORMAN-CLAY-KITTSON-ROSEAU-LAKE OF THE WOODS-
WEST MARSHALL-EAST MARSHALL-NORTH BELTRAMI-PENNINGTON-RED LAKE-
EAST POLK-NORTH CLEARWATER-SOUTH BELTRAMI-MAHNOMEN-
SOUTH CLEARWATER-HUBBARD-WEST BECKER-EAST BECKER-WILKIN-
WEST OTTER TAIL-EAST OTTER TAIL-WADENA-GRANT-TOWNER-CAVALIER-
PEMBINA-BENSON-RAMSEY-EASTERN WALSH COUNTY-EDDY-NELSON-
GRAND FORKS-GRIGGS-STEELE-TRAILL-BARNES-CASS-RANSOM-SARGENT-
RICHLAND-WESTERN WALSH COUNTY-
652 AM CDT SAT JUN 27 2009

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

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS OVER PARTS OF
EASTERN NORTH DAKOTA...NORTHWEST AND WEST CENTRAL MINNESOTA THIS
AFTERNOON AND EVENING. LARGE HAIL IS THE MAIN SEVERE WEATHER THREAT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

ISOLATED THUNDERSTORMS ARE POSSIBLE OVER PARTS OF NORTHWEST
MINNESOTA FOR SUNDAY INTO SUNDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON INTO THIS
EVENING.

NG