FXUS63 KFGF 011835 AAB
AFDFGF

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GRAND FORKS ND
1235 PM CST TUE DEC 1 2009

.UPDATE...THE SOUTHERN EDGE OF THE PRECIP SHIELD IS A MIX OF RAIN
AND SNOW. COLUMN IS BELOW FREEZING...BUT MODELS INDICATE THAT THE
ICE NUCLEI FEEDING LAYER IS RELATIVELY DRY AND THUS SUPERCOOLED
WATER DROPLETS LIKELY. WILL NEED TO MENTION -FZRASN ACROSS THE
GFK-FSE-BJI AREA AND DECREASE SNOW AMOUNTS ACROSS THIS AREA AS
WELL. OTHERWISE FORECAST APPEARS ON TRACK. 

&&

.AVIATION...SFC LOW PRESSURE CENTER PASSING JUST SOUTH OF A GFK-FSE
LINE...WITH MVFR CIGS AND VSBYS...MODERATE SNOW AND INCREASING
NORTHERLY FLOW NORTH. AFT 18Z...MVFR CIGS AND VSBYS SHOULD SPREAD
SOUTHWARD THROUGH ERN ND TO VCNTY FAR AND CONTINUE SPREADING EWD
INTO NCNTRL MN. NORTHWEST WINDS OF 20G35KTS (A BIT STRONGER AT
KFAR) WILL INCREASE AFT 18Z AND SPREAD EWD FROM ERN ND INTO NWRN
MN.

&&

.PREV DISCUSSION... /ISSUED 1029 AM CST TUE DEC 1 2009/ 

DISCUSSION...MAIN CONCERNS ARE SNOW AMOUNTS ACROSS THE NORTH AND
WIND SPEEDS ACROSS THE SOUTH. 

WIND SPEEDS...AREA OF STRONG 850MB COLD AIR ADVECTION WILL MOVE
ACROSS THE SW FA EARLY AFTERNOON. 850MB WIND SPEEDS WILL BE
35-40KNTS...AND MET GUIDANCE INDICATING SFC WIND SPEEDS OF
27-28KNT SUSTAINED. THE COLD AIR ADVECTION IS VERY STRONG...SO
MIXING OF WINDS ALOFT WILL BE EFFICIENT. THUS...WILL ISSUE A WIND
ADVISORY FOR THIS AREA THROUGH THE AFTERNOON HOURS. 

SNOW AMTS...IDEAL BANDED SNOW EVENT SET UP ACROSS THE NORTHERN FA
FOR TODAY WITH STRONG SYNOPTIC LIFT AND MID-LEVEL FRONTOGENESIS
OCCURRING AT THE SAME TIME. UPSTREAM OBSERVATIONS FROM ENVIRONMENT
CANADA SHOW THAT AROUND 6 INCHES HAD FALLEN OVERNIGHT. WOULD
EXPECT SIMILAR REPORTS ACROSS OUR NORTHERN TIER COUNTIES BY THE
TIME ALL IS SAID AND DONE. CONSIDERING WHERE THE HEAVIEST BAND IS
LOCATED NOW...AND RECENT SNOW FALL REPORTS (SEE LATEST LOCAL STORM
REPORTS)...WILL NOT UPGRADE THE ADVISORY TO A WARNING. THERE MAY
BE A FEW ISOLATED REPORTS OF SNOWFALL ABOVE 6 INCHES...BUT THE
MAIN AREA OF HEAVIER SNOW SHOULD BE WITHIN THAT 5-6 INCH RANGE.
CURRENT AREA OF THE ADVISORY LOOKS GOOD (2-5 INCHES FROM DVL-GFK-
BJI). SHARP CUT-OFF FROM SNOW TO NO SNOW EXPECTED...WHICH MAKES
PREDICTING SNOWFALL AMTS ACROSS THE SOUTHERN END OF THE SNOW AREA
DIFFICULT (GRAND FORKS IS RIGHT IN THIS AREA...BUT BEST GUESS 2-4
INCHES AT THIS POINT). 

PREV DISCUSSION... /ISSUED 345 AM CST TUE DEC 01 2009/ 

TONIGHT... WRAPAROUND CLOUDS...SNOW SHOWERS AND NORTHERLY WINDS WILL 
LIKELY CONTINUE WELL INTO THE EVENING. WITH SUCH A FAST MOVING 
SYSTEM... SNOWFALL WILL TAPPER OFF FAIRLY RAPIDLY AFTER PASSAGE OF 
THE LOW. TEMPERATURES WILL STEADILY COOL THROUGH THE MIDWEEK PERIOD 
AND DROP BELOW SEASONAL NORMALS BY WEDNESDAY. 

WEDNESDAY AND THURSDAY... WRAPAROUND CYCLONIC FLOW PERSISTS OVER OUR 
AREA THROUGH MIDWEEK AS THE POLAR VORTEX INTENSIFIES OVR HUDSONS BAY 
AND A SECOND WEEK LOW PRESSURE SYSTEM DROPS SOUTHWARD FROM MANITOBA 
INTO THE DKTAS. EPISODES OF LIGHT SNOW OR FLURRIES ARE EXPECTED 
THOUGH PRECIP AMOUNTS SHOUL BE MINIMAL. 

LONG TERM [THU NIGHT - SUN]...
THE MAIN CHALLENGES IN THE LONG TERM ARE PCPN CHANCES THIS WEEKEND 
AND DAILY TEMPERATURES. THERE ARE STILL CONSIDERABLE DIFFERENCES 
BETWEEN THE MODELS...MAINLY STEMMING FROM THE HANDLING OF TROUGH 
ALONG THE CANADIAN PACIFIC COAST THU AND FRI. THE GFS AND DGEX
CONTINUE TO INDICATE THE TROUGH WILL DIG DEEPER AND INTO THE HIGH
PLAINS...WHICH WOULD INDICATE SLIGHTLY BETTER CHANCES OF PCPN THAN
THE ECMWF AND GEM. THE ECMWF AND GEM CONTINUE TO INDICATE LESS
TROUGHING WITH A CUTOFF LOW NEAR THE AMERICAN NW COAST. LEANED TO
THE DRY ECMWF AND GEM. WHAT SEEMS TO BE MORE CERTAIN ARE COLDER
TEMPERATURES LATE THIS WEEK AND INTO THE WEEKEND...WITH HIGHS
GENERALLY IN THE 20S AND UPPER TEENS. BOTH THE GFS AND ECMWF ARE
HINTING AT AN INFLUX OF ARCTIC AIR EARLY OR DURING THE MIDDLE OF
NEXT WORK WEEK...SO OVERNIGHT LOWS NEAR 0 DEGREES ARE POSSIBLE
NEXT MON AND TUE.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ038-039-049-052-
     053.

     WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR 
     NDZ006>008-014>016-024-026-027-054.

MN...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ003-029.

     WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ001-
     004>009-013>017.

&&

$$
TG