FXUS63 KFGF 160917
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
317 AM CST WED DEC 16 2009

.SHORT TERM...
THE MAIN CHALLENGE WILL BE SNOW CHANCES TONIGHT AND TEMPS. THE
LARGE SCALE PATTERN SHOWS NW FLOW OVER THE NORTHERN PLAINS...WITH
A FAIRLY STRONG SHORTWAVE MOVING ONTO THE PACIFIC COAST. A PIECE
OF THIS ENERGY WILL MOVE THROUGH THE REGION TONIGHT INTO EARLY
THU. THE CURRENT BAND OF LIGHT SNOW/FLURRIES CONTINUES TO MOVE
EAST THIS MORNING WITH TEMPS WARMING ABOVE ZERO WHERE CLOUDS ARE
THICKEST. MODELS ARE IN GOOD OVERALL AGREEMENT THIS MORNING.

FOR TODAY...EXPECT PLENTY OF SUNSHINE FOR MOST AREAS WITH THERMAL
FIELDS WARMING MUCH MORE THAN RECENT DAYS. EVEN WITH A SOUTHERLY
WIND FLOW...EXPECT THE MERCURY TO RISE MUCH MORE THAN THE PAST
WEEK...ALTHOUGH TEMPS WILL STILL REMAIN BELOW NORMAL.

FOR TONIGHT INTO EARLY THU...A SHORTWAVE AND ASSOCIATED WARM MID
LEVEL ADVECTION WILL MOVE THROUGH THE AREA. THE NORTHERN 1/3 OF
THE AREA WILL HAVE THE BEST CHANCE OF ACCUMULATING SNOW...WITH AN
INCH OR SO POSSIBLE. CAN/T RULE OUT SOMEONE GETTING 2 INCHES IN NW
MN...WITH MODERATE 700MB OMEGA AND ISENTROPIC LIFT NEAR 290K. THE
MAIN AREA OF LIFT WILL MOVE THROUGH RATHER QUICKLY...WITH ABOUT A
6 HOUR WINDOW OF ACCUMULATING SNOW MOVING FROM WEST TO EAST. THE
NORTH WILL ALSO BE NEAR THE RIGHT ENTRANCE REGION OF AN UPPER
JET...THAT SHOULD ALSO ENHANCE LARGE SCALE LIFTING. THE FAR SOUTH
MAY NOT EVEN GET ANY SNOW...BUT WILL MENTION A LOW POP HERE FOR A
BUFFER WITH LIKELY POPS IN THE NORTH. TEMPS WILL WARM TONIGHT AND
THEY COULD GET EVEN WARMER THAN CURRENT GRIDS.

FOR THU...TEMPS WILL RISE TO AROUND NORMAL FOR THE ENTIRE
AREA...AND THIS WILL FEEL EVEN WARMER GIVEN THE COLD SPELL WE HAVE
BEEN IN. THERE COULD BE SOME LINGERING MORNING LIGHT SNOW/FLURRIES
IN THE FAR NORTHEAST THROUGH 18Z AND WILL MENTION. 

ON FRI...ANOTHER SHORTWAVE WILL MOVE INTO THE REGION FROM THE
NORTH. THIS WAVE APPEARS TO BE MORE MOISTURE STARVED AND DEEP
LAYERED SATURATION IS NOT TOO IMPRESSIVE. WE WILL MAINTAIN THE LOW
POPS FOR LIGHT SNOW...BUT IT MAY ONLY BE FLURRIES WITH MINIMAL
ACCUMULATION EXPECTED. TEMPS WILL COOL SOME FROM THURSDAY WITH A
SOME COLD AIR ADVECTION BEHIND THE WAVE BY AFTERNOON.

.LONG TERM [SAT - TUE]...

THE MAIN CHALLENGES IN THE LONG TERM FORECAST ARE DAILY 
TEMPERATURES...AS WELL AS PCPN CHANCES ASSOCIATED WITH A LIKELY 
SHORTWAVE PASSAGE OVER THE WEEKEND. THE MODELS ARE IN DECENT 
AGREEMENT...EXCEPT FOR AN ODD DGEX MODEL RUN THAT IS MUCH MORE 
ROBUST AND SLOWER WITH PCPN THIS WEEKEND. THEREFORE...LEANED ON THE 
GFS AND ECMWF.

IT LOOKS LIKE THE NORTHERN PLAINS WILL REMAIN IN COLD NORTHWEST FLOW 
THIS WEEKEND AND INTO AT LEAST EARLY NEXT WEEK. AN UPPER LEVEL RIDGE 
SHOULD REMAIN IN PLACE OVER THE WESTERN US...WHILE AN UPPER LEVEL 
TROUGH SHOULD WOBBLE AROUND THE GREAT LAKES AND NORTHEASTERN US. A 
SHORTWAVE TROUGH PASSAGE MAY DEVELOP SOME LIGHT SNOW ACROSS THE 
NORTHERN PLAINS SATURDAY NIGHT INTO SUNDAY NIGHT. THE FORECASTED 
TEMPERATURES ARE 5 TO 10 DEGREES BELOW NORMAL. DEPENDING ON HOW MUCH 
FRESH SNOW IS ADDED FROM THE SHORTWAVE PASSAGE OVER THE WEEKEND...THE
ADDITIONAL SNOW COULD SIGNIFICANTLY INCREASE THE ALBEDO OF OUR
AGING SNOW COVER. THIS WOULD INCREASE THE ABILITY OF THE SNOW COVER
TO REFLECT MORE SUNLIGHT...WHICH WOULD MEAN NEEDING TO TREND LOWER
ON TEMPERATURES FOR MONDAY AND TUESDAY.

&&

.AVIATION...
EXPECT VFR CONDITIONS TODAY WITH SOUTHERLY WINDS UNDER 15 MPH.
CLOUDS WILL QUICKLY INCREASE TONIGHT WITH SNOW MOVING INTO THE
NORTHERN TAF SITES AND MVFR/IFR CONDITIONS POSSIBLE JUST AFTER 06Z.

&&

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

$$
DK/GROCHOCINSKI