FXUS63 KFGF 272119
AFDFGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
319 PM CST FRI NOV 27 2009

.SHORT TERM...MAIN CHALLENGE WILL BE DEALING WITH UPPER WAVE THAT
WILL PROPAGATE ACROSS THE REGION SAT-SAT NIGHT AND ASSOCIATED
PRECIP CHANCES. OTHERWISE THE USUAL TEMPERATURE CONCERNS. 12Z
MODELS INITIALIZED WITH MINIMAL ERRORS. MODELS IN GENERAL
AGREEMENT...BUT DIFFER WITH DETAILS SAT-SAT NIGHT. WILL USE A
BLEND TO ACCOUNT FOR DIFFERENCES. 

TONIGHT...SFC TROUGH WILL BE THROUGH THE FA THIS EVENING AND
EXPECT ONLY CIRRUS. WINDS SHOULD BECOME LIGHT (AOB 5KNTS). THIS
WILL ALLOW TEMPS TO FALL INTO THE LOW 20S GIVEN UPSTREAM DEW
POINTS AND WENT TOWARD THE LOW SIDE OF GUIDANCE. 

SAT-SAT NIGHT...MAIN CHALLENGES WITH THE UPPER TROUGH PASSAGE WILL
CONTINUE TO BE MOISTURE AVAILABILITY AND DEGREE OF FORCING.
GFS/GEM/ECMWF ARE INDICATING A BIT MORE QPF THAN PREVIOUS MODEL
RUNS WHILE THE NAM IS REMAINING RATHER DRY. DID INCREASE POPS
INTO THE CHANCE CATEGORY ACROSS THE NORTHWEST (SAT AFTERNOON) AND
EASTERN (SAT NIGHT) FA GIVEN GFS/ECMWF SOLUTIONS. GEM IS FURTHER
SOUTH WITH MAIN FORCING AND WAS DISCOUNTED. ANYWAY YOU LOOK AT
IT...WHEN MAIN FORCING ARRIVES COLUMN COOLS BELOW FREEZING AND
MAINLY FLAKES SHOULD FALL. LITTLE TO NO ACCUMULATION EXPECTED.

SUN-MON...DEEP CYCLONIC FLOW WITH MAIN ENERGY REMAINING TO THE
NORTH AND EAST OF THE FA. SHOULD BE MOSTLY DRY...COULD BE A FEW
FLURRIES ACROSS THE NE FA. TEMPERATURES WILL BE DEPENDENT ON CLOUD
COVER...BUT MAIN IDEA WILL BE NEAR TO SLIGHTLY ABOVE NORMAL
VALUES (COLDEST PORTION OF AIRMASS WILL BE EAST).

.LONG TERM (MON NIGHT-FRI)...THE MAIN CHALLENGES IN THE LONG TERM
INCLUDE DETERMINING PCPN CHANCES ASSOCIATED WITH A SURFACE LOW
PRESSURE SYSTEM THAT LOOKS LIKE WILL DEVELOP MONDAY NIGHT INTO
TUESDAY SOMEWHERE OVER SOUTH CENTRAL CANADA OR THE AMERICAN
NORTHERN PLAINS. OTHER CHALLENGES INCLUDE HOW QUICKLY THAT MID
WEEK SYSTEM WILL PUSH OUT OF THE REGION. THE MODELS HAVE
SIGNIFICANT DIFFERENCES IN TIMING AND LOCATION. THE LATEST ECMWF
AND GEM RUNS ARE MORE CONSISTENT WITH THEIR RESPECTIVE PREVIOUS
RUNS THAN THE GFS IS TO ITS PREVIOUS RUN. PLUS...THE ECMWF AND GEM
HAVE BEEN DOING DECENTLY IN THE LONG TERM...SO THIS FORECAST
LEANED ON THE ECMWF AND GEM.

THE DIFFERENCES IN TIMING AND PATH OF THE LOW PRESSURE SYSTEM EARLY 
TO MID NEXT WEEK POSE A CHALLENGE TO NAILING ANY DETAIL ON PCPN 
CHANCES. THE ECMWF/GEM/DGEX ARE FASTER SOLUTIONS THAN THE GFS BY 
ABOUT 6 HOURS. THE ECMWF TAKES THE LOW THE FARTHEST SOUTH...THE GFS 
THE FARTHEST NORTH...AND THE GEM AND DGEX SOMEWHERE IN BETWEEN. AM 
LEANING ON THE FASTER SIDE AND A ECMWF/GEM COMPROMISE IN 
LOCATION...WHICH WOULD TAKE THE LOW TO ABOUT FAR NORTHWEST MINNESOTA 
BY 12Z TUESDAY. THIS BRINGS A SLIGHT CHANCE OF SNOW TO FAR NORTHERN 
MINNESOTA DURING THE DAY ON TUESDAY...WITH MOST PRECIPITATION 
REMAINING NORTH OF THE CANADIAN BORDER. SNOW CHANCES DROP SOUTH TO 
COVER NORTHEASTERN NORTH DAKOTA AND MORE OF NORTHWEST MINNESOTA 
TUESDAY NIGHT AND WEDNESDAY IN THE WAKE OF THE PASSING SYSTEM.

TEMPERATURES LOOK LIKE THEY MAY BEGIN MILD TUESDAY MORNING...BUT 
INDICATIONS ARE THAT COLD AIR ADVECTION COULD CREATE A NON-DIURNAL 
SITUATION. SINCE IT IS SEVERAL DAYS AWAY...WE WILL HOLD OFF CREATING 
NON-DIURNAL TEMPERATURES IN THE GRIDS...BUT EXPECT THE POSSIBILITY 
OF LIMITED WARMING ON TUESDAY. TEMPERATURES THEN LOOK COLD...BUT 
NORMAL FOR THIS TIME OF YEAR...WEDNESDAY AND THURSDAY.

&&

.AVIATION...EXPECT VFR CIGS AND VSBYS WITH A WIND SHIFT TO THE
NORTHWEST FOR THE RED RIVER VALLEY BY EARLY THIS EVENING...AND
AFTER MIDNIGHT AT BJI. THE WINDS SHOULD REMAIN LIGHT. CLOUDS WILL
THICKEN AND LOWER AT DVL TOMORROW MORNING...BUT LOOK LIKE THEY
WILL REMAIN VFR UNTIL AT LEAST 18Z.

&&

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

$$
TG/GROCHOCINSKI