FXUS63 KBIS 050933
AFDBIS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
332 AM CST SAT DEC 5 2009

.SHORT TERM...TODAY THROUGH MONDAY NIGHT...
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE BITTER COLD 
TEMPERATURES LASTING THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. 
WILL ONCE AGAIN UTILIZE AN OVERALL MODEL BLEND.  

CURRENTLY...AN UPPER LEVEL IMPULSE ROTATING AROUND THE HUDSON BAY 
UPPER LOW IS SWINGING SOUTH-SOUTHWEST ACROSS SOUTH CENTRAL CANADA 
AND TOWARDS THE NORTHERN PLAINS...WHILE ANOTHER UPPER LEVEL SHORT 
WAVE TROUGH IS SWINGING THROUGH CENTRAL MONTANA. THIS LATTER FEATURE 
HAS AN ASSOCIATED SFC TROUGH SITUATED OVER THE NORTHERN HIGH 
PLAINS/WESTERN DAKOTAS...WITH BOTH FEATURES GENERATING CLOUD COVER 
OVER THE LOCAL AREA. LIGHT RADAR RETURNS ALONG THE TROUGH AXIS IN 
NORTHERN MT WITH A FEW SITES REPORTING LIGHT SNOW. LAKE AFFECT LOW 
CIGS YESTERDAY EVENING PUSHED OFF OF LAKE SAKAKAWEA NORTHEAST INTO 
MY NORTH CENTRAL COUNTIES...WITH THESE CIGS AND AREAS OF FOG 
PERSISTING.
  
WE FEEL THE EFFECTS OF THE UPPER LEVEL IMPULSE ROTATING AROUND THE 
HUDSON BAY LOW TODAY/TONIGHT AS IT SWINGS SOUTH ACROSS THE STATE 
THIS AFTERNOON AND EVENING BRINGING CAA SOUTH INTO THE REGION. 
DAYTIME HIGHS WILL RANGE ABOUT 5 DEGREES COOLER FROM FRIDAY AS A 
RESULT. IN ADDITION...CHANCES FOR LIGHT SNOW AND PERHAPS SOME LIGHT 
ACCUMULATIONS CONTINUE TO LOOK DECENT ACROSS MY SOUTHWESTERN 
COUNTIES TODAY INTO THIS EVENING...WHEN/WHERE THE UPPER LEVEL 
SUPPORT OF THE CENTRAL MT WAVE COINCIDES WITH THE LOW LEVEL FORCING 
OF THE SFC TROUGH AS BOTH FEATURES PUSH SOUTH-SOUTHEAST. WEAK CAA 
CONTINUES TONIGHT AND INTO MONDAY NIGHT AS COLD CANADIAN HIGH 
PRESSURE SLOWLY DRIFTS SOUTH INTO THE NORTH CENTRAL CONUS. THIS WILL 
RESULT IN SUBZERO/NEAR ZERO LOWS...AND HIGHS FROM THE SINGLE DIGITS 
ABOVE TO LOW TEENS BOTH SUNDAY AND MONDAY. BOTH THE NAM(MET) AND 
GFS(MAV) INDICATE LOW CIGS ADVECTING SOUTH INTO THE FORECAST AREA 
WITH THE CAA TONIGHT AND PERSISTING AT LEAST THROUGH SUNDAY NIGHT. 
MORE OFTEN THAN NOT SCATTERED LIGHT SNOW SHOWERS/FLURRIES WILL 
ACCOMPANY THE LOW CIGS UNDER THIS SORT OF CAA PATTERN DURING THE 
WINTER...SO WILL MAINTAIN SCATTERED FLURRY MENTION TONIGHT THROUGH 
SUNDAY NIGHT...LEAVING THEM OUT DURING MONDAY FOR NOW.  

WILL ALSO MAINTAIN SLIGHT CHANCE POPS ACROSS MY FAR SOUTHERN 
COUNTIES MONDAY NIGHT TO ACCOUNT FOR A MAJOR STORM SYSTEM IMPACTING 
THE CENTRAL PLAINS. TO EARLY TO TELL HOW FAR NORTH THE PRECIPITATION 
BANDS WILL STRETCH...BUT THE GREATEST IMPACT FROM THIS STORM SHOULD 
REMAIN WELL TO OUR SOUTH. 

.LONG TERM...TUESDAY THROUGH FRIDAY
COLD TEMPERATURES REMAIN THE PRIMARY FOCUS DURING THE LONG 
TERM...MAINLY DUE TO THE INFLUENCE OF THE STRONG ARCTIC VORTEX OVER 
NORTHERN CANADA. TROUGHING EXTENDING SOUTH FROM THE LOW INTO THE 
CENTRAL US SHOULD PASS OVER THE HIGH PLAINS TUESDAY...BUT EXPECT 
MOST SIGNIFICANT WEATHER TO STAY WELL TO THE SOUTH. ONCE THE TROUGH 
EXITS...THERE ARE SOME MODEL DIFFERENCES REGARDING THE AMPLIFICATION 
AND TIMING OF THE FLOW ALOFT...BUT MODEL THICKNESSES DO SHOW A 
CONTINUATION OF COLD TEMPERATURES ACROSS THE NORTHERN PLAINS. OTHER 
THAN THE FAR SOUTH ON TUESDAY...WILL KEEP THE EXTENDED DRY DUE TO 
THE LACK OF ANY SIGNIFICANT WEATHER FEATURES...AND KEEP FORECAST 
TEMPERATURES BELOW HPC GUIDANCE...WELL BELOW NORMAL.

&&

.AVIATION...
BANDS OF CLOUDS ORIGINATING FROM LAKE SAKAKAWEA MOISTURE REMAIN 
ACROSS NORTH CENTRAL NORTH DAKOTA EARLY THIS MORNING. DENSE FREEZING 
FOG AND LOG CIGS WILL LIKELY PERSIST AT KMOT FOR AT LEAST A WHILE 
LONGER THIS MORNING BASED ON LATEST TRENDS. A WEAK FRONT WILL EXTEND 
ACROSS SW NORTH DAKOTA TODAY AND -SHSN WILL BE MOST FAVORED AT 
KDIK/KBIS.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SHORT TERM...NH
LONG TERM...BPN
AVIATION...KINNEY