FXUS63 KBIS 082012
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
212 PM CST TUE DEC 8 2009
.SHORT TERM...TONIGHT THROUGH FRIDAY...
THE MAIN FORECAST CONCERNS IN THE SHORT TERM CONTINUE TO BE WELL
BELOW NORMAL TEMPERATURES...WINDS...AND PRECIPITATION CHANCES
OVERNIGHT. THE MODELS CONTINUE TO BE IN GOOD AGREEMENT.
CURRENTLY...TROUGH CONTINUES TO DOMINATE NORTH AMERICA WITH A DEEP
TROUGH IN THE WEST STRETCHING NORTHEASTWARD INTO THE HUDSON BAY
REGION. A POWERFUL DISTURBANCE IS MOVING OUT INTO THE CENTRAL
PLAINS RESULTING IN A DEVELOPING WINTER STORM TO OUR SOUTH.
CANADIAN HIGH PRESSURE IS MOVING INTO NORTHERN NORTH DAKOTA AND
HELPING TO CONFINE HEAVIER PRECIPITATION TO SOUTHERN PORTIONS OF THE
STATE. FRIGID ARCTIC AIR REMAINS IN PLACE ACROSS THE REGION.
PRECIPITATION CONTINUES OVER SOUTHERN PORTIONS OF THE CWA MAINLY
ALONG AND SOUTH OF I-94. EXPECT THE SNOW TO CONTINUE OVERNIGHT
TONIGHT GRADUALLY DISSIPATING WEDNESDAY MORNING FROM WEST TO EAST.
WITH THE SURFACE HIGH MOVING INTO NORTHERN NORTH DAKOTA THIS EVENING
AND THE STRONG DISTURBANCE LIFTING NORTHEASTWARD INTO THE WESTERN
GREAT LAKES A TIGHTER BUT STILL WEAK PRESSURE GRADIENT IS EXPECTED
ACROSS THE STATE ALLOWING WINDS TO INCREASE THIS EVENING INTO
WEDNESDAY MORNING. THE PRESSURE GRADIENT IS TIGHTEST CLOSED TO THE
SURFACE LOW GENERATING STRONGER WINDS OVER SOUTHEASTERN PORTIONS OF
THE CWA. FORECAST TEMPERATES ARE WELL BELOW ZERO SO A WIND CHILL
ADVISORY GOES INTO EFFECT FOR ALL OF WESTERN AND CENTRAL NORTH
DAKOTA THIS EVENING THROUGH TOMORROW MORNING. ALSO WITH THE
INCREASING WINDS AND RECENT SNOWFALL BLOWING SNOW MAY ALSO BECOME A
POSSIBILITY ESPECIALLY ACROSS THE SOUTHEAST WERE THE STRONGEST WINDS
ARE ANTICIPATED.
ANOTHER DISTURBANCE MOVES THROUGH THE REGION WEDNESDAY NIGHT INTO
THURSDAY BRINGING ANOTHER REINFORCING SHOT OF COLD AIR WEDNESDAY
NIGHT INTO THURSDAY AND ALSO INCREASING WIND SPEEDS ALONG WITH A
CHANCE OF SNOW SHOWERS. WIND CHILL HEADLINES MAY ALSO BE NEEDED ONCE
AGAIN ESPECIALLY WITH INCREASED MIXING BEHIND THE TROUGH. ANOTHER
VERY SIMILAR DISTURBANCE MOVES THROUGH THURSDAY NIGHT INTO FRIDAY
WITH ANOTHER REINFORCING SHOT OF COLD AIR.
.LONG TERM...SATURDAY THROUGH TUESDAY...
FRIGID/ARCTIC AIR IS REINFORCED SATURDAY INTO SUNDAY AS ANOTHER
ARCTIC FRONT SLIDES THROUGH SATURDAY. FULLY ANTICIPATE SOME WIND
CHILL HEADLINE(S) OCCURRING SATURDAY INTO MONDAY. IT COULD BE A WIND
CHILL ADVISORY OR WARNING OR A COMBINATION OF BOTH ACROSS THE CWA AS
APPARENT TEMPERATURES ARE EXPECTED TO RANGE BETWEEN -25F AND -40F.
WITH THE FRONT QUICKLY MOVING THROUGH SATURDAY WOULD EXPECT SOME
LIGHT SNOW SHOWER ACTIVITY ALONG AND BEHIND THE FRONT...MOSTLY FLUFF
WITH LITTLE LIQUID CONSIDERING ARCTIC SOURCE REGION. HPC
TEMPERATURES HAVE TRENDED COLDER...AND CONCUR WITH THIS THINKING
BASED ON OVERALL PATTERN. HOW LONG SATURDAYS ARCTIC SURGE LINGERS FOR
THE REMAINING PORTION OF THE EXTENDED IS STILL IN QUESTION...BUT
WOULD FAVOR A SLOW MODIFICATION RATHER THAN A QUICK RECOVERY. THE
GFS SEEMS TOO QUICK IN MODIFYING THE SURGE OF ARCTIC AIR SUNDAY
THROUGH TUESDAY AND THUS HAVE DISCOUNTED IT. THE 12Z ECMWF IS SLOWER
AND PREFERRED. MODEL GUIDANCE IS SHOWING A MODIFICATION OF THE
ARCTIC AIR MASS WEDNESDAY INTO FRIDAY.
.AVIATION...A COLDER AIR REMAINS IN PLACE WITH AN UPPER TROUGH
PASSING THROUGH TONIGHT. STILL EXPECT A CONTINUATION OF MVFR TO LOW
VFR CEILINGS PERSISTING THROUGH WEDNESDAY. OCCASIONAL MVFR
VISIBILITIES ALONG WITH SNOW FLURRIES WILL CONTINUE INTO EARLY
TONIGHT BUT SHOULD END BY 12Z WEDNESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 6 PM CST /5 PM MST/ THIS EVENING TO
NOON CST /11 AM MST/ WEDNESDAY FOR NDZ001>005-009>013-017>023-
025-031>037-040>048-050-051.
&&
$$
DC/HW/KS
