359
FXUS63 KBIS 090931
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
329 AM CST TUE FEB 9 2010
SHORT TERM
TODAY THROUGH THURSDAY NIGHT
HIGH PRESSURE COVERS THE DAKOTAS THIS MORNING. A BAND OF STRATUS
WITH FLURRIES COVERED WESTERN NORTH DAKOTA FROM THE MONTANA
BORDER TO THE MISSOURI RIVER THIS MORNING. THE BAND HAS BEEN
NEARLY STATIONARY THE PAST FEW HOURS...ALTHOUGH THE EAST EDGE HAS
BEEN DISSIPATING SLOWLY. THE GFS AND NAM SHOW SUBSIDENCE AT 850
AND 700 MB SO THE CLOUDS SHOULD DISSIPATE SLOWLY AFTER SUNRISE.
SEE LITTLE CHANCE OF PRECIP OTHER THAN FLURRIES THIS MORNING. THE
UPPER AIR PATTERN TRANSITIONS TO ANOTHER RIDGE OVER THE ROCKIES
WITH NORTHWEST FLOW OVER THE FORECAST AREA. WEAK SHORT WAVES WILL
MOVE THROUGH THE AREA BUT NONE APPEAR STRONG ENOUGH TO GENERATE
ANY SIGNIFICANT PRECIP. WILL KEEP SCATTERED FLURRIES IN THE
FORECAST THURSDAY AS ONE OF THE STRONGER SHORT WAVES MOVE THROUGH
THE AREA...BUT IT STILL APPEARS AT THIS TIME TO BE A TRACE EVENT
AT BEST. TEMPERATURES THROUGH THE SHORT TERM WILL BE BELOW NORMAL.
LONG TERM...FRIDAY THROUGH MONDAY
MODELS AGREE ON PROGRESSIVE FLOW DOMINATING THROUGH SUNDAY WITH 500
HPA RIDGING TO OUR WEST AND NORTHWEST FLOW ALOFT OVERHEAD. AN
ALBERTA CLIPPER FEATURE DROPS INTO THE STATE FRIDAY NIGHT INTO
SATURDAY. MOISTURE APPEARS LIMITED OVER WESTERN AND CENTRAL NORTH
DAKOTA WITH THE BULK OF THE ENERGY AND MOISTURE TO OUR EAST.
STILL...A FEW SNOW SHOWERS ARE A POSSIBILITY...AND NO REASON TO
TINKER WITH PREVIOUS SLIGHT CHANCE POPS. HIGH PRESSURE WILL
REINFORCE A COLD AIRMASS IN THE WAKE OF THE CLIPPER.
BY LATE SUNDAY THE SURFACE HIGH PRESSURE WILL SHIFT TO OUR SOUTHEAST
WITH WEAK RETURN FLOW SETTING UP ACROSS THE REGION. SOUTHERLY FLOW
WILL SPREAD EASTWARD INTO MONDAY AS THE UPPER LEVEL RIDGE BEGINS TO
SHIFT EASTWARD FORCING THE NORTHWEST FLOW INTO MINNESOTA. THE GFS
HAS A WEAK DISTURBANCE TOPPING THE UPPER RIDGE INTO WESTERN NORTH
DAKOTA BY MONDAY EVENING WITH THE ECMWF BRINGING A STRONGER SHORT
WAVE TROUGH INTO THE STATE. THE CURRENT FORECAST REFLECTS THE DRIER
AND WARMER GFS SOLUTION.
AVIATION
SURFACE HIGH PRESSURE IS SLOWLY MOVING INTO NORTH DAKOTA THIS
MORNING WITH LOW CLOUDS AND LIGHT SNOW ACROSS THE WESTERN HALF OF
NORTH DAKOTA WITH GENERALLY MVFR TO IFR CEILINGS. MODELS SHOW A SLOW
EROSION OF THE LOW CEILINGS ACROSS THE REGION FROM EAST TO WEST AS
DRIER AIR IS DRAWN INTO THE STATE. LIGHT SNOW OR FLURRIES TO
CONTINUE WITH THE LOW CEILINGS THROUGH 18 UTC TUESDAY. CONDITIONS
IMPROVE QUICKLY TO IFR WITH DRIER AIR ACROSS THE REGION.
BIS WATCHES/WARNINGS/ADVISORIES
NONE.
TSW/RK/DC
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