000
FXUS63 KBIS 201009
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
410 AM CST THU NOV 20 2008
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
AN UPPER LEVEL SHORT WAVE EVIDENT ON SATELLITE IS MOVING DOWN
ACROSS THE STATE THIS MORNING AND CAUSED LIGHT SNOW TO FALL ACROSS
PORTIONS OF SOUTH CENTRAL ND DURING THE NIGHT. AS THE SHORT WAVE
MOVES SOUTH THIS MORNING...THE HEAVIER SNOW WILL END WITH ONLY
SCATTERED FLURRIES EXPECTED AFTER 12Z. SATELLITE SHOWS A BAND OF
LOW/MID CLOUDS ACROSS WESTERN AND CENTRAL NORTH DAKOTA WHICH IS
MOVING SOUTH. EXPECT THAT BY AFTERNOON CLOUDS SHOULD CLEAR ACROSS
MOST AREAS. HIGH PRESSURE WILL COVER THE STATE IN THE AFTERNOON
PRELIMINARY TO THE NEXT SYSTEM MOVING ACROSS THE ROCKIES. THE
MODELS HAVE BEEN IN AGREEMENT OVERALL ON THE SYSTEM...BUT HAVE HAD
SOME DIFFERENCES ON DETAILS. WILL BLEND BETWEEN THE GFS AND ECMWF
FOR NOW. APPEARS THAT AS THE UPPER LEVEL SHORT WAVE MOVES THROUGH
THE ROCKY MTN RIDGE AN ELONGATED TROUGH WILL DEVELOP ON THE LEE OF
THE ROCKIES TODAY AND TONIGHT THEN MOVE INTO THE PLAINS ON FRIDAY.
APPEARS THAT AT PRESENT THE BEST CHANCE OF PRECIP WILL BE IN
SOUTHWEST ND WITH AROUND 2 INCHES OF NEW SNOW POSSIBLE FROM
DICKINSON SOUTHEAST INTO SOUTH DAKOTA WHICH IS BELOW ADVISORY
CRITERIA. THE SYSTEM SHOULD MOVE ACROSS THE FORECAST AREA FAIRLY
RAPIDLY SO SNOW SHOULD END IN THE SOUTHWEST AND SOUTH CENTRAL
FAIRLY QUICKLY FRIDAY EVENING. ANOTHER SYSTEM WILL MOVE INTO
SASKATCHEWAN BY SATURDAY EVENING BUT THE MAIN DYNAMICS AND SURFACE
LOW SHOULD BE IN CANADA SO SEE LITTLE CHANCE OF PRECIP THROUGH
SATURDAY NIGHT. IN GENERAL SHOULD SEE A WARMING TREND THROUGH
SATURDAY...STARTING BELOW NORMAL TODAY...WARMING ABOVE NORMAL BY
SATURDAY.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
GFS AND EUROPEAN NOW LOOKING SIMILAR IN EXTENDED PERIOD. PROGRESSIVE
FLOW PATTERN CONTINUES TO PROVIDE FAST MOVING SHORTWAVES IN THE
PERIOD. UPPER LOW AND ASSOCIATED COLD FRONT WILL MOVE THROUGH THE
REGION SUNDAY BRINGING GUSTY NORTHWEST WINDS AND COOL TEMPERATURES.
THIS WILL BE FOLLOWED BY A GENERAL WARMUP BY MID WEEK AS A MID LEVEL
RIDGE BRINGS A RETURN TO MILDER TEMPERATURES INTO THE 40S AND DRY
WEATHER. MADE ONLY VERY MINOR CHANGES TO CURRENT FORECAST.
&&
.AVIATION...COLD AIR STRATUS AND SNOW SHOWERS AT 10Z ARE ASSOCIATED
WITH AN UPPER LEVEL FEATURE MOVING THROUGH THE REGION. HIGH PRESSURE
OVER SASKATCHEWAN AT 10Z WILL MOVE SOUTHEAST OVER NORTH DAKOTA
DURING THE NEXT 1 TO 2 DAYS. MVFR CIGS AND VSBYS IN SNOW SHOWERS
WILL DIMINISH AND CIGS WILL BECOME GENERALLY VFR (3 TO 5 THSD) AFTER
15Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TSW/WAA
