FXUS63 KBIS 270947
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
345 AM CST FRI NOV 27 2009
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT...
THE MAIN FORECAST PROBLEM IN THE SHORT TERM FORECAST DEALS WITH
PRECIPITATION CHANCES WITH AN UPPER LEVEL SHORTWAVE TROUGH MOVING
ACROSS THE NORTHERN PLAINS TONIGHT AND SATURDAY.
CURRENTLY...A SURFACE LOW WAS CENTERED OVER SOUTHEASTERN
SASKATCHEWAN...WITH A WARM FRONT EXTENDING SOUTHWARD FROM THE LOW
AND A COLD FRONT EXTENDING WESTWARD FROM THE LOW. THE WARM FRONT WAS
APPROACHING THE MINOT/BISMARCK AREA...AND THE COLD FRONT EXTENDED
WESTWARD ALONG THE CANADIAN/MONTANA BORDER. THE WARM FRONT IS
EXPECTED TO MOVE EAST TODAY AS THE LOW MOVES SOUTHEAST ACROSS NORTH
DAKOTA AND INTO EASTERN SOUTH DAKOTA BY THIS EVENING. MEANWHILE THE
TRAILING COLD FRONT WILL FOLLOW THE WARM FRONT ACROSS THE STATE AS
WELL. THUS SOUTHWEST/WEST WINDS WILL CONTINUE BRINGING WARM AIR TO
THE STATE TODAY...THEN NORTHWEST WINDS BEHIND THE COLD FRONT WILL
BRING SOME COLD ADVECTION.
AN UPPER LEVEL SHORTWAVE TROUGH FOLLOWS WELL BEHIND THE SURFACE COLD
FRONT...REACHING NORTHWESTERN NORTH DAKOTA SATURDAY MORNING AND
EXITING THE SOUTHEAST CORNER OF THE STATE SATURDAY NIGHT. EXPECTING
A CHANCE OF LIGHT PRECIPITATION IN THE FORM OF RAIN OR SNOW SHOWERS
NORTHWEST TONIGHT AND SPREADING TO CENTRAL NORTH DAKOTA SATURDAY AND
SATURDAY EVENING.
EXPECTING ANOTHER WARM DAY TODAY WITH MID 40S NORTHERN NORTH DAKOTA
AND 50S SOUTH. MAINLY HIGH CIRRUS CLOUDS TODAY...WITH INCREASING
CLOUDS TONIGHT AND SATURDAY. COOLER ON SATURDAY AFTER THE COLD
FRONTAL PASSAGE WITH HIGHS FROM THE MID 30S NORTH TO LOWER 40S SOUTH.
MILD PACIFIC AIR REMAINS OVER THE DAKOTAS SUNDAY AS AN UPPER LEVEL
RIDGE BUILDS IN BEHIND SATURDAY'S UPPER LEVEL SHORTWAVE TROUGH.
SLIGHTLY ABOVE AVERAGE TEMPERATURES SUNDAY WITH HIGHS FROM THE MID
30S TO LOWER 40S UNDER PARTLY CLOUDY SKIES.
.LONG TERM...MONDAY THROUGH THURSDAY...
THE GFS AND ECMWF CONTINUE TO AGREE ON A MAJOR SHIFT IN THE WEATHER
PATTERN DURING THIS PERIOD.
THE LONG TERM BEGINS WITH UPPER LEVEL RIDING ACROSS THE WESTERN
UNITED STATES AND A TROUGH IN THE GULF OF ALASKA. THE 500 HPA RIDGE
PUSHES EAST DURING THE DAY ON MONDAY WITH SEVERAL DISTURBANCES
TOPPING THE WESTERN RIDGE OUT OF THE GULF OF ALASKA TROUGH. A STRONG
DISTURBANCE EJECTING OUT OF THE TROUGH BEGINS TO PUSH DOWN THE RIDGE
LATE MONDAY AS A STRONG COLD FRONT DIVES SOUTHWARD OUT OF CANADA.
THE COLD FRONT MOVES THROUGH NORTH DAKOTA LATE TUESDAY WITH GUSTY
WINDS. THE DISTURBANCE CONTINUES TO DROP SOUTHWARD DURING THE DAY
TUESDAY CARVING OUT A TROUGH OVER THE CENTRAL UNITED STATES. THE
OPERATIONAL GFS CONTINUES TO BE AN OUTLIER AS ITS ENSEMBLE MEMBERS
AND THE ECMWF DEVELOP A CLOSED LOW IN THE VICINITY OF THE GREAT
LAKES BY THURSDAY LEAVING NORTH DAKOTA SANDWICHED BETWEEN RIDGING
ALONG THE WEST COAST AND A DEEP TROUGH COVERING THE EASTERN TWO
THIRDS OF THE COUNTRY. MULTIPLE DISTURBANCES CAN BE EXPECTED TO MOVE
THROUGH THE FLOW KEEPING A CHANCE OF PRECIPITATION IN THE FORECAST
EACH DAY...WITH THE BEST CHANCE WEDNESDAY WITH THE ARRIVAL OF THE
MAIN UPPER LEVEL ENERGY.
MUCH COLDER AIR DROPS INTO THE STATE BEHIND THE LATE TUESDAY COLD
FRONT. THIS REPLACES THE ABOVE NORMAL TEMPERATURES FROM NOVEMBER AND
BRINGS THE COLDEST AIR OF THE SEASON SO FAR...THOUGH STILL NOT
BITTERLY COLD WHEN COMPARED TO NORMALS.
&&
.AVIATION...
VFR WEATHER THROUGH THE TAF FORECAST PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JV
LONG TERM...DC/JPM
AVIATION...JPM
