RSS FeedsIssued by NWS Bismarck, ND
000 FXUS63 KBIS 240957 AFDBIS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BISMARCK ND 345 AM CST TUE NOV 24 2009 .SHORT TERM...TODAY THROUGH THURSDAY NIGHT... FORECAST CONCERNS IN THE SHORT TERMS REVOLVE AROUND FOG PROSPECTS EARLY THIS MORNING IN OUR FAR SOUTHEASTERN ZONES...THEN THE PASSAGE OF AN ALBERTA CLIPPER/COLD FRONT THIS EVENING WITH GUSTY WINDS...SNOW SHOWERS AND SOME MINOR ACCUMULATIONS TONIGHT INTO WEDNESDAY. THANKSGIVING DAY INTO THURSDAY NIGHT WILL BE TRANQUIL. CURRENT FOG/STRATUS LOOP NOT SHOWING MUCH AT THIS TIME IN OUR FAR SOUTHEAST ZONES...AS THE STRATUS/LOW CLOUDS ARE CONFINED MAINLY OVER FAR EASTERN NORTH DAKOTA AND WESTERN MINNESOTA. OUR LOCAL WRF AND NAM BUFKIT FOG ANALYSIS FOR KJMS SHOWS THE MOISTURE/HYDROLAPSE EITHER NEUTRAL OR DECREASING WITH HEIGHT WHICH IS NOT FAVORABLE FOR DENSE FOG. THE NAM 925MB RH FIELD CONTINUES TO MOVE THE 90 PERCENT RH AREA WELL EAST OF OUR CWA THIS MORNING WITH DRIER AIR ADVECTING IN. PERHAPS SOME PATCHY FOG MENTION BUT WILL MAKE A FINAL DECISION CLOSER TO PUBLISHING TIME. THE LATEST WATER VAPOR IMAGERY SHOWS BROAD RIDGING MOVING INTO NORTH DAKOTA THIS MORNING WITH HIGH CLOUDS INCREASING OVER SOUTH CENTRAL SASKATCHEWAN AND MOVING SOUTHEAST. THIS LEADING EDGE OF MOISTURE IS ON THE NOSE/LEFT EXIT REGION OF A 300MB 120KT JET STREAK ALONG THE WESTERN BRITISH COLUMBIA COAST. THE LEADING EDGE OF THESE CLOUDS WILL BE ARRIVING IN OUR NORTHWEST ZONES THIS MORNING AND THEN WILL CONTINUE TO INCREASE/THICKEN UP IN THE AFTERNOON AS THEY PROGRESS SOUTHEAST. MOST RECENT SURFACE ANALYSIS WOULD PLACE THE CLIPPER COLD FRONT OVER EASTERN ALBERTA AT 07Z WITH PRESSURE FALLS OCCURRING EAST AND PRESSURE RISES WEST. THE NAM AND GFS ARE IN FAIRLY GOOD AGREEMENT AND VERIFY WELL GIVEN CURRENT FRONTAL PLACEMENT. WITH THAT SAID...EXPECTING THE COLD FRONT TO SWEEP FROM NORTHWEST TO SOUTHEAST THIS AFTERNOON THROUGH THIS EVENING. THE FRONT LOOKS TO MOVE THROUGH OUR NORTHWEST ZONES (KISN) AROUND 21Z TUE...THEN ALONG A LINE FROM MINOT TO DICKINSON AROUND 00Z WEDS...THEN THROUGH BISMARCK BETWEEN 00Z AND 03Z WEDS...AND JAMESTOWN BETWEEN 03Z-06Z WEDS. THE H5 LOW MOVES INTO RUGBY BY 06Z WEDS WITH A DECENT AREA OF OMEGA/UPWARD VERTICAL MOTION. THIS COINCIDES NICELY RIGHT ALONG AND JUST BEHIND THE SURFACE FRONT WHICH WILL RESULT IN THE BEST ACCUMULATING SNOW SHOWERS OVER OUR NORTHEASTERN AND FAR EASTERN ZONES TONIGHT. UP TO 1 INCH OF SNOW ACCUMULATION IS POSSIBLE FROM BOTTINEAU SOUTHEAST TO CARRINGTON. ELSEWHERE...ISOLATED TO SCATTERED SNOW SHOWERS WITH A DUSTING OF SNOW THROUGH 12Z WEDS. NORTHWEST WINDS WILL BE GUSTY OVERNIGHT INTO WEDNESDAY MORNING...SUSTAINED BETWEEN 20 AND 25 MPH WITH GUSTS TO 35 MPH...THEN TAPERING OFF FROM WEST TO EAST WEDNESDAY AFTERNOON. MAY BE SOME BLOWING SNOW TONIGHT WITH THE GUSTY WINDS AND SNOW SHOWERS...HOWEVER NOTHING TOO EXTREME THAT WOULD WARRANT HIGHLIGHTS AT THIS TIME. WILL MENTION THE SNOW SHOWERS AND BLOWING SNOW POTENTIAL IN THE HWO FOR NOW. SKIES WILL BECOME MOSTLY CLEAR WEDNESDAY NIGHT WITH WINDS BECOMING LIGHT AS AN APPROACHING UPPER RIDGE ADVANCES INTO WESTERN NORTH DAKOTA. WARM AIR ADVECTION WITH SOME MID/HIGH CLOUDS RESULTING WILL TRAVERSE THROUGH THE FORECAST AREA THANKSGIVING DAY AND INTO THURSDAY NIGHT...BUT DRY WEATHER WILL PREVAIL. .LONG TERM...FRIDAY THROUGH MONDAY THE GFS AND ECMWF ARE COMING INTO BETTER AGREEMENT BUT BIG DIFFERENCES BETWEEN THE MODELS CONTINUE TO EXIST. THE GFS AND ECMWF DEPICT A 500 HPA RIDGE EXITING THE REGION INTO THE WESTERN GREAT LAKES FRIDAY NIGHT INTO SATURDAY. AS THIS OCCURS...ENERGY MOVING THROUGH A TROUGH IN THE NORTHERN ROCKIES SPLITS. SOME OF THE ENERGY IS FORECAST TO DROP SOUTHWARD TOWARDS THE GREAT BASIN AND THE OTHER PIECE IS SHOWN MOVING ALONG THE US/CANADIAN BORDER. THE 00 UTC GFS IS FASTER MOVING THE TROUGH AND NORTHERN DISTURBANCE EASTWARD INTO SASKATCHEWAN BY SATURDAY MORNING WHILE THE ECMWF HAS ITS ARRIVAL LATE SATURDAY INTO EARLY SUNDAY. THE UPPER LEVEL ENERGY THEN MOVES SOUTHWARD ON SUNDAY AS A NORTHERN STREAM RIDGE AMPLIFIES TO OUR WEST AND UPPER LEVEL FLOW BECOMES NORTH TO NORTHWESTERLY. BOTH MODELS ARE DRIER THAN THEY WERE WITH YESTERDAYS RUN WITH THE BULK OF THE MOISTURE REMAINING WITH THE PREVIOUSLY MENTIONED SOUTHERN STREAM DISTURBANCE. IN EITHER CASE THE SYSTEM STILL LOOKS STRONG ENOUGH TO HAVE SOME LOW POPS FOR THE WEEKEND. AFTER THE PASSAGE OF THE TROUGH THE MODELS MOVE AN UPPER LEVEL RIDGE OVER THE REGION MONDAY INTO TUESDAY WITH TEMPERATURES REMAINING ABOVE NORMAL. && .AVIATION... PATCHY FOG IS POSSIBLE IN THE KJMS AREA FROM 11Z TO 13Z THIS MORNING. OTHERWISE VFR WEATHER IS FORECAST FOR THROUGH THE AFTERNOON. EXPECT AN INCREASE IN MID AND HIGH CLOUD TODAY AS A MID LEVEL DISTURBANCE APPROACHES. AS THE TROUGH PASSES THROUGH TONIGHT IT WILL TRIGGER AREAS OF LIGHT SNOW / SNOW SHOWERS. CIGS / VSBYS SHOULD DROP TO MVFR WITH THE LIGHT SNOW. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ KS/DC/JPM
