328 FXUS63 KBIS 281715 AFDBIS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BISMARCK ND 1215 PM CDT FRI MAR 28 2014 .UPDATE... ISSUED AT 1216 PM CDT FRI MAR 28 2014 WEAK REFLECTIVITIES TRACKING FROM WESTERN INTO CENTRAL NORTH DAKOTA. NO SIGNIFICANT ACCUMULATIONS...BUT A FEW REPORTS OF LIGHT SNOW OR FLURRIES. WILL SPREAD SOME SLIGHT CHANCE TO CHANCE POPS A BIT FARTHER EAST. LOWER CLOUDS ARE SLOW TO BREAK UP NEAR THE INVERTED TROUGH OVER WESTERN NORTH DAKOTA. THUS WILL LOWER FORECAST HIGH TEMPERATURES IN THE WEST WHERE THE SNOW AND CLOUDS WILL INHIBIT THE WARM-UP. UPDATE ISSUED AT 850 AM CDT FRI MAR 28 2014 UPDATE TO BUMP UP POPS/QPF IN THE WEST THIS MORNING. RECEIVED REPORTS OF AN INCH IN DICKINSON AND FAIRFIELD. PUSHED THE EASTERN EXTENT OF PRECIPITATION A LITTLE FARTHER EAST AS SNOW HAS REACHED NEW SALEM AREA IN MORTON COUNTY. HOWEVER...AS PRECIPITATION MOVE FARTHER EAST AWAY FROM AN INVERTED TROUGH AND INTO DRIER HIGH PRESSURE IT IS DISSIPATING QUICKLY. UPDATE ISSUED AT 633 AM CDT FRI MAR 28 2014 UPDATE FOR MINOR ADJUSTMENTS TO POPS AND TEMPERATURE TRENDS. LIGHT SNOW WILL BE CONFINED MAINLY TO WESTERN AND NORTHERN PORTIONS OF THE STATE TODAY...WITH ACCUMULATIONS UP TO A HALF INCH COMMON. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 323 AM CDT FRI MAR 28 2014 LIGHT SNOW WEST WILL HIGHLIGHT THE SHORT TERM TODAY. COOL HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE NORTHERN PLAINS TODAY. LIGHT SNOW ACROSS EASTERN MONTANA AS OF 830 UTC WILL PROPAGATE INTO WESTERN NORTH DAKOTA THROUGH 12 UTC IN ASSOCIATION WITH A WEAK BAROCLINIC ZONE ON THE WESTERN PERIPHERY OF THE HIGH. THE 00 UTC GUIDANCE SUITE IS IN AGREEMENT ON THIS AREA OF LIGHT SNOW DECREASING THROUGH THE AFTERNOON WEST OF HIGHWAY 83...WITH A SECONDARY AREA OF LIGHT SNOW ACROSS THE NORTHWEST AND NORTH CENTRAL FORMING MID TO LATE AFTERNOON WITH INCREASING LOW LEVEL WARM AIR ADVECTION AND A WEAK IMPULSE EMBEDDED WITHIN NORTHWEST FLOW ALOFT. SNOWFALL AMOUNTS ARE EXPECTED TO BE LIMITED TO ONE INCH OR LESS. EXPECT A DRY OVERNIGHT WITH LOWS IN THE 20S GIVEN THE AFOREMENTIONED LOW LEVEL WARM AIR ADVECTION TONIGHT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 323 AM CDT FRI MAR 28 2014 THE MAIN FORECAST ISSUE IN THE LONG TERM PERIOD IS THE POTENTIAL FOR A SIGNIFICANT STORM SUNDAY INTO MONDAY. AN UPPER RIDGE WILL DRIFT ACROSS THE NORTHERN PLAINS SATURDAY WITH BRISKLY SOUTHERLY SURFACE FLOW. EXPECT AFTERNOON TEMPERATURES IN THE 50S OVER MOST OF THE FORECAST AREA...A BIT COOLER IN THE TURTLE MOUNTAINS...AND SLIGHT WARMER ACROSS THE SOUTHWEST. A COLD FRONT WILL THEN MOVE THROUGH THE STATE SATURDAY NIGHT...ACCOMPANIED BY LIGHT RAIN TRANSITIONING TO A RAIN/SNOW MIX. DURING THE DAY SUNDAY...COLD CANADIAN AIR WILL BEGIN SETTLING INTO NORTHERN NORTH DAKOTA...WHILE STRONG LOW PRESSURE BEGINS TO EJECT OUT OF THE CENTRAL ROCKIES. THE BAROCLINIC ZONE AND MOST FAVORABLE FORCING IS EXPECTED TO SET UP ACROSS SOUTHERN COUNTIES...WITH PRECIPITATION MAINLY IN THE FORM OF LIGHT RAIN. ATTENTION THEN TURNS TO THE MAIN PHASE OF THE STORM SYSTEM...SUNDAY NIGHT INTO MONDAY. THE LATEST SUITE OF OPERATIONAL MODEL GUIDANCE...INCLUDING THE ECMWF/GFS/GEM...ARE ALL CONSISTENT WITH PREVIOUS DAY'S GUIDANCE. THE ECMWF CONTINUES TO FAVOR THE STRONGEST SOLUTION WITH ACCUMULATING SNOW OVER MOST OF THE FORECAST AREA (LIGHTEST NORTH AND HEAVIEST SOUTH) AND WINDS STRONG ENOUGH FOR BLIZZARD CONDITIONS SUNDAY NIGHT INTO MONDAY. THE GEM/GFS CONTINUE TO BE MORE AGGRESSIVE WITH THE COLD AIR SURGE...AND KEEP SNOW MAINLY CONFINED TO THE FAR SOUTH. THE GFS ENSEMBLE AND SREF ARE A BIT FARTHER NORTH WITH THE PRECIPITATION SHIELD...LENDING SOME CREDENCE TO THE ECMWF SOLUTION. THE SYSTEM WILL NOT REACH THE PACIFIC COAST UNTIL SATURDAY...SO AM NOT READY TO GO WITH THE WORST CASE ECMWF RIGHT NOW. HOWEVER...THE POTENTIAL FOR MODERATE TO LOCALLY HEAVY SNOW IS BECOMING MORE FAVORABLE OVER AT LEAST THE SOUTHERN 2 TO 3 TIERS OF COUNTIES SUNDAY NIGHT AND MONDAY MORNING. THERE IS STILL TOO MUCH UNCERTAINTY TO WARRANT A WATCH AT THIS TIME...AND WILL OUTLINE THE POTENTIAL THREATS IN THE HAZARDOUS WEATHER OUTLOOK. ANOTHER ROUND OF SNOW CANNOT BE RULED OUT TUESDAY NIGHT INTO WEDNESDAY...ALTHOUGH THE MODEL SPREAD THAT FAR OUT IS SUBSTANTIAL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1216 PM CDT FRI MAR 28 2014 MVFR CEILINGS AND VISIBILITIES LINGERING AROUND KISN AND EXTENDING SOUTH...BUT JUST WEST OF KDIK. LOW VFR CEILINGS AT KDIK...KBIS AND KMOT...WITH SCATTERED LIGHT SNOW TO BEGIN THE TAF PERIOD. COULD SEE PERIODS OF MVFR CEILINGS AT ALL SITES BUT KJMS THIS AFTERNOON AS LIGHT SNOW TAPERS TO FLURRIES. IMPROVING CONDITIONS EXPECTED TONIGHT AS SOUTH TO SOUTHWEST WINDS INCREASE AND LIFT LOWER CEILINGS OUT OF THE AREA. WILL NEED TO MONITOR FOR PATCHY FOG TONIGHT AS SKIES CLEAR...BUT NO MENTION OF FOG AT THIS TIME. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...TWH AVIATION...TWH