974 FXUS63 KLBF 292152 AFDLBF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTH PLATTE NE 352 PM CST MON DEC 29 2014 .SYNOPSIS... ISSUED AT 351 PM CST MON DEC 29 2014 1060 MB ARCTIC HIGH PRESSURE MOVES THROUGH THE GREAT PLAINS TONIGHT THROUGH WEDNESDAY FOLLOWED BY A PERIOD OF WEST WINDS AND CHINOOK CONDITIONS. TEMPERATURES WARM TO NEAR OR SLIGHTLY BELOW NORMAL DURING THE DAY WITH SUNSHINE BUT FALL BELOW NORMAL AT NIGHT WITH THE SNOW COVER. THE FORECAST FOR SUNDAY AND MONDAY IS FOR STRONG ARCTIC HIGH PRESSURE AND COLDER TEMPERATURES. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 351 PM CST MON DEC 29 2014 SURFACE HIGH PRESSURE CONTINUES TO BUILD SOUTH INTO THE REGION. WHAT MOISTURE IS IN THE ATMOSPHERE...IS BEING LIFTED OROGRAPHICALLY THIS AFTERNOON ON NORTHEAST UPSLOPE LOW LEVEL FLOW. THIS COMBINED WITH UPPER LEVEL SUPPORT /JET DYNAMICS ENHANCING UPWARD VERTICAL MOTION/ HAS PRODUCED WIDESPREAD LIGHT SNOW ACROSS MOST OF THE AREA. AS WINDS SLOWLY BACK MORE TO THE NORTH...THE UPSLOPE COMPONENT WILL DIMINISH. UPPER LEVEL SUPPORT WILL ALSO SLOWLY WANE...SO LIGHT SNOW WILL SLOWLY DIMINISH THROUGH THE NIGHT. VERY HIGH SNOW TO LIQUID RATIOS...NEAR 25 TO 1...WILL ALLOW FOR AT LEAST ANOTHER INCH ACROSS SOUTHWEST NEBRASKA...WITH MAYBE 2 INCHES ACROSS FAR SOUTHWEST NEBRASKA YET TONIGHT. THE OTHER STORY WILL BE THE COLD TEMPERATURES. EXPECTING BELOW ZERO READINGS FOR LOWS AT ALL LOCATIONS TONIGHT...BUT THE SAVING GRACE FOR TEMPERATURES BOTTOMING OUT WILL BE CLOUD COVER. SOME BREAKS THROUGH ARE POSSIBLE...AND A FEW SPOTS WILL DROP TO NEAR 10 BELOW. THESE COLD TEMPERATURES WILL COMBINE WITH SOME WIND...AND PRODUCE WIND CHILLS OF 20 BELOW TO NEAR 30 DEGREES BELOW ZERO. LITTLE IMPROVEMENT TUESDAY...WITH HIGHS BARELY REACHING INTO THE SINGLE DIGITS. SOME WIND WILL CONTINUE TO PRODUCE DANGEROUSLY COLD WIND CHILLS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 351 PM CST MON DEC 29 2014 TUESDAY NIGHT THROUGH THURSDAY...THE COLDEST NIGHT OF THE SEASON BECKONS TUESDAY NIGHT AS 1050 MB ARCTIC HIGH PRESSURE MOVES DIRECTLY OVERHEAD AROUND 06Z. THE MODELS THEN TAKE THE HIGH INTO KS BY 12Z WEDNESDAY BUT THIS IS PROBABLY TOO FAST. THE SNOW COVER ACROSS WESTERN NEBRASKA WILL SLOW IT UP SOME. A MESO HIGH MAY EVEN FORM ACROSS THE WRN SANDHILLS AND THE PLATTE VALLEY. THE FORECAST FOLLOWS THE COLDER GUIDANCE PLUS SOME BIAS CORRECTION ACROSS PARTS OF NCNTL NEBRASKA THAT DO NOT DECOUPLE LIKE THE VALLEYS. 8 BELOW TO 24 BELOW ZERO IS THE FORECAST FOR LOWS WEDNESDAY MORNING WHICH IS ABOUT 5 DEGREES COOLER THAN THE PREVIOUS FORECAST AND THE REPRESENTS THE STOPPING POINT FOR LOWERING TEMPERATURES. LIGHT WINDS 5 MPH OR LESS DEVELOP TUESDAY EVENING BUT BECOME WEST AND SOUTHWEST AFTER MIDNIGHT AS THE HIGH MOVES OFF TO THE SOUTH. SOME AREAS WILL KEEP THE LIGHTER WINDS WHILE OTHERS WILL MIX OUT AND WARM UP SLIGHTLY. THUS THE BEST CHANCE FOR THESE LOWEST TEMPERATURES COULD BE AROUND MIDNIGHT IN THE WESTERN SANDHILLS BEFORE WINDS INCREASE. WIND CHILL READINGS OF -30F OR COLDER APPEAR LIKELY ALONG AND WEST OF HIGHWAY 83 INCLUDING CUSTER COUNTY. LATER FORECAST WILL REFINE THE WIND CHILL FORECAST. LOWS THURSDAY MORNING FALL BELOW ZERO IN THE WEST AND SOUTHWEST AS A SMALL HIGH MOVES OFF THE WRN HIGH PLAINS OF WYOMING AND THEN EAST SOUTHEAST THROUGH THE FCST AREA. THE NCNTL ZONES STAY IN A BELT OF STRONGER NORTHWEST WINDS WHICH WOULD HOLD UP LOWS IN SINGLE DIGITS. A 10 DEGREE RISE IN TEMPERATURES SHOULD DEVELOP WEDNESDAY AND THURSDAY FOR HIGHS IN THE TEENS WEDNESDAY AND THEN 20S THURSDAY. THE MODELS INDICATE GENERALLY CLEAR SKIES BOTH DAYS AND H850 TEMPERATURES RISING TO NEAR OR SLIGHTLY BELOW ZERO. THURSDAY NIGHT THROUGH MONDAY...MODERATING TEMPERATURES CONTINUE FRIDAY AND SATURDAY. THE WARMING IS VERY MODEST AS H850MB TEMPERATURES RISE INTO THE LOW SINGLE DIGITS CELSIUS. THE LATEST MODEL RUNS OF THE GEM...GFS...PARALLEL GFS...GEF AND ECM ARE IN VERY GOOD AGREEMENT DROPPING ANOTHER STRONG ARCTIC HIGH INTO THE GREAT PLAINS LATE SATURDAY. THE ECM IS FASTER AND WARMER WITH A MORE EASTERLY TRACK OF THE SFC HIGH. THE PARALLEL GFS AND GEF WERE THE SLOWEST...COLDEST AND MORE WESTERLY WITH THE TRACK OF THE SFC HIGH. THE FORECAST FOLLOWS THE MODEL CONSENSUS FOR HIGHS IN THE TEENS AND 20S SUNDAY BUT 20S AND 30S MONDAY WHICH IMPLIES THE ARCTIC HIGH MOVES OFF QUICKLY EAST. THIS IS CLOSE TO THE OPERATIONAL GFS AND ECM WHICH MOVE THE HIGH OFF QUICKLY EAST MONDAY. THE MODELS INDICATE SOME STRATUS WITH THIS ARCTIC HIGH BUT GIVEN THAT IS THE HIGH IS ON A FAST TRACK THIS SHOULD NOT HAVE MUCH IMPACT ON THE TEMPERATURE FORECAST. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 1120 AM CST MON DEC 29 2014 CONDITIONS WILL SLOWLY IMPROVE AS DRIER AIR MOVES SOUTH INTO THE AREA. CEILINGS WILL LIFT ABOVE MVFR THRESHOLDS THIS AFTERNOON ACROSS NORTHERN NEBRASKA...AND THEN LIFT TONIGHT FOR AREAS TO THE SOUTH. SCATTERED AREAS OF LIGHT SNOW MAY LINGER INTO THE EVENING HOURS ACROSS SOUTHWEST NEBRASKA. WINDS WILL BE NORTHEAST AT 10 TO 20 KTS. && .LBF WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY FROM MIDNIGHT CST /11 PM MST/ TONIGHT TO 1 PM CST /NOON MST/ TUESDAY FOR NEZ056>059-069>071. WIND CHILL ADVISORY UNTIL 1 PM CST /NOON MST/ TUESDAY FOR NEZ004>010-022>029-035>038-094. && $$ SYNOPSIS...CDC SHORT TERM...TAYLOR LONG TERM...CDC AVIATION...TAYLOR