000
FXUS63 KLBF 070936
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
336 AM CST SAT DEC 7 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 336 AM CST SAT DEC 7 2013

LIGHT SNOW CONTINUES OVER THE PINE RIDGE OF NORTHERN SHERIDAN COUNTY
EARLY THIS MORNING. MODELS IN FAIR AGREEMENT IN THE NEAR TERM AND
HAVE USED A BLEND. WILL CONTINUE SNOW OVER NORTHWEST ZONES EARLY
THIS MORNING AND THEN EXPANDING SOUTH ALONG THE EASTERN NEBRASKA
PANHANDLE BY NOON. SOUNDINGS INDICATING A HIGH SNOW RATIO WITH THE
COLDER TEMPERATURES. UPPER LEVEL JET DYNAMICS WILL PLAY A ROLE IN
THE SNOW TODAY WITH 120KT+ UPPER JET OVER HEAD AND AT 850MB LOW
LEVEL 20-30KT SOUTHERLY JET OVER THE EASTERN NEBRASKA PANHANDLE THIS
MORNING. DIVERGENCE ALOFT AT 500MB WITH WAVES MOVING OUT OF THE
UPPER TROUGH TO THE WEST SOUTHWEST OF US. INCREASING CLOUDS THROUGH
THE MORNING WITH TEMPERATURES SLOWLY RISING. FAIRLY STRONG
SOUTHEASTERLY FLOW DEVELOPING AND WILL KEEP WIND CHILL ADVISORY
GOING BUT WILL PUT VALENTINE AREA IN WARNING WITH APPARENT T`S
MEETING CRITERIA THROUGH THE MORNING. WAVE OVER EASTERN COLORADO
WILL MOVE INTO WESTERN NEBRASKA THIS EVENING WITH BEST CHANCES FOR
SNOW FALL ALONG AND EAST OF 83. SLIGHT CHANCES THIS MORNING WITH
CHANCES THIS AFTERNOON AND INCREASING TO LIKELY AND DEFINITE OVER
NORTH CENTRAL NEBRASKA TONIGHT. WITH RATIOS AROUND 18:1 ONE TO TWO
INCHES EAST OF 83 AND AN INCH OVER WESTERN NEBRASKA WEST OF 83.
LIGHT AMOUNTS OF SNOW SHOULD NOT BE TOO MUCH OF A PROBLEM WITH
BLOWING OR DRIFTING.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 336 AM CST SAT DEC 7 2013

12Z SUNDAY AND BEYOND. CROSS SECTIONAL ANALYSIS THAT IS
PERPENDICULAR TO THE THERMAL WIND CONTINUES TO INDICATE A PERIOD
OF AGEOSTROPHIC UPWARD VERTICAL VELOCITY ASSOCIATED WITH WEAK
FRONTOGENESIS...DIVERGENCE ALOFT AND THE DIRECT THERMAL JET
CIRCULATION THROUGH MID/LATE-AFTERNOON SUNDAY. MODEL QPF AMOUNTS
HOWEVER REMAIN LIGHT AS THE MOISTURE TRANSPORT AND STRONGEST
UPGLIDE IS MOSTLY DIRECTED TO THE EAST OF THE FORECAST AREA DURING
THIS TIME PERIOD. THAT BEING SAID THE 07.00Z GFS INDICATES
SATURATION DEFICITS OF ONLY A FEW MB LASTING WELL INTO THE
AFTERNOON AND IS SLIGHTLY MORE AMBITIOUS WITH MODEL QPF AMOUNTS
ACROSS THE EASTERN HALF OF THE CWA THAN COMPARED TO THE NAM. THE
07.00Z NAM ONLY PROVIDES FOR A COUPLE HUNDREDTHS OF ADDITIONAL QPF
DURING THE DAYTIME HOURS FOR THE 83 CORRIDOR AND WEST...EAST OF
THE HIGHWAY...AN ADDITIONAL 0.05" IS SUGGESTED. A COMPROMISE OF
THE TWO CAMPS YIELDS AN ADDITIONAL 0.03-0.10" OF QPF DURING THE
DAYTIME HOURS WITH THE HEAVIEST AMOUNTS EAST OF HIGHWAY 83.
PROXIMITY SOUNDINGS REVEAL A DEEP ISOTHERMAL COLUMN WITHIN A LARGE
PORTION OF THE LOWER TROPOSPHERE LYING IN THE DENDRITIC GROWTH
ZONE. EFFICIENT SNOW PRODUCTION IS ANTICIPATED WITH THIS SYSTEM AS
SNOW TO LIQUID WATER RATIOS ECLIPSE 18:1 OR HIGHER FOR THE ENTIRE
EVENT. ATTM...STORM TOTAL SNOW ACCUMULATION OF GENERALLY 1 TO 3
INCHES SEEM PLAUSIBLE WITH AGAIN THE HIGHEST AMOUNTS EAST OF
HIGHWAY 83 AND ACROSS NORTH CENTRAL NEBRASKA. THESE AMOUNTS ARE
DOWN SLIGHTLY FROM THE PREVIOUS FORECAST AS THE WAVE/UPPER ENERGY
RESPONSIBLE FOR THE SNOW WILL BE EJECTING EAST OF THE AREA
SLIGHTLY QUICKER THAN PREVIOUSLY ANTICIPATED.

HIGHS SUNDAY WILL REMAIN WELL BELOW AVERAGE DESPITE THE WAA
OCCURRING ALOFT...SINGLE DIGIT AND TEENS SHOULD PREVAIL.  CAA BEHIND
THE DEPARTING SYSTEM WILL COMBINE WITH CLEARING SKIES AND ANOTHER
ARCTIC HIGH TO PROVIDE FOR SUB-ZERO LOWS FOR MUCH OF THE AREA.  THE
WIND WON/T BE GUSTY...BUT MAY STAY ELEVATED ENOUGH TO HELP KEEP LOWS
FROM BOTTOMING OUT TOO MUCH MONDAY MORNING.  MORE OF THE SAME FOR
MONDAY...HOWEVER WEAK WAA AND MIXING MAY HELP WARM MAX TEMPERATURES
INTO THE MID TO UPPER TEENS FOR MOST LOCATIONS.

ADDITIONAL SHORTWAVE ENERGY DIVES SOUTH FROM CANADA ACROSS THE
PLAINS ON MONDAY AND AGAIN ON TUESDAY.  NEITHER IS ALL THAT
IMPRESSIVE QPF WISE...HOWEVER THE LONGER RANGE MODELS ARE HINTING AT
SOME LIGHT SNOW EARLY WEDNESDAY MORNING WITH AN APPROACHING UPPER
JET/LOW LEVEL BAROCLINIC ZONE ON THE BACKSIDE OF THE SECOND WAVE.
ALLBLEND INTRODUCED A SLIGHT CHANCE INTO THE FORECAST ACROSS OUR
NORTH...WHICH CANNOT BE DISCOUNTED FOR NOW.  TEMPERATURE WISE
THROUGH LATE NEXT WEEK...THESE QUICK HITTING SYSTEMS WILL PULL
ADDITIONAL COLD ARCTIC HIGHS ACROSS THE PLAINS...HOWEVER THE COLDEST
AIR IS SHOWN TO REMAIN TO THE EAST OF THE CWA.  TUESDAY AND
WEDNESDAY HIGHS SHOULD REBOUND BACK INTO THE 20S AND LOWER 30S FOR
MOST LOCATIONS...SAVE FAR NORTH CENTRAL NEBRASKA WHERE TEENS ARE
ANTICIPATED.  WEDNESDAY SHOULD BE THE COLDEST OF THE TWO DAYS...BUT
THEREAFTER ARCTIC HIGH PRESSURE SHIFTS TO THE EAST TOWARD THE OHIO
RIVER VALLEY WITH SOUTHWEST FLOW RETURNING TO THE CWA...HIGHS
THURSDAY AND FRIDAY SHOULD RISE ABOVE 0C FOR MOST LOCATIONS...LOWS
BOTH DAYS WILL REMAIN MAINLY IN THE TEENS

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1135 PM CST FRI DEC 6 2013

AN AREA OF MID CLOUDS WILL LIFT SLOWLY NORTH ACROSS NORTHERN
NEBRASKA OVERNIGHT...WHILE THE REMAINDER OF WESTERN NEBRASKA TO
REMAIN MOSTLY CLEAR. AS AN UPPER LEVEL SYSTEM APPROACHES THE REGION
SATURDAY...CLOUDINESS WILL INCREASE. LOWEST CLOUD BASES OF BKN040
AT KVTN BY 21Z AND KLBF BY 23Z. P6SM -SN FORECAST AT KVTN AFTER
00Z/8TH. FOR KLBF...ANY FLURRIES OR LIGHT SNOW SHOULD BE DELAYED
UNTIL AFTER 06Z/8TH.


&&

.LBF WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR NEZ004-
007-009-010-022>024-027>029-035>038-059-094.

WIND CHILL WARNING UNTIL NOON CST TODAY FOR NEZ005-006-008-025-
026.

&&

$$

SHORT TERM...POWER
LONG TERM...JACOBS
AVIATION...ROBERG