000
FXUS63 KOAX 102047
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
247 PM CST TUE DEC 10 2013

.SHORT TERM...TONIGHT THROUGH FRIDAY.

MAIN ISSUE IN THE SHORT TERM DEALS WITH FAST MOVING CLIPPER EARLY
TONIGHT.

EARLY AFTERNOON SATELLITE IMAGERY SHOWED UPPER SHORTWAVE ENERGY
DIGGING THRU MT INTO NRN WY. MOISTURE WITH THIS SYSTEM WILL BE
QUITE LIMITED AS IT PASSES THROUGH NEBR...ALTHOUGH WITH ARCTIC
NATURE TO AIRMASS ASSOCD WITH IT...ANY SNOW TO LIQUID RATIOS WILL
BE HIGH AND COULD AVERAGE AROUND 20-1 OR BETTER. ALTHOUGH THERE
WAS FAIRLY DECENT MODEL AGREEMENT IN PLACING THE HIGHER QPF FROM
THIS SYSTEM MOSTLY N-NE OF FORECAST AREA...WITH H5/H7 HEIGHT
FALLS WITH IT AT 12Z OVER WRN MT-ERN WA...SOME DIGGING IS
POSSIBLE. THUS WILL LEAN TOWARD 17Z RAP IN PLACING A SECOND AREA
OF LIGHT PRECIP FARTHER SW REACHING NWRN ZONES BY EARLY EVENING
AND NEAR THE OMAHA METRO AN HR OR TWO EITHER SIDE OF MIDNIGHT.
WITH TEMPERATURES FALLING SHARPLY BEHIND CLIPPER/ARCTIC FRONT LATE
TNGT/WED AM...WILL ADJUST HOURLIES TO ACCOUNT FOR A 14Z LOW NEAR A
MAV/MET BLEND FOR NOW. A FEW NRN COUNTIES TOUCH -20 WIND CHILLS
FOR AN HOUR OR TWO WED MORNING BUT WITH AREAL COVERAGE AND LENGTH
OF TIME OF COLDEST LIMITED...NO HEADLINES AT THIS TIME.

NEXT FAST MOVING CLIPPER WAS FORECAST TO ALREADY BRING RETURN
FLOW TO AREA BY WED EVENING...ALTHOUGH THIS ONE FORECAST TO BE
FARTHER NE AND WEAKER...SO NO PRECIP EXPECTED FOR US. COUNTING ON
ENOUGH DECOUPLING IN THE EVENING TO ALLOW READINGS TO FALL INTO
LOW/MID SINGLE DIGITS...WHICH POSSIBLY MAY NOT BE MUCH LOWER THAN
SOME AFTN TEMPS NERN ZONES. NON-DIURNAL ADJUSTMENTS WILL BE MADE
AS WELL WITH READINGS LEVELING OFF/RISING LATER WED NIGHT.
THURSDAY APPEARS AT LEAST AS MILD AS TODAY IF NOT WARMER AS H85
TEMPS ARE AT LEAST +5 DEG C WARMER THAN TDA. SNOW COVER WILL
MODERATE WARMUP AND THUS MAX TEMPS WERE KEPT ON LOWER SIDE OF
GUIDANCE...EXCEPTION MAY BE THINNER AREA OF SNOW COVER PARTS OF
WCNTRL ZONES NEAR/NW OF COLUMBUS.

WINDS SHOULD DROP OFF THU EVENING AS A WEAK FRONT SLIPS INTO NEBR
...THUS TEMPS WERE LOWERED WITH LIGHTER WINDS EXPECTED AND
RESIDUAL SNOW LINGERING. LEFT FRIDAY DRY FOR NOW AS MOISTURE
ARRIVING PER CROSS SECTIONS WAS SHALLOW UNTIL NEAR OR AFTER 00Z
SAT. THAT SAID A FASTER SOLUTION OR A BIT DEEPER LOW LEVEL
MOISTURE COULD ALLOW FOR A LIGHT PRECIP MIX TO DEVELOP SERN ZONES
LATE IN THE AFTERNOON AND THIS WILL NEED MONITORING IN LATER
FORECASTS. KEPT HIGHS MOSTLY AOB FREEZING.

.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY

MODEL CONTINUITY IS NOT GREAT IN THE EXTENDED...WITH LOW CONFIDENCE
ON TEMPERATURE SWINGS AND CHANCES FOR PRECIPITATION ASSOCIATED WITH
FAST-MOVING AND POORLY-TIMED SHORTWAVES.  AS A RESULT...KEPT
FORECAST GRIDS CLOSE TO THE BLENDS FOR NOW...UNTIL BETTER AGREEMENT
OR RUN-TO-RUN CONSISTENCY FAVORS ONE SOLUTION OVER ANOTHER.
ECMWF/GFS INDICATE SOME POTENTIAL FOR FLURRIES OR LIGHT SNOW ON
FRIDAY NIGHT AS AN UPPER-LEVEL TROUGH KICKS OUT OF THE SOUTHERN
PLAINS AND ACROSS KS/MO...WITH A NORTHERN STREAM TROUGH ALSO
DIVING OUT OF THE DAKOTAS TOWARD IA. BETTER CHANCES OF PRECIP
EXIST TO OUR EAST AS THE TWO WAVES APPROACH EACH OTHER...LIKELY
PHASING OVER THE GREAT LAKES...BUT POTENTIAL FOR LIGHT SNOW
WARRANTS SLIGHT CHANCE POPS IN OUR EAST FOR NOW. IN WAKE OF THE
TROUGH...COLD AIR WILL SPILL INTO THE AREA AGAIN FOR AT LEAST
SUNDAY...BRINGING TEMPS WELL BELOW CLIMO AT LEAST FOR THE DAY
BEFORE SOME MODERATION ARRIVES ON SUNDAY NIGHT/MONDAY. ECMWF
SOLUTION ON MONDAY/TUESDAY HAS 850MB TEMPS SEVERAL DEGREES COOLER
THAN GFS...AND ALSO IS A LITTLE MORE ACTIVE...WITH SHORTWAVES
BRINGING AT LEAST CLOUDS IF NOT VERY LIGHT PRECIPITATION ON BOTH
SUNDAY AND MONDAY...WHILE GFS REMAINS DRY. HAVE KEPT GRIDS DRY
FROM SUNDAY ONWARD...AS ANY PRECIP CHANCES THAT DO APPEAR IN MODEL
SOLUTIONS SEEM VERY LIGHT...WEAKLY FORCED...AND FAST MOVING. BOTH
CLOUDS AND SNOW COVER COULD HOLD TEMPS BACK EVEN IF MID-LEVEL
TEMPERATURES DO WARM INTO THE SINGLE DIGITS ABOVE ZERO...AND
THOUGHT BLENDS CAPTURED TEMPERATURE POTENTIAL WELL ENOUGH FOR NOW.

MAYES

&&

.AVIATION...
18Z TAFS FOR KOMA...KLNK...KOFK.

FAST MOVING CLIPPER SYSTEM COMING OUT OF THE NORTHERN HIGH
PLAINS WILL DRAG ANOTHER COLD FRONT THROUGH EASTERN NEBRASKA
BETWEEN 00Z-06Z WITH WINDS SHIFTING TO THE NORTHWEST AND
INCREASING TO 10-20KTS. MAIN BAND OF SNOW EXPECTED NORTH AND EAST
OF TAF SITES WITH MID LEVEL CIGS THROUGH 09Z THEN CLEARING.

FOBERT

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$