FXUS63 KOAX 232104
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
304 PM CST THU DEC 23 2010
.SHORT TERM...TONIGHT THROUGH SUNDAY.
AS HAS BEEN THE CASE LAST FEW DAYS...FORECAST FOCUS IN SHORTER
TERM REMAINS WINTER SNOW EVENT TNGT INTO MIDDAY FRIDAY AS
ORGANIZING NRN STREAM UPPER TROUGH SHARPENS A LITTLE AS IT DROPS
SE LATE TNGT/FRI. MAIN ENERGY REMAINS IN SRN STREAM WITH A
CIRCULATION CENTER ASSOCD WITH THIS SYSTEM ENTERING NWRN NM PER
AFTN STLT IMAGERY. SNOW HAS BEEN INCREASING AHEAD OF NRN PLAINS
TROUGH OVR SD AND H85/H7 LOW TRACK STILL INDICATES HEAVIEST SNOW MAY
REMAIN NE THRU E OF FCST AREA. HOWEVER...PROLONGED PD OF WARM
ADVCTN/H85-H7 FRONTOGENESIS TNGT WAS FOCUSED FM FAR NERN NEBR
INTO WRN IA. PLUS CROSS SECTIONS INDICATED A PERI0D OF UPRIGHT
INSTABILITY SHIFTING NW TO SE TNGT CLOSELY CORRESPONDING TO HIGHER
MODEL QPF FM 12Z GFS. THIS MODEL QPF FM 12Z OPERATIONAL GFS/NAM/GEM
AND ECMWF ALL INDICATED AROUND AND A LTL OVR 0.25 INCHES ALONG/E
OF MO RIVER TAPERING OFF TO AROUND A TENTH OF AN INCH AROUND OLU.
PD OF ENHANCED LIFT COULD INCREASE AMOUNTS A BIT HIGHER AND
BUMPED UP SNOW TOTALS A BIT...MAINLY ACROSS WRN IA. OTHERWISE
MADE LTL ADJUSTMENTS TO SNOW AMOUNTS. STEADIER WIDESPREAD SNOW
EXPECTED MAINLY TO SPREAD NW TO SE LATER TNGT
...03Z-06ZISH...BUT WEAK JET SEGMENT WAS ENHANCING CLOUDS AND
BRINGING PCPN RETURNS...PARTLY ALOFT...FM SCNTRL NEBR INTO SWRN
IA. THUS SNOW COULD BEGIN QUICKER SECTIONS OF THE S. MADE NO
ADJUSTMENTS TO ADVSRY AREA...ALTHOUGH DID ALTER TIMING EXTENDING
NRN IA ZONES THRU FRI AFTN. H5 THROUGH IN NRN STREAM DOESN/T PUSH INTO
NWRN IA TIL AFT 18Z THUS SOME LGT SNOW SHOULD BE ONGOING NRN
SECTIONS OF IA CWA INTO AFTN BEFORE ACCUMULATING SNOWS QUIT FM N TO
SE WITH PASSAGE OF UPPER TROUGH/ENDING OF WRM ADVCTN. RAISED LOWS
A BIT TNGT BASED ON LOWS THIS MORNING AND CURRENT/EXPECTED DWPTS.
ONLY MINOR DIURNAL CHANGES EXPECTED ON FRI...ALTHOUGH WITH SHARPER
UPPER TROUGH...ASSOCD BIT SHARPER LOW LVL TROUGH POINTS TO A BIT
MORE WIND ON WEST SIDE OF SFC TROUGH.
EXPECT LOW CLOUDS AND EVEN MID CLOUDS IN THE EVENING TO LINGER INTO
EARLY SAT THUS KEPT LOWS IN RANGE OF PREV FCST AND ON HIGH SIDE OF
GUIDANCE. WAS ALSO IN NO BIG HURRY TO DECREASE CLOUDS ON SAT AS
FCST SOUNDINGS FM GFS SUGGESTED MOCLDY MOST OF THE AREA. WITH SFC
RIDGE PUSHING DOWN MO RIVER SAT NGT...CLEARING SKIES COULD ALLOW
READINGS TO FALL TO AT LEAST MEX NUMBERS WITH FRESH SNOW AND DWPTS
FCST FM GFS/ECMWF. NAM WAS QUITE A BIT MOISTER/WARMER WITH SFC
DWPTS/TEMPS SO ATTM JUST TRIMMED FAR NERN ZONES CLOSER TO MEX
NUMBERS WITH READINGS MODERATING S/SW OF THERE.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
COLD TEMPERATURES TO MODERATE THROUGH THE EXTENDED WITH ABOVE NORMAL
TEMPERATURES BY DAYS 6 AND 7...ALTHOUGH THE TRACK OF THIS POTENTIAL
STORM WOULD SIGNIFICANTLY AFFECT THE WEATHER AND TEMPS ASSOCIATED
WITH IT. A RIDGE OF HIGH PRESSURE OVER THE WESTERN HIGH PLAINS WILL
GRADUALLY BE FLATTENED BY AN AREA OF CLOSED LOW PRESSURE THAT BREAKS
THIS RIDGE DOWN. THE GFS/ECMWF/GEM DIFFER ON THE TIMING AS TO THE
SHORTWAVE TROF MOVING THRU TUES OR WED. THE GFS IS SLOWER THAN THE
ECE AND CURRENT FCST IS SLOWER SIMILAR TO THE ECE. 12Z ECMWF
TIMING IS SIMILAR TO GFS. COULD SEE SOME FREEZING DRIZZLE WITH THIS
SYSTEM...SO HAVE A PATCHY FREEZING DRIZZLE MENTION FOR TUESDAY
MORNING.
WEDNESDAY NIGHT INTO THURSDAY...A STRONG MID LEVEL TROF MOVES
ONSHORE AND INDUCES CYCLOGENESIS OVER THE ROCKIES. THERE IS A LOT
OF UNCERTAINTY AS THIS IS DAY 7...BUT FOR NOW TRIES TO MODERATE
TEMPERATURES AS 40-50KT H85 SOUTH WINDS PULL WARM...MOIST AIR
NORTHWARD. THIS IS A LONG WAY OUT AND LOOKS LIKE A POTENT SYSTEM.
FOR NOW HAVE A CHANCE OF RAIN OR RAIN/SNOW MIX IN FOR THURSDAY WITH
HIGHS IN THE 30S AND 40S. THE SYSTEM REALLY WRAPS UP AND PULLS COLD
AIR INTO IT FOR FRIDAY. WE/LL WANT TO SEE HOW THIS STORM PANS OUT AS
WE GET CLOSER TO THE NEW YEAR.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
MVFR TO IFR CONDITIONS ARE EXPECTED AT ALL 3 TAF SITES THRU THE PD.
SNOW IS EXPECTED TO MOVE IN AFTER 02Z AND SHOULD BE PREVAILING THRU
AT LEAST 10-12Z. MAY BE SOME LINGERING FLURRIES AFTER 12Z...OR EVEN
LIGHT SNOW AT KOMA...BUT SHOULD BE WINDING DOWN BY THE END OF THE
TAF PD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
FRIDAY FOR NEZ034.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST FRIDAY
FOR NEZ045-052-053-067-068-090>093.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
FRIDAY FOR NEZ015-018-033.
IA...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
FRIDAY FOR IAZ043-055.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST FRIDAY
FOR IAZ069-079-080-090-091.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
FRIDAY FOR IAZ056.
&&
$$
CHERMOK/ZAPOTOCNY/KERN