FXUS63 KOAX 110940
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
340 AM CST SAT DEC 11 2010
.DISCUSSION...
OBVIOUS FORECAST CONCERN IS DEVELOPING WINTER STORM THAT EARLY MORNING
STLT SHOWED STRONG CURL PUNCHING INTO NEBRASKA VCNTY WHERE MODELS
CLOSE OFF H5 LOW. ALTHOUGH MODELS ON THE LARGER SCALE WERE PRETTY
SIMILAR IN THEIR SOLUTIONS...UNFORTUNATELY THE MINOR DIFFERENCES
IN PLACEMENT OF TRACK OF SFC-H7 LOW AND AMOUNT OF QPF/WARM ADVCTN
ALOFT WRAPPING BACK AROUND SYSTEM THIS AFTN WERE OVER THE NRN 1/2
OF THE CWFA. THIS COULD SPELL DIFFERENCE BETWEEN 3-5 INCHES OF SNOW
AND BLIZZARD CONDITIONS PER GFS/ECMWF OR AN INCH OR TWO WITH A JUST
A MAJOR INCONVENIENCE PER NAM OVER SECTIONS OF SW IA. ATTM SINCE 00Z
NAM APPEARED TOO FAR N WITH SFC LOW TRACK AND WAS A SLIGHT N
OUTLIER W/500 MB TRACK...AND SWING SHIFT BASED UPDATE ON GFS AND
WITH 00Z ECMWF COMING IN LINE WITH THAT MODEL...THE GFS/ECMWF WERE
FOLLOWED. DID USE SOME OF THE RAPID REFRESH DATA IN TRIMMING BACK
PCPN LATER THIS MORNING/AFTN WRN ZONES HOWEVER. THUS WITH GFS AND
ESPECIALLY THE ECMWF KINKING BACK 280/285 K THETA SURFACES INTO
SWRN IA THIS AFTN...SUGGESTING A MORE PROLONGED PD OF TROWAL
GENERATED SNOWFALL...EXPANDED BLIZZARD WARNING TO JUST E OF OMAHA
AND INCREASED SNOW AMOUNTS. ALSO ADDED A TIER OF COUNTIES ON SW
SIDE OF WINTER WEATHER ADVSRY TO INCLUDE OMAHA AND THE REST OF SW
IA WHERE AN INCH OF SNOW WILL BE DRIVEN BY THE WINDS. THESE STRONG
WINDS ARE A GIVEN WITH GUSTS OF 40-45 KTS ALREADY OBSERVED ON W/SW
SIDE OF SFC LOW AND 850 MB WINDS FCST TO STRENGTHEN INTO AFTN AS
SYSTEM DEEPS A BIT MORE. THIS WILL BRING SUBSTANTIAL BLOWING SNOW
TO THOSE LOCATIONS THAT MANAGE TO PICK UP OVER AN INCH OR
TWO...WHICH IS CURRENTLY EXPECTED FM NCNTRL KNOX COUNTY TO ERN
SECTIONS OF POTTAWATTAMIE COUNTY IN WCNTRL IA. FOR SIMPLIFICATION
SOME COUNTIES IN WINTER WX ADVSRY WERE DROPPED FM WIND ADVSRY
ALTHOUGH STRONG WINDS WILL PRECEDE ACCUM SNOWS. WIND CHILL VALUES
WILL BE DROPPING AS TEMPS FALL THROUGH TNGT AND FURTHER
ADJUSTMENTS OF HEADLINES WL PROBABLY BE NEEDED TO ACCOUNT FOR
WHERE SNOW CONTINUES BLOWING COMBINING WITH DANGEROUSLY COLD WIND
CHILLS. FOR NOW JUST KEPT WINTER HEADLINES GOING THRU 06Z SUNDAY.
MAIN CHANGES BEYOND CURRENT STORM WERE TO TRIM BACK TEMPS A FEW
MORE DEGREES NERN 1/2 OR SO MON/TUE WHERE ACCUM SNOW SHOULD LIMIT
DAYTIME WARMING AND FACILITATE BETTER RADIATION/COOLING AT NGT.
WILDCARD REMAINS AMOUNT OF CLOUD COVER WITH WEAK WAVES AND
SUBSEQUENT WARM ADVCTN THROUGH TUESDAY. NO CHANGES TO WED AND BEYOND.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
IFR TO MVFR CONDITIONS ALONG WITH VERY WINDY NORTHWEST SFC WINDS ARE
EXPECTED FOR MUCH OF THE TAF PD AT ALL TAF SITES. ARCTIC FRONT
CONTINUES TO MOVE THRU THE AREA AND PASSED THRU KOFK AROUND 0730Z
TURNING PCPN OVER TO -SN WITH NW WINDS GUSTING TO AROUND 30 KTS.
EXPECT THIS FRONT TO PASS THRU KOMA AND KLNK AROUND 10-11Z THIS
MORNING. SFC WINDS SUSTAINED AT 35 KTS COULD GUST CLOSE TO 50KTS AT
TIMES LATER THIS MORNING AND INTO THE AFTERNOON HOURS. ANY SNOW AT
THE SITES WILL CREATE BLSN AND REDUCED VISIBILITIES. THE HIGHEST
SNOWFALL AMOUNTS ARE EXPECTED AT KOFK WITH LIGHT ACCUMULATIONS
EXPECTED AT KOMA. NOT EXPECTING MUCH IF ANY AT KLNK.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...BLIZZARD WARNING FROM 9 AM THIS MORNING TO MIDNIGHT CST TONIGHT
FOR NEZ034.
WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR NEZ066-078-088>093.
WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR NEZ045-051>053-067-068.
WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR NEZ030-042-043-050-
065.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NEZ016-
017-031>033-044.
BLIZZARD WARNING UNTIL MIDNIGHT CST TONIGHT FOR NEZ011-012-015-
018.
IA...BLIZZARD WARNING FROM 9 AM THIS MORNING TO MIDNIGHT CST TONIGHT
FOR IAZ043-055-056-069.
WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR IAZ079-080-090-091.
&&
$$
CHERMOK/KERN