FXUS63 KOAX 222111
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
311 PM CST WED DEC 22 2010
.SHORT TERM...TONIGHT THROUGH SATURDAY.
FORECAST FOCUS IN SHORT TERM REMAINS WINTER SYSTEM AND SNOW
AMOUNTS IN THU-FRI PD. ALTHOUGH 12Z DETERMINISTIC MODELS HAVE
SLOWED SYSTEM DOWN...IN GENERAL QPF AMOUNTS AND H7 TRACK REMAIN
THE SAME WITH MAIN H5 LOW/TROUGH WELL SOUTH OF THE CWA WITH NRN
STREAM UPPER TROUGH MAIN PCPN/WX PRODUCER FOR THE OAX CWA.
EARLY AFTN WATER VAPOR STLT IMAGERY SHOWED MAIN CIRC CENTER WITH
WEST COAST TROUGH WAS APPROACHING SRN CA ALTHOUGH H5 HGT FALLS PER
12Z UA HAD JUST MINOR 10-20M FALLS. MID LVL MOISTURE/ISENTROPIC
UPGLIDE INCREASES LATE TNGT BUT FORCING BELOW FAVORED ICE CHRYSTAL
GROWTH AREA PLUS STILL SOME DRY AIR NR H85 SO WILL JUST CARRY
FLURRIES LATE TNGT OVR N/NW 1/2 OR SO. SOME BREAKS DVLPG IN LOW
CLOUDS SW OF LNK PER 20Z VSBL STLT...BUT AM COUNTING ON CLOUDS
FILLING BACK IN THIS EVENING AND LOWS WERE KEPT ABOVE GUID WHICH
LOOKED TOO COOL BASED ON LOWS THIS MORNING AND CURRENT DWPTS. AS
NRN STREAM UPPER TROUGH APPROACHES THURSDAY...MID LVL/H7 LOW IS
FCST TO DVLP OVR SD AND TRACK SE THU NGT. USING GFS TRACK...WHICH
WAS A BLEND OF FTHR SOUTH 12Z NAM AND FTHR NE ECMWF...WOULD KEEP
HIGHER SNOW TOTALS IF NOT MOST OF THE SNOW MOSTLY N OF CWA THU AND
HIGHER SNOW AMOUNTS NE OF THE CWA THU NGT. TO ACCOUNT FOR THE
POSSIBILITY OF SNOW DEVELOPING IN WARM ADVCTN BAND/ISENTROPIC
UPGLIDE AREA OF NERN ZONES THURSDAY SE OF H7 LOW TRACK...KEPT
MODESTLY HIGH POPS GOING ACROSS THE NRN CWA ON THU. SINCE BULK OF
ANY ACCUMULATING SNOW APPEARS IT WILL HOLD OFF TILL THU NGT INTO
FRI NO HEADLINES ATTM...PLUS TOTAL AMOUNTS STILL MOSTLY MARGINAL
FOR THE OAX CWA. IN ADDITION...WINDS APPEAR THEY WILL BE
RELATIVELY MODEST/LIGHT THROUGH EVENT.
BASED ON SLOWER TRACK OF THE MID LVL WAVE...SPLIT POPS IN THU
NGT/FRI PDS TO DELAY HIGHEST POPS SRN CWA TIL AFT 06Z FRI AND TO
INCREASE THEM FRI MORNING. SOME ADDITIONAL LIGHT ACCUMULATIONS
COULD LINGER INTO FRIDAY EVENING...BUT FORCING WEAKENS SO NOTHING
SIGNIFICANT EXPECTED AFT 00Z SAT. AGAIN ENTIRE FORECAST BASED ON LTL
EFFECT ON AREA FROM MAIN LOW/SRN SYSTEM. PATCHY FZDZ POSSIBLY
COULD OCCUR PDS WHERE LIFT MIGHT DECREASE OR BE ABSENT ENOUGH TO
LOSE RH IN DENDRITIC LYR...BEFORE PCPN BEGINS THU OR AFTER MUCH
OF IT WINDS DOWN FRI AFTN AND THIS WL HAVE TO BE MONITORED...BUT
ATTM KEPT PCPN TYPE SNOW. LTL/NO CHANGES TO TEMPS THU THROUGH SAT.
IF CLOUDS CLEAR FRI NGT...WHICH ATTM WERE NOT FORECAST TO...
...LOWS COULD BE COLDER THAN GOING FORECAST WITH FRESH SNOW COVER.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
THE SYNOPTIC PATTERN IN THE EXTENDED IS FOR THE MID TROPOSPHERIC
RIDGE OVER THE ROCKIES TO SHIFT EAST INTO THE PLAINS SATURDAY NIGHT
THOUGH TUESDAY. THIS RESULTS IN COLD HIGH PRES EXTENDING FM
MINNESOTA INTO IOWA SUNDAY WITH MODERATING TEMPERATURES THRU WED.
STILL LOOKS DRY...HOWEVER MOISTURE WILL TRY TO WORK INTO THE AREA
TUESDAY-WEDNESDAY AHEAD OF A TROF PASSAGE. TEMPERATURES WILL BE
QUITE COLD SUN AND MONDAY MORNINGS WITH SINGLE DIGITS FOR LOWS AND
POSSIBLE SOME SUB ZERO TEMPS IN THE NORTHEAST IF WE LOSE THE
CLOUDS. HIGHS SUNDAY IN THE TEENS AND 20S...WITH WARMER 20S MONDAY.
STRENGTHENING SOUTHWEST WINDS SHOULD BOOST HIGHS INTO THE 30S
TUESDAY AND WEDNESDAY.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
MVFR CIGS ARE EXPECTED AT ALL TAF SITES THRU PD WITH SOME IFR CIGS
POSSIBLE ACROSS KOFK AND KOMA NEAR 12Z. LIGHT SNOW COULD DEVELOP
OVER KOFK AND KOMA NEAR 12Z AS WELL AND SO HAVE PUT IN A PROB30
GROUP WITH REDUCED VISIBILITIES FOR THURSDAY MORNING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
CHERMOK/ZAPOTOCNY/KERN