FXUS63 KOAX 241141 CCA
AFDOAX

AREA FORECAST DISCUSSION...FORMAT COR
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
541 AM CST THU DEC 24 2009

.DISCUSSION...TODAY THROUGH SATURDAY.

WV IMAGERY THIS MORNING ALREADY SHOWING NRN PLAINS SHORTWAVE
MIGRATING SWD WHICH WILL EVENTUALLY PHASE WITH TX VORT MAX AND EVOLVE
INTO A DEEP CLOSED UPPER LOW ACROSS THE CNTRL PLAINS. MEANWHILE...
SCARY ARCTIC AIRMASS WAS SPILLING SWD THRU MT/WRN DAKOTAS/WY AND INTO
THE NEB PANHANDLE. SFC PRESS INCREASES AROUND 4MB LAST FEW HRS OUT
WEST ARE RESULTING IN NW WIND G30-40MPH. FOR TODAY...CONDITIONS TAKE
A TURN FOR THE WORSE IN RESPONSE TO STRENGTHENING SYSTEM OVER THE
REGION. EARLY THIS MORNING...THERE MAY BE A FEW LOCATIONS IN EXTREME
SW IA AND EXTREME SE NEB WHERE BRIEF FREEZING RAIN MAY CAUSE
ISSUES...BUT CHANGE OVER TO FROZEN WILL COME QUICK ADVANCING CAA. AS
MENTIONED...DETERIORATING CONDITIONS EXPECTED BY THIS AFTN WHEN
SNOWFALL BECOMES A BIT MORE INTENSE AND BLOWING SNOW ENVELOPS THE
CWA. FALLING TEMPS THRU TODAY COUPLED WITH NW WINDS WILL PUSH WIND
CHILL INDIES TO AROUND ZERO TWD AFTN RUSH HOUR. DOWN STREAM BLOCKING
WILL SLOW THE UPPER LOW WHEN IT MOVES INTO IA FRIDAY AFTN. BY THEN
MODELS IN GOOD AGREEMENT MID LYR QG-FRONTOGENESIS AXIS WILL SHIFT
SLIGHTLY EAST AND DISPLACE ASSOCIATED TRANSVERSE AGEOSTROPHIC ASCENT.
THIS COUPLED WITH BACKSIDE VORT ENERGY RIDING DOWN THROUGH WRN IA
WILL THEN LIKELY FOCUS BEST FORCING ORIENTED NORTH/SOUTH GENERALLY
ALONG THE MO RIVER VLY AND ALL THE WAY INTO CNTRL IA. THUS HAVE
TRENDED SNOW ACCUMULATION TOTALS AS SUCH...WITH GENERALLY 8-12
INCHES OVER SW IA...6-9 INCHES NORTHEAST NEB...AND 2-6 INCHES OVER
THE REST OF THE CWA. EXPECT SNOW/BLOWING SNOW WILL GRADUALLY TAPER
OFF SOMETIME ON SUNDAY WHEN THE SYSTEM FINALLY EJECTS EWD TO THE
GREAT LAKES/OH VLY REGION.

.AVIATION...
TAF SITES KOFK/KOMA/KLNK

06Z TAFS

IFR CONDS ARE GENERALLY EXPECTED THRU THE PERIOD. SOME DRIER AIR IS
WORKING IN FM THE NW BEHIND AN INVERTED TROF THIS MRNG AND HAS
ALLOWED FOR SOME MVFR CONDS AT BOTH LNK/OFK. THIS IS LIKELY TO CONT
AT THE OFK AND OCCASIONALLY LNK THRU THE MRNG AND INTO THE AFTN
HOURS. SPOTTY LIGHT SNOW HAS BEEN PERSISTING AT THE TAF SITES THIS
MRNG BUT SHLD GENERALLY SEE A BREAK IN PRECIPITATION THIS MRNG INTO
THE AFTN. WL START THE SN THIS AFTN AT OMA FIRST AND THEN BACK TO
THE W INTO LNK AND OFK. GIVEN THE UNCERTAINTY AS THE TIMING OF THE
HEAVIEST SN WL TEND TO KEEP THINGS IN THE IFR RANGE WITH SN THIS
EVNG AND INTO THE OVERNIGHT HOURS ALTHOUGH THERE MAY BE PERIODS OF
LIFR AT OMA/OFK FOR A TIME OVERNIGHT. NW WINDS WL INCREASE THRU THE
DAY AND LEAD TO BLSN AT THE TAF SITES OVERNIGHT FURTHER REDUCING
VSBYS THRU 12Z FRI. CONDS ARE NOT LIKELY TO IMPROVE AT THE TAF
SITES STILL SOMETIME SAT MRNG.

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR NEZ034-045-
     051>053-065>068-078-088>093.

     WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR NEZ011-012-
     015>018-030>033-042>044-050.

IA...WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR IAZ043-055-056-
     069-079-080-090-091.

&&

$$

DEE/JB