FXUS63 KOAX 102058
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
258 PM CST FRI DEC 10 2010
.SHORT TERM...TONIGHT THROUGH MONDAY.
SFC OBS SHOWING LOW PRESSURE CENTERED OVER WRN SD STRENGTHENING IN
RESPONSE TO APPROACHING SHORTWAVE TROF CROSSING ERN MT PER WV IMAGERY
AND PROFILERS. MAIN ISSUES ARE SWD PUSH OF ARCTIC AIRMASS INTO THE
LOWER 48 TONIGHT/SAT ALONG WITH GUSTY NW WINDS AND POSSIBLE -SN.
NAM/GFS/CMC IN PRETTY GOOD AGREEMENT CAA SURGE SHOULD MAKE IT INTO
THE CWA AROUND 06Z TONIGHT AND QUICKLY SPREAD SWD THRU THE DAY SAT.
APPEARS THAT WIND ADVISORY CRITERIA WILL BE MET INITIALLY OVER THE
NRN CWA WITH FROPA...THEN REST OF CWA AROUND 12Z SAT. PRESSURE
GRADIENT PROGGED TO REMAIN TIGHT THROUGHOUT THE DAY...THUS WILL KEEP
WIND ADV HEADLINE IN EFFECT TILL LATE SAT AFTN. APPEARS THAT WIND
CHILL VALUES WILL NOT BE AN ISSUE UNTIL SAT NIGHT/SUNDAY MORNING TIME
FRAME...AND WILL LIKELY RESULT IN HEADLINES WITH VALUES EXPECTED TO
DROP TO THE 20 BELOW RANGE. FORTUNATELY...BRUNT OF SHORTWAVE FORCING
WILL PHASE WITH BEST AVAILABLE MOISTURE GENERALLY NORTHEAST OF THE
CWA. BUFKIT/COBB DATA PRETTY MUCH SHOWING CHANGE FROM -RA TO -SN WILL
BE QUICK THRU THE CWA LATE TONIGHT. -SN ACCUMULATION...AN INCH OR
LESS...IS PROBABLE AND GENERALLY ANTICIPATE THIS FROM ABOUT KNOX
COUNTY TO THE OMAHA METRO IN ERN NEB...MONONA/HARRISON/SHELBY CO IN
W-CNTRL IA. MODELS HANG ONTO BITTERLY COLD AIRMASS THRU SUNDAY.
SLIGHT WARMING THEN ON MONDAY WHEN LOW AMPLITUDE UPPER RIDGE TRIES TO
BUILD EWD INTO THE CNTRL PLAINS.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
HIGHLY AMPLIFIED UPPER FLOW STARTS OFF THE EXTENDED PERIOD WITH DEEP
TROUGH IN THE EAST AND RIDGING WEST...THEN FLOW BECOMES MORE ZONAL
DURING THE PERIOD AS SERIES OF WAVES MOVE THROUGH AND FLATTEN THE
RIDGE. SOME LIGHT PRECIP POSSIBLE AROUND TUESDAY OR WEDNESDAY AS
BAROCLINIC ZONE SETS UP OVER THE PLAINS BUT HAVE TRENDED DRY FOR NOW
BASED ON HPC GUIDANCE. TEMPERATURES LOOK TO STAY ON THE COLD SIDE
AND MAY NEED TO ADJUST DOWN IN LATER FORECASTS DEPENDING ON EXTENT
AND AMOUNT OF SNOWFALL THAT OCCURS OVER THE NEXT FEW DAYS.
AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
VFR CONDITIONS ARE EXPECTED THROUGH ABOUT 06Z. SOUTH TO SOUTHWEST
WINDS AHEAD OF A STRONG LOW PRESSURE SYSTEM WILL BRING VFR CIGS/SHRA
TO EASTERN NEBRASKA TAF SITES DURING THE EVENING. AS THE SYSTEM
MOVES EAST AFTER 06Z...A STRONG ARCTIC COLD FRONT WILL PASS KOFK
NEAR 07Z AND KOMA/KLNK BY 10Z. NORTHWEST WINDS 20 TO 30 KTS WILL
GUST TO 40KTS THROUGH 18Z BEHIND THE COLD FRONT. LIGHT SNOW COULD
ALSO ACCOMPANY THE STRONG WINDS CREATING MVFR VSBYS AT TIMES. CIGS
WILL ALSO DROP INTO THE FL010-020 RANGE BEHIND THE COLD FRONT. A
BRIEF PERIOD OF FREEZING RAIN IS POSSIBLE FOR ABOUT AN HOUR WITH THE
COLD FRONT...BUT AMOUNTS ARE EXPECTED TO BE QUITE LIGHT AT THE
SURFACE. HOWEVER MODERATE ICING IS LIKELY IN CLOUD LAYERS SFC-FL170
FROM 06Z THROUGH 18Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM 6 AM TO 6 PM CST SATURDAY FOR NEZ034-042>045-
050>053-065>068-078-088>093.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST SATURDAY FOR
NEZ011-012-015>018-030>033.
IA...WIND ADVISORY FROM 6 AM TO 6 PM CST SATURDAY FOR IAZ043-055-056-
069-079-080-090-091.
&&
$$
DEE/FOBERT/SD