FXUS63 KOAX 201945
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
245 PM CDT MON SEP 20 2010
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT.
WV IMAGERY THIS AFTN SHOWING SHORTWAVE ENERGY OVER THE NRN ROCKIES
KICKING OUT CNTRL CONUS RIDGE. SFC LOW OVER THE WRN DAKOTAS CONTINUES
TO STRENGTHEN RESULTING FROM APPROACHING WAVE...AND HAS KICKED UP
WINDS TO/NEAR ADV CRITERIA OVER PORTIONS OF CNTRL/ERN NEB...THUS WILL
KEEP GOING WIND ADV IN PLACE TILL 7PM THIS EVENING. OTHERWISE PCPN
CHANCES ARE REVOLVING AROUND WRN DAKOTAS SFC LOW LIFTING
TOWARD THE UPPER MIDWEST AND DRAGGING A SFC FRONT INTO THE CNTRL
PLAINS TONIGHT. MODELS IN PRETTY GOOD AGREEMENT SFC BNDRY WILL
GET HUNG UP ACROSS NEB/IA THRU AT LEAST WED NIGHT. THUS INFLUX OF
LLVL MOIST AND PERSISTENT FORCING VIA LLVL CONVG WILL ALLOW FOR
THUNDER CHANCES INTO MID WEEK. TEMP FCST PROBLEMATIC AT BEST WITH
THIS FRONT MEANDERING AROUND. SO FOR NOW WILL KEEP HIGHS IN THE
MID/UPPER 70S NORTH WITH LOW/MID 80S SOUTH.
.LONG TERM...THURSDAY THROUGH SUNDAY.
CONFIDENCE QUITE LOW IN LATTER PARTS OF EXTENDED PDS GIVEN
SIGNIFICANT LARGE SCALE DIFFERENCES GOING INTO DAYS 6 AND 7 BWTN THE
GFS AND ECM. HOWEVER...REASONABLE AGREEMENT AMONGST THE GFS/ECM/CMC
DEPICTING STRONG COLD FROPA THURSDAY/THURSDAY NIGHT. LLVL MOIST ADV
LEADING UP TO BNDRY PUSHING THRU IS IMPRESSIVE...KI VALUES 35-40.
POPS ARE IN PLACE AT THAT TIME...SO ONLY MODEST ADJUSTMENTS MADE. AT
THIS POINT IS WHERE THE GFS/ECM DIFFERENCES STAND OUT. THE GFS
ADVERTISES NEAR ZONAL FLOW OVER THE NRN 48 WHILE THE ECM/CMC DIG AN
UPPER TROF INTO THE UPPER MIDWEST WHICH QUICKLY STRENGTHENS INTO A
CLOSED LOW. HOWEVER...THE ECM TAKES IN FARTHER SOUTH DOWN THE MS VLY
WHILE THE CMC LIFTS IT OVER THE GREAT LAKES. BOTH THE ECM/CMC THOUGH
LAY AREA OF QPF ACCOMPANYING A SECONDARY SFC BNDRY PUSHING INTO THE
CNTRL PLAINS. PREVIOUS FRIDAY NIGHT/SATURDAY FCST ALREADY HAS SLGT
POPS IN PLACE...AND AM INCLINED TO LEAVE SOME ROOM FOR ECM/CMC
SOLUTION AND TO AVOID POSSIBLE FLIP-FLOPPING. OTHERWISE TOO MANY
UNCERTAINTIES SAT NIGHT THRU MON THUS WILL LEAVE DRY. ALSO...THINK
OVERALL MAX TEMPS WILL BE AT OR SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...
TAF SITES OFK/KOMA/KLNK
18Z TAFS
GUSTY SOUTH WINDS WILL DECREASE THIS EVENING WITH SOME LOW LEVEL
WIND SHEAR POSSIBLE OVERNIGHT. COLD FRONT WILL CONTINUE TO PUSH
EASTWARD...REACHING KOFK PROBABLY BETWEEN 06Z AND 09Z...THEN TO
KOMA AND KLNK BETWEEN 12Z AND 15Z. FOR NOW KEPT CEILINGS IN THE
VFR CATEGORY BUT COULD SEE SOME MVFR CONDITIONS BEHIND THE FRONT.
DID MENTION -SHRA WITH CB CLOUD GROUPS AT KOMA AND KLNK...BUT NO
MENTION OF -TSRA FOR NOW EXCEPT AT KOFK. WILL UPDATE AS NEEDED.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR
NEZ011-012-015>018-030>034-042>045-050>053-065-066-078-088-
089.
IA...WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR IAZ043-055.
&&
$$
DEE/MILLER