FXUS63 KOAX 011921
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
221 PM CDT MON NOV 1 2010
.SHORT TERM...TONIGHT THROUGH THURSDAY.
WV IMAGERY REVEALING LARGE SCALE FLOW CONSISTING OF TWO STRONG CLOSED
LOWS...ONE ANCHORED OVER THE ALASKAN GULF AND THE OTHER CENTERED
OVER NOVA SCOTIA...WITH RIDGE ACROSS CNTRL CANADA. OVER THE LOWER
48 A SHORTWAVE TROF UNDERCUTTING THE NRN RIDGE WAS ESTABLISHED
FROM THE DAKOTAS DOWN THRU THE WESTERN HIGH PLAINS. MEANWHILE SFC
DUEL HIGH PRESSURE CENTERS SITUATED OVER THE GREAT LAKES AND
CENTRAL ROCKIES WAS THE DOMINATE FEATURE WITH A DISTINCT THERMAL
BOUNDARY CUTTING WEST-EAST THRU THE GULF STATES.
FCST PRETTY STRAIGHT FORWARD THE NEXT SEVERAL DAYS WITH MODELS
ADVERTISE FLOW BECOMING BACKED UP AND UPPER RIDGE BECOMING WELL
AMPLIFIED OVER THE WRN CONUS. WITH NW FLOW ALOFT OVER THE REGION
CAA CANNOT BE FAR BEHIND...WHICH MODELS DO ADVERTISE. THE RUSH OF
COLD AIR SHOULD BEGIN IN EARNEST EARLY WED MORNING WITH THE BRUNT
OF CAA DRIFTING SWD THRU THE GREAT LAKES AND PENETRATING AS FAR
SOUTH TO THE SERN STATES BY LATE THURSDAY. IMPACT OF CAA WITHIN THE
CWA WILL BE RELATIVELY ABRUPT...HIGHS GOING FROM LOW 60S TUES/WED TO
NEAR NORM AROUND 50 ON THURSDAY. FROPA WILL BRING STOUT NW WINDS ON
WED AND AGAIN THURSDAY.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY.
LONG TERM FORECAST WILL CONTINUE DRY. DECENT AGREEMENT BETWEEN 12Z
GFS AND 00Z ECMWF IN ALLOWING UPPER RIDGING TO SPREAD ACROSS THE
CENTRAL U.S. FRIDAY NIGHT/SAT AS AXIS OF EAST COAST TROUGH/LOW
PROGRESSES EWD. THUS A COOL FRIDAY WILL BE REPLACED BY MILDER AIR
SAT AND WITH GFS ACTUALLY COOLER THAN 12Z GEM/00Z ECMWF BY SAT. MADE
LTL/NO CHANGES TO FRIDAY...NEAR MEX...BUT WENT A BIT ABOVE MEX
GUIDANCE ON SAT. AFTER THAT MAIN CHALLENGE WILL BE DETERMINING
STRENGTH/LATITUDE OF ANY WAVE THAT TOPS RIDGE. IF FUTURE WAVES ARE
STRONG ENOUGH AND FAR ENOUGH S THEY COULD PROVIDE COOLING OR AT
LEAST MORE PERSISTENCE LIKE TEMPS OR IF WEAKER/FARTHER N THEY COULD
POSSIBLY AID IN MIXING/WARMING BY BRINGING MORE OF A WRLY COMPONENT
TO SFC WINDS. ATTM LEANED TWD 00Z GFS ENSEMBLE MEAN IN SFC PTN/850
MB TEMPS WHICH KEPT TEMPS ON SUNDAY NORTH AROUND OR SLIGHTLY COOLER
THAN THOSE ON SATURDAY DUE TO WEAK FROPA WHILE ALLOWING TEMPS TO
RECOVER N BACK TO SATURDAYS LEVELS AS FRONT ATTEMPTS TO LIFT BACK
NORTH. TEMPERATURES AT 850 MB ARE QUITE MILD BY THE
WEEKEND...HOWEVER...AND THE UPPER 50S-MID 60S FCST COULD PROVE
CONSERVATIVE SOME AREAS...SPCLY NEAR FRONT ON SUNDAY DUE TO MILDER
START AND FAVORABLE MIXING. HOWEVER...TIME OF YEAR AND POSSIBILITY
OF STRONGER WAVES IN EXTENDED LENT THE CONSERVATIVE TREND IN TEMP
FCST.
&&
.AVIATION...
18Z TAFS
VFR CONDITIONS ARE EXPECTED THRU THE PERIOD WITH ONLY A MID DECK
AROUND 12K FT EXPECTED. SFC WINDS WILL REMAIN LIGHT OUT OF THE
EAST/SOUTHEAST.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
DEE/RC/BK