FXUS63 KOAX 061950
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
250 PM CDT SAT NOV 6 2010
.SHORT TERM...TONIGHT THROUGH TUESDAY
DRY AND QUIET WEATHER CONTINUES ACROSS THE CENTRAL US. SUBJECTIVE
12Z UPPER AIR ANALYSIS INDICATES UPPER-LEVEL RIDGING FROM THE SWRN
US TOWARD NRN MN. UPPER LOW WAS STRENGTHENING IN NRN CANADA...WITH
FALLING 500MB HEIGHTS EXTENDING THROUGH THE ROCKIES AND TOWARD
ANOTHER UPPER LOW OFF THE CA COAST. DEEP TROUGH ALSO WAS IN PLACE
OVER THE APPALACHIANS. STRONG EAST-WEST TEMPERATURE GRADIENT AT
850MB WAS ROUGHLY BETWEEN THE MS-MO RIVER BASINS...WITH WARMING
BUBBLE IN THE HIGH PLAINS/ROCKIES AND SUBZERO TEMPS PUSHED SWD INTO
NRN FL...AND WITH TEMPS ON A WARMING TREND IN THE AREA. DRY LOWER
LEVELS PERSIST...WITH NO MOISTURE TO SPEAK OF AT 850MB FROM THE GULF
THROUGH THE PLAINS...AND WITH SFC DEWPOINTS FROM RELIABLE SITES IN
THE LOW TO MID 20S /WESTERN IOWA SITES HAVE DEWPOINT SENSOR
ISSUES/. INCREASING SFC GRADIENT WAS HELPING DRIVE SFC WINDS INTO
THE 15G25MPH RANGE.
MAIN FORECAST CONCERNS ARE DRY AIRMASS TOMORROW...WITH MILD
TEMPERATURES THROUGH AT LEAST MONDAY AND POTENTIALLY TUESDAY AHEAD
OF THE NEXT FRONTAL PASSAGE. CONDITIONS TODAY WERE APPROACHING
BORDERLINE RED FLAG WARNING CRITERIA IN A FEW LOCATIONS...AND WILL
NEED TO MONITOR TOMORROW AS SIMILAR CONDITIONS ARE EXPECTED. FOR
NOW...HAVE OPTED TO NOT INCLUDE A FIRE WEATHER WATCH AND WILL ALLOW
NEXT SHIFTS TO KEEP AN EYE ON THE EXPECTED DEWPOINTS.
OTHERWISE...MILD AND DRY WEATHER WILL CONTINUE THROUGH MONDAY...WITH
MOISTURE SLOWLY INCREASING UNDER CONTINUED SRLY FLOW AS WRN US
TROUGHING DEEPENS AND UPPER RIDGE AXIS SLIDES EASTWARD. A LEAD
SHORTWAVE IS PROGGED WITH QUITE A BIT OF CONSISTENCY TO SLIDE FROM
NEB INTO ERN SD ON SUNDAY NIGHT...BUT WITH VERY DRY AIRMASS STILL IN
PLACE...EXPECT LITTLE MORE THAN A SLIGHT INCREASE IN CLOUDS. GFS IS
FASTER THAN THE ECMWF/GEM IN PULLING A COLD FRONT THROUGH THE AREA
AS UPPER LOW IN THE NRN PLAINS STRENGTHENS...AND HAVE LEANED TOWARD
THE SLOWER SOLUTIONS GIVEN AMPLIFIED PATTERN. RESULT IS A DRY
FORECAST FOR THE CWA THROUGH TUESDAY...AND HAVE ALSO BUMPED UP TEMP
FORECAST ON TUESDAY UNDER STRONG WARM AIR ADVECTION AHEAD OF THE
FRONT.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
A PROGRESSIVE LONG WAVE PATTERN WILL DOMINATE THE EXTENDED PERIOD
OF THE FORECAST AS A DEEP TROUGH TRANSLATES FROM THE WEST COAST
MONDAY AND INTO THE PLAINS BY WEDNESDAY. THIS PATTER SIGNALS
INCREASING PRECIPITATION CHANCES AND DECREASING TEMPERATURES MID
TO LATE WEEK.
MODELS HAVE BEEN DIVERGENT OVER THE LAST SEVERAL IN HANDLING
PROGRESSION OF TROUGH WITH THE GFS MOST PROGRESSIVE AND ECMWF THE
LEAST. THE ECMWF HAS SUPPORT FROM THE CANADIAN MODEL...BOTH
OPERATIONAL RUN AND MOST OF ITS ENSEMBLE MEMBERS. MEANWHILE...MOST
00Z GFS ENSEMBLE MEMBERS SUPPORT ITS OWN OPERATIONAL RUN. HOWEVER...
THE 12Z GFS HAS TRENDED TOWARD ECMWF/CANADIAN TIMING OF TROUGH AND
ASSOCIATED SURFACE/PRECIPITATION FIELD. SO FORECAST TODAY HAS A BIT
HIGHER CONFIDENCE LEVEL THAN OF LATE. SOME CHANGES WERE MADE TO
PRECIP AND TEMPERATURES WEDNESDAY THROUGH FRIDAY IN LIGHT OF
ABOVE-MENTIONED INFORMATION.
SURFACE FRONT SHOULD BE APPROACHING OUR WESTERN CWA WEDNESDAY
MORNING. A RELATIVELY DRY FRONT WILL YIELD NO MENTION OF
PRECIP...BUT MORNING LOWS WEDNESDAY SHOULD BE MILDER. STRONG
WESTERLY WINDS BEHIND FRONT WILL ALLOW TEMPS TO WARM INTO THE 50S
MOST SPOTS...BUT CLOUDS/COOLER AIR IN OUR NORTHWEST WILL KEEP HIGHS
THERE IN THE 40S. THERE WILL ALSO BE A SLIGHT CHANCE FOR A SHOWER
THERE UNDER DEFORMATION AXIS OF EXITING SHORTWAVE.
UPPER LOW WILL MOVE INTO THE TEXAS PANHANDLE THURSDAY
NIGHT...ROUNDING BASE OF UPPER TROUGH. PRECIPITATION THURSDAY SHOULD
BE CONFINED TO AREAS WELL TO OUR SOUTH. HAVE REDUCED POPS
SIGNIFICANTLY THURSDAY...AND COULD SEE THOSE GO EVEN LOWER IF MODELS
REMAIN CONSISTENT WITH LATER RUNS. BETTER CHANCES FOR PRECIP COME
FRIDAY WITH UPPER LOW MOVING SOUTHEAST OF OUR AREA. HAVE INCREASED
POPS DRAMATICALLY FOR FRIDAY...WITH BEST CHANCES IN OUR SOUTHEAST.
THERMAL PROGS SUGGEST ALL RAIN EVENT WITH LOW LEVEL AND 850 TEMPS
REMAINING WELL ABOVE ZERO. COOLER AIR SPILLS INTO THE REGION BEHIND
THIS SYSTEM FOR SATURDAY...BUT PRECIP WILL EXIT TO OUR EAST FRIDAY
NIGHT.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
VFR CONDITIONS WILL CONTINUE THRU TAF PD. SOUTHERLY SFC WINDS WL
DIMINISH A BIT BY 00Z BUT LLVL WIND SHEAR THEN KICKS IN FOR THE
OVERNIGHT. WINDS PICK UP AGAIN AFTER 15Z ON SUNDAY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
MAYES/DERGAN/FOBERT