FXUS63 KOAX 210211
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
811 PM CST SAT NOV 20 2010
.UPDATE...
GETTING SOME REPORTS OF FREEZING DRIZZLE WITH SOME REDUCED VSBYS
WHERE TEMPERATURES AT THE SURFACE ARE BELOW FREEZING. EARLY ENOUGH
IN THE YEAR WHERE SOME TYPE OF ADVISORY FOR THE PCPN AND POSSIBLE
SLICK ROADS SEEMS JUSTIFIED.
&&
.DISCUSSION...
SURFACE LOW REMAINS IN PLACE OVER NERN KS AND WEAK LIFT WITH LOW
LEVEL MOISTURE IS CAUSING AREAS OF DRIZZLE AND FREEZING DRIZZLE.
THIS SHOULD CONTINUE OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 337 PM CST SAT NOV 20 2010/
SHORT TERM...TONIGHT THROUGH TUESDAY.
SHORT TERM CONCERNS WILL BE LIGHT PRECIPITATION...PRECIPITATION
TYPE...AND TEMPERATURES.
AT 21Z...THE SFC LOW WAS NORTH OF WICHITA KS AND SOUTH OF SALINA
KS...WITH THE WARM FRONT AS FAR NORTH AS ST. JOSEPH MISSOURI. THE
FCST AREA WAS ON THE COOL SIDE OF THE FNT. TEMPERATURES WERE HELD
IN THE 20S AND 30S...HOWEVER CLOSER TO THE WARM FRONT AN WHERE THE
CLOUDS WERE THINNER...TEMPERATURES WERE IN THE 40S. WATER VAPOR
STLT IMAGERY AND LIGHTNING HIGHLIGHTED A TROF OVR THE WEST
COAST...WITH SOME LIGHTNING STROKES WEST OF NRN CALIFORNIA. SW
FLOW ALOFT WAS NOTED FM SRN CA INTO THE ROCKIES AND MIDWEST WITH
AN EMBEDDED SHORTWAVE OVR WRN NEB.
TONIGHT THE H85 FLOW WILL STRENGTHEN WITH WARM AIR BEING LIFTED
OVER THE FRONT...MEANWHILE THE AREA OF LOW PRESSURE WILL MOVE
TOWARD FALLS CITY. THIS SHOULD ALLOW SFC DEWPOINTS TO INCREASE AND
HINDER SFC TEMPS FROM FALLING...WITH FOG/DRIZZLE/FREEZING DRIZZLE
POSSIBLE DEPENDING ON THE GROUND TEMPERATURES. NONE OF THE SHORT
RANGE MODELS HAD A GOOD HANDLE ON THE SFC TEMPS AND USED THE
HRRR/RUC AND THEN ADJUSTED THE NAM/SREF. A MIX OF PRECIP TYPES WAS
MENTIONED NORTHWEST OF A LINE FROM FRIEND TOWARD FREMONT AND
MAPLETON...WITH FOG AND DRIZZLE TO THE SOUTHEAST AND FOG AND
FREEZING DRIZZLE NORTHWEST OF COLUMBUS TO WAYNE. ANY AMOUNTS
SHOULD BE LIGHT...HOWEVER WITH A PERIOD OF FREEZING DRIZZLE COULD
BE ENOUGH TO CAUSE SLIPPERY SPOTS. THIS WILL NEED TO BE WATCHED AS
HIGHER DEWPOINTS SPREAD WESTWARD FROM THE SOUTHEAST. FOG AND
PATCHY DRIZZLE/DRIZZLE WILL LINGER SUNDAY MORNING AND THEN SHIFT
EAST. DRIER WESTERLY FLOW SHOULD DECREASE CLOUDS IN THE SOUTHWEST.
TEMPERATURES TRICKY WITH THE SFC LOW IN OUR SOUTHEAST...TRENDED
COOLER FOR TEMPS SUN ALL BUT FAR SOUTHEAST WHERE SHOULD BE IN THE
WARMER AIR. NAM KEPT ALL OF NEB IN THE COOLER AIR...SO MAY NEED TO
ADJUST OF CANNOT MODERATE IN THE SOUTHEAST SUNDAY.
THE FRONT DOES NOT MAKE IT VERY FAR TO THE SOUTH...AND ONCE AGAIN
THERE SHOULD BE A GRADIENT IN TEMPS FROM NORTH TO SOUTH WITH SOME
LIGHT PRECIP SUNDAY NIGHT. MENTIONED A SMALL CHANCE FOR SHOWERS IN
THE FAR SOUTHEAST AND A SMALL CHANCE FOR LIGHT SNOW ALONG WITH
SOME FREEZING DRIZZLE IN THE NORTHEAST. A SHORTWAVE TROF PASSES
THROUGH WITH THIS SYSTEM AS WELL WITH HIGH PRES BUILDING IN FOR TUES.
LONG TERM...TUESDAY NIGHT THROUGH SATURDAY.
MAIN CONCERN DURING THE PERIOD WILL BE TUESDAY NIGHT/WEDNESDAY AS
AN ASSOCIATED TROUGH AND LOW PRESSURE SYSTEM MOVE ACROSS THE
PLAINS...ALLOWING SOME RATHER COLD TEMPERATURES TO FILTER
SOUTHWARD OUT OF THE NORTHERN ROCKIES. THERE STILL ARE SOME
SIGNIFICANT MODEL DISCREPANCIES WITH THIS SYSTEM...WHICH WILL HAVE
A FAIRLY LARGE IMPACT ON REGIONAL WEATHER TRENDS. THE ECMWF AND
GEM REMAIN THE SLOWEST OF ALL MODELS AS THEY BOTH CLOSE OFF THE
H50 CIRCULATIONS ALLOWING FOR A SLOWER EASTWARD PROGRESSION...BUT
MORE IMPORTANTLY...FOCUS MOST OF THE ENERGY FURTHER NORTH ACROSS
THE NORTHERN PLAINS WHICH WOULD KEEP SNOW OUT OF THE LOCAL CWFA
ALTOGETHER. THE OPERATIONAL GFS IS THE QUICKEST OF ALL MODELS AND
WOULD BRING IN THE BEST CHANCE FOR SNOW TUESDAY NIGHT AND EARLY
WEDNESDAY...WITH THE GFS ENSEMBLE A DECENT COMPROMISE... BUT
DEFINITELY LIMITING THE AREAL PLACEMENT TO ALONG/NORTH OF I80. FOR
NOW...GIVEN VARYING MODEL SOLUTIONS...FEEL THAT CONSISTENCY IS THE
BEST OPTION AND TWEAKED EXISTING GRIDS FOR TIMING AND PLACEMENT
WITH BEST POTENTIAL FOR ACCUMULATING SNOW LATE TUESDAY NIGHT
THROUGH MUCH OF WEDNESDAY...AND MAINLY ALONG/NORTH OF I80.
HAVE TRENDED TEMPERATURES FAIRLY LOW ON WEDNESDAY/THURSDAY...BUT
AGAIN EXACT TIMING OF THE ARRIVAL OF THE COLD TEMPS COULD NEED
ADDITIONAL ADJUSTMENT BASED ON MODEL TRENDS. REMAINDER OF THE
HOLIDAY WEEKEND LOOKS BENIGN WITH MODERATING TEMPERATURES.
AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
MVFR CIGS CURRENTLY AT ALL TERMINALS WILL DETERIORATE TO IFR WITH
OCCASIONAL LIFR TWD 21/05Z PREVAILING. SATURATED LAYER WILL REMAIN
CONFINDED TO LOWEST 5KFT LAYER THRU THE FCST PD...AND ANTICIPATE
BEST FIT FOR PCPN AT KOMA/KLNK WILL BE -DZ BTWN 21/06Z-12Z. WITH
SLGTLY COLDER ENVIRONMENT AT KOFK...BELIEVE TYPE WILL BE -FZDZ.
ALSO...ICING POTENTIAL FL020-030 AGL WILL BE HIGH AFT 21/00Z AND
REMAIN SO THRU AT LEAST 21/12Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 6 AM CST SUNDAY FOR NEZ011-012-
015>018-030>033-042-043-050-065.
IA...NONE.
&&
$$
SHORT TERM...MILLER