FXUS63 KOAX 162000
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
300 PM CDT SAT APR 16 2011
.SHORT TERM...TONIGHT.
WINDS WILL DECREASE THIS EVENING AS HIGH PRESSURE BUILDS OVER THE
AREA. BY 12Z THE HIGH SHOULD STRETCH FROM EASTERN NORTH DAKOTA INTO
CENTRAL MISSOURI. 12Z MODELS SHOWED SOME ISENTROPIC UPGLIDE IN THE
295-300 K LAYER AND VARIABLE AMOUNTS OF MID TROPOSPHERIC FORCING.
THE GFS WAS MORE BULLISH WITH DEVELOPMENT OF PRECIPITATION FOR THE
OVERNIGHT HOURS COMPARED TO THE NAM...ECMWF AND CANADIAN GEM MODEL.
FOR NOW...KEPT THE FORECAST DRY. PATCHY FOG ALSO EXPECTED FOR MOST
LOCATIONS DUE TO LIGHT WINDS AND WET OR SNOW COVERED GROUND FROM THE
RAIN AND SNOW THE PAST FEW DAYS. THE FOG SHOULD HAVE A LITTLE MORE
COVERAGE IN NORTHEAST NEBRASKA WHERE SNOW WAS STILL ON THE GROUND AS
OF MID AFTERNOON. DID NOT MENTION DENSE FOG AT THIS TIME. EXPECT
LOWS MOSTLY IN THE LOWER AND MID 30S...BUT IT MAY DROP INTO THE 20S
FOR LOCATIONS THAT HAVE SNOW COVER.
MILLER
.LONG TERM...SUNDAY THROUGH SATURDAY.
EXTENT AND TIMING OF PERIODS OF PRECIP WILL BE THE MAIN FORECAST
CHALLENGE THROUGH THE PERIOD. MODELS SUGGEST A SERIAL PATTERN OF
WARM ADVECTION IN ADVANCE OF INCOMING UPPER TROUGHS SUPPORTED BY
NUMEROUS SHORT WAVES IN THE FLOW AND LEE SIDE CYCLOGENESIS...
FOLLOWED BY COLD ADVECTION AND SUBSIDENCE BEHIND THE MAIN SYSTEMS
AS THEY TRACK EAST. AT LEAST THREE OCCURRENCES INDICATED AT THIS
TIME. THE FIRST STARTING ON SUNDAY WITH A SHORT BREAK SUNDAY NIGHT
BEFORE NEXT SYSTEM DEVELOPS AND MOVES THROUGH THE AREA MONDAY AND
TUESDAY. NAM SHOWING CONSIDERABLY COLDER TEMPERATURES THAN GFS AND
ECMWF ON TUESDAY WITH SNOW POTENTIAL FOR NORTHERN PARTS OF THE
AREA AGAIN IF RIGHT. HAVE TRENDED TOWARD THE WARMER MODELS FOR NOW
AND KEPT ONLY MENTION OF RAIN DURING THAT TIME. BREAK THEN LATE
TUESDAY NIGHT INTO WEDNESDAY BEFORE NEXT ROUND DEVELOPS AND MOVES
THROUGH THE REGION WEDNESDAY NIGHT INTO FRIDAY.
TEMPERATURES EXPECTED TO AVERAGE BELOW SEASONAL NORMALS DURING
THE PERIOD AS CLOUDS AND PRECIP LIMIT WARMING. SNOW FIELD OVER
NORTHERN PARTS OF THE CWA HAVING A BIG IMPACT ON TEMPERATURES
INITIALLY BEFORE MELTING OFF...HOPEFULLY ON SUNDAY.
FOBERT
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
WEAK HIGH PRESSURE WILL BUILD OVER THE TAF SITES THIS EVENING WITH
VFR CONDITIONS AND LIGHT WINDS. SOME MVFR CONDITIONS ARE POSSIBLE
OVERNIGHT DUE TO PATCHY FOG...BUT DID NOT INCLUDE AT THIS TIME...
EXCEPT AT KOFK. MID LEVEL CLOUDINESS SHOULD THICKEN OVERNIGHT BUT
CEILINGS SHOULD REMAIN ABOVE 8000 FEET.
MILLER
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$