FXUS63 KOAX 280753
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
253 AM CDT MON MAR 28 2011
.DISCUSSION...
UNSETTLED PATTERN TO PERSIST ACROSS ERN NEBRASKA/SW IOWA REGION
THROUGH MIDWEEK AS A SERIES OF SHORTWAVE TROUGHS MOVE ACROSS
CENTRAL PLAINS. MODELS ARE HAVING A SOMEWHAT DIFFICULT TIME
HANDLING SPECIFIC IMPACT ON TIMING OF ANY PARTICULAR WAVE.
FIRST WAVE WAS LIFTING ENE ACROSS EXTREME NE WY WITH TRAILING LOBE
INTO WRN NEBRASKA PER EARLY MORNING WATER VAPOR IMAGERY. THIS SYSTEM
WAS SPREADING A BAND OF SNOW TOWARD NERN NEBRASKA WHICH WAS
ENCOUNTERING DRIER AIR THAT WAS IN PLACE OVER THE FORECAST AREA.
SHORT RANGE QPF FROM 4KM WRF AND 3KM HRR SHOWED PRECIP WEAKENING
OR EVEN DISSIPATING SOME THIS MORNING AS IT APPROACHES/MOVES INTO
FAR WRN ZONES BEFORE FINALLY SPREADING OVER THE AREA THIS
AFTERNOON. ALTHOUGH ADJUSTED POPS UPWARD SOME...BULK OF PRECIP
PROBABLY WILL NOT ARRIVE UNTIL THIS AFTERNOON. ANY PRECIP THIS
MORNING SHOULD BE SNOW AND WITH EVAPORATIVE COOLING IT COULD
REMAIN SNOW THIS AFTERNOON. HOWEVER...THE DELAY IN PRECIP UNTIL
AFTERNOON E/SE ZONES COULD PROVIDE ENOUGH TEMPERATURE RECOVERY IN
BOUNDARY LAYER TO ALLOW SOME RAIN OR RAIN SNOW MIX. SO CARRIED
SOME LIQUID MENTION S AND FAR E THIS AFTN AND FAR SERN ZONES THIS
EVENING. AS WAS THE CASE YESTERDAY PARTIAL SUN OR BRIGHTER SKIES
COULD ALLOW ERN SECTIONS TO CLIMB CLOSE TO MAV/MET GUIDANCE BLEND
TODAY BUT WESTERN ZONES LIKELY AGAIN COOLER THAN GUIDANCE. IMPACT
OF THIS WAVE TO LESSEN OVERNIGHT PER GFS/NAM/ECMWF AND THUS
TRENDED POPS DOWNWARD FROM LATE AFTN/EVENING.
ECMWF WHICH DOWNPLAYED PRECIP WITH WAVE FOR TUESDAY ON 00Z/27 RUN
DOES IT EVEN MORE SO WITH LATEST 00Z/28 RUN AS BATTLE PERSISTS
BETWEEN BLOCKING RIDGE OVER GREAT LAKES AND WAVE TRAIN OVER PLAINS.
21Z/27 SREF CONTINUED TO BE RATHER BULLISH WITH PRECIP...HOWEVER.
SO ALTHOUGH POPS WERE TRIMMED ON TUE...ESPECIALLY EASTERN
ZONES...WAS SOMEWHAT RELUCTANT TO PULL THEM ENTIRELY AT THIS
TIME. KEPT TEMPERATURES GENERALLY ON THE COOLER SIDE OF GUIDANCE.
YET ANOTHER WAVE DROPPING SE ACROSS NEBRASKA ON WEDNESDAY COULD
TRIGGER A FEW SHOWERS...POSSIBLY MIXED WITH SNOW N...PER 00Z
ECMWF/GFS...AND SMALL POPS WERE ADDED. CONTINUED WARM ADVECTION
THEN INTO THU COULD EVEN TRIGGER AN ISOLATED THUNDERSTORM AS MID
LEVEL LAPSE RATES STEEPEN...ALTHOUGH IMAGINATION HAD TO BE
STRETCHED BASED ON GFS FORECAST SOUNDINGS. SO ALTHOUGH DID NOT
MENTION THUNDER...DID MENTION SMALL SHOWER CHANCE WED NIGHT AND SE
ON THURSDAY. ALTHOUGH WARM ADVECTION NOT OVERLY STRONG ON WED DUE
TO EXPECTED CLOUD COVER...IT COULD BE ENOUGH TO WARRANT A BUMP UP
IN MAX TEMPS...ALTHOUGH NOT AS MUCH AS MAV/MET WOULD SUGGEST.
TEMPERATURES APPEAR THEY WILL RECOVER TOWARD/PERHAPS A BIT ABOVE
NORMAL LATE IN THE WEEK INTO THE WEEKEND...ALTHOUGH LATEST RUNS
WERE NOT QUITE AS OPTIMISTIC ON WARMING THROUGH SATURDAY AND
GENERAL PATTERN BEYOND THAT STILL APPEARS TO FAVOR BELOW NORMAL
TEMPERATURES OVERALL. NO CHANGES MADE BEYOND THURSDAY.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
VFR CONDITIONS ARE EXPECTED TO BECOME MVFR TO IFR AFTER 18Z AS NEXT
UPPER LEVEL WAVE MOVES INTO THE CENTRAL PLAINS. SOME LIGHT SNOW MAY
SPREAD INTO KOFK AND KLNK TOWARDS 00Z THEN BECOME MORE WIDESPREAD
OVER EASTERN NEBRASKA AFTER 00Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
CHERMOK/FOBERT