FXUS63 KOAX 172000
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
300 PM CDT SUN APR 17 2011
.SHORT TERM...TONIGHT.
EARLY AFTERNOON SATELLITE IMAGERY SHOWED SHORTWAVE ENERGY DIGGING
ESE TOWARD ERN WY. THIS WAVE WILL CROSS FORECAST AREA EARLY IN THE
PERIOD BRINGING DECENT FORCING...A LARGE PART FRONTOGENESIS IN
H85-H7 LAYER. FELT THIS WARRANTED AN INCREASE IN POPS N THROUGH THIS
EVENING WITH A SMALL CHANCE ADDED MUCH OF THE SOUTH. OTHERWISE
TIME/HEIGHT CROSS SECTIONS/FORECAST SOUNDINGS INDICATED AFTER WAVE
PASSES...THERE WAS A STRONG LIKELIHOOD OF LOW CLOUDS AND AREAS OF
FOG REFORMING OVER THE AREA. THUS INCREASED SKY GRIDS AND ADDED FOG
AFTER 06Z. GENERALLY LEANED TOWARD A MET/MAV COMPROMISE FOR LOWS.
CHERMOK
.LONG TERM...MONDAY THROUGH SUNDAY.
OVERALL LITTLE CHANGE TO MAIN FORECAST TRENDS FOR THE PERIOD.
PRIOMARY FORECAST CONCERNS STILL REVOLVE AROUND TIMING AND
AMPLITUDE ISSUES OF A SERIES OF EMBEDDED SYSTEMS MOVING THROUGH
FAST FLOW ALOFT.
SURFACE WARM FRONT STRETCHED ACROSS NORTHERN KANSAS INTO NORTHERN
MISSOURI AT 19Z. MODELS CONTINUE TO KEEP THIS BOUNDARY WELL SOUTH
OF THE AREA THROUGH TUESDAY AS STRONG UPPER WAVE MOVES INTO THE
PLAINS REGION. MAIN FOCUS APPEARS TO BE NORTH OF THE 850MB
BOUNDARY AS STRONG LOW LEVEL WARM ADVECTION OCCURS MONDAY NIGHT
INTO TUESDAY WITH ADDITIONAL SUPPORT FROM THE MID LEVEL WAVE TUESDAY
INTO TUESDAY NIGHT. RESULT IS EXTENSIVE AREA OF PRECIP ACROSS
NEBRASKA INTO IOWA STARTING LATE MONDAY THROUGH TUESDAY. SOME
POTENTIAL FOR SNOW AGAIN IN NORTHEAST NEBRASKA TUESDAY NIGHT BUT
LITTLE ACCUMULATION EXPECTED AS BETTER MOISTURE IS ALREADY OFF TO
THE EAST BY THAT TIME. DRY BUT COLD WEDNESDAY WITH BREEZY
CONDITIONS MOST OF THE DAY AS HIGH PRESSURE BUILDS INTO THE AREA.
ENSEMBLE MEANS PREFERRED BY HPC IN THE EXTENDED PORTION OF THE
FORECAST THURSDAY THROUGH SUNDAY AS GFS AND ECMWF CONTINUE TO OFFER
DIFFERENT SOLUTIONS IN THE FAST FLOW ALOFT. AS A RESULT CONFIDENCE
ON THE LOW SIDE DURING THIS PERIOD ESPECIALLY REGARDING PRECIP TIMING.
&&
FOBERT
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
A DISTURBANCE CROSSING NEBRASKA EARLY TONIGHT WILL SPREAD SCATTERED
SHOWERS ACROSS THE AREA. TEMPO SHOWER GROUP WAS INCLUDED IN
KOFK/KOMA TAFS WHERE CHANCES SEEMED A BIT HIGHER ALTHOUGH ANY PRECIP
WILL BE LIGHT AND HAVE MINIMAL AVIATION IMPACTS. OTHERWISE AS
SYSTEM PASSES THE AREA THIS EVENING...LOW CLOUDS AND AREAS OF FOG
AGAIN LIKELY TO DEVELOP. THUS TAF SITES WERE BROUGHT DOWN INTO IFR
OR LOWER CONDITIONS LATER TONIGHT WITH ONLY A SLOW IMPROVEMENT
EXPECTED MONDAY MORNING.
&&
CHERMOK
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$