FXUS63 KOAX 282115
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
415 PM CDT SAT MAY 28 2011
.SHORT TERM...TONIGHT THROUGH TUESDAY.
STORM CHANCES TONIGHT CONTINUE TO REVOLVE AROUND HOW FAR NORTH WILL
STALLED SFC BNDRY CURRENTLY EXTENDING ACROSS SRN KS/SRN MO LIFT...AND
HOW MUCH OF A FACTOR WILL CAP OVER CNTRL PLAINS BE. NAM/GFS BOTH SHOW
BNDRY LYR MOISTURE CONVERGENCE AXIS STRADDLING THE NEB/KS TO NRN MO
BETWEEN 06Z-12Z TONIGHT. AT THIS POINT AM GUESSING CONVECTIVE
INITIATION...WITH A FEW SEVERE STORMS POSSIBLE...WILL BE ON NORTHERN
EDGE OF DECREASING MLCINH/NOSE OF LLVL JET WHICH WOULD PRETTY MUCH BE
OVER THE SRN CWA. THUS WILL BUMP POPS UP TO LIKELY CAT SOUTH OF I-80.
WARM FRONT WILL BE SLOW LIFTING ON SUNDAY...AND CONCERN TURNS TO
POSSIBLE SEVERE STORM DEVELOPMENT LATE AFTN INTO SUNDAY EVENING.
GIVEN ENVIRONMENT WILL BE PLENTY MOIST/UNSTABLE...CHANCES FOR SEVERE
STORMS INCREASE GREATLY MAINLY NORTH OF I-80 WHERE BNDRY LYR-6KM
SHEAR VALUES AROUND 60 ARE PROGGED. GIVEN FAVORABLE COMBINATION OF
MUCAPES/MLLCL...MLLFC/0-1KM SRH/SWEAT INDEX...TORNADIC STORMS OVER
THE NRN CWA CANNOT BE RULED OUT. ANOTHER ROUND OF SEVERE STORMS
POSSIBLE MONDAY AFTN/EVENING WHEN SFC LOW QUICKLY LIFTS NE OUT OF ERN
CO AND ATTENDANT COLD FRONT SWEEPS INTO CNTRL PLAINS.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY.
ANTICIPATE RETROGRADING HIGH PRESSURE DOME DURING THE EXTENDED PDS
WILL FOR THE MOST PART HELP HINDER ACTIVE WEATHER FROM DEVELOPING
THRU DAY 7 OVER THE CNTRL PLAINS. THE EXCEPTION BEING POSSIBLE
STORMS WED NIGHT. BOTH THE GFS AND ECM LAY QPF ALONG A STAGNANT SFC
BNDRY EXTENDING ACROSS NEB/IA. AT THIS POINT WILL OPT FOR ONLY
20 POPS GIVEN HIGH MLCINH ALONG NO SIGNIFICANT SHORTWAVES PASSING
THRU TO HELP ERODE CAPPING. LARGE SCALE FLOW BEGINS TO EVOLVE
FRIDAY/SAT WHEN DEEP WEST COAST UPPER LEVEL TROF BEGINS TO MOVE
ASHORE AND KICKS CNTRL U.S. RIDGE EAST. AT THE SAME TIME POTENT
SHORTWAVE CROSSING SRN CANADA WILL SWEEP THE NEXT COLD FRONT INTO
THE LOWER 48. GFS/ECM RELATIVELY SIMILAR WITH FRONT AT WRN CWA
PERIPHERY BY 12Z SAT. FOR NOW WILL HOLD OFF ADDING POPS.
DEE
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
GENERAL TRENDS THROUGH TAF FORECAST PERIOD WILL BE FOR SFC WINDS TO
BECOME ENE AND CIGS TO LOWER...MOST LIKELY AFTER 29/10Z FOR BOTH.
SURFACE WARM FRONT WILL BE DEVELOPING/LIFTING NWD ACROSS KS
TONIGHT/SUNDAY AND LOW CIGS WILL LIKELY FORM NORTH OF THE BOUNDARY.
18Z FORECAST LOWERED CIGS INTO MVFR CATEGORY...BUT THEY COULD EVEN
GO LOWER THAN THAT...ESPECIALLY AT KOFK. SHOWERS IN MID CLOUDS THIS
AFTERNOON WILL BE SPOTTY AND NOT INCLUDED IN 18Z FORECASTS.
THUNDERSTORMS EXPECTED TO DEVELOP BY EVENING S OF NEBRASKA AND THIS
ACTIVITY COULD WORK NORTH LATE TONIGHT/SUNDAY MORNING.
COVERAGE/DEVELOPMENT COULD BE LIMITED BY WARMER MID LEVEL
TEMPERATURES THAT WILL BE SPREADING NWD AND THIS COULD SUPPRESS
ACTIVITY...ESPECIALLY ON SUNDAY. THUS CONFIDENCE IN SHOWER/TSTM
CHANCES NOT VERY HIGH.
CHERMOK
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$