FXUS63 KOAX 201947
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
247 PM CDT SUN MAR 20 2011
.SHORT TERM...TONIGHT THROUGH WEDNESDAY.
WEAK COLD FRONT WAS MOVING THROUGH EASTERN NEBRASKA AT 19Z
STRETCHING FROM NORTHWEST IOWA...SOUTHEAST NEBRASKA INTO SOUTHWEST
KANSAS. MODELS CONTINUE TO STALL THIS FRONT NEAR THE KANSAS
NEBRASKA BORDER TONIGHT THEN GRADUALLY LIFT IT NORTH AS A WARM
FRONT MONDAY AND MONDAY NIGHT. COLD FRONT THEN MOVES THROUGH LATE
TUESDAY.
MAIN FORECAST CHALLENGE CONTINUES TO REVOLVE AROUND TEMPERATURES
AND RAIN CHANCES ASSOCIATED WITH THE SURFACE BOUNDARY IN THE AREA.
SOME LOW POPS FOR MONDAY AFTERNOON AND MONDAY NIGHT NEAR AND
AHEAD OF THE WARM FRONT AND ALSO ON TUESDAY AND TUESDAY NIGHT
AHEAD OF THE COLD FRONT. FORECAST SOUNDINGS SUGGEST SOME CAPPING
WILL BE IN PLACE DURING THIS TIME SO CONVECTION DEPENDENT ON
STRENGTH OF CAP. DYNAMICS LOOK GOOD OTHERWISE WITH SPC PLACING
MUCH OF THE CWA IN OUTLOOK FOR MONDAY AND MONDAY NIGHT CONTINGENT
ON OVERCOMING THIS CAPPING.
TEMPERATURES DURING THE PERIOD WILL ALSO BE DEPENDENT ON THE
BOUNDARY LOCATION AND EXTENT OF CLOUD COVER AND PRECIP THAT DOES
DEVELOP. HAVE TRENDED TOWARD GUIDANCE BLEND FOR NOW WHICH
GENERALLY REMAINS CONSISTENT WITH EARLIER FORECAST NUMBERS.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY.
PERIOD BEGINS WITH A STRONG LOW MOVING ACROSS THE NRN PLAINS. A SLUG
OF COLD AIR JUST TO OUR NORTHEAST MAY OR MAY NOT SLIDE SOUTH INTO
OUR AREA...DEPENDING ON THE TIMING AND STRENGTH OF AN APPROACHING
UPPER SHORTWAVE RIDGE. 00Z ECMWF SINKS THE COLD AIR INTO THE CENTRAL
PLAINS AS IT BUILDS A SFC HIGH SOUTH INTO THE REGION. THE 12Z GFS ON
THE OTHER HAND MAINTAINS WARMER CONDITIONS WITH SOUTHERLY LLVL FLOW
SETTING UP RATHER QUICKLY. NOT QUITE SURE WHAT TO BELIEVE SO HAVE
GONE WITH A MIDDLE OF THE ROAD APPROACH. A QUICK APPROACHING PIECE
OF SHORTWAVE ENERGY MOVES TOWARD THE AREA LATE THURSDAY NIGHT INTO
FRIDAY AND WILL CONTINUE A CHANCE FOR MIXED PCPN. ANOTHER
APPROACHING SHORTWAVE TROF BEGINS TO MOVE INTO THE AREA SATURDAY.
WILL CONTINUE WITH THE POTENTIAL FOR SHOWERS OUT AHEAD OF THE
FEATURE THROUGH SATURDAY.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
AREA OF LOWER CIGS...MOSTLY IN MVFR CATEGORY...SHOULD EITHER BE
QUICKLY SHOVED EAST OF NEBRASKA BEFORE 21/00Z OR LIFT ABOVE 3K FEET
AS A WIND SHIFT PUSHES ACROSS EASTERN NEBRASKA. THIS BOUNDARY WILL
STALL OUT FROM NORTHERN MO ACROSS NORTHERN KANSAS TONIGHT. A FEW
STORMS COULD DEVELOP ALONG IT TONIGHT...BUT IF THEY DO THEY SHOULD
BE EITHER S OR SE OF TAF SITES. THE FRONT AND LOW LEVEL MOISTURE
WILL LIFT NORTH ON MONDAY AND LIKELY BRING LOWERING CIGS BACK TO THE
REGION. THE CONFIDENCE IN THE TIMING OF THIS TREND WAS NOT VERY
HIGH AND WILL LIKELY NEED ADJUSTING IN LATER TAF FORECASTS. SOME
THUNDERSTORM DEVELOPMENT MAY OCCUR NEAR FRONT AS IT LIFTS NORTH ON
MONDAY...BUT SOME NEGATIVE INFLUENCES IN THIS EXISTS...I.E. A STRONG
CAP. THUS THE CONVECTION CHANCES/TIMING/LOCATION ARE ALSO A
RELATIVELY LOW CONFIDENCE EVENT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT/KERN/CHERMOK