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000
FXUS63 KOAX 202040
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
340 PM CDT MON MAY 20 2013

.DISCUSSION...
FORECAST CONCERNS OVER THE NEXT FEW DAYS WILL MAINLY BE SPORDIC
SHOWERS...AND ISOLATED THUNDERSHOWERS THIS EVENING...THEN
TEMPERATURES.

AT 12Z A SEASONABLY STRONG H30 JET WITH 80 TO 100KT WINDS DOVE
SOUTH THROUGH UTAH ACROSS NORTHERN NEW MEXICO AND THE TEXAS
PANHANDLE AN RE-CURVES NORTHEAST ACROSS IOWA. THE FORECAST AREA IS
UNDER THE INFLUENCE OF A LARGE AREA OF CLOSED LOW PRESSURE
CENTERED OVER SOUTH DAKOTA AND NORTHERN NEBRASKA...THAT ELONGATES
BACK ACROSS COLORADO. THE H7 AND H85 WERE SIMILARLY VERTICALLY
STACKED. DECENT MOISTURE WAS NOTED PER THE 12Z KLBF RAOB TO 440MB
AND THE KOAX RAOBS TO 560MB.

BY LATE AFTERNOON AND TONIGHT...THE H5 LOW WILL REMAIN IN THE
SAME LOCATION...THEN GRADUALLY WEAKEN AND SEND SOME ENERGY AROUND
THE LOW. CONVECTIVE TEMPERATURES ARE IN THE UPPER 70S AND THERE IS
SOME MID LEVEL WARM ADVECTION THROUGH THE EVENING. THE ATMOSPHERE HAS
BECOME CONVECTIVELY UNSTABLE WITH SURFACE BASED CAPE 500-1000
J/KG. A FEW SHOWERS HAVE DEVELOPED AND SOME THUNDERSTORMS COULD
ALSO DEVELOP. ALTHOUGH THE COVERAGE MAY BE TOUGH TO PIN DOWN...THE
OPERATIONAL/EXPERIMENTAL MODELS ARE SPLIT WITH SOME DRY AND
OTHERS GENERATING SOME ISOLD TO SCATTERED PRECIP. LOOKING AT THE
NAM/HRRR/RAP/HOPWRF ENSEMBLES/4KM WRF/GFS TEND TO FOCUS THE HIGHER
PRECIP CHANCES OVER THE FAR SOUTHEAST NEB AND SOUTHWEST IOWA
COUNTIES OR IN THE NORTHWEST EARLY THIS EVENING WITH ISOLD
ELSEWHERE...WITH A GENERAL DOWNWARD TREND IN AND LOCAL PRECIP
AFTER SUNSET.

WE CONTINUE TO BE UNDER THE INFLUENCE OF CYCLONIC FLOW THROUGH
WEDNESDAY...THUS A CLOUDY AND COOLER PERIOD WITH SOME CHANCE OF
SHOWERS. ANY PRECIPITATION SHOULD BE ON THE LIGHT SIDE. HIGHS
TUESDAY AND WEDNESDAY IN THE 60S AND 70S. WE SEE A BREAK WITH
RIDGING OVER THE AREA WEDNESDAY NIGHT THROUGH THURSDAY NIGHT
HOWEVER CLOUDS WILL BE ON THE INCREASE. THE NEXT CHANCE FOR
THUNDERSTORMS WILL BE FRIDAY AND LAST INTO THE WEEKEND. THE 12Z
EURO IS A LITTLE MORE PROGRESSIVE WITH THE WEATHER AND DRIES IT
OUT BY SATURDAY AFTERNOON. SO...THE SAT AFTERNOON INTO MONDAY
FORECAST WILL LIKELY SEE SOME ADJUSTMENT AS THE LONG RANGE MODELS
COME INTO BETTER AGREEMENT.

&&

.AVIATION...
18Z TAFS FOR KOFK...KLNK AND KOMA.

GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH TUESDAY MORNING.
SCATTERED TO BROKEN CUMULUS NEAR FL050 IS FORECAST THROUGH THE
AFTERNOON. A FEW SHOWERS OR ISOLATED THUNDERSTORMS COULD DEVELOP
BRINGING MVFR CONDITIONS TO SOME AREAS. HOWEVER CHANCES AT TAF
SITES ARE RATHER SLIM. PRECIPITATION SHOULD DISSIPATE WITH THE
SETTING SUN...THEN CIGS NEAR FL040 WILL OVERSPREAD EASTERN
NEBRASKA FROM THE NORTH. SOME MVFR CIGS ARE POSSIBLE IN NORTHEAST
NEBRASKA NEAR KOFK AFTER 06Z...BUT HAVE LEFT OUT OF TAF FORECAST
AT THE MOMENT.

DERGAN

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

ZAPOTOCNY