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000
FXUS63 KOAX 190837
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
337 AM CDT WED JUN 19 2013

.DISCUSSION...

ALTHOUGH WE ARE NOT EXPECTING A CONTINUOUS PERIOD OF SHOWERS AND
THUNDERSTORMS OVER THE NEXT 48 HOURS...IT REALLY IS DIFFICULT TO
DISCERN ANY PERIOD IN THAT TIME THAT SHOULD NOT WARRANT AT LEAST
A SLIGHT CHANCE POP. THEREFORE...WE WILL BE CARRYING A SMALL POP
FOR PORTIONS OF THE CWA THROUGH THIS TIME WITH GREAT UNCERTAINTY
ON TIMING/LOCATION. MODEL GUIDANCE HAS PERFORMED RATHER POORLY ON
WEAK CONVECTIVE EVENTS IN THE PAST COUPLE DAYS AND SO FORECASTER
CONFIDENCE REMAINS LOW.

UPPER AIR ANALYSIS AND WATER VAPOR IMAGERY SHOW A LARGE TROUGH OFF THE
PACIFIC COAST WITH THE LOW PRESSURE CENTERED JUST OFF THE
OREGON/WASHINGTON COASTS. OUT AHEAD OF THIS IS A WEAK RIDGE OF
HIGH PRESSURE EXTENDING FROM THE SOUTHERN PLAINS INTO THE WESTERN
DAKOTAS. SEVERAL WEAK IMPULSES ARE EMBEDDED WITHIN THE SOUTHWEST
FLOW IN BETWEEN THE MAIN FEATURES. THE FIRST SHORTWAVE OF CONCERN
IS CURRENTLY LOCATED OVER THE NEBRASKA PANHANDLE. LATEST REGIONAL
RADAR MOSIAC SHOWS A CONVECTIVE COMPLEX SLOWLY DRIFTING EAST AND
WEAKENING ACROSS WESTERN NEBRASKA WHILE ANOTHER MOVES SLOWLY
NORTHEAST ACROSS NORTHWEST KANSAS AND WEAKENS. LATEST RAP BRINGS
A HINT OF THIS ACTIVITY INTO THE FORECAST AREA THROUGHOUT THE
MORNING AND AM GOING TO TWEEK POPS ACCORDINGLY. BROAD SCALE LIFT
ASSOCIATED WITH THE MID LEVEL IMPULSE WILL STILL BE PRESENT INTO
THE AFTERNOON AND AS INSTABILITY INCREASES WITH DAYTIME
HEATING...FEEL THUNDERSTORMS HAVE A CHANCE TO CONTINUE ACROSS THE
FORECAST AREA IN A BROAD LOW LEVEL WARM AIR ADVECTION REGIME.

LOW LEVEL JET WILL VEER SLIGHTLY OVERNIGHT AND COULD SUSTAIN
CONVECTIVE ACTIVITY...THEREFORE WILL CONTINUE A POP THROUGH THE
OVERNIGHT. BY THURSDAY...THE UPPER RIDGE AXIS WILL BE DIRECTLY
OVERHEAD AND EXTEND INTO THE EASTERN DAKOTAS. IN ADDITION...A SFC
COLD FRONT WILL EXTEND SOUTH ACROSS THE CENTRAL DAKOTAS AND INTO
NORTHWEST NEBRASKA WHICH WILL LIKELY BE THE FOCUS FOR THUNDERSTORM
DEVELOPMENT. VERY STRONG INSTABILITY WILL EXIST IN OUR NORTHERN
CWA HOWEVER A QUITE STOUT CAP WILL ALSO BE IN PLACE WHICH MAY
PROHIBIT THE EASTWARD EXPANSION OF TSTMS. SPC HAS INCLUDED OUR
NORTH IN THE SWODY2 FOR ANY MCS ACTIVITY MOVING SOUTHEAST FROM NRN
PLAINS CONVECTION. THIS WILL BE AIDED BY A VEERING SOUTHWEST LOW
LEVEL JET AND SO HAVE HIGHER POPS GOING IN OUR NORTH.

THE AREA IS DOMINATED BY SOUTHWEST FLOW ALOFT INTO THE WEEKEND WITH
THE MAIN UPPER LOW MOVING ACROSS THE PACIFIC NORTHWEST AND TOWARD
THE NORTHERN PLAINS. THE MAIN SFC BOUNDARY WILL REMAIN TO OUR
NORTH LEAVING THE REGION IN THE WARM SECTOR. HIGHS WILL LIKELY TOP
OUT IN THE LOW 90S.

AS THE UPPER LOW MOVES TOWARD THE NORTHERN PLAINS BY SUNDAY...THE
SFC FRONT WILL DROP SOUTH INTO THE AREA AND BE THE POTENTIAL FOCUS
FOR THUNDERSTORMS.

KERN

&&

.AVIATION...

06Z TAFS FOR KOMA...KLNK...KOFK.

VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH HIGH LEVEL CIGS
ACROSS THE AREA MUCH OF THE TIME. SOME CHANCE OF ISOLATED THUNDER
AFTER 18Z BUT NOT INCLUDED AT THIS TIME.

&&

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

$$