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000
FXUS63 KOAX 231130
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
630 AM CDT WED JUL 23 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 231 AM CDT WED JUL 23 2014

...MAIN FORECAST CONCERNS ARE THUNDERSTORM CHANCES...

DURING THIS FORECAST PERIOD THE UPPER RIDGE OVER THE HIGH PLAINS
SHOULD DEAMPLIFY AND BECOME RELATIVELY FLAT OVER THE FORECAST
AREA...ALLOWING FOR A MINOR SHORTWAVE TO RIDE OVER THE RIDGE AND
INTO THE AREA. THIS WAVE WILL BE ACCOMPANIED BY A SURFACE LOW AND
ASSOCIATED COLD FRONT WHICH IS EXPECTED TO PUSH THROUGH ON
FRIDAY.

THE WATER VAPOR LOOP EARLY THIS MORNING SHOWED A COUPLE OF AREAS
OF SHEARED VORTICITY MOVING UP THE WEST SIDE OF THE UPPER RIDGE
INTO IDAHO...WHICH SHOULD END UP BEING THE SHORTWAVE THAT DROPS
DOWN THE EAST SIDE OF THE RIDGE THURSDAY AND FRIDAY. AT THE
SURFACE...A COLD FRONT HAD MOVED THROUGH THE FORECAST AREA
TUESDAY EVENING WITH SURFACE HIGH PRESSURE OVER THE DAKOTAS PER
THE 08Z SURFACE ANALYSIS. AIRMASS OVER THE REGION WILL BE SOMEWHAT
DRY UNTIL RETURN FLOW CAN BE ESTABLISHED ON THURSDAY. THIS IS
SIGNIFICANT BECAUSE MOST MODELS TRY TO DEVELOP PRECIPITATION...
TRIGGERED BY SHORTWAVE...OVER EASTERN NEBRASKA WEDNESDAY
AFTERNOON AND EVENING. GENERALLY WE THINK THE AIRMASS OVER THE
AREA WILL BE TOO DRY AND STABLE TO SUPPORT THIS...AND HAVE
THEREFORE KEPT POPS LOW OR DRY WEDNESDAY INTO WEDNESDAY NIGHT WITH
SOME MENTION ONLY IN THE FAR NORTHERN COUNTIES.

ON THURSDAY/THURSDAY NIGHT...THERE IS INCREASED SUPPORT FOR RAIN
CHANCES DUE TO THE RAPID INTENSIFICATION OF THE LOW LEVEL FLOW
OUT OF THE SOUTH...AND QUICK RETURN OF HIGH SURFACE DEWPOINTS.
THIS COMBINED WITH VERTICAL MOTION FROM APPROACHING FRONT AND THE
UPPER SHORTWAVE COULD BE ENOUGH TO SUSTAIN EITHER ON-GOING
CONVECTION MOVING INTO THE AREA FROM THE WEST...OR PERHAPS THE
DEVELOPMENT OF NEW CONVECTION. THEREFORE KEPT GOING POPS ALL
AREAS...BUT STILL ONLY 20-35 PERCENT WITH HIGHER CHANCES NORTH IN
SLIGHTLY LESS CAPPED AREAS.

THE SOUTH FLOW SHOULD RESULT IN FAIRLY WARM TEMPERATURES AGAIN FOR
FRIDAY...WITH SOUTHERN AREAS HITTING MID 90S AND 70+ DEWPOINTS.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 231 AM CDT WED JUL 23 2014

THE ABOVE MENTIONED WAVE AND FRONT SHOULD MOVE THROUGH FRIDAY
NIGHT WITH THE AREA BEING DOMINATED BY A LARGE AREA OF HIGH
PRESSURE AT THE SURFACE THAT SLOWLY BUILDS INTO THE REGION FROM
CANADA...WHICH WILL BE A REFLECTION OF THE REBUILDING UPPER RIDGE
OVER THE NORTHERN ROCKIES. MINOR SHORTWAVES WILL LIKELY MOVE
THROUGH THE FLOW...BUT BOUNDARY LAYER IS EXPECTED TO BE DRY AND
STABLE ENOUGH TO GREATLY LIMIT ANY THUNDERSTORM DEVELOPMENT.
TEMPERATURES SHOULD BE CLOSE TO NORMAL...WITH BELOW NORMAL
TEMPERATURES EXPECTED BY EARLY NEXT WEEK.

&&

.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 628 AM CDT WED JUL 23 2014

MAINLY VFR CONDITIONS ARE FORECAST THROUGH THURSDAY MORNING. MID
LEVEL WAVE TRIGGERING THUNDERSTORMS IN CENTRAL NEBRASKA SHOULD
KEEP THAT ACTIVITY WELL WEST OF TAF SITES TODAY. ONLY HIGH CLOUDS
ARE EXPECTED WITH LIGHT NORTHEAST WINDS. ANOTHER MID LEVEL WAVE
WILL MOVE INTO THE REGION OVERNIGHT COULD TRIGGER MORE
THUNDERSTORMS AFTER 06Z. THESE COULD AFFECT KOFK BEFORE 12Z BUT
WILL LIKELY REMAIN NORTHWEST.

&&

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

$$

SHORT TERM...NIETFELD
LONG TERM...NIETFELD
AVIATION...DERGAN