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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS63 KOAX 222038
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
338 PM CDT TUE APR 22 2014

.SHORT TERM...
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(TONIGHT THROUGH FRIDAY)
ISSUED AT 330 PM CDT TUE APR 22 2014

MAIN FORECAST CONCERN WILL BE CENTERED AROUND THUNDERSTORM CHANCES
THROUGH THURSDAY MORNING.

MID/UPPER LEVEL TROUGH AXIS EXTENDS ACROSS THE INTERMOUNTAIN WEST WITH
IMPRESSIVE 130M HEIGHT FALLS OUT AHEAD OF IT. THIS TROUGH WILL
CONTINUE TO MOVE EAST AND AHEAD OF IT...A DEEPENING LEE SIDE SFC
LOW WILL EXTEND ACROSS THE HIGH PLAINS BY 12Z WED. AHEAD OF ALL OF
THIS...STRONG LOW LEVEL SOUTHERLY FLOW WILL BRING BOTH WARM AND
MOIST AIR ADVECTION INTO THE REGION. AN FEW RADAR RETURNS ARE
SHOWING UP UNDER THE ACCAS FIELD OVER CENTRAL NEBRASKA THIS
AFTERNOON. THE HRRR HAS PICKED UP ON THIS BUT WITH LITTLE UPPER
LEVEL SUPPORT IN THE AREA JUST YET...THINK THESE WILL FADE AS
THEY APPROACH A MUCH DRIER AIRMASS THIS EVENING. NOCTURNAL 850MB
WINDS ON THE ORDER OF 50-60KTS ARE FORECAST OVERNIGHT WHICH WILL
HELP ADVECT +8 TO +10C DEWPOINTS INTO THE AREA BY WED AFTERNOON.
WILL CONTINUE OVERNIGHT/EARLY MORNING TSTM CHANCES IN ASSOCIATION
WITH THE STRENGTHENING LLVL JET. A TIGHTENING SURFACE PRESSURE
GRADIENT BETWEEN THE RETREATING HIGH PRESSURE CURRENTLY OVERHEAD
NOW AND THE APPROACHING HIGH PLAINS LOW WILL BRING QUITE GUSTY
WINDS TO THE AREA WED MORNING AND THROUGH THE EARLY AFTERNOON.
WITH COORDINATION FROM SURROUNDING OFFICES...WILL HOIST A WIND
ADVISORY FOR PORTIONS OF OUR WEST AND NORTH FROM 15-21Z.

EXPECT A LULL IN TSTM ACTIVITY DURING THE LATE MORNING/EARLY
AFTERNOON HOURS WEDNESDAY. THE SFC LOW WILL BE ENTERING INTO
WESTERN KANSAS BY 00Z THU WITH COLD FRONT PUSHING THROUGH CENTRAL
NEBRASKA. THE GREATEST INSTABILITY WILL EXIST OVER NORTH CENTRAL
KANSAS AND SOUTH CENTRAL NEBRASKA AT THIS TIME WITH BULK 0-6KM
SHEAR ON THE ORDER OF 50KTS. CONVECTION IS LIKELY TO DEVELOP
ALONG/AHEAD OF THE COLD FRONT AND SPREAD EAST THROUGH THE LATE
AFTERNOON AND EARLY EVENING HOURS WITH LARGE HAIL AND DAMAGING
WINDS AS THE PRIMARY HAZARDS. PW`S BY EARLY EVENING DO INCREASE TO
AROUND 1.50" SO THE POTENTIAL EXISTS FOR SOME HEAVIER RAINFALL
AMOUNTS.

THE UPPER TROUGH IS FORECAST TO SWING THROUGH CENTRAL NEB BY 12Z
THURSDAY WITH THE SFC COLD FRONT WELL INTO IOWA BY THAT TIME.
LINGERING POST FRONTAL PCPN IS QUITE POSSIBLE IN OUR EASTERN
COUNTIES IN THE MORNING.

BROAD/WEAK UPPER RIDGING WILL MOVE OVERHEAD ON FRIDAY WITH STRONG
SOUTHERLY FLOW SO WE SHOULD BE ABLE TO WARM INTO THE LOW 70S
FRIDAY.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 PM CDT TUE APR 22 2014

GLOBAL MODELS ARE CONSISTENT IN MOVING A TROUGH ACROSS THE ROCKIES
AND INTO THE CENTRAL PLAINS THIS WEEKEND. THE MODELS DIVERGE TO SOME
DEGREE AS TO HOW QUICKLY TO MOVE THE TROUGH OUT OF THE AREA WITH
LITTLE IN THE WAY OF AN UPSTREAM KICKER. THE 00Z ECMWF IS HOLDING
ONTO THIS TROUGH INTO THE DAY ON MONDAY AS THE SLOWEST SOLUTION.
AHEAD OF THE SYSTEM MODIFIED GULF AIR WILL BE ADVANCING NORTHWARD ON
SATURDAY. MOST OF THE DAY ON SATURDAY SHOULD BE DRY BUT A COLD FRONT
WILL MOVE INTO NORTHEAST NEBRASKA BY AFTERNOON AND THIS COULD BE THE
IMPETUS OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS BY AFTERNOON.
AS LARGER-SCALE FORCING INCREASES ON SATURDAY NIGHT...ALONG WITH
STRONGER LOW LEVEL WARM-AIR ADVECTION WE SHOULD SEE AN INCREASE IN
THE AREAL EXTENT OF THE PRECIP...AND LIKELY POPS APPEAR WARRANTED AT
THIS TIME. THE 00Z GFS/GEM WOULD THEN SHIFT THIS FORCING/PRECIP
SOUTH OF THE AREA BY SUNDAY NIGHT WHILE THE ECMWF WOULD CONTINUE
SOME THREAT INTO MONDAY. ALTHOUGH THE SLOWER SOLUTION OF THE ECMWF
ISN`T OUT OF THE QUESTION...GIVEN THE LIMITED SUPPORT WILL CONT WITH
A DRY FORECAST FOR SUNDAY NIGHT THROUGH TUESDAY.

TEMPERATURES WILL WARM INTO THE 70S FOR MOST AREAS ON SATURDAY AHEAD
OF THE COLD FRONT...BUT WITH THE PRECIP AND CAA ON SUNDAY
TEMPERATURES WILL LIKELY HOLD IN THE 60S. TEMPERATURES SHOULD BE ON
THE INCREASE FOR MON/TUE AS A WESTERN US RIDGE DEVELOPS EAST INTO
THE CENTRAL US.
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&&

.AVIATION...
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(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1212 PM CDT TUE APR 22 2014

GENERALLY LOOK FOR VFR CONDITIONS THROUGH THE PERIOD. CEILINGS
MAINLY ABOVE 5000 FEET COULD DEVELOP LATER TONIGHT WITH -SHRA
ACTIVITY. DID NOT MENTION -TSRA IN TAFS FOR NOW...SINCE COVERAGE
MAY BE LIMITED. DECIDED TO ADD IN LOW LEVEL WIND SHEAR FOR TONIGHT
AS WINDS ALOFT BELOW 2000 FEET INCREASE INTO THE 40 TO 50 KNOT
RANGE OR MORE.
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&&

.OAX WATCHES/WARNINGS/ADVISORIES...
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NE...WIND ADVISORY FROM 10 AM TO 4 PM CDT WEDNESDAY FOR NEZ011-012-
     015>018-030>034-042>044-050-051-065-066-078-088-089.

IA...WIND ADVISORY FROM 10 AM TO 4 PM CDT WEDNESDAY FOR IAZ043.
-- End Changed Discussion --

&&

$$

SHORT TERM...KERN
LONG TERM...MILLER
AVIATION...MILLER