FXUS63 KOAX 060807
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
307 AM CDT MON OCT 6 2008

.DISCUSSION...

LONG WAVE TROF ACROSS THE WESTERN CONUS WL CONTINUE TO PUSH INTO
THE CNTRL PLAINS IN NEXT COUPLE OF DAYS BRINGING WIDESPREAD PCPN
TO THE CWA. MODEL TRENDS CONTINUE TO SHOW A SLOWER PROGRESSION IN
MOVING THE TROF ACROSS THE CNTRL PLAINS. SCATTERED SHOWERS
CONTINUE ACROSS MUCH OF THE CNTRL PLAINS AS SEVERAL IMPULSES HAVE
EJECTED OUT AHEAD OF MAIN TROF AXIS. ISENTROPIC LIFT AHEAD OF THE
SYSTEM ADDS TO FORCING FOR SCATTERED ACTIVITY.

PCPN IS EXPECTED TO BECOMG MORE WIDESPREAD FROM WEST TO EAST BY
LATE THIS AFTERNOON/EARLY EVENING AS FORCING FROM LEAD IMPULSES
MOVES EAST TOWARD IOWA. PLENTY OF MOISTURE WILL BE IN PLACE BY
LATE THIS AFTERNOON WITH PW'S BY 00Z AROUND 1.50". STRONGEST
FORCING FOR ASCENT SHOULD OCCUR OVR THE FORECAST AREA THIS EVENING
INTO THE OVERNIGHT HOURS AHEAD OF THE MAIN TROF AS IT MAKES ITS
WAY THRU CNTRL NEB. REGIONAL CROSS SECTIONS SHOW STRONG 700-500MB
FRONTOGENETICAL FORCING ACROSS CNTRL AND ERN NEBRASKA BETWEEN 00Z-06Z.
AT THE SAME TIME...SFC CDFNT WL BE PUSHING EWD THRU THE FORECAST
AREA. BREEZY CONDITIONS EXPECTED BEHIND THE FRONT WITH A TIGHT SFC
PRESSURE GRADIENT AND NEARLY 50KTS AT 850MB.

PCPN IS EXPECTED TO LINGER INTO TUESDAY MORNING...ENDING FM WEST
TO EAST BY AFTERNOON. WEAK UPPER RIDGING BUILDS IN QUICKLY BEHIND
THE TROF FOR OVERNIGHT TUESDAY INTO EARLY WEDNESDAY. AREAS OF FOG
QUITE POSSIBLE DURING THIS TIME FRAME AS WK SFC RIDGE BUILDS ACROSS
THE AREA. HAVE DROPPED LOWS CLOSER TO MOS GUIDANCE FOR WED MORNING
WHICH BRINGS UPPER 30S TO LOW 40S INTO THE FAR NRN COUNTIES.

MODELS ARE IN AGREEMENT FOR A MILD AND DRY DAY ON THURSDAY. AFTER
THAT HOWEVER...DISAGREEMENT IN EXTENDED MODELS LEADS TO LOW
FORECASTER CONFIDENCE THRU THE REMAINDER OF THE EXTENDED. WL LET CURRENT
EXTENDED GRIDS RIDE.

&&

.AVIATION...

FOR TAF SITES KOMA/KLNK/KOFK THRU 07/06Z.

SCT -SHRA WILL CONTINUE TO AFFECT KOFK THRU THE PERIOD...BECOMING
PREVAILING BY ABOUT 14Z. VFR CONDITIONS INITIALLY...BUT TEMPORARY
MVFR CIGS AND VISBYS FROM ABOUT 16Z-20Z...THEN PREVAILING MVFR
CONDITIONS BY 20Z AND BEYOND. BEST POTENTIAL FOR ANY CONVECTION
APPEARS TO BE FROM ABOUT 20Z-00Z...AND THEN IFR CONDITIONS IN RAIN
BY 00Z AS THE FRONT MOVES THROUGH AND WINDS SHIFT TO THE NORTHWEST.

AT KLNK/KOMA...VFR AND DRY CONDITIONS ARE FORECAST UNTIL MUCH
LATER...WITH FIRST CHANCE FOR ANY SCT -SHRA AT KLNK BY 15Z...AND NOT
UNTIL 17Z AT KOMA. MVFR CIGS AND PREVAILING -SHRA ARE EXPECTED AT
KLNK BY 19Z...AND KOMA BY 21Z. AGAIN...APPEARS TO BE ABOUT A 4 HOUR
WINDOW FOR CONVECTION AT EITHER SITE...BY 20Z AT KLNK AND 22Z AT
KOMA...THEN TRANSITIONING TO IFR CONDITIONS BY 00-02Z. FRONT ARRIVAL
AND SUBSEQUENT WIND SHIFT NOT EXPECTED AT KLNK/KOMA UNTIL 06Z-12Z...
WHICH WILL BE ADDRESSED IN THE TAF ISSUANCE.

&&

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

$$

GRIFFIS/DEWALD


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