000
FXUS63 KOAX 080720
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
220 AM CDT MON SEP 8 2008
.DISCUSSION...
UPPER DIVG ASSOCIATED WITH RRQ OF NEAR ZONAL JET MAX INFLUENCING
HEAVY BAND OF POST-FRONTAL PCPN THIS MORNING ALONG THE SD/NEB BORDER.
ALSO AIDING WAS EMBEDDED IMPULSES MIGRATING WITHIN BROAD SCALE UPPER
LEVEL TROF ACROSS THE NRN CONUS. MEANWHILE...ATTENDANT SURFACE COLD
FRONT EXTENDED FROM ABOUT NRN IA TO NE CO WITH SECOND LARGE AREA OF
CONVECTIVE PCPN IN NE CO/NW KS. MODELS IN VERY GOOD AGREEMENT
SCENARIO SETTING UP FOR LIKELY HEAVY RAINFALL EVENT THIS MORNING...
ESPECIALLY OVER THE SRN CWA WHEN UPPER TROF AXIS FORCES DEEP LYR
FRONTOGENESIS SOUTHWARD INTO MORE MOISTURE RICH ENVIRONMENT. MODELS
ADVERTISE BRUNT OF DYNAMICS/MAX LIFT GRADUALLY SHIFTING INTO THE MID
MS VLY THROUGH LATE AFTERNOON WITH DOWNGLIDE/SUBSIDENCE FILLING IN
FROM THE NRN PLAINS. AT THIS POINT...GUESSING PCPN AMOUNTS WILL
GENERALLY RANGE ANYWHERE FROM HALF AN INCH TO AN INCH...WITH
POTENTIALLY UP TO 2 INCHES LOCALLY. DRY CONDITIONS THEN ON TAP MONDAY
NIGHT THRU WEDNESDAY MORNING. NEXT SHORTWAVE TROF PUSHES ACROSS THE
PAC NW LATE WEDNESDAY AND INDUCES CYCLOGENESIS OVER THE CNTRL HIGH
PLAINS. LLVL SLY FLOW AHEAD OF THIS SYSTEM ALLOWS STOUT INFLUX OF
GULF MOISTURE/UNSTABLE AIRMASS INTO THE PLAINS...THUS SETTING UP
THUNDER CHANCES WEDNESDAY AFTERNOON AND NIGHT. MODELS AGAIN SEEM TO
BE IN RATHER GOOD AGREEMENT WITH QPF PLACEMENT...THUS INCREASING
CONFIDENCE. BY EARLY THURSDAY MORNING...SFC COLD FRONT BEGINS
CROSSING THRU THE CWA PROMPTING CONTINUATION OF POPS THRU THE DAY.
AS FOR TEMPS...LOW 40S FORECASTED TONIGHT FOR OMA AND LNK WILL
APPROACH RECORD LOWS AT BOTH. MEANWHILE...WARMEST DAY IN THE SHORT
TERM PD SHOULD BE WEDNESDAY WITH MID-UPPER 70S IN WAA FLOW ACROSS THE
AREA.
&&
.AVIATION...
FOR TAF SITES KOMA/KLNK/KOFK VALID THRU 09/06Z.
RAIN WAS SHOULD CONTINUE AT KOFK THROUGH 18Z WITH COVERAGE EXPECTED
TO INCREASE AT KLNK AND KOMA BY 12Z. PCPN THEN SHOULD PERSIST AT
KLNK AND KOMA THRU 21Z BEFORE BECOMING MORE INTERMITTENT BEFORE
ENDING BY 00Z. VSBYS IN THE RAIN SHOULD GENERALLY BE ABV 5SM BUT
COULD OCNLY DROP TO 2-3SM. APPEARS CONVECTION SHOULD RMN S OF TAF
SITES...ALTHOUGH A TSTM COULD GET CLOSE TO KLNK IN 12Z-18Z PD.
WDSPRD MVFR CIGS SHOULD DVLP OVR TAF SITES BY 12Z WITH AN OCNL DROP
INTO IFR RANGE PSBL AT KOFK AND KLNK. MVFR CIGS EXPECTED TO
LIFT/CLR OUT IN KOFK VCNTY IN 21Z-24Z PD AND BTWN 00Z AND 03Z AT
KOMA AND KLNK.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
DEE/RC
