FXUS63 KOAX 240828
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
328 AM CDT FRI SEP 24 2010
.DISCUSSION...
MAIN CONCERN IS CHANCE FOR PCPN FROM TONIGHT INTO SATURDAY NIGHT.
WATER VAPOR LOOP SHOWED SYSTEM THAT MOVED ACROSS THE NRN AND CNTRL
PLAINS YESTERDAY CONTINUED TO PUSH EWD. SEVERAL SHORTWAVE TROUGHS
WERE MOVING EASTWARD FROM THE PACIFIC NW AND NRN ROCKIES IN FAST
NEARLY ZONAL MID TROPOSPHERIC FLOW. AT THE SURFACE...HIGH PRES WAS
BUILDING EWD FROM THE WRN PARTS OF THE DKTS...NE AND KS. THIS WILL
MOVE ACROSS THE AREA TODAY...WITH RETURN FLOW DEVELOPING OVER OUR
WRN ZONES BY EARLY THIS EVENING. BASED ON EXPECTED MIXING...THE
PREVIOUSLY FORECAST HIGHS IN THE LOWER AND MID 70S SEEMED ON TRACK
AND ONLY MADE VERY MINOR CHANGES.
ALTHOUGH WE WILL NOT HAVE NEARLY THE SAME AMOUNT OF MOISTURE TO WORK
WITH LATE TONIGHT AND SATURDAY...COMPARED TO THURSDAY...ISENTROPIC
UPGLIDE IN THE 305-310K LAYER SHOULD BE ENOUGH TO HELP GENERATE
PCPN. (THURSDAY MORNING THE PRECIPITABLE WATER AT KOAX WAS 2.17
INCHES AND THE 850 MB DEWPOINT WAS 17.4 DEGS C.) 00Z NAM FORECAST
SOUNDINGS SUGGESTED PRECIPITABLE WATER VALUES UP TO ABOUT 1.30 INCHES
AHEAD OF THE COLD FRONT AND SURFACE LOW ON SATURDAY. LAPSE RATES
STILL LOOK STEEP ENOUGH FOR AT LEAST SOME ISOLATED TSTMS...AND THERE
IS ALSO SOME WEAK NEGATIVE EPV. THE BEST BET FOR TSTMS THAT COULD
APPROACH SEVERE LIMITS LATER TONIGHT AND EARLY SATURDAY MORNING IS
ON THE NOSE OF 40-50 KT LOW LEVEL JET...MOST LIKELY ACROSS PARTS OF
NERN NE AND WCNTRL IA.
CHANCE OF MEASURABLE PCPN SHOULD DECREASE QUICKLY SATURDAY EVENING
AND ONLY KEPT A SLIGHT CHANCE IN FOR EXTREME SERN CWA TO BLEND IN
WITH NEIGHBORS. IT LOOKS LIKE THERE WILL BE SOME LOW CLOUDS AROUND
THROUGH NOON SUNDAY...BUT OTHER THAN MAYBE SOME DRIZZLE OR A FEW
SPRINKLES IT SHOULD BE MAINLY DRY.
LARGE SCALE FLOW WILL BE MAINLY FROM THE NORTHWEST FOR THE REST
OF THE WEEK...AS RIDGE OVER THE SWRN U.S. MOVES EWD. DID NOT
MENTION ANY PCPN...BUT THERE WILL BE A COUPLE OF FRONTAL PASSAGES
DURING THIS TIME AND MAY NEED TO REVISE IN FUTURE FORECASTS.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
SYNOPSIS...AT 06Z CDFNT EXTD SWWD FROM SFC LOW THRU ERN IA-ERN
KS-ERN CO. VFR CONDITIONS EXPECTED TO PREVAIL THRU THE FCST PD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
DISCUSSION...MILLER
AVIATION...DEE