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000
FXUS63 KOAX 241952
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
252 PM CDT FRI MAY 24 2013

.DISCUSSION...

TIMING OF BEST PRECIPITATION CHANCES THROUGH MEMORIAL DAY WEEKEND
AND BEYOND MAIN CHALLENGE AND CONFIDENCE OF SKILL BEYOND
CLIMATOLOGY...I.E. HIGHEST POPS AT NIGHT...NOT THE HIGHEST.

18Z SURFACE + 12Z UPPER AIR ANALYSIS HAD SURFACE TO 850 MOIST
AXIS AND SUBJECTIVELY PLACED WARM FRONT FM SCNTRL KS INTO SWRN
NEBR. ALTHOUGH A FEW HIGH BASED SHOWERS DEVELOPING NE OF BOUNDARY
IN SCNTRL NEBR AND OTHER POSSIBLE HIGHER BASED ACTIVITY ACROSS
NRN/NERN ZONES EARLY WILL HAVE TO BE MONITORED...MAIN ACTION OVER
THE FORECAST AREA WILL PROBABLY BE FROM LATE THIS EVENING THROUGH
OVERNIGHT HOURS. ANY CONVECTION THAT INCREASES THROUGH THIS
EVENING WRN HIGH PLAINS WILL BE AIDED BY DECENT THETA ADVECTION
INTO BOUNDARY AS LOW LEVEL JET STRENGTHENS. 12Z GFS WAS PROBABLY
SUFFERING FEEDBACK ISSUES BY 12Z SAT IN SRN PLACEMENT OF MCS.
HOWEVER...SOME SRN EXTENSION OF AN MCS COULD MAKE IT INTO FAR
SWRN ZONES EARLY TONIGHT THUS LIKELY POPS ALL OF WRN ZONES JUST
AFT 06Z WITH ANY ACTIVITY THEN FOCUSING MORE ACROSS NERN ZONES SAT
MORNING BEFORE EXPECTED DECLINE.

AFTER TONIGHT DEEPER MOISTURE WILL OVERSPREAD MUCH OF THE
FORECAST AREA WITH MUCH HIGHER THAN NORMAL PRECIPITABLE WATER
VALUES GENERALLY LOCKED IN TILL MUCH OF THE ENERGY FROM WRN U.S.
TROUGH EJECTS LATE NEXT WEEK. WITH MOISTURE/INSTABILITY IN PLACE
AND SOME SORT OF WARM FRONT OR CONVECTIVELY ENHANCED BOUNDARY
POSSIBLY REMAINING OVER OR NEAR AREA...STRENGTHENING NOCTURNAL LOW
LEVEL JET PLUS ANY DISTURBANCES LIFTING OUT OF WRN TROUGH COULD
KEEP ACTIVE PATTERN IN PLACE...ESPECIALLY THROUGH HOLIDAY WEEKEND
AND THEN AGAIN BY NEXT THURSDAY. ALTHOUGH DID TRY TO DIURNALLY
DECREASE CHCS FROM SW TO NE ACROSS AREA ON SATURDAY...AFTER THAT
MADE LITTLE CHANGES TO POPS THROUGH MONDAY...WITH LIKELY POPS
GENERALLY RESERVED FOR NIGHTTIME WITH DECREASED DAYTIME POPS IN
TUE/WED PERIOD.

OVERNIGHT/EARLY SATURDAY CONVECTION COULD REINFORCE BOUNDARY
ACROSS FORECAST AREA SATURDAY...THUS KEPT TEMPS CLOSER TO A 00Z
ECMWF/12Z NAM COMPROMISE NRN AREAS WITH ANY 80+ MENTION CONFINED
TO SOUTHERN ZONES. AFTER MOISTURE BECOMES MORE UNIFORM OVER THE
AREA BEYOND SATURDAY...BETTER SFC THERMAL GRADIENT MAY SHIFT NE
OF AREA THUS PROVIDING MORE UNIFORM TEMPS ALTHOUGH 00Z ECMWF KEPT
SOME BOUNDARY/SLIGHTLY COOLER TEMPS OVER AREA THROUGH MONDAY.

CHERMOK

&&

.AVIATION...
18Z TAFS FOR KOMA...KLNK AND KOFK.

VFR CONDITIONS WILL PREVAIL AT LEAST THRU EARLY THIS EVENING.
THEREAFTER...EXPECT SCT TSRA DEVELOPMENT IN CNTRL NEB WITH
ACTIVITY PUSHING INTO ERN NEB TWD MIDNIGHT. OCCASIONAL STRONG
TSRA WILL BE POSSIBLE IN RESPONSE TO STRENGTHENING LLVL JET. EARLY
SAT MORNING...INFLUX OF LLVL MOISTURE WILL RESULT IN IFR CIGS
SETTLING IN OVER ERN NEB THRU MOST OF THE MORNING HOURS.

DEE

&&

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

$$

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