FXUS63 KOAX 150924
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
324 AM CST WED DEC 15 2010
.DISCUSSION...
MAIN FORECAST CHALLENGE THIS MORNING IS CHANCES OF PCPN AND PCPN
TYPE.
VIGOROUS TROF MOVING ACROSS MT WL CONT TO MOVE E/SE TODAY AND WL
SEND A COUPLE OF QUICK MOVING PIECES OF ENERGY ALONG THE BOTTOM OF
THE TROF EWD ACROSS NEB/SD TODAY. BROAD AREA OF SFC LOW PRESSURE
CURRENTLY EXTENDS ACROSS THE HIGH PLAINS REGION AND IS FORECAST
TO BECOME MORE ORGANIZED ACROSS ERN COLORADO AND BEGIN QUICKLY
TRACKING SEWD INTO THE SRN PLAINS THIS AFTERNOON. BY 18Z...A WEAK
INVERTED TROF WL EXTEND FROM THE LOW PRESSURE CENTER OVER SERN CO
INTO NERN NEB AND ERN SD. ATMOSPHERE REMAINS FAIRLY DRY AHEAD OF
THIS TROF IN THE LOWER AND MID LEVELS THRU 18Z BUT BEGINS TO
SATURATE QUICKLY THIS AFTERNOON AHEAD OF THE APPROACHING SHORTWAVE
ENERGY AND AS SFC TROF WASHES OUT. INCREASING LARGE SCALE VERTICAL
MOTION AHEAD OF THE SHORTWAVE ENERGY IN ADDITION TO ISENTROPIC
LIFT AROUND 295K SFC SHOULD PROVIDE ENOUGH LIFT TO PRODUCE AREAS
OF PCPN ACROSS OUR NORTHERN COUNTIES AS MOISTURE CONTINUES TO
INCREASE THIS AFTERNOON. UNCERTAINTY LIES IN HOW FAR SOUTH TO
BRING PCPN...WITH THE GFS BEING THE ODD MODEL OUT. 03Z SREF/06Z
NAM AND 00Z ECMWF HAVE ALL COME IN WITH SLIGHTLY HEAVIER QPF
VALUES THAN PREVIOUS RUNS SO HAVE UPPED THE POPS TO HIGH CHANCE
CATEGORY IN THE NORTH. AS FAR AS PCPN TYPE...LOOKS LIKE SFC TEMPS
WL REMAIN BELOW 32F WITH A MID LEVEL WARM LAYER BETWEEN .5 AND 3C
WHICH BY TOP DOWN METHOD WOULD INDICATE MORE SLEET/SNOW THAN
FREEZING RAIN...ALTHOUGH A FEW PERIODS OF -FZRA IN THE VERY ONSET
OF PCPN CANNOT BE RULED OUT. HAVE GONE PRIM ARLY WITH SN/SLEET IN
THE AFTERNOON...WITH A CHANGE OVER TO ALL -SN AFTER 00Z. FORCING
MECHANISMS WEAKEN SIGNIFICANTLY AFTER 00Z SO NOT EXPECTING MUCH
IF ANY ACCUMULATING SNOW AFTER 00Z WITH THE EXCEPTION OF OUR FAR
NERN COUNTIES WHERE AN ADDITIONAL FEW TENTHS COULD BE POSSIBLE.
ALL TOTAL...LOOKS LIKE NORTHERN COUNTIES COULD SEE AN INCH OR LESS
OF ACCUMULATING SLEET/SNOW WITH LESS IN THE SOUTH.
AFTER THIS SYSTEM MOVES THRU...WEAK HIGH PRESSURE BUILDS SOUTH
OVER THE AREA WITH CONTINUED VERY WEAK CAA. DOES NOT LOOK LIKE SFC
HIGHS WL WARM OVER THE FREEZING MARK ANYTIME SOON FOR MUCH OF THE
AREA. WESTERN COUNTIES MAY BE AN EXCEPTION EARLY NEXT WEEK AND
SLIDE INTO THE LOWER 30S. CURRENTLY HAVE A DRY FORECAST GOING
AFTER TODAY WITH NO MAJOR SYSTEMS ON THE HORIZON.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
VFR CONDITIONS INITIALLY AT ALL TAF SITES. MVFR CIGS SHOULD DEVELOP
AT KOFK BY 18Z...WITH A SMALL CHANCE OF SOME -FZRA FROM
19-23Z...THEN 2SM -SN FROM 23-02Z...WITH IFR CONDITIONS BEYOND THEN.
PRECIP WILL LIKELY REMAIN NORTH/EAST OF KLNK/KOMA...ALTHOUGH MVFR
CIGS SHOULD DEVELOP BY 16/03Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
KERN/DEWALD