000
FXUS63 KOAX 050857
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
257 AM CST FRI DEC 5 2008

.DISCUSSION...
CHANCE FOR PCPN FROM TONIGHT THROUGH MONDAY NIGHT AND TEMPERATURES
OVER THE NEXT SEVERAL DAYS ARE THE MAIN FORECAST CONCERNS. OVERALL
DID NOT MAKE ANY SIGNIFICANT CHANGES FROM THE PREVIOUS FORECAST.
SURFACE ANALYSIS EARLY THIS MORNING SHOWED COLD HIGH PRESSURE OVER
MUCH OF THE PLAINS. CENTER OF THE HIGH HAD PUSHED DOWN INTO KANSAS
AND MISSOURI...SO WARMER AIR WAS ALREADY RETURNING ALOFT FROM OUR
AREA NORTHWARD. EXPECT A DECENT WARMUP FOR TODAY...COMPARED TO THE
COLD AND BLUSTERY CONDITIONS OF YESTERDAY. MODELS STILL INDICATED
INCREASING 1000-500 MB THICKNESS VALUES AND LOW LEVEL WARM AIR
ADVECTION. 850 MB TEMPERATURES SHOULD REACH -4 TO -6 C ACROSS THE
WESTERN ZONES AND -7 TO -8 C IN THE EASTERN ZONES. KEPT HIGHS FOR
THIS AFTERNOON MAINLY IN THE LOWER AND MID 30S...WITH SOME UPPER
30S ACROSS PARTS OF SOUTHEASTERN NEBRASKA. SOUTHWEST WINDS SHOULD
PROVIDE A MODEST DOWNSLOPE COMPONENT.

WE GENERALLY REMAIN IN A NORTHWEST FLOW PATTERN ALOFT THROUGH THE
FIRST PART OF THE WEEKEND...THEN FLOW DOES FLATTEN AND BECOME A
BIT MORE ZONAL ON SUNDAY. THE WARM UP TODAY WILL BE SHORT LIVED.
THE NEXT FRONT OF INTEREST WILL BE PUSHING DOWN OVER THE NORTHERN
PLAINS THIS EVENING AND INTO OUR AREA FOR LATE TONIGHT. SHORTWAVE
TROUGH WILL DROP QUICKLY SOUTHEAST FROM THE NORTHERN ROCKY MOUNTAIN
REGION...BRINGING A SLIGHT CHANCE FOR SNOW. BEST LIFT SHOULD BE OFF
TO OUR NORTH AND EAST...SO KEPT POPS MOSTLY AROUND 20 PERCENT FOR
TONIGHT. SOME FLURRIES COULD LINGER SATURDAY MORNING...THEN A COLD
RIDGE OF HIGH PRESSURE BUILDS IN. LOW LEVEL WARM AIR ADVECTION/
ISENTROPIC UPGLIDE ON THE BACKSIDE OF THE HIGH INCREASES FOR LATE
SATURDAY NIGHT INTO SUNDAY. WILL HAVE TO KEEP AN EYE ON THIS ONE
BUT FOR NOW...THINK SNOW AMOUNTS AROUND AN INCH ARE POSSIBLE IN
NORTHEAST NEBRASKA. AMOUNTS SHOULD BE LESS FARTHER SOUTH. MIXING
RATIO VALUES IN THE 700-750 MB LAYER COULD BE 3 G/KG OR MORE FROM
THE 00Z GFS...BUT OMEGA VALUES ARE NOT OVERLY IMPRESSIVE AND SEEM
TO PEAK AROUND 06Z IN NORTH CENTRAL NEBRASKA.

ONLY MADE MINOR TWEAKS TO THE REST OF THE FORECAST.

&&

.AVIATION...
FOR TAF SITES KOFK/KOMA/KLNK THROUGH 06/06Z.

VFR CONDITIONS EXPECTED AT ALL SITES THRU 0600Z WITH MID-HIGH LEVEL
CLOUDS SPILLING INTO THE REGION IN ADVANCE OF NEXT CLIPPER SYSTEM
TRACKING ACROSS CANADA TOWARD THE UPPER GREAT LAKES. MVFR CONDITIONS
DEVELOPING AFTER 0600Z AS NEXT SURGE OF COLD AIR SWEEPS INTO THE
REGION.

&&

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

$$

DISCUSSION...MILLER
AVIATION...FOBERT