588 
fxus63 koax 202028 
afdoax 


Area forecast discussion 
National Weather Service Omaha/valley NE 
228 PM CST Thursday Nov 20 2008 


Short term...tonight through Sunday. Temperatures are expected to 
really drop this evening as a 1040mb high pressure center moves 
overhead. This will allow winds to become light and skies to clear 
which will be ideal radiative conditions. Still continue to prefer 
the colder met/NAM guidance over the warmer mav guidance...especially 
in favored low lying valleys and where winds go calm. 


Now that the wave moving into the Pacific northwest is well within 
the upper air coverage network...models are very consistent in 
their timing and latitudinal placement of the next round of snow 
scheduled for Friday afternoon/night...and mostly just north of 
our County warning forecast area. However...some flurries may still develop across 
northeast Nebraska Friday afternoon...but the best lift will 
remain across South Dakota. Some light flurries or snow showers 
may also occur in extreme northern County warning forecast area Friday night as the nose 
of the warm air advection pattern moves through. H850 temperatures warm to just below 
freezing...thus was some concern that there could be a wintry 
mixture of precipitation on the southern edge...but will keep it just a 
20 percent chance of snow for now. 


We do begin a decent warmup on Saturday as the return flow sets 
up...with 850 mb temperatures warming to +2 to +5 by Saturday evening. This 
should result in temperatures in the upper 40s to lower 50s. Another front 
is expected to move into the region on Sunday. As with yesterday's 
front...it should be fairly mild along/ahead of the front...thus 
boosted temperatures into the upper 40s to lower 50s once again...and 
temperatures could even be raised a degree or two more...especially if a 
slightly slower NAM solution verifies. 


Long term...Sunday night through Thursday. Little change to 
current trend of the forecast in the extended period. Active 
weather expected north and east of the area during this time as 
another strong wave drops out of central Canada and tracks across 
the Great Lakes region into the northeast. 00z European model (ecmwf) and 12z GFS 
ensemble similar with ridging indicated over the Central Plains 
until late in the period on Thursday when timing issues develop 
with a southern stream wave as flow begins to split. 








&& 


Aviation... 
for taf sites kofk/koma/klnk 


Scattered to broken MVFR ceilings will continue through daylight hours with 
VFR conditions expected thereafter as high pressure builds into the 
area. Gusty northwest winds of 15 to 25kts should begin to subside 
after dark as well with winds becoming light and variable overnight. 


&& 


Oax watches/warnings/advisories... 
NE...none. 
Iowa...none. 
&& 


$$ 


Dewald/fobert/griffis