578 
fxus63 koax 281858 
afdoax 


Area forecast discussion 
National Weather Service Omaha/valley NE 
158 PM CDT Thursday Aug 28 2008 


Discussion... 
very short term concerns will be any lingering thunderstorms early 
this evening in southeast Nebraska/SW Iowa...otherwise...mainly a temperature 
forecast through Monday. 


The latest surface analysis had the surface fnt south of Nebraska from northern MO 
into eastern and central Kansas...with a secondary front from WI through Iowa into 
southeast Nebraska and western Kansas. Isolated thunderstorms and rain have developed in the vicinity of 
this secondary fnt on the gradient of the higher deep relative humidity and 
instability along with some forcing. The morning oax sounding was 
impressive...moisture and instability-wise...however...there was not 
enough forcing to touch off thunderstorms and rain. Have isolated thunderstorms and rain in the far 
southeast zones for now and before sending out forecast will look at trends 
to see how the coverage is going. 


Big drop in surface dewpoint at Lincoln this hour going from 66 to 57 
and 30s/40s dewpoints are upstream. Tonight/S lows are looking 
cool and the mav MOS for ofk gives them a near record low of 41. 
Looks like ideal cooling conditions with surface high pressure building 
in...light winds drier dewpoints and clear skies. Local effects 
will play large role in lows tonight...so did not go quite that 
low...but have most lows in the upper 40s to lower 50s across the County Warning Area 
for Friday morning...but could be cooler or warmer locally. Surface 
high pressure and light winds Friday...then the surface high retreats to 
the east Sat. Both NAM/GFS have some moisture return Sat afternoon 
with some cumulus possible. Highs in the 80s to lower 90s Friday/Sat and 
left mainly dry. 


Sunday through Thursday...we start out with a large middle level 
trough in the west and a large ridge in the east. In- between...we 
will have srly flow. The moisture that had been supressed to the 
south by the surface hi...has returned middle level temperatures are prognosticated 
not to be too warm...thus the combination of moisture and weak to 
modate instability along with heating or the nocturnal low level 
jets may allow scattered to isolated storms to develop. Without a 
boundary to focus on...do not feel enough to include isolated thunderstorms and rain in 
the extended until the front moves into and through the area Monday 
night through Tuesday night. Surrounding fo/S have also kept it dry 
unti Monday night as well. Think Tuesday into Tuesday evening will be 
the best chance for precipitation. Again...the mainly part of the storm 
heads into Canada. The timing in the extended is similar with the 
GFS/UKMET...however the European model (ecmwf) is less progressive holding on to 
the precipitation into Wednesday and beyond. Blended in with my neighbors and 
kept low probability of precipitation in my far southeast. Temperatures in the 80s to lower 90s 
sun- Tuesday...then cooler 70s/80s Wednesday and Thursday. 


&& 


Aviation... 
cool high pressure will build over the area tonight. Expect skies 
to be mostly clear at kofk through 12z Friday. Clouds will decrease 
at koma and klnk late this afternoon and evening...then it should 
be mostly clear. North winds will drop off this evening...then be 
light and variable late. Some fog is possible late tonight...but 
did not go less than 5 mile visibilities for now. High pressure is 
expected to move eastward on Friday with winds becoming south or 
southeast. 


&& 


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


$$ 


Zapotocny/Miller