Weather

122 
fxus63 kdmx 281808 aaa 
afddmx 


Area forecast discussion 
National Weather Service Des Moines Iowa 
107 PM CDT Thursday Aug 28 2008 


Updated for 28/18z aviation discussion... 


Discussion... 
forecast concerns primarily centered on today as boundary pushes 
through the state. Currently...convection advancing eastward across 
the County Warning Area in area of strong Theta-E advection ahead of cold front. 
Initial line has made good progress to the east...but nearly 
stationary outflow in eastern Nebraska has acted as a focus for 
redevelopment into western Iowa. High precipitable waters  and deep warm layer have 
led to efficient rainfall producers...however progressive nature of 
initial line has kept amounts of around and inch or lower. Will have 
to watch area in western Iowa where outflow become more east-west oriented 
with low level jet crossing nearly perpendicular to the layout. Some 
locations of heavy rainfall are likely through the early morning 
hours before the focus begins to push east as front become more 
progressive. Models indicating that ongoing convection should 
diminish through the morning...however destabilization will lead to 
new development by early afternoon. Given good bulk shear and 
instability...the threat for severe will remain in the southeast County Warning Area 
this afternoon prior to convection exiting the area. 


Passage of the front will allow a dry Canadian airmass to settle into 
the state tonight and Friday with temperatures holding below normal 
during that time. However...warm air advection will take over fairly quickly by 
midday Friday and continue through the weekend. At this 
point...expect to see decent diurnal ranges with clear skies and a 
dry airmass leading to good swings in temperatures from night to day. The 
threat for precipitation will be minimal during this time with 
negligible forcing and moisture. Still appears that Tuesday into 
Wednesday of next week may see the next threat of precipitation as a 
western trough develops and lifts through the plains. 


&& 


Aviation...28/18z 
a cold front across southeast Iowa will be the focus for potential 
convection this afternoon. Still uncertainty as to whether or not 
the airmass will destabilize enough in vicinity of kotm to get things 
going...so have maintained thunderstorms in the vicinity group there after 20z. 
Otherwise...high pressure will build quickly into Iowa behind the 
front with clearing skies. Some overnight fog is likely in the south 
as well with light winds and lingering low level moisture. 


&& 


Dmx watches/warnings/advisories...none. 


$$ 


Long term/short term...cogil 
aviation...Kinney