413 
fxus63 kdmx 220439 
afddmx 


Area forecast discussion 
National Weather Service Des Moines Iowa 
1139 PM CDT sun Mar 21 2010 


Short term /tonight/... 
hi pressure over northwest Iowa will sink southeastward tonight with clear skies and light winds. 
Dropped temperatures to at or below MOS values...especially in the nish valley 
where middle teens or below are likely. Gusty northeasterly winds over southeastern Iowa will 
diminish with sunset. 


Long term /Monday through Saturday/... 
high pressure in place for the beginning of the week...with 
southwesterly flow at the surface. Warming pattern Monday should 
allow temperatures to push into the 50s maybe approaching 60 across the 
County Warning Area. Weak cold front to move through the area Tuesday...with warmer 
temperatures expected across the southern County Warning Area ahead of the front. Frontal 
passage should be dry with maybe an increase of middle/high clouds. 
Somewhat cooler temperatures in place with high pressure into Wednesday and 
Thursday...so have dropped temperatures a bit into the upper 40s to lower 
50s. Stronger cold front to move in Thursday night but colder air to 
quickly shove eastward as southerly flow kicks in ahead of a 
developing southern stream low to the west. Long range models in 
better agreement with the progression of this system into the 
weekend...but still big enough differences to create uncertainty. 
Two weak waves moving through the area...a northern stream system 
and a southern stream system. Previous GFS run indicating some 
phasing of the two creating a stronger slower system into the 
weekend with much colder air. Latest run more like the ec...bringing 
the system across in two parts with a stronger southern stream 
system. This looks like a warmer solution keeping precipitation types more 
rain with maybe a rain/snow mix Saturday night. This also more of a 
progressive system. Therefore will have to monitor the later runs to 
gain more certainty in the precipitation type/amount and progression 
of this system. 


&& 


Aviation... 
22/06z...widespread VFR conditions are expected for the taf forecast 
period as surface ridge passes across the state. Surface winds will be light 
and variable tonight becoming southeast and increasing during the 
day on Monday as the ridge slides to the east and south of Iowa. 
Visibilities will remain unrestricted with any ceilings at or above bkn200. 


&& 


Dmx watches/warnings/advisories...none 


$$ 


Short term...MS Mar 10 
aviation...cogil 
long term...beerends