FXUS63 KDMX 222353

Area Forecast Discussion
National Weather Service Des Moines IA
653 PM CDT Tue Aug 22 2017

.SHORT TERM.../Tonight through Wednesday/
Issued at 331 PM CDT Tue Aug 22 2017

Large and dominant surface high pressure will continue to build
into the state tonight into tomorrow providing plenty of cool air
and clear skies. Winds look to decouple and diminish b/t 23z and
01z tonight and likely become light and variable with the surface
high directly overhead. With the radiational cooling set up
tonight into Wednesday morning, certainly cannot rule out some
fog development prior to sunrise tomorrow within the low lying
areas and/or locations that received some rainfall over the past
few days. However, low confidence in mentioning at this time as
the dew point depressions remain too large overnight, the
widespread nature of the fog, and the dry air mass settling into
the state. For temps, went at or slightly below guidance for low
temperatures tonight.

.LONG TERM.../Wednesday night through Tuesday/
Issued at 331 PM CDT Tue Aug 22 2017

Very large, strong surface high pressure remains in control of the
weather pattern through the end of the work week and into the
beginning of the weekend. A few weak ripples embedded within the
upper level northwest flow aloft bring a few shots of showers and
an isolated thunderstorm early Thursday, early Friday morning, and
again Friday night into Saturday across northern Iowa. However,
low confidence any significant QPF with no deep moisture
available, very elevated weak forcing, and highly elevated LCLs
throughout the week. The best potential for any widespread rain
looks to be Saturday night into Sunday with a slow moving upper
level low pressure system. Temperatures remain near or slightly
below normal throughout much of the extended period.


.AVIATION.../For the 00Z TAFS through 00Z Wednesday evening/
Issued at 653 PM CDT Tue Aug 22 2017

There is high confidence in VFR conditions through the period with
little in the way of clouds. Winds should be light from the west
or northwest.





SHORT TERM...Podrazik
LONG TERM...Podrazik

NWS DMX Office Area Forecast Discussion