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Area forecast discussion 
National Weather Service Des Moines Iowa
1131 PM CDT Sat Jul 12 2014

Short term /tonight/...
issued at 1128 PM CDT Sat Jul 12 2014
will end precipitation across the south after midnight. Light
winds...plentiful boundary layer moisture and clearing skies will
likely result in patchy fog overnight.

Long term /Sunday through Saturday/...
issued at 326 PM CDT Sat Jul 12 2014

Main concern remains focused on unseasonably cold temperatures to
filter into the state Monday through Wednesday...and then mild
and dry conditions through the end of the work week.

Sunday into Monday...secondary trough/cold front looks to push
across the state on Sunday and may bring a few light showers and
an isolated thunderstorms in the afternoon with some marginal
instability recovering from convection tonight. Surface dewpoints
look to be about 10 degrees less than today but enough moisture
available combined with weak forcing with boundary moving
through...so kept slight probability of precipitation going in the afternoon Sunday.
Another stronger cold front to bring the well anticipated
unseasonably cool temperatures will push through the state during
the day Monday. Good mixing behind the front by the afternoon and
tweaked up winds slightly. Low confidence with mention the non-
diurnal temperature trend on Monday with the cold air advection as sun angle still high
enough to warm temperatures up in the afternoon.

Tuesday through Saturday...very cold airmass for this time of year
to filter into the state as 850mb temperatures drop to +5c to +6c by early
Tuesday morning. Kept mention of near record lows for Tuesday
morning as surface ridge looks to be centered over eastern Iowa into
the western Great Lakes by 12z Tuesday and expecting decent
radiational cooling to develop. Surface dewpoints drop to around 50f
by Tuesday morning and with the radiation cooling event...could see
some shallow fog develop if winds drop off entirely. Something to
consider with next forecast package.

Cool airmass remains in place through much of the work week before
it begins moderate back to normal temperatures by Friday into
Saturday of next week. No significant system to bring precipitation
to central Iowa from middle to late week next week.

&&

Aviation...13/06z
issued at 1128 PM CDT Sat Jul 12 2014

Skies cleared this evening over northern Iowa. Light
winds...plenty of boundary layer moisture and clearing skies
should result in fog overnight. The patchy nature of the fog will
result in variable conditions at taf locations with visibilities
lowering to IFR at times. Deep mixed layer on Sunday with
northwest winds should result in scattered cumulus deck and VFR
conditions.

&&

Dmx watches/warnings/advisories...
none.
&&

$$

Short term...Johnson
long term...podrazik
aviation...Johnson

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