000
FXUS63 KDVN 230453
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1153 PM CDT Tue Aug 22 2017

...AVIATION UPDATE...

.SYNOPSIS...
Issued at 239 PM CDT Tue Aug 22 2017

18Z surface data has a cold front from lower Michigan into southeast
Kansas while high pressure was over the Plains. Dew points around
and ahead of the front were in the 60s and 70s. Dew points in the
40s and 50s were across the Plains and upper Midwest.

&&

.SHORT TERM...(This Evening through Wednesday)
ISSUED AT 239 PM CDT Tue Aug 22 2017

Quiet and pleasant conditions will be seen from late this afternoon
through Wednesday as high pressure moves through the Midwest.
Temperatures will average below normal.

.LONG TERM...(Wednesday Night through Tuesday)
ISSUED AT 239 PM CDT Tue Aug 22 2017

The beautiful taste of late summer weather will continue through
the end of the week, before a low confidence, and complicated
pattern sets up for the weekend and early next week. High pressure
will remain in place over the local area at the surface for
Wednesday night through Thursday night, but there is now an
expectation for some mid level cloud cover, and even a
sprinkle/virga in the north as mid level warm advection begins
toward late Wednesday night.

The clear evening will allow for chilly lows Wednesday night, and
temperatures near 50 are expected before thick cloud cover arrives
after midnight. This cloud cover will linger into Thursday, and
could really limit high temperatures.  For now, will go slightly
under guidance, but if they do remain fully in place, I could see
mid to upper 60s for highs Thursday. Banking on some patchy sun,
will go lower 70s northeast to upper 70s southwest Thursday. This
same set up could make for a cool Friday, but with somewhat stronger
winds Friday gives higher confidence on a recovery well into the
70s.

High pressure will move east far enough for surface moisture return
by Saturday and Sunday, and this is when models are now picking up
on better rain chances as the upper low interacts with this slightly
more moist air. The forcing is not a progressive situation, and
upper lows of this type are not usually well forecast, thus, I will
hold pops to the 20 to 30 percent range, despite the potential for
stratiform coverage. In the end, this will give higher confidence
for continued cool daytime temperatures, and slightly more mild
overnight lows as clouds and higher dewpoints are in place through
Tuesday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
ISSUED AT 1152 PM CDT Tue Aug 22 2017

Surface high pressure settling into the Midwest under northwest
flow aloft will result in VFR conditions through the forecast
period.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

SYNOPSIS...08
SHORT TERM...08
LONG TERM...Ervin
AVIATION...Wolf