000
FXUS63 KDVN 110443
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1143 PM CDT Thu Aug 10 2017

...06Z AVIATION UPDATE...

.SYNOPSIS...
Issued at 259 PM CDT Thu Aug 10 2017

18Z surface data has a cold front running from central Wisconsin
into far northern Kansas. Dew points were in the 60s ahead of the
front with 50s behind the front.

&&

.SHORT TERM...(This Evening through Friday)
ISSUED AT 259 PM CDT Thu Aug 10 2017

The cold front will sweep through the area this evening. Showers and
thunderstorms will be seen along and ahead of the front through
sunset.

After sunset, convection will quickly dissipate with all but the far
south clear of precipitation by midnight.

After midnight, any lingering showers in the far south will
dissipate with the entire area dry by sunrise Friday.

On Friday, dry conditions will be seen across the area as high
pressure builds into the area. Wrap around clouds from the departing
storm system are expected to persist through the morning north of
highway 30 before clearing occurs during the afternoon.

Temperatures tonight and Friday will average a little below normal.

.LONG TERM...(Friday Night through Thursday)
ISSUED AT 259 PM CDT Thu Aug 10 2017

Friday and Saturday

Sfc high pressure will overspread the Upper Midwest behind the
departing sfc low and cold front. Slightly below average temps in
the upper 70s to lower 80s for highs and 50s for lows are expected.
Humidity will be very comfortable with dewpoints also in the 50s.

Sunday

Chance for showers (20-30%) across the south on Sunday. SE low-level
flow in the sfc-850mb layer will increase moisture transport and
isentropic lift across northern Missouri and southern Iowa into west-
central Illinois.

The NAM/GFS have showers as early as the afternoon lasting into
Sunday night, while the ECMWF is dry until the evening. Overall,
forcing appears weak and instability will be low, so left thunder
out of the forecast.

Monday and Tuesday

Beautiful August weather continues. Another sfc high is forecast to
slowly slide through the Upper Midwest and Great Lakes through early
next week. Model blend has highs near 80 F Monday then lower to
middle 80s by Tuesday (warmest southwest CWA).

Wednesday and Thursday

Approaching shortwave trough warrants shower chances mid to late
week. As low-level moisture increases, chances for thunderstorms
will return as well.  Synoptically this does not look like a strong
system, which means the threat for widespread significant rain
through Thursday is very low.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
ISSUED AT 1137 PM CDT Thu Aug 10 2017

Fast moving upper level wave will bring sprinkles and spotty
light showers to areas south of I-80 prior to daybreak, and have
handled with vcsh wording at BRL but left out at MLI. Otherwise,
front nearing Mississippi River will gradually shift southeast
of the terminals by sunrise with N/NW winds 4-8 kts. Some patchy
fog is possible overnight through daybreak, but enough uncertainty
given unfavorable northerly wind even being light precludes from
mention. Late tonight and Friday morning anticipate stratus with
areas of low VFR to MVFR cigs to develop at all sites, except for
BRL. There is a low probability of IFR cigs at DBQ Friday morning.
High August sun angle and drying on increasing NW winds around
10 kts during Friday should bring about a gradual lifting of cigs
to VFR toward midday into the afternoon, with clearing by evening.

&&

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

$$

SYNOPSIS...08
SHORT TERM...08
LONG TERM...Uttech
AVIATION...McClure