Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 190225
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
925 PM CDT WED MAY 18 2016

.UPDATE...
Issued at 912 PM CDT Wed May 18 2016

Low temperature forecast tonight is a bit challenging. Latest
observations show pooling low level moisture with dew points in
the 40s over northern Illinois, with some mid level clouds noted
within this moisture axis. Light easterly flow the rest of tonight
is likely to advect these higher dew points at least into far
eastern Iowa. Anticipate the increasing low level moisture to
keep lows in the lower to mid 40s for far eastern Iowa and
northwest Illinois. Coolest lows look to be found across portions
of the western county warning area where the drier air will hold
on longer, and could result in some upper 30s in drainage areas.

&&

.SYNOPSIS...
Issued at 300 PM CDT Wed May 18 2016

18z surface data has high pressure from the Great Lakes into the
Plains. Dew points were in the 40s and higher from the Ohio Valley
to southern Plains on south. Dew points in the 30s ran from the
Great Lakes into the northern Plains.

&&

.SHORT TERM...(THIS EVENING THROUGH Thursday)
ISSUED AT 300 PM CDT Wed May 18 2016

Quiet and dry conditions will be seen across the area from late this
afternoon through Thursday as high pressure slowly moves toward the
east coast. Temperatures will continue to average below normal.

.LONG TERM...(Thursday NIGHT THROUGH Wednesday)
ISSUED AT 300 PM CDT Wed May 18 2016

Thursday Night...High pressure over the Great Lakes and Upper
Mississippi River Valley will continue the light winds and dry
conditions. Models have a vorticity max moving across southern
Missouri and southern Illinois - well south of E Iowa/W Illinois.
Lows are forecast in the upper 40s on avg.

Friday through Sunday...Spectacular stretch of weather with
gradually warming temperatures, light winds, and low humidity.
Expect lower 70s Friday, then upper 70s by Sunday.

Monday...Central U.S. ridge begins to break down as upper level
low drops into the Southwest U.S. Downstream of the upper low,
mid-level heights will fall and winds will increase out of the
southwest.

At the sfc...breezy southerly winds to advect higher dewpoints
into E Iowa/W Illinois. Consensus dewpoints are near 60 F in the
SW forecast area by the aftn and slightly lower to the E/NE.
Absence of a front or disturbance aloft should result in a dry
day. However, there is a very low probability for an isolated
shower or storm developing during the aftn or evening in the far
western CWA (15-20% PoPs). Highs are again forecast in the upper
70s.

Monday Night through Wednesday...Models are in agreement on
tracking a relatively weak shortwave and sfc boundary through the
Midwest. Scattered showers and thunderstorms are expected with
this system; however, questions remain on how widespread the
activity will be. Precip chances are generally in the 30-50
percent range at this lead time.

Of higher confidence are dewpoints rising well into the 60s which
will make it feel much more humid compared to the past few weeks.
Uttech

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z Thursday EVENING)
ISSUED AT 626 PM CDT Wed May 18 2016

Diurnally driven cumulus will dissipate with sunset leaving behind
a mainly clear sky the rest of tonight, with a light and variable
wind. On thursday, expect scattered to possibly areas of broken
coverage of high vfr based cumulus late morning through afternoon,
with southeast winds 6-12 kts.

&&

.DVN Watches/Warnings/Advisories...
IA...None.
IL...None.
MO...None.
&&

$$

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



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