Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 251958
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
258 PM CDT MON JUL 25 2016

.SHORT TERM...(This evening through Tuesday)
ISSUED AT 258 PM CDT Mon Jul 25 2016

Despite cold front dropping southward toward the Ohio River Valley,
the airmass remains quite moist across central Illinois this
afternoon, with 18z/1pm surface dewpoints generally in the lower to
middle 70s.  The significantly drier air lags well behind the front
across Iowa and far northern Illinois where dewpoints have mixed
into the lower to middle 60s.  Mid/high clouds currently blanketing
the area will gradually push E/SE and should be largely confined to
locations along and south of the I-70 corridor tonight.  12z Jul 25
models all show scattered showers and thunderstorms across the SE
KILX CWA this afternoon and tonight, while areas further north
gradually clear out.  Have maintained low chance PoPs along/south of
I-70 through tonight accordingly.  Elsewhere around the area, have
gone with a dry forecast with patchy fog developing overnight.

High pressure will build into the Great Lakes on Tuesday, providing
mostly sunny and dry weather across most of the area.  The exception
will be south of I-70, where a few showers and thunderstorms will
remain a possibility in closer proximity to the stalled frontal
boundary near the Ohio River.  High temperatures will reach the
middle to upper 80s.

&&

.LONG TERM...(Tuesday night through Monday)
ISSUED AT 258 PM CDT Mon Jul 25 2016

High pressure will slowly drift east of the area Tuesday night and
allow the frontal system to begin to lift back north and become
oriented northwest to southeast across MO and into southern IL. As
the high pressure continues to move east the front out west will
slowly get closer to the CWA and bring the return of showers and
thunderstorms to the southwest third of the state beginning Wed.
Then more showers and storms will advect northward as the front
lifts further north and then cover the entire CWA Wed night and
Thur. As the associated mid level trough rotates through the area,
somewhat cyclonic flow/northwest flow will setup. This will keep the
sfc boundary near the area through the rest of the week, which will
keep chance of showers and thunderstorms over the CWA through the
rest of the week and into the weekend. Things should improve some
the latter part of the weekend as the chance of showers and
thunderstorms will be limited to the east and southeastern parts of
the CWA.

High pressure will also bring cooler temps for Wed and Thur. And
with cyclonic/northwest flow setting up over the area, slightly
cooler temps will prevail the remainder of the week and into the
weekend.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1225 PM CDT Mon Jul 25 2016

Winds are light and variable at the central Illinois terminals
early this afternoon as a cold front sinks slowly southward into
the area. Boundary is ill-defined by surface obs, but is expected
to drop south of the TAF sites later this afternoon/evening. A
thick layer of mid-level clouds is in place at 12000-15000ft with
visible satellite also showing lower diurnal clouds developing at
around 1500-2500ft. Aside from perhaps a brief MVFR ceiling,
forecast soundings are suggesting the lower clouds will remain
scattered. As the front drops southward and the diurnal clouds
dissipate, skies will become mostly clear this evening. With clear
skies, light winds, and ample low-level moisture in place, think
patchy fog will develop overnight. Have therefore dropped visbys
to 3-5SM between 09z and 14z.


&&

.ILX Watches/Warnings/Advisories...
NONE.
&&

$$

SHORT TERM...Barnes
LONG TERM...Auten
AVIATION...Barnes



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