Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 122340

Area Forecast Discussion
National Weather Service Lincoln IL
640 PM CDT Wed Aug 12 2020

Issued at 316 PM CDT Wed Aug 12 2020

Isolated showers and thunderstorms will be possible this evening
across southeast Illinois, along a semi-stationary boundary
stretching across southern Illinois. Otherwise, mostly clear and
dry weather is expected across central and east central Illinois
tonight with temperatures falling into the 60s. Conditions
tomorrow will be similar to today.


.SHORT TERM...(This evening through Thursday)
ISSUED AT 316 PM CDT Wed Aug 12 2020

Frontal boundary still sitting over southern IL will remain semi-
active through tomorrow and might slowly lift to the north
Thursday. However, any convection will be confined to southern IL
tonight through Thursday with only a chance of precip expected in
southeast IL. A slight chance of precip is possible a little
further north of this area, but most of the CWA should be dry
through the period. Overnight lows are expected to be in the 60s
with afternoon highs, Thursday, rebounding into the middle 80s.

.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 316 PM CDT Wed Aug 12 2020

A frontal boundary will be near the CWA through the first part of
the extended forecast with the chance of precip still confined to
southeast IL for Thur night and Fri. After this, as the pattern
becomes more progressive, only a slight chance of precip is
expected Sat through Sun. A cold front will then move through the
area Sun, with a small chance of precip, though will not be
mentioned at this time in the worded forecast. Beyond this, Sun
night through Wed, dry weather is expected with temps becoming


.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 640 PM CDT Wed Aug 12 2020

The latest surface observations indicate a moisture gradient with
higher dew point air from about KMQB-KSPI-KDEC-KDNV and southward.
Surface high pressure in Michigan was providing an light easterly
flow across central Illinois with the drier air generally north
of the I-72 corridor. This should keep the northern TAF sites in
VFR conditions through the night and into much of Thursday.

Locations with higher moisture levels can expect light fog to
develop by daybreak with MVFR visibility from KSPI to KCMI. Lower
clouds will also develop around 14-15z, keeping the MVFR
conditions across central Il into early afternoon due to the
proximity to a weak upper level low in south central IL. Mixing
will be limited due to the morning cloud cover and light winds,
but increasing surface temperatures should allow cloud bases to
climb to VFR levels by 18z in the southern half of Illinois.




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