Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 261533

Area Forecast Discussion
National Weather Service Lincoln IL
1033 AM CDT TUE JUL 26 2016

Issued at 1033 AM CDT Tue Jul 26 2016

A stationary frontal boundary draped along the Ohio River
continues to provide clouds and occasional showers to southeast
Illinois this morning. 15z/10am radar imagery shows earlier
convection that dropped 1-2 inches of rain along I-70 has now
pushed eastward into Indiana, temporarily leaving behind dry
conditions across the SE KILX CWA.  With the boundary remaining
in place, additional showers will be possible from time to time
through the afternoon...although recent runs of the HRRR/Rapid
Refresh suggest most of the activity will remain just south of the
CWA toward the I-64 corridor.  Will maintain chance PoPs
along/south of I-70 to cover the possibility of scattered
showers/thunder re-developing this afternoon.  Meanwhile further
north, a 1019mb high centered over Iowa will bring mostly sunny
and dry weather to the remainder of the area.  High temperatures
will generally be in the middle 80s, with a few lower 80s across
cloud-covered east-central and southeast Illinois.


.SHORT TERM...(Today and tonight)
ISSUED AT 333 AM CDT Tue Jul 26 2016

The airmass in central IL north of the stationary front remains
relatively moist late tonight, with dewpoints still in the upper 60s
to low 70s. Patchy dense fog has been confined to our southeast
counties near Lawrenceville, with patchy light ground fog in
neighboring areas but not showing up at many observation sites. Will
keep a mention of fog in the forecast until shortly after sunrise.

Thunderstorm chances should remain primarily in our southeast
counties. The latest radar trends show a storm drifting north of I-70
toward Shelbyville and stretching toward Mattoon. That trend matches
the latest HRRR and RAP projections that storms will affect areas as
far north as a line from Shelbyville to Paris. The northward surge
of storms should retreat southward after 3 pm this afternoon,
eventually ending in our southern counties later this evening.
Spotty storm chances will continue south of I-70 overnight, but most
areas should remain dry tonight.

High temperatures today look to climb into the mid to upper 80s, as
dewpoints range from the mid 60s near Galesburg to the mid 70s
toward Lawrenceville. So humid conditions will continue today, but
no oppressive heat will develop. Low temps tonight will drop into
the upper 60s, with patchy fog once again.

.LONG TERM...(Wednesday through Monday)
ISSUED AT 333 AM CDT Tue Jul 26 2016

For tomorrow, some very low pops in the southern tier of the
state invof the remainder of the front as the next system approaches
from the northwest, bringing the chance of widespread precip with it
for Wed night/increasing into Thursday.  Models not very detailed
with the genesis of the precip, and the ECMWF and GFS definitely
having continuity with handling the exit of the shower/ts threat.
GFS more progressive with amplifying NWrly flow, ending as soon as
Friday...with the ECMWF hanging on through the first half of the
weekend.  Favor the GFS solution at this point, but the blends still
maintaining some pops for the end of the week.  Have started
trending back somewhat.

High pressure ridge builds into the Midwest and have started pulling
back on the pops from the blended forecasts as well.  The building
heat in the western half of the CONUS begins to shift eastward again
towards the end of the weekend, putting another warming trend in
place for the region.


.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 641 AM CDT Tue Jul 26 2016

A line of storms along I-70 and areas just north of I-70 are
drifting to the E-NE. It appears that the storms will not affect
any terminal sites today. A few showers are bubbling up east of
CMI, and have included a VCSH for a couple hours early this
morning, otherwise have kept a dry forecast for all terminals the
next 24 hours. That is due to high pressure building into the
region, bringing in slightly drier air.

Despite the drier air, air temperatures are expected to drop to
near the dewpoint late tonight, with MVFR vsbys in fog possible
between 09z-12z. Scattered to broken cumulus will be possible by
late this morning into the afternoon hours with cig bases in the
4000-5000 foot range. Light and variable winds early this morning
will become light east-northeast. Prevailing speeds should remain
less than 10 kts.


.ILX Watches/Warnings/Advisories...


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