Area Forecast Discussion
Issued by NWS Central Illinois

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000
FXUS63 KILX 220741
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
241 AM CDT Tue Aug 22 2017

.SHORT TERM...(Today and tonight)
ISSUED AT 241 AM CDT Tue Aug 22 2017

Both 00z model suites and more recent CAMs show a speed up
of the precipitation ending across the forecast area. This seems
reasonable given the progression of the energy moving across
western Missouri this morning. As it interacts with the digging
trough and help to intensify it. Will be ending the precip from
northwest to southeast.

Due to training nature of some of the storms tonight, soil
moisture should be high in some areas. Will have to watch for the
potential for fog tonight. Will leave it out for now and let day
shift analyze precip reports and wind forecasts to determine if
mention is warrented.

&&

.LONG TERM...(Wednesday through Monday)
ISSUED AT 241 AM CDT Tue Aug 22 2017

Cool northwest flow will persist at least through the first part
of the weekend. Several waves will rotate through the trough
during the period, but with limited moisture available the biggest
impacts may be a brief increase in clouds and a reinforcement of
the cool air in place. Temps should be 5-10 degrees below normal.

There are several differences in the way the models are handling
the tropical moisture associated with the remants of Harvey and
its interaction with the longwave trough over the eastern U.S. For
now will keep rain chances low Monday given the uncertainty.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1201 AM CDT Tue Aug 22 2017

Line of convection between KBMI and KCMI should be near KCMI by
TAF valid time and will start them off with a either a VCTS or a
tempo ground depending on where the line sits at issue time.

Vort max over eastern Kansas evident in water vapor imagery is
main trigger for strong storms between Kansas City and Springfield
MO this evening. The storms will be moving eastward into a less
unstable airmass before they reach Illinois so expect intensity
should be on the decline before reaching central Illinois
terminals. Will have to watch KSPI as the more unstable air may
advect into the site from the southwest.

Large area of stratiform precip with embedded convection stretches
ahead of a cold front that stretches near Green Bay WI to Iowa
Falls IA at 04z will likely persist much of the night as the
associated upper wave digs quickly southeast with the
amplification of the upper trough over the eastern U.S. Upstream
IFR Cigs and Vsbys are evident in the stratiform shield and will
likely advect into the TAF sites as the front approaches through
sunrise. Will time IFR conditions into terminals from 08z to 13z
from northwest to southeast. Front should be through KDEC and
KCMI by 18z and will shift winds and rapidly improve cigs.


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Barker
LONG TERM...Barker
AVIATION...Barker


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