Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 250819

Area Forecast Discussion
National Weather Service Lincoln IL
319 AM CDT THU AUG 25 2016

.SHORT TERM...(Today and tonight)
ISSUED AT 318 AM CDT Thu Aug 25 2016

Showers and isolated storms will be ongoing this morning, mainly
north of I-72. However, this precip will begin diminishing through
the morning hours. With boundary still sitting in the area, will
have to keep some form of pops in the forecast for rest of the
morning and through the afternoon. So, will have likely pops early
int the northeast and then chance elsewhere. However, with precip
decreasing, pops will be more slight chance, or isolated, into the
afternoon. Given the diminishing precip, the flash flood watch
has been cancelled early. Temps should be around normal north of the
sfc boundary, but above normal for areas south of the boundary,
which would be most of central and southeast IL...along and south of


.LONG TERM...(Friday through Wednesday)
ISSUED AT 318 AM CDT Thu Aug 25 2016

Latest model guidance does not push the cold front as far south as
previous runs, and already begins to lift it back north as a warm
front on Friday. Consequently, added some 20-30% PoP`s to the
southwest parts of the CWA during the day. Most of the models focus
on some sort of MCS development across Iowa/Missouri Friday night
and track it northeast, with the ECMWF most bullish with a more
eastward track into Illinois by morning. Have not gone that extreme
yet, but have bumped up PoP`s from the earlier forecasts and
included a period of 60% PoP`s northwest of the Illinois River by
Saturday morning.

Late weekend and early next week remains a bit challenging, with the
potential breakdown of the southeast U.S. upper high. GFS and ECMWF
have wildly different solutions with tropical weather potential and
how it would break down the ridge. The GFS is in the much weaker
camp for the tropical system and thus keeps quite a bit of
convection going north of the ridge, while the ECMWF solution is
more of a diurnal nature for our area. Will largely only carry
slight chances of rain/storms in the extended periods, with some
30`s here and there, mainly in the southern CWA.

No real significant push of cool air expected behind the current
system, so most of the CWA should still see highs in the mid-upper
80s on Friday. Good portion of the forecast range beyond that will
remain muggy, with highs in the mid 80s.


.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1100 PM CDT Wed Aug 24 2016

Coverage of TSRA was increasing out to our west and expect
that trend to continue with the main challenge, at least in
the short term portion of this forecast will be what TAF
sites are affected the most. It still appears that areas
from SPI to BMI and west will see the most concentrated
area of showers and thunderstorms overnight, with more
scattered coverage further east. As a result, will hit the
lower cigs/vsbys the hardest in our west and north TAF sites
thru the early morning hours. It appears the best timing
will be from 06z through 12z before the precip begins to
move out and cigs improve during the late morning hours
of Thursday. With some of the heavier thunderstorms, we
may see cigs briefly low to IFR before returning to MVFR.

Any lingering MVFR cigs will gradually lift to VFR between
17-19z. Surface winds will be light southerly tonight with
speeds of 5 to 10 kts, and then begin to switch into the
west and then northwest by afternoon as a weak cool front
moves through the area. Wind speeds will range from 8 to 13
kts by afternoon. Winds will be quite variable in direction
and speed in and near any thunderstorms tonight into early
Thu morning.


.ILX Watches/Warnings/Advisories...


LONG TERM...Geelhart
AVIATION...Smith is the U.S. government's official web portal to all federal, state and local government web resources and services.