Area Forecast Discussion
Issued by NWS Central Illinois

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434
FXUS63 KILX 260841
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
341 AM CDT MON SEP 26 2016

.SHORT TERM...(Today and tonight)
ISSUED AT 341 AM CDT Mon Sep 26 2016

Light rain will continue across the eastern half of central and
southeast Illinois today as the 500mb short wave moves through the
area. Clouds will also be on the decrease from west to east through
the day. This should dry things out nicely today with ridging
building in. Northwest winds will return to the area and these winds
should become breezy with gusts of over 20-25mph at times...with
highest gusts in the north. Conditions this afternoon will
definitely feel fall-like as temperatures will only reach into the
lower to middle 70s and combine with the breezy winds out of the
northwest. Overnight lows are expected to drop into the upper 40s
under clear skies.

&&

.LONG TERM...(Tuesday through Sunday)
ISSUED AT 341 AM CDT Mon Sep 26 2016

The main weather story for much of the upcoming week will be
something we haven`t seen for awhile - several days of below normal
temperatures. An upper level low from the western Great Lakes will
bring cooler air into the Midwest through the end of the week.
However, the medium range models disagree as to the position of this
low and how long it may linger in the region.

Many of the forecast details hinge on the upper low position Tuesday
through Friday. Most of the models drop the low southward from the
Michigan UP later Tuesday into Wednesday. The European model
continues to be the outlier by moving the low more SW/W than the
GFS, Canadian and the last few model run hours of the NAM. This is
significant for us since the farther SW/W track of the European
would result in several periods of clouds and light rain much of
this week.

For now will introduce slight chance PoPs for isolated showers
mainly along and north of the I-74 corridor for Tuesday evening
ahead of developing secondary cold front dropping in from the north.
This front and advancing upper low will reinforce the low level cold
air advection for Wednesday resulting in a very cool, autumn day. A
few more clouds could also keep temperatures down, with highs
Wednesday mainly in the mid 60s, which is about 10 degrees below
normal.

Toward late week the models diverge even further as the upper low
becomes cut off. They all depict the low just wobbling around, with
spokes of energy creating areas of light rainfall. The GFS is
farthest to the east with the low mainly located around West
Virginia, while the European model is the furthest west (eastern
Indiana), and the Canadian model in between the other two. Due to
the high level of uncertainty will keep the mention of rain out of
the late week forecast for now as the model blends keep central and
eastern IL dry with a very gradual warming trend.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1134 PM CDT Sun Sep 25 2016

An upper level trough will cross the central IL area overnight
bringing scattered -shra to the area until 9-12Z. Primarily VFR
conditions expected, although brief MVFR cigs possible. Clearing
skies by dawn. Winds W-WNW through the period. Speeds generally
around 10 kts through the night...then increasing to 12-15 kts
after 15Z with gusts 22-25 kts. Winds and gusts decreasing again
after 01Z Tuesday.


&&

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

$$

SHORT TERM...Auten
LONG TERM...Miller
AVIATION...Onton



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