Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 180502

Area Forecast Discussion
National Weather Service Lincoln IL
1202 AM CDT TUE OCT 18 2016

Issued at 916 PM CDT Mon Oct 17 2016

High clouds are covering the area this evening and will continue
during the overnight hours. Models continue to show some clouds
developing west of the area and moving east into the area toward
morning and continuing east during the morning hours. Current
forecast has a good handle on this. Looks like forecast is doing
fine this evening, so no need for an update at this time. However,
will do some tweaking to the wind and wind gusts grids sincy windy
conditions continue.


.SHORT TERM...(This evening through Tuesday)
ISSUED AT 257 PM CDT Mon Oct 17 2016

Another warm overnight expected with south/southwesterly winds
continuing, and remaining gusty until the morning.  The next storm
system remains confined out to the west and the next front is not
expected until midday tomorrow, with little moisture to work with

Overnight, high pressure ridge to the southeast puts the Midwest
under return flow as WAA dominates the overnight.  Mid/low level
speed max develops over the region and edges to the northeast before
dawn. With the gusts beginning through the afternoon and the WAA in
place...the real issue in the forecast overnight is the gusts.
Forecast soundings are placing the overnight inversion closer to mid
levels/850mb... but bringing the speed max down to 1000ft off the
ground.  This would maintain some turbulent mixing and overnight
gusts.  Keeping the 20-26kt gust in the forecast through at least
06z, then decreasing as the max drifts to the NE...and decoupling
may be more likely after midnight.  Otherwise a blustery, albeit
warm overnight.

Tomorrow, a frontal boundary brings a wind shift to the NW mid day.
However, with the mixing down of some relatively dry mid level air
through the overnight, the soundings are drying as well through the
column. Forecast is dry through Tuesday afternoon...with some clouds
increasing in the evening for the SE...but withholding any pops
until after 00z tomorrow.

.LONG TERM...(Tuesday night through Monday)
ISSUED AT 257 PM CDT Mon Oct 17 2016

A cold front, that currently extends from the Great Lakes region
into the central Plains, is forecast to stall in the vicinity of the
Ohio River Valley Tuesday night as it becomes parallel to the upper-
level flow. There continues to be model disagreement with respect to
exactly where the front will stall, and this will have an impact on
local precipitation chances later Tuesday night into Thursday as a
vigorous upper-level wave digs into the eastern United States. The
best forcing with the upper wave locally should occur
Wednesday/Wednesday night, and this the period where we have
confined the highest PoPs. The best rain (and thunder) chances
should occur along/south of the I-70 given this areas expected
proximity to the stalled front.

Temperatures, while cooler than today, will remain above normal
until the strong wave pulls east of the area on Thursday. Then,
temperatures should be closer to seasonal normals through the
weekend. In addition to more normal temperature levels, the balance
of the forecast period looks to be dry.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1203 AM CDT Tue Oct 18 2016

VFR conditions will prevail at all TAF sites next 24hrs. High
cirrus will remain over the area overnight, but low clouds around
5kft will develop just west of the area and then move over the TAF
sites during the early morning hours, around 11z. Clouds will be
broken for about 4-5hrs and then become scattered during the late
morning to early afternoon. Scattered clouds should continue into
the afternoon and then skies should clear out late morning at all
sites. Winds will remain gusty overnight but then decrease in
speed during the early morning. By late morning, gusts will be
gone, but southwest winds will continue just ahead of the front.
This front will come through dry and then winds will become west,
then northwest during the afternoon. Winds will decrease more in
speed out of the northwest around sunset. Low level winds remain
very strong right now, but with sfc winds still gusty, do not
believe LLWS criteria will be reached overnight.


.ILX Watches/Warnings/Advisories...


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