Area Forecast Discussion
Issued by NWS Central Illinois

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358
FXUS63 KILX 171624
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1124 AM CDT Tue Oct 17 2017

.UPDATE...
Issued at 1115 AM CDT Tue Oct 17 2017

The only clouds of note for the rest of today over central and
southern Illinois will be thin cirrus clouds triggered by a weak
wave of upper level energy. That will do little to limit the
insolation from the sun this afternoon. The dry surface air will
continue to steadily heat into the upper 60s to lower 70s.

Southwest winds will become even more gusty this afternoon as the
pressure gradient across Illinois tightens between high pressure
to our southeast and low pressure to the northwest. Wind gusts
of 20-25 mph will be common across the area this afternoon, with
diminishing gusts toward sunset.

The overall forecast looks on track, and no formal updates will be
needed this morning.

&&

.SHORT TERM...(Today and tonight)
ISSUED AT 332 AM CDT Tue Oct 17 2017

Not a lot of large scale changes in this round of the forecast.
Models still in a warming trend with nothing in the way of precip
until the weekend. A break in the continuity of the weekends
system is hinted in the 00z run.

High pressure ridge is still in place, with the axis stretching
from the Southern Plains to New England. A small disturbance
creating a few clouds over the region the only break in the mild
weather. This morning is slightly warmer than yesterday, and the
beginning of a warming trend through the week. Todays highs should
reach around or near 70 degrees across Central IL, with
southwesterly winds assisting warm air advection for the region.
Tonight will be a couple degrees warmer than this morning...again
continuing the trend.

.LONG TERM...(Wednesday through Monday)
ISSUED AT 332 AM CDT Tue Oct 17 2017

Latter half of the work week continues the warming trend with
temperatures considerably warmer than climatology. By Friday, 850
mb temps climb to 15C-18C, and reflective high temperatures are
expected in the mid to upper 70s. Have boosted the max temps a
degree or two above guidance Wed-Fri. Aloft, the trof shifts
eastward, beginning a trend to a more zonal flow for the end of
the week. With the ridging over the south/southeastern CONUS, the
more active stream shifts north, minimizing a wave midweek for the
area. Forecast remains dry and well above normal through the end
of the work week.

Models agree with a break in the pattern moving into the weekend
with a more amplified wave digging in over the western half of the
CONUS. However, the 00z run of the ECMWF is now dropping the
energy into a cut off low to the south, chopping the QPF depiction
in half...and potentially putting Central IL in a break. For now,
forecast keeping to a fropa and associated pops this weekend...but
have limited to likelies...and pulling categorical should the GFS
shift similarly. The cold front is slated to move through the
region late Saturday/early Sunday, resulting in a rainy weekend.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 604 AM CDT Tue Oct 17 2017

VFR conditions will prevail at all TAF sites for next 24hrs. A
little bit of cirrus is advecting over the sites for today, but
clear skies expected tonight. Southwest winds will be light to
start but increase toward late morning with gusts at all sites of
19 to 22kts. Then around 00z, winds will become southerly with
speeds less than 10kts.


&&

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

$$

UPDATE...Shimon
SHORT TERM...HJS
LONG TERM...HJS
AVIATION...Auten



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