Area Forecast Discussion
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FXUS63 KILX 010836

336 AM CDT THU OCT 1 2015

.SHORT TERM...(Today)

A large area of high pressure to our north has brought a rather
chilly start to the new month as temperatures have dipped into the
lower 40s over our northern counties as of 200 am. Further
southeast, some mid and high level clouds have kept temperatures
in the middle 50s. The main concern in the short term will be the
extent of cloud cover and their affect on afternoon temps along
with some gusty winds again this afternoon.

An upper level low situated over extreme southern IL this morning
will drift southeast with additional energy forecast to move into
the base of the trof later today helping to intensify the upper
low. The combination of the large cool Canadian high to our north
and the deepening upper level system to our southeast will help
to produce a rather tight pressure gradient over the Midwest which
will result in some gusty winds again today out of the northeast.
In addition, short term models suggest some increase in clouds this
morning from the east with forecast soundings showing a deeper layer
of moisture than what we saw yesterday, this time from about 2500 to
3500 feet. Both the RAP-13 and HRRR models showing the band of
clouds tracking west from Indiana later this morning, affecting
mainly the eastern half of the forecast area. Think the models may
be overdoing the depth of moisture, especially as it tracks west
into the surface ridge axis so not going to go as pessimistic as
the short term models suggest, but we will see more clouds mix in
with the sun than what we had yesterday.

Forecast soundings also suggest prevailing northeast winds of 12 to
17 kts with gusts around 25 kts at times later this morning thru
most of the afternoon. Most models indicate 850 temps a bit lower
than what we saw yesterday which should yield afternoon temperatures
mostly in the mid to upper 60s.


.LONG TERM...(Tonight through Wednesday)

00Z forecast models continue to deepen upper level trof over the
lower TN/OH river valleys southward into a cutoff low over AL and FL
panhandle Thu night into Friday. This trough will influence the
track of major hurricane Joaquin with winds up to 120 mph and near
the eastern Bahamas. HPC official track of hurricane is on a more
northerly track to near the mid Atlantic coast by Sunday night into
Monday. The 00Z ECMWF model continues to have a more eastern track
of hurricane out to sea this weekend. The 00Z GFS is further west
track but has trended a bit further east toward NJ/NYC area by
Monday. GEM model brings hurricane into NC Sat night. So models
still differ greatly on track of hurricane and still awaiting
evolution of deepening upper level trof/cutoff low into the
southeast states. Most models show just light patches of qpf over
eastern IL Fri into Sunday morning though NAM is wetter over IL and
an outlier and not followed. Did not make too many adjustments to
forecast through this weekend, though did add more cloud cover and a
bit cooler highs in 60s and elevated lows/dewpoints slightly from
Friday night through Sunday night. Breezy northeast winds to
continue next few days with gusts in the 20-30 mph range during
daytime period.

Weak high pressure ridge builds into IL Monday providing more
sunshine and lighter winds and a bit milder highs in the lower 70s.
Temps continue to moderate into low to mid 70s Tue and mid to upper
70s Wed with increasing southerly flow on back side of high pressure
ridge moving into the mid Atlantic states. Chances of rain showers
during middle of next week, starting over IL river valley Tue night
and into central IL Wed and southeast IL Wed night/Thu as a cold
front trackes into the region.


.AVIATION...(For the 06Z TAFS through 06Z Thursday night)

High pressure centered just NW of Illinois will provide VFR
conditions and nearly cloud free skies the next 24 hours. The
pressure difference between the surface high and an elongated
area of low pressure along the East Coast will keep northeast
winds in the 10-14kt range the rest of the night. Sustained winds
are now looking to climb into the 15-20kt range by 15z and
continue through the day. Wind gusts will be frequently be near
23-25kt. Wind gusts will diminish by 03z, but sustained winds
will remain 13-15kt through Thursday evening.




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