Area Forecast Discussion
Issued by NWS Chicago, IL

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FXUS63 KLOT 250711

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
211 AM CDT Wed Apr 25 2018

207 AM CDT

Through tonight...

North winds have generally been gusting 20-30 mph with a few gusts
to 35 mph behind a cold front crossing the CWA early this
morning. This will continue into the daylight hours with an
enhanced pressure gradient in place as weak troughing slowly exits
central/southern Illinois. Expect these winds to ease slightly by
this afternoon, then quickly diminish tonight as a weak surface
ridge builds in from the west.

A rather dry airmass per upstream RAOBs and satellite trends will
supports sunny skies today with some passing cirrus and maybe a few
cumulus clouds through early afternoon. Guidance has continued to
show a slight cool-bias with sunny days over the past week, so have
increased max temps a couple degrees away from the moderation of
Lake Michigan. Max temps today are expected to range from the upper
40s along the immediate shore to the low 60s well inland.



230 PM CDT

Wednesday night through Tuesday...

Overview...Looking at a pretty quiet extended with an early taste of
summer possible early next week.

High pressure will dominate the pattern Wednesday night through
Thursday evening. Seasonal temps and dry conditions are expected. A
lake breeze is possible Thursday afternoon, possibly leading to
cooler temps along the lake.

An upper level wave and cold front move across the region Thursday
night/Friday. Could see a ribbon of rain shift southeast across
the forecast area. Winds become northerly behind the front and
cooler air will lead to highs in the 50s to around 60 Friday.
Highs will be around 50 along the lake.

A large ridge builds over the CONUS over the weekend, and looking at
above normal temperatures early next week. 70s and maybe even 80s
are possible. High temps Monday and Tuesday could be warmer than
currently forecast, but I`d rather stick with the blend`s high temps
this far out. Guidance hints that clouds and perhaps showers and
storms could limit temps Tuesday.



For the 06Z TAFs...

A cold front will track southward across northern IL over the next 1-
2 hours, ushering in gusty N to NNE winds. A period of high-end MVFR
ceilings are also expected for a 2-3 hour window behind the front.
Drier air will then allow for much of the cloud cover to dissipate
by daybreak Wednesday. The gusty winds will gradually abate during
the afternoon and evening as a weak surface ridge edges into the



230 PM CDT

A cold front will move down Lake Michigan this evening and overnight
with northerly flow strengthening in its wake. Wind gusts are
expected to peak around 30 kt late this evening and overnight, then
should very gradually diminish through the day Wednesday as a ridge
of high pressure spreads across the region. A small craft advisory
remains for the Illinois and Indiana nearshore waters for this
evening through Wednesday evening. Winds flip to southwest behind
the ridge axis on Thursday and ahead of another approaching cold
front. This next front is expected to sweep across the Lake Thursday
night possibly bringing another period of north winds gusting to
around 30 kt.



LM...Small Craft Advisory...IL nearshore waters until 10 PM

     Small Craft Advisory...IN nearshore waters until 1 AM Thursday.




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