Area Forecast Discussion
Issued by NWS Chicago, IL

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KLOT 190849

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
349 AM CDT Mon Mar 19 2018

348 AM CDT

Through tonight...

Another day of generally quiet weather expected today, though
becoming rather breezy by late morning.

As low pressure tracks through southern Missouri later this morning
and then continues into the Ohio Valley, while strong high pressure
remains parked over central Canada, northeast winds will be in the
increase through the day.  By late morning or early afternoon, winds
should increase to 15 to 25 mph with occasional gusts as high as 30
to 35 mph.  While temperatures inland should remain relatively
moderate, with highs in the upper 40s to lower 50s under layered
clouds and filtered sunshine, the lakefront will remain cooler as
the northeast winds draw lake-cooled air onshore.  Lakefront
locations should see temps top out in the low 40s.  Strong, gusty
northeast winds could cause some issues with spray impinging on the
immediate lakefront areas.  Blustery conditions should remain into
the evening and overnight as the low continues through the Ohio
Valley. Temperatures overnight tonight are expected to drop into the
upper 20s.  When combined with 10 to 15 mph winds overnight,
apparent temperature will be in the middle teens.


348 AM CDT

Tuesday through Sunday...

Blustery conditions should continue through Tuesday as northeast
winds continue with highs ranging from the middle 30s across nern IL
to the lower 40s well inland.  Some moderation for much of the area
is expected for midweek as a ridge of high pressure extends from
Hudson Bay to along the Mississippi River.  However, persistent flow
off of Lake Michigan should keep lakefront locations a bit cooler
than inland areas.  The next significant chance for precipitation is
still not expected until Friday and through the weekend.  The longer
range guidance remains consistent in amplifying the upper level
pattern by the end of the week, with an area of low pressure quickly
tracking across the Central Plains late Friday.  However, there are
still significant differences among the models as to the exact track
and intensity of the system into next weekend.  The general model
consensus at this point does indicate the decent potential for
precipitation as a mid-level shortwave tracks across the region, the
models diverge significantly on the track of the associated surface
low moving through central IL. IN general, thermal profiles
generally support rain or a rain/snow mix across the area, with the
greatest potential for any snow occurring during the diurnally
cooler nighttime periods.


For the 06Z TAFs...

Gusty northeast winds today and tonight will be the item of
interest for this aviation forecast with otherwise VFR conditions.
Northeast winds will begin increasing around daybreak and
continue the trend upward through early-mid afternoon and then
remain at their peak through the evening. Occasional gusts in
excess of 25 kt remain possible at ORD and MDW during the late
afternoon and evening time.

Despite flow off the lake, low clouds are not expected due to dry
air upstream and not enough cool air for lake effect cloud
generation. It is possible few/scattered 3000 ft or so clouds
could be seen near daybreak Tuesday, but no impacts expected.



115 AM CDT

Northeast times more due north or due east...will
prevail across Lake Michigan through the entire week.

Speeds will be on the increase early this morning as the lake
finds itself between strong high pressure to the north and passing
low pressure well to the south. Small Craft Criteria winds and
shortly after waves are expected to develop along the Illinois
shore this morning and Indiana shore by mid-afternoon. The
highest wind and wave time in the Illinois and Indiana nearshore
looks to be tonight and Tuesday during the day. This will be a
fairly long lasting event, with gusty winds and high waves
lasting through Wednesday morning, and probably some 3-5 ft waves
lingering even longer into Wednesday.

Another low pressure is expected to move eastward across the
middle of the country, likely south of the lake, late in the
week/early weekend. This again will strengthen east or northeast



LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742...9 AM Monday to 9
     AM Wednesday.

     Small Craft Advisory...LMZ743-LMZ744-LMZ745...3 PM Monday to 9
     AM Wednesday.




WWW.YOUTUBE.COM/NWSCHICAGO is the U.S. government's official web portal to all federal, state and local government web resources and services.