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Area Forecast Discussion (AFD)

Issued by Chicago, IL (LOT)

FXUS63 KLOT 230540

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1240 AM CDT Fri Aug 23 2019

248 PM CDT

Through Friday night...

There are no weather concerns for most of the area through Friday
night. The only concern is at the beaches, where brisk 
northeasterly winds are likely causing dangerous swimming 
conditions due to high waves and strong currents. A Beach Hazards 
Statement is already in effect through 10am Friday and may need to
keep it going through later in the day, as winds are progged to
uptick again on Friday afternoon through early evening. Currently
not anticipating needing a Lakeshore Flood Advisory, as waves thus
far have topped out around 5 feet at the Wilmette buoy, but will
certainly monitor observations.

Outside of this, high pressure north of the Great Lakes with
ridging extending down to our area will gradually settle south,
keeping dry and comfortable conditions in place, with seasonably
cool nighttime temperatures. Skies going mostly clear tonight and
lighter northeast winds will support lows in the 50s outside of
Chicago and lower 60s in the city. Favored locations along and
west of the Fox Valley will likely dip into the lower 50s. On
Friday, the diurnal Cu/strato-Cu field inland may be a little 
less pronounced than today. Slightly cooler thermal profiles will 
yield highs in the mid to upper 70s inland and lower-mid 70s 
lakeside, with very low dew points for late August (lower-mid 
50s). We should be able to shave a couple degrees off tonight's 
lows for Friday night's lows as high pressure center draws closer.
This means a few of the favored cool spots may even drop to 
48-49 degrees.



151 PM CDT

Saturday through Thursday...

Surface high pressure is expected to dominate across the Great
Lakes region through much of the upcoming weekend. Overall, this 
is expected to result in pleasant (early autumn-like) weather 
across the area. High temperatures are expected to be mainly in 
the 70s, with overnight lows in the 50s Saturday night. Winds 
will primarily be onshore, especially Saturday. 

Early next week forecast guidance continues to be in good 
agreement with a well defined mid/upper level trough digging over
the Upper Midwest. With an associated surface frontal trough 
likely to approach the area later Monday and Monday night, we will
have some decent chances for some showers and thunderstorms. 
However, these chances should abate quickly during the day Tuesday
as the surface front shifts east-southeast of the area. This 
looks to result in mainly dry and pleasant weather with seasonal
temperatures again for much of Tuesday and at least Wednesday. 



For the 06Z TAFs...

For the Chicago area TAFs today the main story are northeast
winds, with high confidence in these being 10+ kt from 14Z-01Z.

High pressure gradually building into the Upper Great Lakes will
continue northeast winds over the area. Early this morning there 
is 20-25 kt flow just 2,000 ft aloft per radar VWP. There will be
some fluctuation in wind direction between mainly 030 and 060 
degrees at Chicago airports today, but speeds should be fairly 
steady around 12 kt from mid-morning through afternoon. There will
likely be occasional gusts given the winds just off the deck, 
although those will ease some through the morning resulting in 
gusts largely if not entirely below 20 kt at ORD and MDW. Winds 
will gradually ease in the 00Z-03Z time similar to last evening. 



IL...Beach Hazards Statement...ILZ006-ILZ014 until 7 PM Friday.

IN...Beach Hazards Statement...INZ001-INZ002 until 7 PM Friday.

LM...Small Craft Advisory...nearshore waters 
     until 10 AM Friday.