615
FXUS63 KLOT 061152
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
552 AM CST Fri Mar 6 2026

.KEY MESSAGES...

- Periods of showers and thunderstorms through Saturday morning.
  Some thunderstorms may be strong to severe, especially this
  afternoon and early Saturday morning.

- Areas of dense fog improving from south to north today, ending
  last along the IL Lake Michigan shore.

- Chance for thunderstorms next Tuesday night.

&&

.DISCUSSION...
Issued at 206 AM CST Fri Mar 6 2026

Dense fog continues across much of the area south of I-80 and
then over Lake Michigan and the lakeshore areas. Expecting
gradual improvement from south to north this morning as the warm
from lifts north but this may also allow dense fog to develop
across areas north of I-80 for a few hours before precipitation
arrives later this morning. Overall confidence is low and trends
will need to be monitored. Dense fog will likely persist along
the IL lakeshore for much of the day, finally dissipating later
this afternoon or early this evening near the IL/WI state line.

A large area of thunderstorms extending from southern MN into
far northern MO is expected to continue lifting northeast,
reaching the western cwa around daybreak and then continuing
across the northern two thirds of the area through the morning
hours. Most recent guidance suggests there may be a sharp cutoff
on the southern edge of this precipitation with the southern
third or so of the area possibly remaining mainly dry for today
and if that trend were to pan out, pops would need to be lowered
for this area with later forecasts. As this precipitation
spreads across the area, any remaining dense fog would begin to
lift/dissipate, at least slowly.

The severe threat with this morning`s activity looks to be
fairly low with possibly some isolated large hail being the main
threat during this time period. Locally heavy rain would also be
possible.

There remains quite a bit of uncertainty for additional
thunderstorms as well as coverage this afternoon into early this
evening. The warm front will be lifting north across the area
with favorable conditions for at least isolated severe storms.
It appears the best chances for additional thunderstorms would
be along and north of I-80 but given the uncertainty for how
much will develop have maintained only chance pops during this
time. If thunderstorms do develop, all modes would be possible,
large hail, damaging winds and possibly a tornado. But at this
time, low coverage is expected. This activity would end during
the early evening as the warm front is expected to be north of
the area with a lull in the precipitation expected during the
mid evening.

Additional thunderstorms are expected late this evening into
early Saturday morning ahead of a strong cold that will be
moving across the region and passing across the local area mid/
late Saturday morning. Coverage during this time looks to be a
bit better, perhaps precipitation across most of the area, but
this activity would likely be in the form of a line and moving
fairly quickly. Strong to isolated severe thunderstorms would
also be possible during this time. This activity would be
exiting the local area by mid morning Saturday.

Temps are currently holding steady in the mid 40s for much of
the area, 50 south and then upper 30s near the lake. Temps will
be steadily rising this morning with highs well into the 70s
south of I-80 later today. Temps will likely slow their rise
across northern IL with the expected precipitation through
midday. High temps could be in the late afternoon or even the
early evening in these areas. Temps by Saturday morning may
still be in the upper 50s/lower 60s for most areas and then as
the cold front moves east across the area Saturday, temps will
begin to fall and its possible that temps will be in the
lower/mid 40s by early Saturday evening.

West/northwest winds may gust into the 35-40 mph range with and
just behind the cold front Saturday and the pattern looks to
remain breezy/windy Sunday into Monday with above normal temps
in the 60s Sunday and lower 70s Monday.

Models show another potential storm system for the Tuesday/
Wednesday time period next week with a frontal boundary possibly
across the local area with a large temperature gradient. Showers
along with thunderstorms for at least part of the area would be
possible during this time period. cms

&&

.AVIATION /12Z TAFS THROUGH 18Z SATURDAY/...
Issued at 552 AM CST Fri Mar 6 2026

- LIFR/VLIFR conditions this morning in fog and low stratus.
  Improvement expected from south-to-north after about 15-16z.

- Winds turning S and SSW this afternoon. Strengthening gusts
  this afternoon, particularly INVOF GYY and MDW where gusts
  could eclipse 30 knots.

- Prolonged period of VCTS and/or TSRA at RFD today.

- Scattered showers and storms expected later this morning into
  the afternoon in the vicinity of the c90 tracon.

- Period of LLWS this evening and overnight.

- Additional waves of showers and embedded thunderstorms tonight
  into Saturday morning.

Widespread LIFR/VLIFR conditions are ongoing across the region.
At RFD, vsbys and cigs should begin to lift as showers and
thunderstorms arrive through about 13z, but VCTS and periodic
on-station thunderstorms will likely continue through the
balance of the day. At the Chicago-area terminals: improvement
from south-to-north is anticipated after about 15-16z as winds
increase. This should help to lift and erode the lowest cigs and
vsbys, although AMDs will likely be needed to refine this
timing a bit. Waves of showers and thunderstorms will spread
east through the morning. At this time, the greatest chances for
VCTS and brief TEMPO TSRA exists at ORD and DPA, with
relatively lower chances near GYY. Additional rounds of
thunderstorms are possible this afternoon and evening, although
confidence in storm development during this timeframe remains
somewhat low. For the time being, have continued with PROB30
mentions for TSRA.

As a warm front works its way northward this afternoon, winds
will turn S and then SSW. It`s unclear how far north the front
will make it, with indications pointing to the strongest winds
materializing at MDW and GYY this afternoon. It`s possible that
a brief period of gusts over 30 kts materializes during the
afternoon as the front lifts northward.

Another round of showers and embedded thunderstorms will develop
late tonight into Saturday morning. The potential for TS remains
a bit too nebulous at the Chicago-area terminals to justify
TEMPO groups or VCTS at this time, but have introduced a mention
at RFD. Eventually, winds will become westerly and gusty into
Saturday morning with low MVFR conditions in the wake of a cold
front.


Carlaw

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Dense Fog Advisory until 10 AM CST this morning for ILZ003-
     ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-ILZ012-ILZ013-
     ILZ019-ILZ020-ILZ021-ILZ023-ILZ032-ILZ033-ILZ039-ILZ103-
     ILZ104-ILZ105-ILZ106-ILZ107-ILZ108.

IN...Dense Fog Advisory until 10 AM CST /11 AM EST/ this morning
     for INZ001-INZ002-INZ010-INZ011-INZ019.

LM...Dense Fog Advisory until 3 PM CST this afternoon for the IL
     nearshore waters.

     Dense Fog Advisory until 10 AM CST this morning for the IN
     nearshore waters.

&&

$$

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