Hessville, Indiana Weather Forecast Discussion

486
FXUS63 KLOT 260818 CCA
AFDLOT
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
318 AM CDT Fri Sep 26 2025...CORRECTED
.KEY MESSAGES...
- Areas of fog early this morning, locally dense, especially
  east of I-55.
- Dry and mild to unseasonably mild weather into next week.
&&
.DISCUSSION...
Issued at 313 AM CDT Fri Sep 26 2025
We`re looking at a very quiet stretch of weather here over the
next week or so. To kick things off, we`re seeing areas of fog
early this morning, primarily across areas near and south of
I-80 and east of I-55. Visibilities at various sites around
these parts have gotten as low as a quarter of a mile, but these
lower visibilities have been generally intermittent so far this
morning. Widespread dense fog can be found just outside of the
CWA across parts of northern IN and southwest lower MI. Looking
at webcams from around the area and out of our own window in
Romeoville, the fog looks largely shallow with cooler, low-lying
areas being the most impacted. Conceptually, would think fog
would continue to expand and thicken up at least some as we
still have a little bit of cooling to do before the morning
commute opens up, but it`s unclear how widespread the more dense
coverage will get. We will keep a close eye on trends and the
need for an SPS or Dense Fog Advisory through the early morning.
Expect seasonably cool conditions to start your day today with
morning temperatures sitting in the upper 40s and lower 50s
outside of the city. Steady height rises will take place over
the region today through this weekend as an upper high breaks
down over the Intermountain West shunting the polar jet to our
north and spreading the warm air aloft east into the Plains and
Midwest. As a result, 925mb temps over 20C in addition to lots
of sunshine and dry boundary layer air will support highs in the
lower and middle 80s today through the early part of next week.
Slightly cooler conditions are favored toward the middle of
next week as winds through the column turn northerly.
Turning attention to precip chances, they are very slim over
the next seven days. A weak cold front up in central WI early
this morning will drop into northern IL this afternoon, but
won`t amount to anything more than perhaps some fair weather
cumulus or a localized breeze. Surface high pressure will
dominate the region through the weekend and into next week.
Another front will get hung up in the area this weekend, but
guidance agrees that it again won`t be supportive of precip
production amid the subsidence and awfully dry layer air.
Instead, expect mostly sunny skies both Saturday and Sunday.
There is support for some fog to develop late tonight near and
behind where that front ends up (mostly north of I-80). Most
guidance avoids visibilities less than a few miles and there
remains enough uncertainty where opted not to include fog in the
forecast for tonight and tomorrow morning yet, but the day
shift will have another look. The next noteworthy chance for
precip appears to be close to next weekend when medium range
guidance wants to drive some sort of synoptic system through the
region, possibly interacting with remnant tropical moisture.
Doom
&&
.AVIATION /06Z TAFS THROUGH 12Z SATURDAY/...
Issued at 1152 PM CDT Thu Sep 25 2025
A large high pressure system will deliver generally quiet
conditions to the region through the TAF period.
Patchy fog will continue to expand from Indiana and potentially
impact GYY throughout the night. Fog is not expected to impact
RFD/DPA/ORD/MDW.
Relatively light westerly (230 to 260 degrees) winds will
prevail through the morning and afternoon hours. A weak frontal
boundary may slip south of the Wisconsin state line this
afternoon, causing winds to turn northeasterly wile remaining
fairly light (aob 10kt). The latest iteration of model guidance
has backed off on the front reaching the terminals, but for
consistency, will keep the inherited wind shift between 22-23Z
for ORD/MDW/DPA/RFD for now. Patchy fog may develop close to
wherever the front ends up toward the end of the TAF period.
Borchardt
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.
&&
$$
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NWS LOT Office Area Forecast Discussion