Elgin, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

403
FXUS63 KLOT 100512
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1212 AM CDT Fri Jul 10 2026

.KEY MESSAGES...

- A threat for isolated to widely scattered thunderstorms
  through this evening.

- Mainly dry and increasingly warm weather this weekend onward,
  though it will be cooler lakeside until later next week.

&&

.DISCUSSION...
Issued at 237 PM CDT Thu Jul 9 2026

This Afternoon:

A weak remnant MCV (mesoscale convective vortex) has slowly
pushed across the area through early this afternoon. It appears
that the timing of the disturbance was early enough to curtail
stronger destabilization from a combination of thicker cloud
cover and already marginal mid-level lapse rates of <6C/km.
Forcing on the backside of the MCV, subtle confluence, and a bit
better destabilization south of I-80 recently enabled an uptick
in coverage of smaller footprint pulse type convection. As the
forcing from the MCV pushes farther east, a somewhat subsident
regime may result in the current activity struggling for a bit.
Farther north, the aforementioned more subsident regime as well
as meager low-level convergence from close to due westerly
boundary winds will probably keep convective coverage at a
minimum for a few hours.

Late Today through Tonight:

Based on upstream radar presentation as of this writing, a weak
approaching cold front should provide enough lift for a modest
uptick in showers and isolated to widely scattered thunderstorms.
Winds shifting onshore near the lake from an early evening lake
breeze could plausibly provide modestly a modestly enhanced
focus. However, the weakly forced, weak deep layer shear, and
modest mid-level lapse rate environment does not appear that it
will be conducive to much in the way of storm organization.
Earlier concerns of localized flash flooding appear to be
trending downward even if a few storms materialize into this
evening, as they will likely continue to be smaller footprint
and pulse-type (shorter-lived). Favorable moisture parameters
and high freezing levels would thus be offset by limited areal
coverage and duration of any heavy rainfall. If a more focused
corridor of showers and embedded storms does not materialize by
this evening, with a likely diurnal component to the activity,
the flood threat for the rest of the night should be limited.

Overnight into early Friday as the cold front sags south, light
winds and low dew point spreads may support fog development and
localized visibility below 1 mile. Maintained areas of fog
mention closer to the lake in northeast Illinois and far
northwest Indiana, though confidence isn`t all that high.

Friday Onward:

The sagging front will force the instability axis southward
Friday and Saturday, and with it the threat for any showers and
storms. Have confined chance PoPs to near and south of the
Kankakee River Friday afternoon and evening and then primarily
south of US-24 on Saturday afternoon (which may be too generous).
For the rest of the area, a couple pleasant days with more
comfortable humidity levels, and seasonably warm temperatures
in the lower to mid 80s are in store. Synoptic onshore flow from
surface high pressure settling over the Great Lakes will keep
highs near the lake in the mid 70s to around 80F.

For Sunday into early to mid next workweek, an expansive and
anomalously strong/warm mid-level ridge will establish itself
from the central and northern Plains to the Midwest.
Increasingly warm 850 to 925 mb temps underneath the influence
of the ridge will result in a warming trend away from the lake.
Meanwhile, the surface high pressure will remain in place until
midweek or thereabouts, resulting in daily lake breezes and
associated lake cooling. In addition, dew points and thus
humidity levels will be held in check vs. our previous very warm
to hot stretch. The ridge may become sufficiently flattened
sometime later next week for a return of convective chances.
Until then, a several day stretch of continued drying will help
river and streams to return back to more typical flows.

Castro

&&

.AVIATION /06Z TAFS THROUGH 12Z SATURDAY/...
Issued at 1212 AM CDT Fri Jul 10 2026

The main aviation weather concerns are:

- Lingering showers and a few embedded thunderstorms in the
  central and southern parts of c90 tonight

- Developing IFR cigs and possible BR/FG overnight

An axis of showers, occasionally with a few embedded
thunderstorms, continues to shift slowly southeastward. The
general expectation is for storm coverage to diminish
overnight, but at least isolated/spotty activity will probably
fester through much of the overnight in the vicinity of an ARR-
GYY line. Coverage and confidence remains too low for any TSRA
mentions.

An area of IFR cigs continues to work its way slowly
southwestward off the lake. Currently, this area of low stratus
appears to be somewhat localized, but guidance suggests this
will expand with time overnight. Continue with various TEMPO
mentions for IFR overnight and into early Friday, with some
potential future updates may need to prevail these conditions.
In addition, some MVFR BR will be possible given the generally
light low-level flow and moist airmass. Cigs should then
gradually lift/scatter towards midday with VFR conditions
expected through the rest of the TAF period.

Light/variable to northeasterly winds tonight will get a bit of
a northeasterly boost with a lake breeze Friday afternoon.

Carlaw

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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