Aurora, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

207
FXUS63 KLOT 082332
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
632 PM CDT Sun Jun 8 2025

.KEY MESSAGES...

- Isolated to scattered showers and thunderstorms will continue
  to move through the area this afternoon. Another round of
  scattered showers and storms is expected again tomorrow
  afternoon.

- A few instances of pea to nickel size hail as well as 40 to 50
  mph winds may occur with the strongest storms this afternoon
  and tomorrow.

- A period of dry and warmer weather is expected midweek.

- Shower and thunderstorm chances return late in the week.

&&

.DISCUSSION...
Issued at 214 PM CDT Sun Jun 8 2025

Through Monday:

Recent satellite imagery and surface observations depict a cold
front moving east across northern Illinois at press time.
Temperatures in the mid to upper 70s and surface dew points in
the lower 60s are contributing to around 1000 J/kg of MLCAPE
along the front, which will continue to support isolated to
scattered storms as the front pushes across the area through
this evening. Kinematic profiles characterized by weak low-level
shear/storm relative inflow but strong mid-level shear will
maintain mini-supercell structures with an attendant threat for
pea to nickel size hail and gusty winds to 50 mph. The threat
for storms will end from west to east this afternoon behind the
front, tapering in northwestern Indiana by 8 to 9 PM. Behind the
front, a quick hit of gusty westerly winds is expected thanks
to a local tightening of the surface pressure gradient (have
noted a few gusts as high as 35 mph in eastern Iowa). In
addition, scattered showers may develop and continue behind the
front through the early overnight hours as a jet streak moves
overhead, as well.

Clouds will attempt to clear from west to east overnight,
allowing for temperatures to quickly cool into the 50s by
daybreak.

Tomorrow, attention will be on the sharp upper-level shortwave
currently racing southward from southern Canada into North
Dakota as it propagates into the Lower Great Lakes. Relatively
cold 500mb temperatures of -20 to -22C will support steepening
mid-level lapse rates as the shortwave approaches, allowing for
a band of showers and thunderstorms to develop and sweep across
the area from late morning through early afternoon. Relatively
low freezing levels and a strengthening low-level wind field
will allow for the strongest storms to produce pea to nickel
size hail and locally strong wind gusts to 50 mph. Outside of
showers and storms tomorrow, highs will range from the upper 60s
(northwest) to mid 70s (southeast) amidst breezy west winds.

Borchardt


Monday Night through Sunday:

Our thoughts for the long term portion of the forecast period
have not changed.

The upper-level flow pattern will begin to deamplify on Tuesday
as the Great Lakes trough/low ejects into southeastern Canada.
Rising heights in its wake will result in the development of a
quasi-zonal type flow pattern across the northern CONUS for the
second half of the week. The main result of this changing
weather pattern for our weather will be the turn from seasonably
cool conditions on Tuesday (highs in the 70s) to much warmer
temperatures (highs back in the 80s) by Wednesday.

Primarily dry weather is anticipated for Tuesday and Wednesday,
and it is certainly plausible that most of our area will remain
free of precipitation and very warm through the end of the work
week. In spite of this, the official forecast will begin to
carry some chances (~30-50%) for showers and thunderstorms
during the Wednesday night through Friday timeframe. However,
storm chances during this period will ultimately be dependent
upon how far south a west-to-east oriented surface cold frontal
boundary reaches before stalling ahead of the next impulse
shifting into the Dakotas late in the week. If this front ends
up stalling to our north across WI, the primary focus for waves
of showers and storms Wednesday night through much of Friday
would also likely largely remain to our north in WI. However,
due to the inherent uncertainties at this time range, we made no
changes to the NBM POPs.

Another feature that will need to be monitored for driving
storm chances later next week is the southern stream impulse
that is expected to slowly migrate its way eastward from the
Desert Southwest on Tuesday into the Ozarks region into early
next weekend. This feature will also be a daily driver of
showers and thunderstorms, but with it`s slow eastward movement,
much (if not all) of the thunderstorm activity will remain
south and southwest of our area through the end of the week.

Ultimately, our best shot at a period of higher coverage storms
may end up coming sometime next weekend (possibly on Saturday?)
as the late week system moving across the Dakotas finally looks
to drive the surface cold front southward across our area.
Unfortunately, the specifics with timing this far out are of low
confidence. Stay tuned.

KJB

&&

.AVIATION /00Z TAFS THROUGH 06Z MONDAY/...
Issued at 632 PM CDT Sun Jun 8 2025

Aviation forecast concerns for the 00Z TAFs:

- TSRA threat has ended for this evening. Brief period of
  sprinkles/light rain lingers through 00-01Z especially for
  GYY.

- Scattered SHRA/TSRA again Monday late-morning to mid-
  afternoon. Small hail and gusty winds in excess of 30 kts
  possible with these.

- Breezy west-southwest winds gusting 25+ kts outside of any
  convection Monday midday/afternoon.

Surface cold front has pushed east of the terminals early this
evening, with TSRA threat now over. A narrow band of light
rain/sprinkles trails the front and will be east of ORD/MDW by
00-0015Z, so have only indicated in GYY for an hour or so to
start their TAF. Surface winds which had shifted northwest
immediately behind the storms/front are in the process of
backing to the west-southwest, and may become breezy briefly (as
noted in current obs across IA/far western IL) with gusts near
20 kts before mixing diminishes with sunset this evening.

Another deep mid-level disturbance is forecast to dig southeast
across the region on Monday, with a reinforcing surface cold
front pushing across the terminals during the afternoon.
Increasing forcing ahead of the wave and cold front combined
with cooling air aloft will provide instability sufficient to
develop scattered SHRA and TSRA across the area. Timing looks to
be perhaps as early as very late morning at RFD and by early
afternoon for the Chicago sites. Some of the stronger cells may
produce small hail and wind gusts in excess of 30 kts through
mid-late afternoon, before this activity moves off to the east
by early evening.

Even outside of any convective cells, west-southwest surface
winds will become breezy by midday/early afternoon, with gusts
likely in the 25-30 kt from midday through the afternoon hours.

Ratzer

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Small Craft Advisory from 1 PM to 8 PM CDT Monday for the IL
     and IN nearshore waters.

&&

$$

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