Buffalo Grove, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

981
FXUS63 KLOT 160530
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1230 AM CDT Fri May 16 2025

.KEY MESSAGES...

- A threat of rapid fire spread exists Friday due to a
  combination of strong winds and dry conditions.

- A threat of severe thunderstorms exists late Friday afternoon
  and early evening (Threat level 1 to 2 out of 5).

&&

.DISCUSSION...
Issued at 309 PM CDT Thu May 15 2025

Late This Evening Through Friday Night:

The threat for severe thunderstorms will come to an end from
west-to-east this evening as a cold front/dry line shifts
eastward across the area. A much drier airmass will move in
across the area in the wake of this feature tonight, and this
will set up a rather quiet night across the area.

This very dry airmass will persist across the area into Friday
and will act to foster deep diurnal mixing of the boundary layer
as temperatures warm into the mid to upper 80s. With mixing
heights expected to top 6,000 ft AGL into a layer characterized
by 40-45 kt of flow, increasingly gusty surface winds are
expected across the area late Friday morning and afternoon. We
also would not be surprised to see some surface gusts reach
these magnitudes, which would be right around wind advisory
criteria (45 mph). If this occurs, it looks to be the most
favored across my northern IL counties. Given the expectation of
these very windy, dry and warm conditions a Fire Weather Watch
was issued for my northern IL counties. See the fire weather
discussion below for more on this.

The other concern from these strong gusty winds on Friday is
the potential for blowing dust, particularly in areas of north
central and northwestern IN that misses out of storms this
evening. Very dry soils and recent farm field work will make for
favorable conditions for dust to be picked up and blown in the
wide open areas of northern IL. At this point no headline is
planned for this, but a wind advisory and/or a blowing dust
advisory could be needed for parts of northern IL west of the
Fox Valley.

Later Friday afternoon we should see a better northward return
of low-level moisture (low 60s dew points) across eastern IL
into northwestern IN in advance of another approaching cold
front. At this time it appears the best low-level moisture
return will be mainly along and east of I-55 late in the
afternoon and evening. This thus appears to be the best
potential area for scattered late day and early evening
thunderstorm development. The SPC highlights this general area
in a level 2 of 5 severe risk. Conversely, the activity looks to
remain more isolated farther to the northwest of I-55.
Regardless, any storms that develop will be capable of producing
damaging wind gusts given the inverted-V type soundings with
strong low-to-mid level lapse rates. Instances of very large
hail would also be plausible, particularly with any supercells.
Expect the storm threat to come to an end by mid to late Friday
evening following the passage of this second cold front.

KJB

Saturday through Thursday:

A strong, slow-moving Hudson Bay high will gradually shift
eastward this weekend into early next week as western CONUS
troughing settles toward the central Great Plains. Breezy
conditions with seasonable temps in the upper 60s to low 70s are
expected Saturday. A backdoor cold front crossing the area from
the northeast early Sunday will result in high temps ranging
from the mid 50s near the lake to the mid 70s well inland.

The trough will then slowly cross the Ohio River Valley and
bring a a period of unsettled with with period of showers and
some storms amid cooler conditions late Monday through midweek.

Kluber

&&

.AVIATION /06Z TAFS THROUGH 12Z SATURDAY/...
Issued at 1230 AM CDT Fri May 16 2025

The key aviation weather messages are:

- Increasingly gusty south-southwesterly winds Friday morning
  and afternoon. Some potential for non-thunderstorm winds to
  gust 40+ knots for a brief period during the mid to late
  afternoon.

- Chance for thunderstorms during the late afternoon and early
  evening. Any storms that develop could produce wind gusts in
  excess of 50 knots.

- Winds shifting to the WSW Friday evening and will remain
  gusty, with some potential for 30+ knot gusts through the
  overnight.

VFR conditions with southwesterly winds will prevail tonight.
Winds will increase steadily through Friday morning and into the
afternoon and will become south-southwesterly. During peak
heating, there is some potential for intermittent gusts of 40+
knots at times (roughly during the 20-23z timeframe), although
confidence in persistent gusts this high was not high enough to
introduce higher gusts at this time.

Thunderstorms appear likely to develop late in the afternoon,
although confidence in them directly impacting the terminals
still remains a bit unclear, with the greatest coverage
currently depicted just south. Made no significant alterations
to the inherited PROB30 groups, but consideration for upgrades
to TEMPOs will be needed in future TAF updates if model trends
continue. Any storms that develop will have very high cloud
bases (near 10 kft) and will be capable of producing severe wind
gusts/microbursts.

Winds will shift out of the WSW Friday evening. Another "pop" of
strong winds is possible late in the evening and overnight, and
there is a signal that gusts could be a bit higher than the
current TAFs indicate. MVFR cigs may eventually develop, but
these look to hold off until the very end of the extended
ORD/MDW TAF window or just beyond.

Carlaw

&&

.MARINE...
Issued at 309 PM CDT Thu May 15 2025

Key Messages:

- Severe thunderstorms possible late afternoon into early
  evening
- Gale Warning in effect Friday afternoon/evening for IL
  nearshore to Gary, IN

Thunderstorms appear poised to develop just west of if Lake
Michigan late this afternoon into the evening. Any storm may
produce gale to storm force winds and damaging hail. A brief
period of southwesterly gale force winds cannot be ruled out
behind the storms, as well. A small craft advisory is in effect
this afternoon into the evening.

Finally, a period of southwesterly gale force winds are expected
Friday afternoon, particularly northwest of Gary, Indiana. A
Gale Warning has been issued to account for this.

Team LOT

&&

.FIRE WEATHER...
Issued at 1138 AM CDT Thu May 15 2025

We have issued a Fire Weather Watch for our northern IL counties
for Friday.

A much drier airmass is expected to shift over the area in the
wake of a cold frontal passage later this afternoon. The dry
airmass will remain in place across most of northern IL through
most of Friday afternoon, before some better moisture recovery
occurs late in the day across parts of east central IL and
northwestern IN. As temperatures warm into the mid to upper 80s
by early Friday afternoon, very low RH`s in the 20 to 25 percent
range are expected, particularly across northern IL. These very
dry conditions are likely to combine with strong and gusty
south winds (gusting up to 45 mph), thus creating a period of
critical fire weather conditions.

A period of showers and thunderstorms are expected across parts
of northeastern IL and northwestern IN late this afternoon into
the early evening. Rainfall from these storms could help
mitigate the degree of the fire weather threat to some extent
for Friday, but areas that receive little to no rainfall will be
primed for rapid wildfire spread on Friday as dry and windy
conditions develop during the mid to late morning hours.

Very late in the day on Friday (after 4 or 5 pm), some better
low-level moisture return is anticipated from the south in
advance of another approaching cold front. At this time, it
appears this better moisture return (near 60 degree dewpoints)
will occur generally along and east of the I-55 corridor. This
may thus result in quickly improving conditions for these areas
late in the afternoon, though this moisture may foster some very
gusty late afternoon and evening storms. Farther northwest of
I-55, continued dry and windy weather through the afternoon will
likely continue the threat of wild fire spread through around
sunset before abating winds and improving RH`s end the threat.

KJB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Fire Weather Watch from 10 AM CDT this morning through this
     evening for ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
     ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
     ILZ023-ILZ032-ILZ033-ILZ039.

IN...None.
LM...Small Craft Advisory until 1 AM CDT early this morning for the
     IL and IN nearshore waters.

     Gale Warning from noon today to 10 PM CDT this evening for
     Winthrop Harbor IL to Gary IN.

&&

$$

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