Area Forecast Discussion
Issued by NWS Marquette, MI

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600
FXUS63 KMQT 042017
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
417 PM EDT Sat Oct 4 2025

.KEY MESSAGES...

- Unseasonable warmth continues through Sunday with daytime highs 15-
20 degrees above normal. Max high temperature records could be
broken across several spots this weekend.

-Breezy across the area tonight into Sunday, with a few spots
potentially gusting as high as 40-45 mph at times.

- Warm, breezy, and dry weather may lead to marginally elevated fire
weather conditions through Sunday afternoon.

- Southerly gales are possible across Lake Superior Sunday afternoon
into Sunday evening.

&&

.DISCUSSION...
Issued at 417 PM EDT Sat Oct 4 2025

High pressure continues to dominate the eastern half of the CONUS
today while the west remains under the influence of broad upper
level troughing anchored by a closed low beginning to lift out of
the Great Basin. An elongated surface trough extends northeast from
a low developing in the lee of the Colorado Rockies into western
Ontario. This yields warm, sunny, and breezy conditions across Upper
Michigan this afternoon as ridging remains in place in the mid and
upper levels of the atmosphere, while a tightening surface pressure
gradient ahead of the trough results in increasing south-southwest
winds gusting to 20-30 mph. Temperatures have climbed well into the
80s and put daily records in jeopardy in some locations as of 3 PM
Saturday, with southerly downslope winds even contributing to a few
readings of 90 degrees along the Lake Superior shoreline in
Ontonagon County. Locations along Lake Michigan are a little cooler,
with temps mostly in the 70s due to southerly winds off the lake.

Southerly winds will continue to increase across the area this
evening as the surface low ejects out of the Front Range onto the
Northern Plains, resulting in widespread 30-35 mph gusts across much
of the area overnight. Contemplated the need for a Wind Advisory for
some areas near Lake Superior tonight as model soundings from the
NAM and other hi-res guidance depict 925 mb winds as high as 45-50
kt near or just beneath a low level inversion. Ultimately opted
against issuing anything as hi-res guidance has a tendency to
overperform in these scenarios and any higher end gusts should be
fairly isolated in nature. That said, would certainly not be out of
the question to see a few spots gusting to 40-45 mph at times
overnight.

Warm and breezy conditions continue into Sunday as the region
remains in deep layer southwest flow between the two major synoptic
features. Temperatures will likely be a few degrees cooler as the
ridge axis shifts eastward and 850 mb temps come down from 16-18 C
this afternoon to more like 14-15 C on Sunday. Still, expect highs
generally in the upper 70s to around 80 degrees across much of the
area on Sunday. Continued breezy conditions along with minimum
humidity values in the mid to upper 30s could result in some
elevated fire weather concerns across parts of the west, but do not
expect any critical thresholds to be met at this time. A cold front
will sweep across the UP late Sunday evening as the shortwave
currently over the Great Basin lifts NE into Ontario and Hudson Bay.
This will bring the chance for a few showers and thunderstorms
through Sunday night, but do not expect any strong storms as
instability remains meager with MUCAPE on the order of a few hundred
J/kg.

Expect showers to diminish and winds to drop off fairly quickly on
Monday morning as surface high pressure builds in behind the
departing front. This will usher in a much more fall like pattern to
begin next week as high temperatures fall back into the low 60s. The
prospects for lake effect rain showers during the first half of next
week continue to diminish as surface high pressure lingers and a
passing trough remains farther to the north, keeping 850 mb temps up
in the 0-5 C range for the most part. Thus expect mostly dry zonal
flow with temperatures near seasonal norms in the upper 50s to low
60s through at least the first half of the week. Forecast confidence
decreases beyond Wednesday, but precipitation chances tick upwards
Thursday into Friday as another frontal system potentially impacts
the region.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 113 PM EDT Sat Oct 4 2025

VFR conditions will prevail through the TAF period. Expect breezy
southerly winds this afternoon with gusts to near 30 knots possible.
Tonight low level winds will strengthen above the surface
resulting in LLWS to 55 knots. LLWS will diminish Sunday morning
but it will remain breezy through the day.

&&

.MARINE...
Issued at 417 PM EDT Sat Oct 4 2025

Southerly winds will continue to increase to 20-30 kt this evening
as low pressure moves from the Plains into northwestern Ontario.
Could see some localized Gale Force gusts along the south shore of
Lake Superior tonight into Sunday morning, but expect these to be
sparse enough in coverage as to preclude any headlines.
Ahead of and immediately behind a cold front passing through the
lake late Sunday, south to southwest gales up to 40 knots could
potentially occur, with the strongest winds expected near the
Keweenaw, near Isle Royale, and the eastern open waters. Chances for
low-end (35 knot) gales or greater remain around 50 to 80%, with the
highest chance for gales over the eastern open lake. Could see a few
thunderstorms Sunday evening with the cold front, but chances remain
low at this time.

Once the cold front passes, expect winds to rapidly weaken, becoming
generally 20 knots or less again by Monday afternoon. Westerly zonal
flow from Monday into Tuesday could allow winds to pick up to 20 to
25 knots between the Keweenaw and Isle Royale Monday night into
Tuesday before another shortwave dropping a cold front through the
lake sometime Tuesday/Tuesday evening brings west to northwest winds
of 20 to 30 knots back over the lake.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Gale Watch from Sunday afternoon through late Sunday night for
     LSZ162-242>250-263>266.

Lake Michigan...
None.

&&

$$

DISCUSSION...CB
AVIATION...NL
MARINE...CB/LC