Chatham, Michigan Weather Forecast Discussion

762
FXUS63 KMQT 092009
AFDMQT
Area Forecast Discussion
National Weather Service Marquette MI
409 PM EDT Tue Sep 9 2025
.KEY MESSAGES...
- Locally heavy rainfall and associated flood concerns winding
  down this evening.
- High temps mainly in the 60s and 70s expected for the
  remainder of this week.
- Drier weather beyond Wednesday.
&&
.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 405 PM EDT Tue Sep 9 2025
A slow moving frontal boundary continues to sag south and eastward
across Upper Michigan this afternoon, with an associated band of
steady rain now oriented along a line from roughly Alger and
northern Schoolcraft Counties in the east to Dickinson and southern
Iron Counties in the west. Rain has been heaviest today in the
western portion of that line across Iron and Dickinson Counties,
where modest instability on the order of 100-300 J/kg MUCAPE is
supporting a cluster of slow-moving embedded thunderstorms which
have produced hourly rainfall rates of 1.5 to locally as much as 2.5
inches across a narrow swath along and north of Hwy 69 according to
radar estimates. Flash flood guidance has remained on the marginal
side in these locations for the most part, but have issued a Flood
Advisory through 4 PM to account for ponding of water and potential
localized flooding issues. Will continue to monitor flood potential
into this evening as moderate to locally heavy rain continues to
track slowly eastward over the next few hours, however expect
rainfall to gradually diminish in intensity as stronger forcing
departs the area and helps to limit convective development along the
weakening frontal boundary. This should thus help to limit any
ongoing flood concerns into the overnight hours.
Elsewhere, still seeing a few gusts to around 25 mph over northern
Lake Michigan and along the Lake Superior shoreline from Marquette
eastward this afternoon, but winds have generally been on a downward
trend from west to east across the area since the stronger
gusts were observed this morning. Expect that trend to continue
into this evening as the stronger LLJ continues to move off to
the north and east. That said, gusty south-southwest winds over
northern Lake Michigan will continue to bring dangerous
conditions to Schoolcraft County beaches through later this
evening. As winds go lighter overnight, will have to keep an eye
on the potential for some areas of dense fog to develop
overnight, especially across the west given to today`s rainfall.
Isolated to light rain showers will continue across the U.P. tonight
into Wednesday as a weak mid level trough moves across northern
Wisconsin. Expect any rainfall with this feature to remain light,
with model QPF values showing only a tenth or two of an inch at most
across the area on Wednesday.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 405 PM EDT Tue Sep 9 2025
Conditions trend drier Wednesday night into Thursday as an upper
level ridge amplifies over the central Plains and Upper Midwest.
This will yield clearing skies across the U.P. on Thursday, with
increased sunshine and rising 500 mb heights allowing high
temperatures to climb into the upper 60s to low 70s across the area.
Temperatures look to remain near or even slightly above seasonal
norms around 70 degrees into the weekend as upper level ridging
remains entrenched just upstream.
The one caveat to the upcoming dry conditions will be a disturbance
passing north of the area and potential bringing some rain Friday
into Saturday. Guidance has continued to trend weaker with this
feature, but the bulk of Euro ensemble members and about half
of GEFS members depict at least some measurable precip across
the area in this time frame. Continuing to ride with 30-40% NBM
PoPs for now. Regardless, any rainfall amounts look to be rather
minimal and will will thus limit any impacts. Latest guidance
favors dry weather returning Sunday into the early part of next
week as WPC ensemble clusters show increasing agreement on
stronger high pressure centered over northern Ontario through
Tuesday.
&&
.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 203 PM EDT Tue Sep 9 2025
Persistent showers and isolated thunderstorms are concentrated over
SAW this afternoon and will continue to stream over that area into
tonight. Elsewhere, IWD and CMX are not completely rain free, yet,
either. But, rain has subsided over both of those TAF sites for now.
MVFR has been the predominant flight category and will continue to
be through this evening. However, expect further deterioration to
IFR/LIFR tonight as widespread fog overspreads the area. For now,
IWD and CMX are expected to have the worst visibilities and will
need to be monitored for worsening conditions to even VLIFR or worse
early Wednesday morning. Meanwhile, the strong southwest winds have
since weakened over the last few hours and will become light
and variable...conducive to fog formation.
&&
.MARINE...
Issued at 405 PM EDT Tue Sep 9 2025
Gusty south-southwest winds continue to diminish through this
evening as a stronger LLJ departs the region. Marginal Small
Craft Advisory level conditions will linger over northern Lake
Michigan into this evening. Otherwise, winds generally remain
near or below 10 kt for much of the rest of the week as high
pressure builds just to the west, with wave mainly in the 1-2 ft
range. Lighter winds may yield areas of dense fog tonight into
Wednesday morning as the rain comes to an end.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Beach Hazards Statement until 10 PM EDT this evening for
     MIZ014.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...CB
LONG TERM...CB
AVIATION...TDUD
MARINE...CB

NWS MQT Office Area Forecast Discussion