Vulcan, Michigan Weather Forecast Discussion

859
FXUS63 KMQT 151901
AFDMQT
Area Forecast Discussion
National Weather Service Marquette MI
301 PM EDT Mon Sep 15 2025
.KEY MESSAGES...
- A few showers and possibly a rumble of thunder are possible tonight
  over the western U.P.
- Warm and humid weather through early next week.
- Areas of fog are possible again tonight; fog could be dense.
- Cooler air moves back in for the late week.
&&
.DISCUSSION...
Issued at 300 PM EDT Mon Sep 15 2025
The upper air pattern was messy this afternoon across the United
States and Canada. The ridge continues to get squeezed over the
Great Lakes and a closed high has developed overhead. A trough was
over the western U.S with two upper level low pressures, one over
North Dakota and the other over the Idaho Panhandle and western
Montana. Yet another upper level low was over northern Saskatchewan
ahead of a stronger low over the Gulf of Alaska.  Finally, another
low was centered over the southeastern U.S. It was warm and humid
this afternoon with highs in the 70s to low 80s under sunny skies.
Showers and a few thunderstorms have developed this afternoon over
western WI along a CAPE gradient that extends northward to the
western U.P. SPC mesoanalysis showed deep moisture convergence and
CAPE 1000+ J/kg in western WI up to the far western UP along with
weak upper level divergence in the entrance region of a 300mb jet
streak. CAMs are not handling this convection well but most do show
at least some spotty showers making their way into the western U.P
and Keweenaw tonight. Added slight chance PoPs for the west and
Keweenaw for tonight into early Tuesday morning.
Fog will redevelop again tonight over the southeast U.P, and
possible Tuesday night, as favorable conditions continue for good
radiational cooling and light winds. With light southerly flow
suspect that fog is less likely in the lower elevations along Lake
Superior and the western U.P where winds should provide enough
mixing to limit fog development.
It will be warm the next few days with highs reaching into the 80s
on Tuesday and Wednesday. The warmest temperatures will be over the
west on Tuesday, with highs in the mid 80s. These temperatures will
likely fall short of any records, which are mainly in the upper 80s,
but it will feel very warm for September and dewpoints in the 60s
will add a mugginess factor. The messy upper air pattern doesn`t get
much better over the next few days. The two upper level lows in the
western U.S will pivot through the trough tonight into Wednesday.
Most of the stronger forcing with these systems will stay west of
the area limiting our precipitation chances. The low over ND will
lift northeast into Manitoba, reaching the Hudson Bay by Wednesday
and dragging a trough and associated cold front into Upper Michigan.
This will bring a better chance for shower and a few thunderstorms
across the U.P on Wednesday along with cooler temperatures for
Thursday through the weekend, back closer to seasonal averages (60s
to near 70).
Another upper low will dive south out of Saskatchewan and merge with
an upper low over the central Rockies through Thursday. This low
will move very slowly to the Upper Great Lakes through Monday. The
result will be a chance for showers and a few thunderstorms
continuing into Thursday and Friday with a frontal boundary stalled
across the area. As the main system pushes through on the weekend
there could be a period of more widespread precipitation. The NBM
has trended upwards some, with PoPs in the chance category for
Saturday night into Sunday (30% to 40%).
&&
.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 135 PM EDT Mon Sep 15 2025
Clear skies and light winds prevail this afternoon at all sites.
Convective activity in west-central WI presses nearly directly north
and may skirt into IWD this evening, however, confidence is low. By
the time this line reaches the UP, waning instability may diminish
showers/storms altogether, thus opting to leave any impacts out of
the TAF for now. Tonight, patchy dense fog is once again possible,
mainly at SAW where HREF guidance shows a 10-40% chance for 

NWS MQT Office Area Forecast Discussion