341
FXUS63 KMQT 171749
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
149 PM EDT Tue Jun 17 2025

.KEY MESSAGES...

- Showers and a few thunderstorms are possible Wednesday, mainly
  across the central and east.

- A hot and humid airmass is expected over Upper Michigan this
  weekend into early next week. Those sensitive to heat,
  especially those without effective cooling and/or hydration,
  may be impacted.

- Hot and humid conditions will support daily thunderstorm
  chances most days this weekend and early next week.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 148 PM EDT Tue Jun 17 2025

Early afternoon RAP analysis and GOES satellite imagery reveal
decent clearing across the UP as a sfc low continues its
northeastward departure towards far southern James Bay. This feature
is dragging a weak cold front across the east UP, though mostly
sunny skies are allowing temps to climb into the low 70s to near 80
across the interior. Through the rest of this afternoon and evening,
the building mid-level ridge should keep the CWA dry with partly
cloudy skies. Peak afternoon temps will continues to climb into the
mid to upper 70s area wide and low 80s s-central. Nearby Lake
Superior, expect a nice day around 70.

The next shot at precipitation arrives late tonight through
tomorrow as a shortwave trough lifts out of the Rockies and into the
Great Lakes. Underneath the entrance region of this shortwave, an
unseasonably strong sfc low (NAEFS MSLP 10th percentile) is expected
to develop in the central Plains, tracking across the Mississippi
River Valley and into Lower Michigan by late Wednesday/early
Thursday. Ahead of this system, S to SW flow will allow ample
moisture advection and the development of rain showers; however,
despite the event being a day away, guidance is in poor agreement on
the overall system track and thus rainfall amounts. Previous 00z and
06z ensemble probability guidance and meteograms hinted at the s-
central UP receiving a localized 2-4" of rain but this signal is now
nearly gone as the latest 12z guidance has continued a southward
trend, focusing heaviest precip amounts in lower MI. 12z HREF
guidance and individual CAMs hint at a line of convection likely
aided by a lake breeze, developing across the central UP. With
MUCAPE values >500 j/kg and PWATs 0.75-1.25", locally heavy rainfall
amounts 1-2" may be realized where thunderstorms activity persists
the longest.

Otherwise, seasonable temperatures are expected with highs in the
mid to upper 70s across the interior, slightly cooler near the
lakeshores.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Issued at 322 AM EDT Tue Jun 17 2025

A cold front is expected to press southeastward, moving into the
forecast area on Thursday. This front will swing through Upper
Michigan Thursday afternoon and evening, likely resulting in
scattered showers and thunderstorms across the region. Upper level
ridging builds into the Central Plains Friday while a surface high
stretches into the Upper Great Lakes. This largely looks to keep us
dry through the day. However, a ridge roller pressing eastward along
the ridge top will press eastward through the day. Guidance
continues to highlight this pressing into Upper Michigan Friday
evening/early Saturday. Afterwards, the ridge will shift southeast
into the South while a deep trough presses through the Rockies. This
will result in an amplified trough/ridge pattern across CONUS. The
first wave/warm front ejecting out of the trough may move through
the region Sunday.

Temperatures in this forecast period are largely expected to trend
upwards in time, with near normal temperatures becoming above
normal. Expect 60s and 70s to become widespread mid 80s by Sunday.
Overnight lows follow the same pattern, with 40s and 50s becoming
widespread 60s by Sunday night.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 148 PM EDT Tue Jun 17 2025

VFR conditions should prevail through the rest of the 18z TAF period
as drier air aloft has filtered into the UP behind a departing low
pressure system. IWD has stubbornly held onto very borderline MVFR
cumulus ceilings, however, this should continue to rise and
eventually scatter out this evening. Gusty W to NW winds upwards of
20 kts may persist at all TAF sites this afternoon, especially at
SAW, but are expected to diminish this overnight as we decouple.
Another low skirts into Lower MI towards the tail end of the TAF
period bringing chances of showers and t-storms. At this time, have
opted to leave any impacts out of this TAF issuance.

&&

.MARINE...
Issued at 322 AM EDT Tue Jun 17 2025

West-southwesterly winds gusting 20 to 30 knots through early this
afternoon finally fall below 20 knots late as weak sfc ridging sets
up across the area. At that point, light and variable winds will
prevail into Thursday when gusts in the 15 to 20 knot range return
through the weekend.

Outside of some storms over the eastern half of the lake this
morning, expect Lake Superior to be fairly quiet convection-wise
until this weekend. The marine dense fog is expected to dissipate
later this morning as well.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.

&&

$$

SHORT TERM...BW
LONG TERM...JTP/TAP
AVIATION...BW
MARINE...TAP/TDUD