733
FXUS63 KMQT 030822
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
422 AM EDT Thu Jul 3 2025

.KEY MESSAGES...

- Hot and humid conditions return Friday and Saturday. Please
  practice necessary heat safety measures if you plan on
  participating in outdoor holiday weekend festivities.

- A warm front may bring scattered showers and storms to the
  western UP Friday morning (15-35% chance).

- Isolated to scattered storms are possible in the afternoon and
  evening of Friday, the Fourth of July, then better chances for
  showers and storms return Saturday.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 412 AM EDT Thu Jul 3 2025

A tranquil summer day is in store for Upper Michigan today as upper
ridging over the central CONUS places a ~1018 mb sfc high pressure
directly atop the northern Great Lakes. Light northerly flow will
keep the nearshore Lake Superior areas a little cooler than
yesterday with forecast highs in the low to mid 70s. Elsewhere,
expect seasonal temps in the upper 70s to low 80s. Calm conditions
persist into the evening and overnight hours, cooling down into the
low 60s east and 50s central/east. No weather hazards are
anticipated at this time for individuals and townships planning
firework activities.

Come Friday, the 4th of July, the upper ridge shifts overhead the MS
River Valley as troughing makes landfall in the PNW and a strong
shortwave presses east through Sask/Manitoba. This will allow a much
warmer/humid airmass to flood north into the Upper Great Lakes.
Recent 00z HREF guidance suggests elevated showers/thunderstorms
developing along the initial warm front in WI/MN moving into the
western UP by ~12z, however, individual CAMs are not in great
agreement on the overall timing and coverage, thus have bumped up
PoPs early Friday across the western UP. Behind the warm front
Friday afternoon/evening, the increased humidity will aid in MUCAPE
values climbing as high as 2000-2500 j/kg across the west above a
stout capping inversion. Without a real "trigger" to kick off
convection and realize such strong instability, thunderstorms may
not be able to develop. If isolated convection can get going, model
soundings point to potentially gusty thunderstorms with hail
possible. For now, adding in some low chance PoPs to account for
this scenario. Otherwise, the rest of Friday looks rather quiet.

The other hazard will be the heat/humidity. High temperatures on the
holiday look to climb into the upper 80s/low 90s across the west
half, cooling off slightly into the central and east to the mid to
low 80s. Additionally, with Tds increasing to the 60s to near 70
(west), apparent temperatures or "Heat Indices" will push the mid to
upper 90s in the west, again slightly cooling with eastern extent
across Upper Michigan.

If you plan on taking part in outdoor festivities, please practice
necessary heat safety precautions!

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 422 AM EDT Thu Jul 3 2025

Hot and active weather returns as we head into the holiday weekend.
Better chances for showers and storms move in early Saturday as the
aforementioned Canadian shortwave moves east towards the Hudson
Bay, eventually dragging a cold front through sometime later in
the day Saturday through early Sunday. MUCAPE increases to
around 1500 j/kg ahead of the cold front, with healthy bulk
shear at around 30-40kts indicating a potential for some
stronger storms producing hail and gusty winds. Storms wrap up
early Sunday behind the exiting front.

Otherwise, look for hot and humid conditions for the holiday
weekend. Saturday, temperatures again reach the upper 80s to near
90F in the eastern UP ahead of the cold front (lower near Lake
Michigan). To the west, behind the front, temperatures peak in the
lower to mid 80s.

Dry weather is favored Sunday into early next week with lower to
midlevel ridging building northward behind the exiting weekend
system. However, PoPs return as early as Tuesday as the ridge shifts
eastward. Following the period of hot weather, temperatures come in
near to below normal Sunday onwards.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 132 AM EDT Thu Jul 3 2025

VFR conditions are ongoing and are expected to continue throughout
this TAF period at all sites as chances of overnight FG formation
have fallen below 15 percent at all terminals. Light and variable
winds will increase out of the north and east this afternoon, most
notably at CMX where gusts to 15-20 kt are 50+% possible. Besides
haze from Canadian wildfire smoke, expect mostly SKC conditions.

&&

.MARINE...
Issued at 339 PM EDT Wed Jul 2 2025

W-SW winds below 20 kts this evening become light and variable
tonight. NE winds increase to 15-20 kts across the W half of the
lake Thursday afternoon while remaining light and variable across
the E half. Winds ease below 20 kts across the entire lake Thursday
night while backing SE across all areas except the extreme W lake.
SSE winds increase to 15-20 kts across the E half Friday with NE 15-
20 kts for the extreme W. Elevated winds are expected through the
weekend. Waves less than 4 ft are expected through the end of the
week with waves approaching 4 ft Friday night and Saturday.

&&

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

&&

$$

SHORT TERM...BW
LONG TERM...BW/LC
AVIATION...GS
MARINE...PK