254
FXUS63 KMQT 221918
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
318 PM EDT Thu May 22 2025

.KEY MESSAGES...

- Cooler than normal temperatures to finish this week. Warming up
this weekend through next week.

- Frost possible over the interior west multiple nights this week.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 318 PM EDT Thu May 22 2025

Afternoon satellite imagery and RAP analysis reveal broad midlevel
troughing over the Great Lakes  and northeast CONUS, with a couple
of embedded features: a fairly tight surface low centered over Lake
Erie and another shortwave dropping from Northern Ontario into the
northern Great Lakes. With surface high pressure over the Northern
Plains, we remain under cool northerly flow - somewhat breezy, too,
given the tighter pressure gradient. Wind gusts around 20-25mph are
most common, but higher gusts up to 30mph have been observed at
times. Meanwhile, upslope flow and plenty of lower-level moisture is
keeping much of the central and western UP under low cloud cover,
with light rain showers and drizzle apparent on radar. This won`t
amount to much by way of precipitation, with the only real hazard
being a somewhat gloomy afternoon. Temperatures are peaking only in
the upper 40s under cloudy skies, and in the lower 50s where more
breaks of sunshine are occurring (eastern UP, far western Gogebic
and Ontonagon counties).

Moving into tonight, expect to see light rain/drizzle showers linger
mainly  over the north wind upslope areas of the Keweenaw, north
central, and east; however, with weak radar returns this afternoon
reaching as far as the WI border, wouldn`t be surprised to see some
sprinkles elsewhere across the area. We could even see a mix with
snow along the Huron Mountain range into the Michigamme Highlands
tonight into Friday morning as temperatures drop. However, given
that lows tonight are projected to only get down into the mid 30s in
the coldest spots, no accumulations are expected. While the moisture
will help prevent frost formation across most of the area tonight,
the exception seems to be in Gogebic County where cloud cover and
precipitation could be a little more patchy. Given the uncertainty,
will hold off on an advisory at this time.

Expect Friday to be nearly identical to today - breezy, cloudy,
lingering upslope sprinkles/showers in the northern tier of the UP.
That said, temperatures turn a couple of degrees warmer as cold air
advection ceases and light rain/drizzle showers with time as the
parent low phases eastwards away from our area. As high pressure
encroaches the area on Friday evening, expect the cloud cover to
progressively dwindle across the U.P.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 318 PM EDT Thu May 22 2025

As we head into the weekend, surface low pressure will be moving
over New England, with high pressure centered over northern Ontario
extending ridging into the Upper Great Lakes. This will keep us
under northerly flow through the weekend, but a moderating airmass
will have 850mb temperatures climbing to around 0C with a gradual
warming trend kicking off. Temperatures still start off generally in
the 30s both mornings, but highs range in the lower to perhaps mid
60s with sunny skies across much of the UP Saturday and Sunday.
Nearer to Superior, onshore flow should keep temperatures in the
50s. Meanwhile, with light winds, more breaks in the clouds, and
temperatures dropping into the mid 30s or lower in the interior-
western UP each morning, frost could become more widespread early
Saturday  and Sunday, potentially necessitating headlines in future
forecast cycles.

Our warming trend continues into next week. In this period, the
airmass at 850mb will warm to +3-4C Tuesday before cooling again
Wednesday night below zero C. This will support daytime temperatures
potentially well into the 0s across most of the UP Monday and
Tuesday, and generally in the 50s near Lake Superior. Daytime mixing
and the dry airmass Monday/Tuesday will also yield RH values dipping
into the 30s and perhaps 20s. At the moment, elevated fire weather
conditions are not expected given lighter winds...but even this
could prove problematic as lake-breeze development could cause
sudden shifts in wind direction. Following several generally dry
days, this could still be a period worth watching.

Midweek onwards, midlevel troughing or perhaps even a cutoff low
ejects out of the Plains, with an associated surface low closing off
over the central Mississippi valley and heading towards the Lower
Great Lakes. This could graze us with some rain showers by the end
of the forecast period, but confidence is low as ridging may hold
strong over us and suppress this next feature too far to our south
for any impacts to be felt here. Otherwise, expect temperatures to
continue to trend upwards, reaching the 70s across much of the UP by
Thursday afternoon.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 118 PM EDT Thu May 22 2025

Ceilings have lower to MVFR at CMX & SAW and eventually drop to
IFR/LIFR tonight over these terminals as wrap around moisture from a
low pressure sitting over southern Ontario moves over us; as for
IWD, it should remain VFR until MVFR cloud cover moves in late
tonight. The moisture from the low pressure is expected to bring
light rain/drizzle showers to CMX and SAW tonight into Friday. Other
than that, expect breezy northerly winds across the terminals, save
for lighter/calmer winds by IWD (in comparison) today and tonight.

&&

.MARINE...
Issued at 318 PM EDT Thu May 22 2025

Low pressure over the Lower Great Lakes today moves into New England
Friday into the weekend. On the back side of this feature, primarily
north to northwest flow persists over Lake Superior at least through
the weekend. Wind gusts of 20-25kts, occasionally up to 30kts,
remain common across the eastern half of the lake today through
tonight, gradually falling back below 20kts by late in the day
Friday. Winds remain light through the weekend and into next week.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Beach Hazards Statement until 10 PM EDT this evening for
     MIZ005-006.

Lake Superior...
None.
Lake Michigan...
None.

&&

$$

SHORT TERM...LC
LONG TERM...LC
AVIATION...LC
MARINE...LC