Beach Hazards Statement 4, NWS Marquette, MI

Area Forecast Discussion
National Weather Service Marquette MI
244 AM EDT Mon May 25 2026

.KEY MESSAGES...

- A warming trend early this week may cause increased heat risk
  for vulnerable and sensitive populations.

- Thunderstorm chances (20-40%) persist in the forecast through
  Tuesday as multiple disturbances move through; however,
  confidence is low.

- Dry weather returns on Wednesday, likely persisting into the
  weekend.

&&

.UPDATE...
Issued at 245 AM EDT Mon May 25 2026

The going forecast remains mostly on track this morning as GOES-East
Nighttime Microphysics RGB imagery shows a swath of the eastern UP
under a bank of low clouds that matches up with METAR observations
of a half mile or quarter mile visibility. With a consensus of short
term guidance supporting continued low visibility until after
sunrise, a Dense Fog Advisory has been hoisted for Schoolcraft and
Luce Counties, though it is worth noting that similar conditions are
patchy in nature in Alger and Delta counties as well. The only CAMs
that show convection for the remainder of the overnight period also
show convection over the lake that would be ongoing, and with no
such convection, it is assumed that the subsidence and/or capping is
strong enough that whatever is keeping convection off the lake will
keep the UP dry through the early morning as well.

Today, with warm southwesterly flow continuing a warming trend in
the forecast with NBM highs in the low to mid 80s (though raw
guidance suggests upper 70s instead). CAMs are a bit scattered in
solutions for this afternoon, with most being clear, but a few
showing some CI around 21Z in an environment that is generally
expected to have 1000-1250 J/kg of SBCAPE and virtually no CIN,
though fairly meager shear and a significant lack of moisture. Thus,
severe weather is not expected in the afternoon. What CAMs are more
in consensus about is a line of convection moving into or through
the MN Arrowhead around 00Z this evening and decreasing in intensity
of dissipating altogether as it crosses the western arm of Lake
Superior into the UP by 03-06Z. The SPC has trimmed the UP out of
the Marginal Risk with this round, though some situational awareness
should be maintained with it as nocturnal storms with NW-SE
trajectories crossing Lake Superior have overperformed in the past.

The warming trend continues into Tuesday, though once again bias-
corrected guidance and raw model output continue to differ notably
in the highs, with NBM deterministic output calling for 90+ degree
highs for much of the Central Time Zone, yet LREF guidance continues
to only suggest only about a 35% chance of even getting within 5
degrees of this. Should the warmer temperatures win out, this would
be the warmest air mass of the year, so populations that are
vulnerable/sensitive to heat hazards should keep an eye on the
forecast. Beyond Tuesday, ensemble spread remains too high to
deviate from the NBM.

&&

.DISCUSSION...
Issued at 347 PM EDT Sun May 24 2026
Amended at 245 AM EDT Mon May 25 2026

The first half of the week contains multiple disturbances which
complicate the forecast, but weather quickly becomes quiet for the
latter part of the week as a persistent high pressure pattern sets
up. Temps this morning settle into the mid 40s to mid 50s.

A shortwave arriving near the WI/MI state line early Memorial
Day brings the next potential for showers/storms over the
west/central UP. If the prior round does occur, this will work
over the environment instability, but otherwise warm and moist
air advection keep elevated instability overnight. Given the
developing cap, not expecting strong to severe storms with this
round. Anything that does develop should fizzle out as it
progresses to the east late morning/early afternoon. WAA ramps
up today, bringing high temps into the 70s to mid 80s for most;
upper 60s in the east near Lake Michigan where there is
moderating onshore flow. Diurnal convection ramps up in the
afternoon as CAPE increases to 1000-1500 J/kg, highest in the
west, with model soundings indicating the cap erodes by late
afternoon. Strengthening low level winds could help convection
break the weak lingering cap moving further east and helps
increase bulk shear again to 35 kts. The proximity to the
shortwave earlier in the day could leave much to desire for
afternoon convection...noted in the limited CAMs response.

Better forcing for showers and storms arrives this
evening/tonight. A shortwave diving across northern Ontario
brings a low pressure system with it, sending a cold front
southeast over the UP. This keeps PoPs in the forecast, but they
remain low (15-30%) over the far west and north as dry air
plays a limiting role. Afternoon instability set up from today
does bring strong to severe storm potential with steep lapse
rates, aforementioned CAPE up to 1000+ J/kg, and 30-35 kts of
shear. Uncertainty quickly grows as this progresses over Lake
Superior and the sun sets. The SPC had a Marginal Risk for
large hail and damaging winds scraping the far western UP which
matches where confidence begins to drop off. Temps stay mild in
the 50s to low 60s.

WAA primes the region for a hot day on Tuesday with highs soaring
into the 80s for most away from the Great Lakes. Lake Superior and
eastern Lake Michigan lakeshores peak in the 70s, some interior
south spots reach low 90s! This may cause increased heat risk for
vulnerable and sensitive populations. Drier air in the wake of the
cold front means instability does not climb quite as high as Monday
mean values ~1000 J/kg or less, but afternoon showers and storms
potentially kicked off from Lake Breezes are possible 15-30%
chance...highest south-central UP. Dry weather returns Tuesday night
as high pressure over western Hudson Bay builds southeast into the
Great Lakes. Temps settle into the 50s.

A persistent high pressure pattern is expected to set up for late
week into the weekend as an amplified mid level ridge becomes
centered over the Midwest. An upstream closed low over the west
CONUS may force this pattern northeast as it lifts north to Canada,
this would briefly weaken the surface high pressure hold over the
region. That said, the trough to the east and resulting surface low
dropping over Quebec and New England likely will be too far east for
precip to materialize over the Upper Great Lakes given the
antecedent dry airmass in place. With that in mind, the GFS and GEFS
suite likely too progressive to consider. Another high pressure is
likely to return to the Great Lakes/Midwest early next week
regardless, keeping the dry and warm pattern going. Expect highs
late week and weekend in the 60s to low 80s, warmest interior west.
Lows will be in the 40s to low 50s.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 112 AM EDT Mon May 25 2026

VFR conditions will prevail throughout the period as models and
satellite trends show that this morning's fog will stay east of SAW.
IWD has a ~15% chance of -TSRA from 09Z to 12Z, but probabilities
are too low to include in this TAF. This afternoon, some -SHRA with
the potential for TS will pop up in the interior western UP today,
too far inland to impact IWD but around 30% likely to impact SAW, so
a PROB30 has been included here. Tonight, some LLWS will be in the
region with a LLJ, but confidence is only high enough in
occurrence at CMX to include for this TAF cycle.

&&

.MARINE...
Issued at 347 PM EDT Sun May 24 2026
Amended at 245 AM EDT Mon May 25 2026

With abundant high pressure influence during the forecast, winds by
and large remain 20 kts or less through next week. This keeps
significant wave heights below 4 ft. The main focuses will be marine
dense fog and thunderstorms.

Areas of dense fog are expected to persist through this morning
over the eastern lake. Given the patchy nature of the fog west
of Stannard Rock, all Dense Fog Advisories were canceled except
266/267. Confidence is low, but strong to severe storms seem
unlikely until this evening/tonight when a low pressure system
to the north sends a cold front over the lake. This round could
bring large hail and strong winds to western Lake Superior.
Mostly dry weather is otherwise expected Wednesday through next
weekend.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Dense Fog Advisory until 8 AM EDT this morning for MIZ007-014-
     085.

Lake Superior...
  Dense Fog Advisory until 8 AM EDT this morning for LSZ251-266-
     267.

Lake Michigan...
  Dense Fog Advisory until 11 AM EDT this morning for LMZ221-248-
     250.

&&

UPDATE...GS
DISCUSSION...77/GS
AVIATION...GS
MARINE...77/GS

Hazardous Weather Outlook
National Weather Service Marquette MI
355 PM EDT Sun May 24 2026

MIZ001>007-009>014-084-085-252000-
Keweenaw-Ontonagon-Northern Houghton-Baraga-Marquette-Alger-Luce-
Gogebic-Iron-Dickinson-Menominee-Delta-Southern Schoolcraft-
Southern Houghton-Northern Schoolcraft-
355 PM EDT Sun May 24 2026 /255 PM CDT Sun May 24 2026/

This Hazardous Weather Outlook is for portions of central Upper
Michigan and western Upper Michigan.

.DAY ONE...Tonight

There is a slight chance of thunderstorms in the west this evening
through tonight.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

There is a chance of thunderstorms Monday through Tuesday.

.SPOTTER INFORMATION STATEMENT...

The need for weather spotter reports is not anticipated at this
time.

LSZ162-240>251-263>267-252000-
Lake Superior west of a line from Saxon Harbor WI to Grand
Portage MN beyond 5NM-Saxon Harbor WI to Black River MI-
Black River to Ontonagon MI-
Ontonagon to Upper Entrance of Portage Canal MI-
Upper Entrance of Portage Canal to Eagle River MI-
Eagle River to Manitou Island MI-
Manitou Island to Point Isabelle MI-
Point Isabelle to Lower Entrance of Portage Canal MI-
Lower Entrance of Portage Canal To Huron Islands MI Including
Keweenaw and Huron Bays-Huron Islands to Marquette MI-
Marquette to Munising MI-Munising to Grand Marais MI-
Grand Marais to Whitefish Point MI-
Lake Superior from Saxon Harbor WI to Upper Entrance to Portage
Canal MI 5NM off shore to the US/Canadian border including Isle
Royale National Park-
Lake Superior from Upper Entrance to Portage Canal to Manitou
Island MI 5NM off shore to the US/Canadian Border-
Lake Superior West of Line from Manitou Island to Marquette MI
Beyond 5NM from shore-
Lake Superior East of a line from Manitou Island to Marquette MI
and West of a line from Grand Marais MI to the US/Canadian Border
Beyond 5NM from shore-
Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off
shore to the US/Canadian border-
355 PM EDT Sun May 24 2026 /255 PM CDT Sun May 24 2026/

This Hazardous Weather Outlook is for portions of Central Lake
Superior...Eastern Lake Superior and Western Lake Superior.

.DAY ONE...Tonight

There is a slight chance of thunderstorms in the west this evening
into tonight.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

There is a chance of thunderstorms Monday evening and Monday
night.

.SPOTTER INFORMATION STATEMENT...

The need for weather spotter reports is not anticipated at this
time.

LMZ221-248-250-252000-
Green Bay North of line from Cedar River MI to Rock Island
Passage-Seul Choix Point to Point Detour MI-
5NM East of a line from Fairport MI to Rock Island Passage-
355 PM EDT Sun May 24 2026

This Hazardous Weather Outlook is for portions of Northern Lake
Michigan.

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

There is a slight chance of thunderstorms in the afternoon and
evening on Monday and Tuesday.

.SPOTTER INFORMATION STATEMENT...

The need for weather spotter reports is not anticipated at this
time.

77