412
FXUS63 KMQT 191103
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
703 AM EDT Tue May 19 2026

.KEY MESSAGES...

- Cooler than normal temperatures today through the rest of the
  work week.

- Up to 35% chance of frost impacting the early portion of the
  growing season Friday AM.

&&

.UPDATE...
Issued at 254 AM EDT Tue May 19 2026

The going forecast remains on track this morning as the prior
day`s downward trend in the thunderstorm forecast for the early
morning hours this morning proved correct with KMQT radar
returns showing a broken line of showers with scattered thunder,
mostly clustered in Baraga County and along the state line
adjacent to Iron County as of 6Z. Elsewhere, fog is observed
ahead of the cold front as moisture- rich easterly and
southeasterly flow upslopes from Lake Michigan and upslopes
towards the higher terrain of the west half. As the front mixes
the boundary layer and winds shift to be out of the northwest,
some low stratus and slight chances (mainly 15-30%) of lingering
showers is forecast but fog is not expected to persist, so the
Dense Fog Advisories will be allowed to gradually expire from
west to east as originally intended.

Otherwise, the main impactful weather will be the remnant gusty
conditions and choppy waters creating conditions hazardous to small
craft today and the potential for frost for the morning of the 22nd
with the resumption of frost/freeze headlines as agricultural
growing season approaches. Despite high pressure dominating the
local weather pattern for the work week, cold advection in the wake
of the passing trough results in 850mb temperatures being in the
25th percentile or lower relative to the climatology of 850mb temps
for this time of year, translating to surface temperatures that are
up to 5-10 degrees below normal. The LREF shows up to 35% chances of
Friday morning`s low falling to 36 or lower, with the NBM
deterministic low around that temperature for much of the interior
UP.

&&

.DISCUSSION...
Issued at 331 PM EDT Mon May 18 2026
Amended at 254 AM EDT Tue May 19 2026

Quiet and benign weather follows the ongoing passage of a cold
front for most of the remainder of the week.

Isolated to scattered showers linger into today, however
instability will likely be elevated and only briefly uncapped in
the east/south-central for a few hours at best. Thunder is in
the forecast, but strong to severe storms are not expected.
Highs in the east half today will be in the upper 50s to upper
60s, lower in the northwestern UP where mid 40s to mid 50s are
expected.

From there, the low departs to the northeast and high pressure over
the Plains replaces it. This maintains over the Great Lakes through
most of the work week yielding dry weather until the weekend.
Lingering troughing aloft keeps colder northwest flow through
Wednesday, resulting in temps between 5-15 degrees below normal;
highs in the 40s and 50s and lows in the 30s. A warming pattern is
then expected toward next weekend as mid level ridging slowly builds
over the southeast and extends up into the Great Lakes. Another
trough over the Rockies on Friday looks to move toward the Upper
Great Lakes during the weekend, bringing back precip to the UP.
Instability with this is lacking, so impactful strong to severe
storms are not anticipated.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 702 AM EDT Tue May 19 2026

In the wake of a cold front, damp conditions are leading to
LIFR conditions at SAW and MVFR conditions at CMX as of 11Z,
though CMX did spend much of the overnight period at airport
minimums. While chances of further precipitation after 12Z are
20-40%, the atmosphere dries out after noon and conditions
improve to at least MVFR at all sites, though lingering ceilings
will prevent a clearing to VFR until overnight tonight at the
soonest. With the front past IWD/CMX, northwest winds will
continue throughout the period, with SAW still observing
southerly winds until the front fully passes this morning.

&&

.MARINE...
Issued at 331 PM EDT Mon May 18 2026
Amended at 254 AM EDT Tue May 19 2026

A low pressure moves northeast over Upper Michigan and Lake
Superior today. This tightens the pressure gradient and
increases northeast winds over the west and north- central
portions of the lake to 20-30 kts early this morning. As the
low moves overhead, winds become northwest and strongest winds
shift from the west half to the east as colder air moves in.
Probabilities of gales to 35 kts are 25% or less, highest in the
east this afternoon. Showers and storms are expected with this
system into this morning, however severe storms are no longer
expected. This rainfall will prolong fog over the east into
this morning. High pressure returns winds to 20 kts or less by
Wednesday afternoon, winds likely maintain light into the
weekend.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Dense Fog Advisory until 11 AM EDT this morning for LSZ244-
     264>266.

  Dense Fog Advisory until 8 AM EDT this morning for LSZ245>251.

  Dense Fog Advisory until 2 PM EDT this afternoon for LSZ267.

Lake Michigan...
  Dense Fog Advisory until 1 PM EDT this afternoon for LMZ221-
     248-250.

&&

$$

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