940
FXUS63 KMQT 121851
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
251 PM EDT Sat Jul 12 2025

.KEY MESSAGES...

- A Marginal Risk (category 1 of 5) of severe thunderstorms is in
place for the UP through this evening mainly for the eastern half.
Isolated storms could produce wind gusts to 60 mph and small hail
from about 3-9 pm (5-15%). Locally heavy rainfall is also possible.

- Wildfire smoke from Canada will be over the area through at least
Sunday night resulting in air quality concerns and reduced
visibility.

- Periods of showers and thunderstorms possible Tuesday into
Wednesday (30-60%).

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 249 PM EDT Sat Jul 12 2025

Water vapor imagery shows a shortwave trough pivoting into western
WI with modest lift ahead of it. This has resulted in areas of
showers and a few embedded storms across the UP thus far today.
Surface analysis shows a weak cold frontal boundary across central
portions of the UP moving east. A line of showers and a couple
embedded storms has developed along this line, but thus far has been
fairly weak. There is an area of clearing ahead of this line
resulting in a narrow window of destabilization, where 12Z CAMs have
favored convection becoming more invigorated. Effective bulk shear
of 30-40 kt suggests organization is possible in convective storms,
but thermodynamics are more marginal with HREF mean SBCAPE topping
out around 1000 J/kg. Window for stronger storms is likely 3-9 pm
mainly over the eastern half. HREF LPMM has an area of 1-2" of rain
over portions of the east, suggesting a threat for locally heavy
rainfall. The other story is the Canadian wildfire smoke mixing
down to the surface behind the front, with widespread 1-5SM
vsby from the western UP back into northern MN. Michigan EGLE
issued an Air Quality Alert through noon Monday, starting today
in the western half and tonight in the eastern half. HRRR smoke
model suggests the smoke will be with us at least through Sunday
night if not Monday.

Any showers/storms should quickly dissipate tonight with dewpoints
decreasing behind the boundary. Lows, mainly upper 50s to low 60s.
On Sunday, low pressure lifts into James Bay with high pressure over
the mid-Mississippi Valley. Resulting SW flow will keep temps on the
mild side with highs mainly in the 80s, although humidity will not
be a factor in most areas, and precipitation is not expected.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 249 PM EDT Sat Jul 12 2025

A few showers or perhaps a thunderstorm will be possible Sunday
night as a weakening boundary tries to move through from the west.
For early next week, zonal midlevel flow initially will become
more amplified with time over the northern tier of the CONUS as
troughing digs into the northern Plains, resulting in SW flow
over the local area. At the surface, an area of low pressure
will develop over the Rockies/central Plains, with a warm front
extending NE into the northern Plains or upper Great Lakes.
After a dry and seasonably warm day Monday (highs mainly in the
80s), precipitation chances enter the picture again
Tuesday/Wednesday as impulses in the SW flow team up with
diurnal instability to generate areas of showers and
thunderstorms. There is still uncertainty with timing and
placement of the front upon which most of the activity should be
focused, so general broad-brush chance to low-likely (30-60%)
PoPs will suffice, with Wednesday having relatively higher
probabilities for precipitation over most areas. With relatively
more ensemble members having the front north of our area on
Tuesday, another warm day in the 80s looks likely, with a cool-
down becoming more likely Wednesday on the back side of the
front. Gradually trending drier and seasonably cool for the end
of the week as high pressure builds over the northern
Plains/Great Lakes.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 107 PM EDT Sat Jul 12 2025

Main aviation hazards in the 18Z cycle are IFR/LIFR cigs early in
the TAF period, potential for thunderstorms mainly at SAW this
afternoon, and areas of wildfire smoke reducing visibility this
afternoon through the end of the TAF period. IFR/LIFR cigs are
around as of 17Z, but these should lift to at least MVFR levels by
18-19Z as diurnal heating helps to mix the atmosphere. A line of
showers with an embedded storm or two along a frontal boundary
should reach near SAW near the start of the TAF period at 18Z;
PROB30 included for TS potential 18-19Z. Another round of storms is
possible in the 20-22Z frame; TEMPOs included for this. Finally,
wildfire smoke is already reducing vsby behind the front, with
widespread 1-4SM vsby noted over the western UP and northern MN.
Kept vsby in the MVFR range for now but could see some IFR vsby as
well; will continue to monitor. Westerly wind gusts to 20 kt will
continue at CMX for most of the period.

&&

.MARINE...
Issued at 249 PM EDT Sat Jul 12 2025

A weak boundary will bring a chance of thunderstorms mainly over the
eastern half through this evening. Behind this line, visibility will
likely be reduced in areas of fog and wildfire smoke into Sunday.
Winds will increase tonight into Sunday with west-southwesterly
gusts to 20-25 kt through Sunday, mainly over the western half.
Winds diminish early in the week, but could increase to near 20 kt
from the north late in the week behind a frontal boundary. Unsettled
weather returns Tuesday/Wednesday with additional rounds of showers
and thunderstorms possible, plus the potential for fog where
rainfall occurs.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Air Quality Alert until noon EDT /11 AM CDT/ Monday for
     MIZ001>005-009>011-084.

  Air Quality Alert from midnight EDT /11 PM CDT/ tonight to
     noon EDT /11 AM CDT/ Monday for MIZ006-007-012>014-085.

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

&&

$$

SHORT TERM...Thompson
LONG TERM...Thompson
AVIATION...Thompson
MARINE...Thompson