386
FXUS63 KMQT 131303
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
903 AM EDT Sun Jul 13 2025

.KEY MESSAGES...

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

- This evening, a few showers and thunderstorms may arrive in the
western UP. A few of these storms may be strong to severe, with a
Marginal Risk (category 1 of 5) for damaging winds and 1+" hail.

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

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 344 AM EDT Sun Jul 13 2025

Upper air pattern (per RAP analysis) consists of a negatively tilted
trough (cut off at and below 700mb) over northern Ontario with a
minor embedded shortwave extending southwest from the trough over
the Plains. With minor ridging and height rises over the UP in the
wake of the main trough`s passage yesterday, subsidence has kept
wildfire smoke from upstream fires in northwest Ontario and Manitoba
near the surface over the UP, with many UP METARs showing visibility
sub-6 miles this evening and PurpleAir sensors showing PM2.5 AQI of
150-215+. Even if those sensors are biased high by a category, the
air quality is poor enough that people in sensitive groups may
experience some health issues, especially those with poor air
filtration or those that cannot prevent smoke from getting inside
their homes. RAP-Smoke and HRRR-Smoke show little improvement
throughout the morning and even show increasing concentration of
near-surface smoke in the western UP this afternoon. Anyone with air
quality concerns should refer to the Air Quality Alert in effect for
more information including links to health information and best
practices. Despite the smoke, high temperatures today will still be
around the 80 degree mark with otherwise sunny skies expected.

Attention then turns upstream as the aforementioned minor Plains
shortwave approaches, forcing isolated convection upstream.
Increasing flow aloft will provide better shear environments than
much of the recent convective setups with the HREF showing mean 0-
6km shear values of around 30 kt and increasingly sickle-shaped
hodographs in the lower levels allows 0-3km SRH values to climb to
the 100-200 range. There is a question of available instability as
the timing of when showers/storms would arrive would be around 0Z-
6Z, after the peak of diurnal heating, so HREF mean SBCAPE is only
around 750 J/kg, but there is considerable spread in the minimum and
maximum modeled values (especially given that smoke could dampen the
ability for the surface layer to destabilize). Additionally, the
surface trough will be weakening as it approaches the UP, so forcing
will be weakening. Available moisture will not be an issue though as
much of the short range guidance has dew points in the 60s in the
west ahead of this activity. To recap: good shear, weakening lift,
questionable instability, and good moisture. All of this
combines for a conditionally marginal severe setup, as if
convection does have enough forcing and instability over the
region, the shear and moisture will support some isolated
supercells capable of severe wind and hail. However, given the
failure of better forced and more unstable events this summer,
confidence in storms even lasting to reach the UP is not
particularly high, with PoPs only up to 35 percent. Even with
storms petering out after 06Z, the boundary will help mix out
some of the wildfire smoke, bringing some (at least brief)
relief to the hazy skies. Expect low temperatures to fall to the
low 60s tonight.

&&

.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 /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 728 AM EDT Sun Jul 13 2025

Wildfire smoke from Canada is causing hazy skies and reducing
visibility to MVFR conditions this morning. While periods of VFR vis
are possible for periods of time today, the most common visibility
is expected to be in the MVFR range with a few spurts down to 2SM
possible but unlikely. The only thing interrupting primarily dry
conditions is the chance for some isolated TSRA at IWD (and to a
lesser extent, CMX) this evening after 00Z, which could bring some
erratic and gusty winds but chances of TSRA actually impacting the
terminal are only around 20-30 percent at IWD and 10-20 percent at
CMX. Expect winds primarily out of the west to southwest today at
around 5-10 kt with some gusts to 15 kt possible.

&&

.MARINE...
Issued at 903 AM EDT Sun Jul 13 2025

Visibility will continue to be reduced in areas of fog and wildfire
smoke into Monday. Winds will increase with west-southwesterly gusts
around 20 kt through today, mainly over the western half. A
weakening band of showers and thunderstorms is possible over the
western lake this evening (40% chance). 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>007-009>014-084-085.

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

&&

$$

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