093
FXUS63 KMQT 150542
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
142 AM EDT Tue Jul 15 2025

.KEY MESSAGES...

- Periods of rain and thunderstorms, some strong to severe, are
  expected Tuesday through Wednesday along a slow moving frontal
  boundary.

- Seasonably warm through Tuesday, then sharply cooler Wednesday
  into Thursday.

&&

.UPDATE...
Issued at 955 PM EDT Mon Jul 14 2025

Low level f-gen supported a round of -shra that crossed Lake
Superior this evening and have progressed over the W spine of the UP
so far. These will continue to push inland, but likely will slowly
diminish as they depart from their lifting mechanism. That said,
this afternoon`s CAM suite did not capture this well and the last
few HRRR runs continue to drop precip all together within a hour or
two of initialization...which so far has not panned out this evening.
Additional short term updates may be needed tonight. Otherwise no
major changes have been made to the fcst.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 212 PM EDT Mon Jul 14 2025

Afternoon RAP analysis and GOES satellite imagery reveal a mostly
quiet scene across the UP and Lake Superior under quasi-zonal flow
aloft. At the surface, a very diffuse frontal boundary is being
dragged along the s-central and eastern UP. Here, now agitated cu
and a few isolated showers are starting to take shape amidst
building instability. This boundary, aided by developing lake breeze
circulations may be the foal point for additional
showers/thunderstorms this afternoon. Marginal shear below 25 kts,
weak mid-level lapse rates, and a somewhat dry sfc layer indicated
by model inverted-v profiles will work to limit convective potential
and organization, however. Have included some low chance PoPs for
development within the next few hours.

Elsewhere, under mostly clear skies temps have risen in the 70s to
low 80s. Smoke from Canadian wildfires continues to plague the
region as webcams depict hazy/milky skies where elevated smoke is
being mixed down to the sfc. Air quality sensors range from the
yellow to orange (moderate to unhealthy for sensitive groups) range,
while upstream sensors in MN have fallen into the red unhealthy
category. RAP/HRRR model smoke guidance suggests the near sfc smoke
expanding across the UP from upstream this afternoon and evening,
where sensors across the UP could fall further into the unhealthy
ranges before clearing out early Tuesday.

Attention turns upstream to a few shortwaves within the zonal flow
aloft descending into the N Rockies, introducing height falls across
the Upper Midwest and developing sfc low pressure into the northern
Plains. This will push a warm front into the UP Tuesday
morning/afternoon, allowing afternoon temps to climb into the 80s to
near 90. Additionally, increasing moisture characterized by PWATs
climbing ~1.5", moderate isentropic ascent, and ample instability,
will lead to the development of showers and thunderstorms. 12z CAM
guidance, however, varies wildly on the timing, strength, and
overall placement of developing convection- some developing a line
of convection passing through the west and Keweenaw as early as 12z,
and some missing the UP completely until the front sags back south
Tuesday afternoon/evening. CAMs have better agreement on a secondary
line of convection developing during the afternoon/evening hours,
where strong diurnal instability and moderate speed shear could lead
to thunderstorms producing severe wind gusts and hail, thus, SPC has
included the west half of the UP in a Slight Risk (2 of 5) for
severe thunderstorms tomorrow. Further, with the general movement of
storms parallel to the WSW/ENE boundary, training showers and storms
could produce rainfall totals between 1-2" through Tuesday night,
particularly in the west half. For this reason, WPC has included the
far western UP and Keweenaw in a Slight Risk (2 of 5) for flash
flooding through Wednesday morning.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 313 PM EDT Mon Jul 14 2025

The low-level front continues to linger in the area Wednesday into
Thursday, with consensus supporting the surface portion of it
sagging mainly south of the area. This will result in sharply cooler
temperatures by Wednesday, with highs stuck in the 60s (and maybe
even 50s closer to the still below-normal temperatures of Lake
Superior) over most of the northern half. Additional rounds of
showers and perhaps thunderstorms are expected along the front, with
LREF and NBM guidance suggesting a 50-60% chance for an additional
0.5" of rain Wednesday through Thursday morning across the western
half of the UP. Latest 12z Euro Ensemble suggests a 50-70% chance
for total rainfall amounts >2" between Wednesday and Thursday
morning along the spine of the Keweenaw southwest across the Porkies
into far northern Wisconsin. Showers begin to wrap up Thursday
morning/afternoon, kicking off a gradual drying trend for the end of
the week as high pressure builds in the wake of this front, with
temps likely rebounding closer to normal Friday into Saturday.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 142 AM EDT Tue Jul 15 2025

VFR conditions are expected to persist through early this afternoon,
however a slow moving frontal boundary will support shra/tsra and
eventually deteriorating conditions into tonight. Confidence in
timing for shra/tsra has improved enough to include some tempo
groups and deterministic shra/tsra, but fcst confidence
progressively gets lower with time as spread in model guidance
increases prior to this evening. Kept plenty of PROB30 groups near
the end of the period to capture the later rounds of tsra and
deteriorating conditions into tonight. Some storms this evening
could be strong to severe. Otherwise some -shra tracking E over Lake
Superior are expected near or at CMX early. S to SW winds increase
today to 8-12 kts with gusts expected ~20 kts.

&&

.MARINE...
Issued at 326 PM EDT Mon Jul 14 2025

Visibility will continue to be reduced in areas of fog and wildfire
smoke into tonight. Winds will remain below 20 kts through
Tuesday. However, they will increase to 20-25 kt from the north
to northeast on Wednesday mainly across the western half of the
lake with the remainder of the lake in the 15 to 20 kt range
into Thursday. After that, light and variable winds will prevail
into the weekend. Rounds of showers and thunderstorms will be
possible, though, on Tuesday and Wednesday with the potential
for damaging winds and large hail in any storms that do form.
Plus, there is potential for fog where rainfall occurs.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.

&&

$$

UPDATE...Jablonski
SHORT TERM...BW
LONG TERM...BW
AVIATION...Jablonski
MARINE...TDUD