352
FXUS63 KMQT 231947
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
347 PM EDT Mon Jun 23 2025

.KEY MESSAGES...

- A hot and humid conditions persist through the afternoon ahead of
a cold front. Those sensitive to heat, especially those without
effective cooling and/or hydration, may be impacted.

- A Slight Risk (category 2 out of 5) of damaging severe winds and
hail exists across the area for today as a cold front pushes
through. A Severe Thunderstorm Watch is in effect for much of the
Upper Peninsula.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 345 PM EDT Mon Jun 23 2025

The cold front is working through the western UP this afternoon,
with the vis-ir sandwich revealing agitated cu (not quite glaciated
just yet) developing along it. Some spotty associated radar returns
are just now beginning to pop. Meanwhile, the spotty pre-frontal
convection continues to move into the eastern UP and over eastern
Lake Superior. This has been rather lackluster over the land, but
with the cold front continuing to track through, we anticipate more
numerous showers/storms to develop across the central and eastern UP
through the rest of the day. The front is moving into an environment
featuring MLCAPE up to 2000j/kg, along with steepening midlevel
lapse rates and a comfortable 30-40kts of bulk shear - favorable for
some strong to severe storms. The main concern is gusty, potentially
damaging outflow winds (especially if we can see these individual
cells congeal into line segments), but large hail will also be
possible. The severe threat quickly wraps up this evening as the
front exits the eastern UP around/just after 00Z. A Severe
Thunderstorm Watch has been issued for much of the Upper Peninsula
through this evening.

Meanwhile, hot and humid conditions continue ahead of the front,
with temperatures largely ranging in the mid/upper 80s so far.
Nearer to Lake Michigan, southerly flow is limiting temperatures to
a more comfortable lower-mid 70s. South/SW winds remain on the gusty
side, with gusts around 20-25mph finally falling back after the
front moves through later this evening.

We`ll finally have some relief from this stretch of heat tonight as
temperatures falling back into the mid to upper 50s across most of
the area. The far eastern UP may struggle to fall below 60F tonight.
On Tuesday, with synoptic forcing being very weak as a ridge builds
in, expect the lake breezes to be the main driver in regards to high
temperatures and winds; high temperatures are expected to be around
to maybe even slightly below normal on Tuesday, with the 60s
expected near Lake Superior and the 70s seen in the interior areas.
Clouds begin to creep in from the south Tuesday night, which should
limit overnight lows to the lower/mid 50s in the western and south-
central UP while temperatures fall back further into the upper 40s
in the north and east.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 345 PM EDT Mon Jun 23 2025

Expansive 500mb ridging will remain over the US Southeast by midday
Tuesday, but some hints of a shifting pattern will begin to emerge,
first in that the flow over the Rockies becomes split, with ridging
over the Canadian Rockies and deep troughing remaining over the US
Rockies. Throughout Wednesday into Thursday, a 500mb cutoff low
moving into Florida, helping erode the blocking ridge over the
eastern CONUS. With the split flow over the Rockies also moving east
and deamplifying, flow goes quasi-zonal, allowing for the former
Rockies troughing feature to shift through the Great Lakes, bringing
with it disturbed weather for the latter half of the work week.
Deterministic and ensemble guidance diverge this coming weekend
onward, with some showing weak ridging recovering Saturday and
others staying more zonal. However, there are some early indications
of a prominent trough moving into the region sometime in the late
Sunday to early Tuesday timeframe which could bring yet another
round of disturbed weather. In the wake of today`s cold front, the
temperatures for the midweek period are forecast to be close to
normal (perhaps a few degrees cooler) with a warming trend late in
the week into the weekend.

Chances of rain begin to creep up Wednesday as a subtle impulse
riding the upper ridge forces precipitation over the area. The Gulf
connection persists with flow aloft arcing from the Texas/Louisiana
coastline to the Great Lakes, so moisture will be plentiful, though
somewhat nebulous forcing and cooler surface temperatures limiting
instability will keep most thunderstorm chances at bay. Guidance
continues to favor a widespread one to two tenths of an inch, with a
"worst case scenario" 90th percentile of around three-quarters of
an inch..

Thursday is when the more pronounced troughing that used to be over
the Rockies arrives in the Great Lakes. Instability is still fairly
limited, but with more robust forcing, expect a few thunderstorms
(30 percent chance, highest in the south). Stronger forcing with
PWATs pushing 1.5 inches will result in higher QPF, with the LREF
showing chances of 2 inches of rain at about 10 percent by the end
of the day Thursday. Everyone is likely to get at least a soaking,
as chances of a half inch of rain is 40-60 percent (highest south,
lowest Keweenaw). The WPC is watching the UP for flash flooding
potential, giving a Slight Risk of Excessive Rainfall (category 2 of
4, or around 15 percent).

Heading into the weekend, some slight chance PoPs (15-25%) linger in
the forecast due to the increasing spread in solutions, but
generally drier conditions are expected as ridging in the wake of
the trough moves over the UP. Attention then turns upstream to the
next trough dropping down from Canada sometime in the Sunday-Tuesday
range, which could bring with it showers and thunderstorms. In the
meantime, a warmup is expected for the weekend, with the NBM
deterministic forecasting highs in the 80s Saturday and Sunday.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 137 PM EDT Mon Jun 23 2025

A cold front is beginning to move into the western UP this
afternoon, with a broken line of convection ahead of it currently
extending across the central UP. Showers and VCTS around SAW
beginning over the next couple of hours may bring brief drops MVFR
or lower restrictions, otherwise expect VFR throughout the forecast
period at all terminals. Meanwhile, SW to W winds remain elevated
this afternoon, gusting to around 20-25kts. Winds fall back through
the late afternoon as the front moves into the eastern UP, then turn
light and variable this evening.

&&

.MARINE...
Issued at 345 PM EDT Mon Jun 23 2025

Winds are shifting mainly to the west this afternoon, with
widespread gusts around 20-30kts finally falling back below 20kts
this evening behind a cold front. In the meantime, expect scattered
showers and storms to persist through the afternoon and evening as
the front moves through. After winds turn lighter tonight, they
appear to remain light through at least midweek. Thursday, northeast
winds briefly increase to around 20kts across the western arm of the
lake before falling back again Friday. Another round of showers and
storms will also be possible Thursday into Friday.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Beach Hazards Statement until 10 PM EDT this evening for
     MIZ014.

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

&&

$$

SHORT TERM...LC
LONG TERM...LC
AVIATION...LC
MARINE...LC