648
FXUS63 KMQT 261944
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
344 PM EDT Thu Jun 26 2025

.KEY MESSAGES...

- A second round of rain is expected this afternoon into Friday.
Widespread amounts in excess of 1 inch of rain is ~50% likely with
locally higher amounts in the west, north central, and east by late
Friday morning. The WPC Outlook for Excessive Rainfall is a Slight
Risk (category 2 of 4).

- A brief warmup into the 80s is expected this weekend into Monday,
with showers and thunderstorms possible (around 50%).

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 139 PM EDT Thu Jun 26 2025

Despite a mostly clear KMQT radar at noon eastern today, GOES-East
Visible imagery shows expansive remnant cloud cover from the first
round of precipitation that dropped up to an inch and a half of rain
over the central UP this morning. Aloft, RAP analysis shows
deamplifying troughing moving over the Plains states today
supporting a weak surface trough axis extending from Colorado to the
Michigan Lower Peninsula. This break in the rain is only momentary
as CAMs show showers pushing into the western UP this afternoon and
overspreading the UP tonight. With more robust forcing with the
trough moving overhead, CAMs show a more convective look relative to
the broader look of things early this morning. If training can occur
(most CAMs say not much training but a few such as the HRRR do),
saturated soils combined with longer duration convective
rainfall rates would lead to flash flooding concerns. Confidence
in this remains low as each CAM looks a bit different in
regards to the placement of convection and whether it trains or
not. HREF LPMM 6- hour QPF charts show the potential for
1.15+"/6hr rates as a worst case scenario, though HREF chances
of 1+"/6hr rates are only up to 20 percent and mostly over areas
that got less than an inch of rain the previous night, so soils
may not be as saturated. With factors for and opposed to flash
flooding potential, WPC`s outlook for Excessive Rainfall remains
at a Slight Risk (category 2 of 4). Chances of thunderstorms
are higher tonight than last night with widespread values around
30 percent, though severe weather is not expected as despite
decent MUCAPE values around 500 J/kg, the shear in the MU layer
is unidirectional and doesn`t have much speed shear.

Rain ends from southwest to northeast throughout the morning hours
of Friday except for some remaining upslope light rain/drizzle for
any areas with a NW-facing slope. The remnant light precip and
clouds will keep high temperatures lower in the north and west
relative to the clearing in the south and east, with highs ranging
from around 60 degrees from the Keweenaw through the Copper Country
compared to near 70 for the south-central and eastern UP.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 343 PM EDT Thu Jun 26 2025

Friday night, with increasing surface pressure behind the departing
surface low, ongoing upslope light rain/drizzle will gradually end
from W to E. Despite this, limited clearing of skies will keep low
temperatures falling only to around the 60 degree mark except for
the Keweenaw, which will fall into the mid-50s per NBM guidance.

An extremely zonal pattern will be over the northern tier of the
CONUS through the weekend, though looking north, a shortwave trough
will push into western northern Ontario by 12Z Sunday. This will
support a 1000-1005mb surface low pressure with a cold front draped
south of it passing into the UP in the overnight hours of Saturday
into Sunday. Increasing warm southerly flow ahead of the front will
allow for a notable warmup with NBM highs near 80. As the front
itself will be passing after peak heating, instability will be
present aloft (Euro ensemble suggesting MUCAPE in excess of 2000
J/kg in the west by 06Z Sunday) but lesser for surace-lifted parcels
(LREF SBCAPE under 1500 J/kg and beneath a cap in excess of -125
J/kg of MUCIN). Some shear will be present, but severe weather seems
unlikely at this time. As the frontal showers continue to push in
for Sunday, further questions are raised by increased model spread
in forcing, shear, and instability, though Euro ensemble joint
probabilities of at least 500 J/kg of MUCAPE and 30+ kt of bulk
shear are in the 40-60% range, so severe weather cannot be ruled
out, but uncertainty remains high.

The pattern will begin to amplify once again for the early portion
of next work week as ridging builds over the Canadian and northern
US Rockies with troughing developing over the Great Lakes Basin. The
northwesterly flow aloft will keep temperatures close to seasonal,
but amplification of the troughing is expected to bring more
periodic chances of precipitation and thunderstorms especially in
the evening hours with peak heating. This could cause some hazards
for outdoors plans this week ahead of Independence Day, so planners
should monitor the forecast for changes as the pattern becomes more
defined and details emerge.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 139 PM EDT Thu Jun 26 2025

Abundant low level moisture associated with disturbance bringing
SHRA and chances of TSRA this afternoon through tonight will also
lead to lowered ceilings and vis for much of this TAF period. FG and
ceilings are beginning to lift at SAW from the airport minimums this
morning to LIFR now and will continue to trend to MVFR this evening,
with only a 30 percent chance of seeing a brief period of MVFR.
Elsewhere, the SCT deck just above 3kft at CMX is expected to fill
in and descend to MVFR this evening. IWD is already at MVFR and will
remain such until dusk. Then, as -SHRA expands across the UP,
ceilings and vis begin to lower, eventually lowering ceilings at all
sites to IFR and then LIFR. Chances of embedded -TSRA tonight is
about 30 percent at SAW and IWD but under 15 percent at CMX. Limited
improvement is expected tomorrow afternoon as moist upsloping flow
keeps low clouds in the forecast in spite of -SHRA ending.

&&

.MARINE...
Issued at 343 PM EDT Thu Jun 26 2025

Northeasterly wind gusts will increase to 20-25 kt tonight in the
western arm of Lake Superior with easterly to northeasterly gusts to
25 kt overspreading much of Lake Superior by early Friday morning.
Wind gusts fall below 20 kt late Friday morning as low pressure
sweeps across the region. Wave heights will peak Friday morning in
the 3-6 ft range, highest north of the Apostle Islands. Waves fall
below 3 ft by Friday night. Winds and waves then remain mostly calm
as only weaker pressure systems affect the lake for the weekend into
next week, though periodic thunderstorms may occasionally be over
the lake, with the highest chances being late Saturday night through
Sunday evening.

&&

.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...GS
LONG TERM...GS
AVIATION...GS
MARINE...GS