822
FXUS63 KMQT 301146
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
746 AM EDT Mon Jun 30 2025

.KEY MESSAGES...

- Scattered showers and storms are expected this afternoon and
  evening. Stronger storms may bring gusty winds and small hail,
  but severe weather is not expected.

- Isolated and scattered thunderstorm activity is possible
  Wednesday. Thunderstorms are also possible in the afternoon
  and evening of Friday, the Fourth of July.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 443 AM EDT Mon Jun 30 2025

Goes WV imagery and early morning RAP analysis show a mid level
trough extending from the Manitoba/Ontario Province line SW into the
Dakotas with some minor impulses downstream of it over the Upper
Great Lakes. At the sfc, two slow moving boundaries are noted within
our region: a cold front over the far W and a stationary/warm front
just NE of the CWA. WV imagery highlights a drier airmass over the
far W, which has helped work away at the cloud cover. The remainder
of the tonight period will see a continued drying and slow
clearing pattern as temps hold in the 60s.

A deeper trough to the NW over the Dakotas and Manitoba will pivot
overhead through tonight and send another cold front across the
region this evening. With this prior round of precip expected to
clear the region this morning, scattering cloud cover and diurnal
heating will help bring back instability as temps warm into the mid
70s to mid 80s. The 6/30 0Z HREF mean SBCAPE reaches around 1000j/kg
across much of the CWA and although deterministic solutions are not
solid on location, several plot SBCAPE values up to 2000j/kg in
spots within the UP. This is accompanied by DCAPE up to 700-1200j/kg
(model dependent) and low level lapse rates around 8-8.5C/km.
Although bulk shear will be more than sufficient earlier in the day
(35-45 kts), this drops off from W to E as the better forcing of the
shortwave and supplemental frontal boundary progress through. Also,
mid level lapse rates struggle to reach 6C/km. Diurnal iso/sct
shra/tsra are expected this afternoon, possibly with the assist of
converging lake breezes over the E. Severe weather is not expected,
but a few storms could produce gusty winds in brief downpours as
well as small hail. Note: the Keweenaw may miss out on most if not
all precip.

As the trough pivots overhead tonight and the sun sets, convective
activity diminishes from W to E with most returning dry by around
midnight EDT. Expect temps to settle into the 50s tonight.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Issued at 231 PM EDT Sun Jun 29 2025

Long term period begins Tuesday with downstream trough axis
stretching south through the Lower Great Lakes with upstream ridging
building up western CONUS and Canada. To the north, upper level low
is expected to be over northern Manitoba with a preceding shortwave
in western Ontario. At the surface, high pressure stretches across
the Plains. As the day progresses, the surface high will settle
southeast some, then flatten out over the middle Mississippi River
Valley Wednesday. The aforementioned waves to the north are expected
to press southeastward, with the first moving along the northern and
eastern lakeshores of Lake Superior by Tuesday afternoon. Despite
its slightly southern placement compared to yesterday`s guidance
package, precip probabilities appear minimal and mostly confined to
Ontario given little forcing and dinurally driven instability. The
second wave also has trended more south, but overall, there continue
to be geographic and temporal differences among the deterministic
suites, which is reflected into their ensemble counterparts. These
same packages are in agreement on this upper level low intensifying
as it takes on a negative tilt over central Ontario, resulting a
deepening surface low. A cold front associated with these features
looks to drop southeast through Upper Michigan Wednesday night into
early Thursday. Diurnally driven instability may result in isolated
showers or thunderstorms by afternoon Wednesday, perhaps aided by
lake breezes, but the better forcing appears focused north and south
of our forecast area. Should any showers or storms develop, severe
weather is not expected. Surface high builds in afterwards which
will linger Thursday overhead. This will work to keep the region
mostly dry.

Friday, the 4th of July, weak ridging to near zonal flow sets up
across the northern tier with multiple weak impulses embedded within
the flow. Closer to the surface, a warm front looks to stretch
across the Northern Plains or Upper Midwest. 12z guidance continues
to suggest timing could result in impacts to afternoon and evening
plans in Upper Michigan. In addition, latest LREF suggests a non-
zero chance for strong to severe thunderstorms. This is likely given
the temporal and geographical differences of these features among
the ensemble members. As we get closer, suspect better consensus of
when and where peak instability and forcing for ascent will align.

Daytime temperatures Tuesday and into the weekend look largely to
span the upper 70s to low 80s, with potential for heating into the
mid 80s Friday. Overnight lows are expected to fall mostly into the
50s to low 60s, except widespread 60s Friday night.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 746 AM EDT Mon Jun 30 2025

VFR flight conditions are expected for most, if not all, of the 12Z
TAF period. Sct shra/tsra in the afternoon/early evening may briefly
lower IWD/SAW to MVFR, but confidence was only high enough to carry
mention via PROB30 groups. Otherwise, E winds increase today to
around 10 kts with gusts up to 20 kts at CMX.

&&

.MARINE...
Issued at 443 AM EDT Mon Jun 30 2025

Winds largely remain under 15 kts lake wide this morning. SW winds
increase to 15-20 kts this afternoon ahead of a cold front this
evening. As this moves W to E across the lake, winds veer W and
become ~10-15 kts across the lake. Pressure rises behind a departing
low pressure on Tuesday will increase W to SW to 15-25 kts,
strongest over the W half of the lake. This will build waves up to 4
ft over the N Central portion of the lake for Tuesday evening. Winds
settle below 20 kts Tuesday night, allowing for waves to settle
below 4ft again. W to SW winds rise to ~15-20 kts again over the W
half of the lake on Wednesday before becoming light (mainly 15 kts
or less) and variable into the late portion of the work week.

&&

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

&&

$$

SHORT TERM...Jablonski
LONG TERM...JTP
AVIATION...Jablonski
MARINE...Jablonski