090
FXUS63 KMQT 151159
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
759 AM EDT Sun Jun 15 2025

.KEY MESSAGES...

- Besides a slight chance of a morning shower along the state
  line (15%), a dry Sunday is expected.

- An active pattern then begins tonight and lasts through this
  coming week with almost daily chances for rainfall (30-50%
  chance), although confidence remains low on timing. The most
  likely period for showers and possibly some thunderstorms is
  Monday night into Tuesday (50-75% chance).

- Generally below normal temperatures continue through today,
  then warming back up to near normal for next week.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 406 AM EDT Sun Jun 15 2025

Morning RAP analysis shows a 1022mb high centered over Lake
Superior. This is helping keep the UP dry despite disturbed weather
being observed on satellite from the Upper Great Lakes through the
Central Plains associated with a shortwave axis centered over the
Minneapolis metro extending southwest. CAMs now show 15% chances of
precip or less today, and if anywhere gets a light shower, it would
be along the MI/WI state line. The warming trend in high
temperatures continues today, though highs in the mid 60s around
Marquette are still about 5 degrees below normal, though the low 70s
expected in the eastern UP is within a couple degrees of normal.
Winds shift to the southeast today, though remain light enough that
CAMs resolve lake breezes along the Great Lakes.

Tonight, PoPs increase from the southwest to northeast as 500 mb
height falls and PVA are experienced over the region with the
shortwave passing south of the area. The 12Z HREF suite did show a
couple of plausible solutions with thunder over the UP shortly after
midnight but none of the 00Z suite has stronger precip signatures
until around 12Z Monday. The issue seems to be disagreement in the
placement of forcing as the Euro ensemble does show sufficient
MUCAPE (around 250 J/kg) for some sub-severe thunderstorms in the
overnight period. QPF will be dependent on the exact placement of
individual showers, as shown by the mean of HREF QPF being around a
tenth of an inch, yet even the 75th percentile of the ensemble is
closer to half a tenth of an inch. Increased cloud cover streaming
in will flatten the diurnal curve somewhat with lows in the 50s
expected.

Monday`s thunderstorm potential will be likely dependent on upstream
thunderstorm development as synoptic forcing is nebulous with the
main 500mb shortwaves being over southern Wisconsin and over
northern Minnesota respectively. CAMs show a few discrete cells
forming in the , which is not unexpected with mean HREF surface CAPE
growing to 500-1000 J/kg with a weak cap in the late morning to
early afternoon hours, though PoPs are only around 50 percent. The
higher PoPs and higher severe weather potential comes in the
afternoon to early evening hours with a potential mesoscale system
forming. Such a mesoscale system would be able to maintain itself
with the aforementioned instability as well as 20-35 kt of mean 0-
6km shear. However, each of the CAMs has a different idea of the
placement of such a system, so uncertainty for the UP remains high
as the potential exists that the strongest elements of such a system
could avoid the UP entirely. However, the ceiling of impacts is too
high to ignore entirely, with severe hail and wind being the primary
threats into Monday night (5 percent threats each per the SPC
outlook).

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 406 AM EDT Sun Jun 15 2025

The work week brings an active pattern as zonal mid level flow sends
many shortwaves across the region resulting in daily chances for
precip somewhere within the UP into next weekend. This above normal
pattern for precip is accompanied by near to slightly above normal
temps as highs warm into the 70s to low 80s for many away from the
Great Lakes; lows primarily will reside in the upper 40s to 50s.
This pattern does leave much to desire for model agreement as
positioning and timing of more subtle shortwaves is low.

Better PoPs hold off until Mon night when a more notable as well as
more agreed upon shortwave moves in from the W. Instability
increases through the day and is anticipated to hold a few hundred
j/kg into the early overnight hours with mid level lapse rates of
near 7C/km ahead of the attendant cold front. Bulk shear is
variable, but should at least be around 30-35 kts on the lower end.
Timing is too spread at this point, but conditions seem favorable
for some organized, likely linear convection bringing some gusty
winds. This continues overnight into Tue. Widespread QPF between
0.25-0.75" is fcst, highest amounts to the N and W.

Another subtle shortwave is possible late in the day Tue through Tue
night to support some additional shra/tsra. The most organized
system in the extended follows that up as a deeper shortwave over
the C Plains Tue night lifts NE over the Great Lakes Wed night
through Thu, sending a sfc low with it. Spread in sfc low track is
large, but latest trends have shifted precip chances to the SE. If
this trend continues, tsra could be removed from the fcst leaving
just shra for the middle to late part of the work week. A lull then
looks to follow until the next shortwave for Fri night/Sat.

For the remainder of next weekend into the following week: some
above normal temps are favored as 850mb temp anomalies briefly climb
to between +5-8C above normal overhead as the mid level ridge over
the Plains moves to the OH River Valley. This alongside elevated
moisture of PWATs likely around 1-1.5" and Tds in the 60s to even
70s(!) favors periods of notable instability lifting into the region
and better tsra potential. That said, the predictability remains
very low as synoptic lift is weak or absent. Overall takeaway is
that the active period likely will continue, which is reflected in
both the 6-10 day and 8-14 day CPC outlooks.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 759 AM EDT Sun Jun 15 2025

VFR conditions are ongoing at all sites this morning. The IFR deck
that impacted IWD overnight has scattered out, but guidance suggests
that at least BKN coverage will return to the terminal this morning,
bringing at least low-end MVFR ceilings to the terminal. Ceilings
then lift to high-MVFR and VFR this afternoon and evening before an
approaching disturbance brings MVFR ceilings with 40 percent chances
of IFR overnight into Monday morning. CMX will remain VFR for
virtually this entire period until high-end MVFR becomes about 50
percent likely by around 10Z Monday. SAW is expected to remain VFR
throughout this entire period. Rain shower chances of 20-40 percent
are expected Monday morning at all sites. Expect mainly light and
variable winds around 5 kt for this TAF period.

&&

.MARINE...
Issued at 243 PM EDT Sat Jun 14 2025

Aside from some northeasterly winds funneling into the western arm
of the lake through this evening, winds should be fairly weak at
less than 20 kt for the rest of the weekend into the upcoming week.
Stronger winds cannot be ruled out in and around thunderstorm
episodes which will become possible Monday into Tuesday (30-40%
chance). Areas of fog will be possible early next week as moisture
increases over the cold lakes, especially where it rains.

&&

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

&&

$$

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