140
FXUS63 KMQT 310755
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
355 AM EDT Fri May 31 2024

.KEY MESSAGES...

- Seasonably mild temperatures expected through the weekend.

- Scattered showers and isolated thunderstorms possible in the
  west Friday, and across the UP Saturday, although it will not
  be a washout.

- More widespread showers and thunderstorms expected Sunday
  night into Monday.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 355 AM EDT Fri May 31 2024

Southerly flow with increasing moisture, in addition to high clouds
building into western Upper Michigan has produced a mild night
across the forecast area, except interior portions of the east where
dry air and light winds have supported effective radiational cooling.
So far interior temps have fallen into the upper 30s while the
lakeshores have remain in the 40s or 50s. Across the west, min temps
in the 50s and even some low 60s have been observed so far.
Upstream, a line of showers with some preceding isolated showers has
been observed moving through northern Minnesota, pressing northeast
as a weakening cold front advances. Some lighting has been observed,
but activity has waned in the past couple of hours.

As we move through the remainder of the morning hours and into
today, showers and storms across central Minnesota will lift
northeast as the boundary presses eastward into the Arrowhead and
western Lake Superior. Some rumbles of thunder can`t be ruled out.
The weak boundary will continue pressing east while upper level
support shifts northeast, bringing with it increasing pops for the
west. Onset is a little tricky given the anticipated dwindling line
as it approaches, but the overall consensus is for light rain to
move into the west by late morning. While the boundary inches across
the Arrowhead, continued convergence with growing weak instability
out in front will result in continued shower chances through the
afternoon for the west half. Thunderstorms can`t be ruled out, but
severe weather is not expected. In the east, dry air will win out,
likely resulting in clear to partly cloudy skies. This, coupled with
dinural heating, will support mixing and enable drier air aloft to
mix down to the surface. Model soundings suggest mixing only to
around 2k feet, which would support RH percentages dipping down into
the mid 20s. If we are able to warm more and mix higher then
expected though, lower RH near 20% will be possible. Daytime highs
across the region should climb into the 70s, except remain in the
60s by Lake Michigan.

&&

.LONG TERM /FRIDAY THROUGH THURSDAY/...
Issued at 337 PM EDT Thu May 30 2024

Midlevel ridging continues to shift east of the area Friday into
Saturday, while anomalous closed low remains relatively stationary
over the northern Prairie Provinces. At lower levels, an area of
confluence between airflows on the back side of the retreating high
and the cyclonic circulation around the Prairies low will remain
more or less stationary, wavering over the western and at times
central UP. This area of confluence is collocated with a plume of 1-
1.25" PWATs. A few showers will be around over the west on Friday,
but overall weak forcing should limit coverage. Meanwhile in the
central and east, another pleasant day is expected with slightly
warmer highs ranging through the 70s (although staying in the 60s to
the lee of Lake Michigan). Forcing increases Friday night into
Saturday morning over the west as the right entrance region of the
upper jet becomes favorably positioned over the area. On Saturday,
the confluent zone and moisture plume expand somewhat to the east,
and so too will the coverage of showers and isolated storms.
However, the thinning moisture plume, overall fairly weak forcing,
and meager instability will mean that it won`t be a washout, and the
rain may be more of a minor nuisance than anything. With increased
clouds, highs around 70 can be expected. QPF totals should mainly be
insignificant, but the 90th percentile of the HREF suggests that
some isolated spots in the west could see up to an inch due to
possible repeated rounds of rainfall Friday into Saturday.

The pattern becomes more zonal on Sunday as the last in a series of
shortwaves lifts northeast of the area. This should put us in a lull
in terms of forcing and a dry day is expected, with southerly flow
boosting highs back in the mid to upper 70s (aside from the Lake
Michigan shoreline). Will then watch the potential for a complex of
showers and storms firing over MN Sunday evening to push into the UP
Sunday night. Sunday night into Monday will be the highest
probability of precipitation during the forecast. Some stronger
storms cannot be ruled out as deep layer shear looks good and there
will likely be some decent low-level moisture return with dewpoints
increasing into the 60s by Monday. A dry day is favored Tuesday in
the wake of this system, while another trough could generate more
showers and storms by the middle of next week. This trough may cut
off and linger for the 8-14 day period, with CPC favoring below
normal temperatures during this timeframe, although there is
uncertainty if the cutoff low will remain over the Great Lakes (EPS
mean) or push further into the Northeast (GEFS mean).

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 123 AM EDT Fri May 31 2024

VFR conditions are likely to continue through the TAF period.
Moisture will increase from the southwest late tonight into
Friday at IWD and CMX with cigs lowering to 4-5kft under
isolated showers by late Friday morning into early afternoon. A
period of low-level wind shear is expected between roughly
07-14Z at IWD as southwesterly winds increase to around 40kt
between 1-1.5kft AGL.

&&

.MARINE...
Issued at 337 PM EDT Thu May 30 2024

High pressure slides to the east tonight into Friday, resulting in
winds becoming southerly, but stability and a fairly weak gradient
should keep winds less than 20 kt. There is a slight (20%) chance of
thunderstorms at times Friday into Saturday, with a better chance
(30-50%) Sunday night into Monday.

&&

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

&&

$$

SHORT TERM...JTP
LONG TERM...Thompson
AVIATION...Voss
MARINE...Thompson