537
FXUS63 KMQT 301938
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
338 PM EDT Thu May 30 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 117 PM EDT Thu May 30 2024

Shortwave ridging at midlevels is located along the Upper
Mississippi into Ontario, between troughing over the northern
Rockies and Northeastern US. This configuration is ideal for
subsidence over the local area with high pressure centered near the
Door Peninsula. A dry airmass was sampled by the 12Z KGRB/KAPX
RAOBs, measuring PWATs of 0.32 and 0.22 inches, respectively. This
has resulted in a clear and dry day with a quick warm-up from chilly
morning lows. Lake breezes have kicked up and are keeping areas
adjacent to the Great Lakes cooler, although CAMs suggest the
strengthening southerly gradient on the back side of the highs will
limit inland penetration for areas roughly west of Marquette County.

Northern Rockies troughing shifts east a bit tonight, but the lead
shortwave will take a more northeasterly track into the Canadian
Prairies, which will limit the overall eastward push of the better
moisture and forcing. Still, a plume of 1" PWATs is expected to
approach the western UP by 12Z Friday, and convergence along the
weakening low-level cold front will allow some showers to approach
that area late tonight. Meanwhile in the east, it looks like another
good radiational cooling night with a small area of PWATs around
0.20" forecast. Went toward the NBM10 percentile there with lows in
the upper 30s interior east and south, while the continued southerly
gradient and increasing clouds will likely keep lows elevated in the
50s for the west.

&&

.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 /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 117 PM EDT Thu May 30 2024

VFR conditions are likely to continue through the TAF period.
Moisture will increase from the southwest tonight at IWD with cigs
lowering to 4-5kft and a chance of showers late tonight into Friday.
A period of low-level wind shear is expected between roughly 08-13Z
at IWD as southwesterly winds increase to around 40kt at 2kft 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...Thompson
LONG TERM...Thompson
AVIATION...Thompson
MARINE...Thompson