591
FXUS63 KMQT 281730
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
130 PM EDT Tue May 28 2024

.KEY MESSAGES...

- Light rain showers will move southeast through the UP near the
stateline today.

- Below normal temperatures for the first half of the week, with dry
weather returning midweek.

- Areas of frost expected Thursday morning.

&&

.SHORT TERM /THROUGH TODAY/...
Issued at 217 AM EDT Tue May 28 2024

GOES 16 IR base and derived products and surface observations
highlight a mix of clouds across the region with overnight
temperatures in the 40s and 50s. Upstream, radar returns from the
DLH radar show light rain showers exiting the Arrowhead and pressing
southeast into western Lake Superior, the Apostles, and northwest
Wisconsin. A little further west, another patch of showers is moving
through northern Minnesota. GOES 16 Water Vapor and RAP height
analysis suggest both of these patches appear to be associated with
two weak shortwaves rotating through the base of a closed upper
level low. As we progress through the remainder of the overnight
period, both will inch closer to the western U.P. The forward most
patch may support some sprinkles or light rain here and there
beginning in the next hour or so, and then continuing past sunrise.

Today, the closed mid-level low in western Ontario will press south
into Lake Superior, pushing these shortwaves through the Upper
Midwest/Great Lakes. Guidance suggests both will press southeast,
with the forward most one supporting showers along the stateline
counties. The second shortwave looks to press further south and
avoid our region. Further upstream in Minnesota and western Ontario,
vort max rotating through the mid-level low, aided with some dinural
instability, may kick off showers and maybe some thunderstorms.
These may drop into western Lake Superior/Isle Royale this afternoon
and evening, but the stable lake and decreasing heating into the
evening should limit how far these press south over the lake. A
cooler airmass will also rotate into the region through the day.
Under northerly and northwesterly flow, this should support highs in
the 50s by Lake Superior and low-mid 60s elsewhere.

&&

.LONG TERM /TONIGHT THROUGH MONDAY/...
Issued at 315 AM EDT Tue May 28 2024

Upper air pattern consists of a 500 mb trough on the west coast, a
ridge over the Rockies and a trough in the ern half of the U.S. 00z
Wed. The ridge moves into the northern plains on Wed and into the
upper Great Lakes on Thu. Troughing moves into the northern plains
Thu night. Pops will dissipate after sunset over the far south late
tonight and then dry weather lasts into Thu night with below normal
temperatures. Did keep in frost in the forecast for Wed night as the
sky will be clear with calm wind and ideal radiational cooling
conditions set up, so widespread frost away from the Great Lakes
shorelines continues to look likely.

In the extended, the GFS and ECMWF show a broad 500 mb trough across
the west half of the U.S. and a ridge across the Mississippi River
Valley and a trough on the east coast 12z Fri. The ridge shifts to
the ern U.S. 12z Sat. Troughing moves into the Rockies 12z Sun and
into the northern plains 12z Mon and into the upper Great Lakes 12z
Tue. Temperatures remain near to above normal for this forecast
period. A weak sfc cold front affects the western cwa on Fri before
dissipating on Sat.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 129 PM EDT Tue May 28 2024

VFR conditions will prevail in this forecast period at all TAF
sites. The biggest threat to this will be a low-probability but high-
impact possibility for low clouds early overnight at SAW and late
overnight at IWD. About 20% of guidance shows IFR or lower cloud
bases and vis at IWD around sunrise tomorrow with 10-20% chances of
MVFR or IFR cloud bases tonight at KSAW. With the supermajority of
guidance showing VFR with approaching high pressure, the TAF will
reflect VFR, with light and mainly northerly winds overnight.
Skies go to FEW/SKC for early tomorrow morning.

&&

.MARINE...
Issued at 315 AM EDT Tue May 28 2024

Northwest winds will be 10 to 20 knots today and then be below 20
knots tonight through Thursday as a high pressure ridge moves into
the area. The wind continues to be at or below 20 knots into Sat
with no strong pressure systems nearby.

&&

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

&&

$$

SHORT TERM...JTP
LONG TERM...07
AVIATION...GS
MARINE...07