961
FXUS63 KMQT 281842
AFDMQT

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

.KEY MESSAGES...

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

- Areas of frost expected Thursday morning.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 241 PM EDT Tue May 28 2024

RAP analysis shows a 500mb shortwave axis over western Lake Superior
while the main surface features are a 992mb low over Quebec and a
1026mb high over Manitoba. Surface flow will be mainly northerly
through the forecast period, which will help keep the Lake Superior
shores in the 50s for highs today while the Lake Michigan shores
stay in the mid-60s. The shortwave approaching the western portions
of the UP this afternoon has been deamplifying much of today,
reducing the forcing available for showers. Persistent cloud cover
through the first portion of the day today has also limited diurnal
heating. These have factored into a reduction in the chances of
thunderstorms in the interior west and south today, though enough
CAMs have simulated reflectivity values above 40 dBZ near Menominee
to keep at least 15% chances of thunder along the WI/MI border in
Menominee County.

Overnight, a subtle shortwave will drop from the north over Lake
Superior overnight. While some model runs in the past 24 hours had
resolved showers here, the airmass descending onto the lake should
dry out the column as it approaches the UP. There is enough upslope
forcing to keep clouds in the forecast through the overnight period
for the central UP, but rainfall is not expected. This cloud cover
will act to reduce radiational cooling, with only isolated portions
of the interior west now expected to see patchy frost overnight.
Lows will mainly be around 40 tonight.

&&

.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...GS
LONG TERM...07
AVIATION...GS
MARINE...07