518
FXUS63 KMQT 102345
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
745 PM EDT Mon Jun 10 2024

.KEY MESSAGES...

- Chilly and dry again tonight with high pressure overhead.
  Frost is possible.

- A couple rounds of showers and thunderstorms expected Tuesday
  afternoon through Thursday night. This will be accompanied by
  generally warmer than normal temperatures that continue into
  the weekend.

- Strong and potentially severe storms look possible Wednesday
  afternoon and evening across the west half of Upper Michigan.

&&

.UPDATE...

The forecast remains on track this evening. Skies stay clear into
the night, and though winds remain breezy at least across the
eastern UP, expect winds to turn calmer after sunset. Temperatures
still hover well in the 50s and lower 60s across most of the UP, but
will quickly fall back tonight with much of the area on track to
bottom out in the lower to mid 30s.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 305 PM EDT Mon Jun 10 2024

Upper air pattern consists of a 500 mb trough in the ern U.S. with a
shortwave in the northern Rockies and a ridge over the northern
plains. This upper ridge moves into the upper Great Lakes by 12z
Tue. Put out a frost advisory for tonight for most places as
temperatures drop to the lower to mid 30s. The sky will be clear and
with light winds, ideal radiational cooling conditions will set up
so widespread frost will be likely well inland away from the warmer
shorelines of the Great Lakes.

&&

.LONG TERM /TUESDAY THROUGH MONDAY/...
Issued at 319 PM EDT Mon Jun 10 2024

Overnight ridging will breakdown Tuesday as a shortwave and surface
low press through Manitoba and into Ontario. By evening, an
associated weakening cold/occluded front will press into the western
UP. Ahead of the boundary by mid-late afternoon, showers with some
embedded thunderstorms will press into western Upper Michigan, then
continue east through the U.P. overnight as activity wanes. Guidance
suggests instability will be limited (MLCAPE of 500 j/kg or less),
so strong to severe storms are not expected. Daytime highs Tuesday
should climb to near 70F while overnight lows Tuesday night only dip
into the low 50s.

Near-zonal flow with a couple embedded shortwaves will follow across
the northern Tier into the Great Lakes. While these shortwaves
progress close or through the Great Lakes, prevailing southerly low-
level flow and warm air advection will support increased warming
Wednesday and Thursday. This warm and moist airmass could support a
couple rounds of showers and thunderstorms as these shortwaves press
into the region Wednesday and Thursday. Beginning with a breakdown
of Wednesday, a weak shortwave/PVA stream will move west to east
through Lake Superior and Upper Michigan through the day. A 850mb
LLJ to near 30-35kts alongside a jet exit region by afternoon may
support large scale ascent and deep layer shear of 50-60kts. While
the NAM is certainly an outlier with its 2-3k j/kg MLCAPE, the
general consensus of 500-1000j/kg MLCAPE across the west half with
the wind profile may support some strong or severe thunderstorms. It
should be noted that the better forcing is expected to be south and
west of the region, but steep mid-level lapse rates present in NAM,
NAM3k, and GFS soundings suggest that if something does develop in
our area, hail and stronger winds will be possible. Initial timing
among the various deterministic systems suggest earliest onset would
be in the afternoon in the west, but there`s a better signal for mid-
late afternoon in the west, then increasing coverage in the evening
U.P.-wide.

By Thursday morning, another shortwave looks to press southeast
through Lake Superior while a surface low lifts north through
Ontario. There`s timing differences among the models as to when the
trailing cold front will press through Upper Michigan, but the
general consensus is that the front should clear the region by
afternoon. Similarly to Wednesday, the strongest instability is out
of our forecast area, but strong deep layer shear would be enough to
support strong storms if they materialize ahead of the boundary.
Post frontal dinural mixing may also support a gusty day on
Thursday. Steeping low level lapse rates may be able to mix up into
strong winds a loft. At the moment, current forecast is for 20-25
kts, but this may trend up in future forecasts. Another shortwave
may follow Thursday night into early Friday, but confidence is low
(<25%) at this point.

Both Wednesday and Thursday, daytime highs may climb to the upper
70s or low 80s with overnight lows mostly in the 50s. Cooler airmass
builds in for Friday which will support highs in the upper 60s to
mid 70s. This is expected to be brief given guidance`s suggestion of
a warming trend going for the weekend and into next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 744 PM EDT Mon Jun 10 2024

VFR prevails at all terminals for most of the forecast period. Skies
remain clear overnight, but clouds gradually thicken through the
morning ahead of an approaching disturbance. This should bring in
some scattered showers, and perhaps a rumble of thunder, from west
to east during the afternoon and evening. Confidence in any
associated MVFR restrictions are highest at IWD. Otherwise, expect
shifting winds this evening to turn to the south into Tuesday, with
some gusts around 20kts possible especially at IWD.

&&

.MARINE...
Issued at 319 PM EDT Mon Jun 10 2024

High pressure over the region has supported winds mainly 20kts or
lower across Lake Superior. A series of fronts will move through the
lake Tuesday - late Thursday. Ahead of these fronts, southerly winds
may support 20-25kt winds and showers and thunderstorms. Strongest
storm potential will be Wednesday afternoon and evening across
western Lake Superior. High pressure builds in on Friday, returning
dry and calmer conditions with winds below 20kts to start of the
weekend.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Frost Advisory from 2 AM EDT /1 AM CDT/ to 8 AM EDT /7 AM CDT/
     Tuesday for MIZ002>007-009>014-084-085.

Lake Superior...
None.
Lake Michigan...
None.

&&

$$

UPDATE...LC
SHORT TERM...07
LONG TERM...JTP
AVIATION...LC
MARINE...JTP