377
FXUS63 KMQT 240733
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
333 AM EDT Fri May 24 2024

.KEY MESSAGES...

- Another shortwave and low pressure system will bring a round
  of showers and a slight chance (around 20% chance) for some
  thunder to Upper MI late Friday into early Saturday.

- There will be more opportunities for rain next week although
  model uncertainty leads to low forecast confidence on
  timing/extent.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 344 PM EDT Thu May 23 2024

Current RAP analysis shows the mid level low along the southern end
of James bay with it`s associated 995 mb low pressure center still
over James bay, but just northwest of the mid level low. With weak
sfc high pressure at around 1012 mb building over the CWA, mostly
sunny skies have been the predominant sky conditions for much of the
UP this afternoon. This has allowed for temps to warm up into the
60s for much of the UP; onshore flow has kept cooler temps along
Lake Michigan between Manistique and the Mackinac Bridge as well as
near Lake Superior. The sunny skies have also helped mixing yield a
breezy day with west to northwest gusts up to 20-30 mph, strongest
in the Keweenaw. Winds will gradually diminish into this evening
as high pressure continues to build in. Some diurnal cumulus has
developed over the southern UP and will continue to increase
this afternoon with the support of a mid level shortwave moving
east through northern WI. Afternoon highs are expected to peak
in the mid 50s to mid 60s near Lake Superior, 60s along Lake
Michigan east of Manistique, and upper 60s to mid 70s elsewhere.


Some slight chances for showers return to the forecast along the
WI/MI state line with the best chances for showers in Menominee
County late this afternoon where there is better instability (5/23
12Z HREF mean MUCAPE up to 250 j/kg in south central). Accumulations
will likely be only a few hundreths at best, but showers moving
through Menominee county could bring up to 0.1" to 0.2" of rain on
the high end if the NAM Nest solution is favored.

As daytime heating ends and high pressure continues to build in
tonight, skies will mostly clear out helping temps settle slightly
cooler than normal into the upper 30s to upper 40s. While mostly
clear skies are expected with dry weather, cloud cover increases
late into Friday ahead of the next low pressure system. This
approaching low will also turn light winds northerly then
eventually easterly by Friday morning.

&&

.LONG TERM /TONIGHT THROUGH THURSDAY/...
Issued at 333 AM EDT Fri May 24 2024

Upper air pattern consists of a deep 500 mb trough on the west
coast, a negatively tilted shortwave and closed 500 mb low in the
upper Mississippi Valley 00z Sat. This shortwave heads northeast
into the upper Great Lakes 12z Sat and across Ontario on Sat night.
Upper troughing then remains over the area into 12z Mon as more
energy comes out of the west coast trough and keeps troughing over
the area. A wave of pcpn will come in tonight and move out late
tonight into Sat morning with dry weather moving in for most of
Saturday before the next system moves in for Sun. There are some
pops that could make it into the far west by Sat evening and have
slights in there to cover it. Otherwise, did not make too many
changes to the going forecast.

In the extended, the GFS and ECMWF and Canadian all show a 500 mb
trough in the Great Lakes region 12z Mon which moves to the lower
Great Lakes region 12z Tue. Ridging then moves into the northern
plains 12z Wed and into Thu. Upper troughing then moves into the
northern plains 12z Fri. Temperatures look to be near normal for
this forecast period. Only prolonged dry period looks to be Wed for
now. With troughing, does look unsettled.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 120 AM EDT Fri May 24 2024

Dry air mass associated with sfc high pres ridge drifting across the
area overnight will allow VFR to continue at IWD/CMX/SAW. Winds will
also be light, mostly under 5kt. During the day today, low pres
lifting across the Northern Plains will swing an occluded front to
the ne. That front will cross Upper MI tonight. Although some shra
well ahead of the front may push into the w half of Upper MI mid and
late aftn, the main area of shra and isold tsra will hold off until
early evening. So, fcst only reflects vcsh at IWD this aftn. Expect
-shra/MVFR cigs to arrive at IWD around 22z, spreading to CMX/SAW
during the evening hrs. IFR will be possible at CMX/SAW near the end
of the fcst period under increasing low-level moisture and upsloping
winds. E to SE winds will increase during the day, becoming gusty to
around 25kt at IWD, to around 30kt at CMX, and to around 20kt at
SAW. LLWS is also a possibility this aftn and evening, but guidance
is lacking in agreement on strength of low-level jet shifting over
the area.

&&

.MARINE...
Issued at 333 AM EDT Fri May 24 2024

East winds will begin to ramp up to 20 to 30 knots today in advance
of another low pressure lifting from the Northern Plains towards
Lake Winnipeg. Northeast gales to 35 knots will continue across the
far western part of the lake today. Winds over the west half
becoming southwest behind the low and the passage of its cold front
late tonight into Saturday and generally stay in the 15 to 25 knot
range. Winds decrease late Saturday behind the exiting system, then
expect light winds of 20 knots or less across Lake Superior for the
rest of this weekend as a high pressure ridge builds over the area.
Looking ahead to early next week, another system moving out of the
Plains will head towards the Great Lakes.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Gale Warning from 11 AM EDT /10 AM CDT/ this morning to 8 PM
     EDT /7 PM CDT/ this evening for LSZ162.

Lake Michigan...
None.

&&

$$

SHORT TERM...Jablonski
LONG TERM...07
AVIATION...Rolfson
MARINE...07