212
FXUS63 KMQT 041926
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
326 PM EDT Thu Jul 4 2024

.KEY MESSAGES...

- Low chance (15-30%) of showers/storms this afternoon roughly from
Ironwood eastward to Manistique.

- Widespread moderate rain expected late tonight into Friday
evening. Some thunder possible.

- While not a washout...scattered shower and thunderstorm chances
return for Sunday.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 326 PM EDT Thu Jul 4 2024

This afternoon, weak high pressure ridging remains over Upper
Michigan ahead of another shortwave that is analyzed over the
Dakotas. A couple waves of convection associated with this are
moving through MN and into northern WI, and cirrus continues to
stream into the UP from this upstream convection. Meanwhile, closer
to home, the Superior lake breeze is quite apparent on radar,
already heading well inland into the UP. So far, just agitated cu
with this sporadically apparent on satellite beneath the cirrus
deck, but weak radar returns are finally popping on the Lake Michigan
boundary in the eastern UP. Will not rule out spotty shower activity
(and perhaps some rumbles of thunder) along the lake boundaries,
mainly across the central and eastern UP. Heading into the late
afternoon and evening, spotty showers and storms currently across
northern WI may be able to make it into the southern UP, but better
chances for rain hold off until later tonight (more on that later).
By then, with several hundred j/kg of CAPE, some thunder will be
possible. Any thunderstorm could put down some gusty winds and a
brief heavy downpour.

Otherwise, winds remain on the lighter side, but may shift suddenly
with the passing lake boundaries. Temperatures inland have been able
to climb well into the 70s and even around 80F, but where onshore
flow is having an impact, temperatures are hovering in the lower to
mid 70s, even falling back into the 60s.

Overnight, the shortwave moves over MN and into WI with a surface
low closing off over central WI. Expect showers (with some thunder)
to increase in coverage after midnight, mainly across the western UP
as the surface low continues its eastward trek. There is a chance
for some decent rainfall amounts at times in the resulting
deformation zone; href ensembles note a potential (20-30% chance)
for rainfall rates rainfall rates of a quarter-inch per hour in the
heaviest downpours overnight. So, while not a washout, we could
expect a widespread quarter to half-inch of rain over the western
half of the UP, with some isolated spots seeing even higher amounts
closer to an inch. Temperatures, meanwhile, stay fairly mild
overnight with lows generally in the mid 50s.

&&

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
Issued at 239 AM EDT Thu Jul 4 2024

An active weather period continues through the extended period as
the cycle of shortwaves followed by high pressure ridging continues
until around the middle to end of next week. More details follow
below.

Expect some showers and thunderstorms to make there way into the
U.P. tonight as a shortwave low over the Northern Plains is phased
with a low lifting from the Southern Plains. While the chances for
rain look best along the Wisconsin border by the time fireworks
start this evening, the rain chances look to continue increasing
across the rest of the area late tonight as the low`s center moves
through central Wisconsin. While a strong storm or two could be seen
near the Wisconsin border this evening due to MUCAPEs possibly being
as high as 1000 J/kg and 0-6 km bulk shear possibly squeaking out as
much as 30 knots, no severe weather is generally expected as the
CAPE within the atmosphere looks to rapidly deplete as the sun sets.
That being said, we could see some gusty winds, locally-heavy rain,
and small hail in the strongest storms early on. Expect rain showers
and a few thunderstorms to continue across the U.P. Friday as the
low moves through northern Lake Michigan. CAMs are kind of all over
the place right now with the rain coverage Friday. However, they are
all showing that the rainfall will be on-and-off across the region
Friday. Therefore, if you`ve got a quick outdoor activity that needs
to be done Friday, you may have a few small windows of opportunity
to do it. While flooding is not looking to be a concern tonight
through Friday night, CAMs do show some heavier rain showers and
thunderstorms occurring from time to time. Therefore, we could see
some localized heavy rainfall at a few spots up to a couple of
inches. With cloud cover hanging across the area and well-below
normal temperatures aloft moving through, expect the high
temperatures tomorrow to be notably cooler than today. This will be
most noticeable in the west, where highs will struggle to get into
the low to mid 60s. Meanwhile, highs may get close to 70 over in the
east. The rain and thunderstorm chances depart the U.P. Friday night
as the low lifts away through Lake Huron into Canada.

Expect drier and more normal temperatures come Saturday as ridging
builds in from the west. However, a shortwave low from the Canadian
Prairies looks to bring additional rain showers and thunderstorms
back over the area Sunday and Sunday night. Medium range guidance
keeps this trend of shortwaves lows followed by high pressure
ridging continuing through around the first half of this week.
However, once we get to the end of the forecast period and beyond
(last half of next week), we could see ridging remain over the area
as high pressure builds over the Central CONUS.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 125 PM EDT Thu Jul 4 2024

VFR will prevail today at IWD/CMX/SAW. There a may be a shra/tsra
late aftn/early evening around IWD and potentially SAW if anything
can fire on the lake breeze, but potential of the terminal be
impacted is too low to include anything in the TAF. Shra coverage
will increase tonight across the w half of Upper MI as a low pres
system moves ene into WI. Some tsra are also possible. With the
increasing coverage of shra, conditions will deteriorate as well.
Expect IWD/SAW to fall to IFR and CMX to MVFR. IFR ceilings may
finally settle in at CMX into Friday morning. Winds will be light,
under 10kt, thru this fcst period.

&&

.MARINE...
Issued at 239 AM EDT Thu Jul 4 2024

Light winds of 20 knots or less dominate the period as high pressure
ridging gives way to low pressure shortwaves and vice versa over the
next several days. That being said, we could see some thunderstorms
over the lake during the times when shortwave lows move near/over
the Upper Great Lakes, including this evening through Friday night
and again Sunday through Sunday night. Ridging looks to become
dominant over the Upper Great Lakes by the middle to end of next
week as high pressure builds over the Central U.S.

&&

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

&&

$$

SHORT TERM...LC
LONG TERM...TAP
AVIATION...LC
MARINE...TAP