131
FXUS63 KMQT 182320
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
720 PM EDT Tue Jun 18 2024

.KEY MESSAGES...

-Showers and thunderstorms possible tonight, particularly over
 the far west. Some severe weather is possible over the far
 west.
-More showers and thunderstorms possible for the latter half of
 this week.
-Potential heavy rain event this weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 242 PM EDT Tue Jun 18 2024

A scattered cu deck has formed over the western half this afternoon
whereas the eastern half is mostly cloud free as strong southerly
winds off of Lake Michigan are helping to stabilize the air a
little. Observations have already shown temperatures reaching the
80s across much of the area, with some spots such as Ontonagon and
L`Anse already getting to 90+F. Meanwhile, a shortwave low moving
through MN is continuing to lift along a cold front boundary over
the area. As the cold front continues to move eastwards into our
area tonight, expect showers and thunderstorms to move into the far
west before midnight local time. We could see some severe hail and
winds come this evening as the convection moves into our western
area, as models show MUCAPEs in the 1k-3kJ/kg range and shearing
very high in the lowest levels of the atmosphere as a low-level jet
screams across our area. In addition, the hodograph and LCL levels
are supportive of a very small chance (<5%) for an isolated tornado
late tonight. However, with CAMs showing a lot more of the
convection dying than previously anticipated, the severe weather
potential looks to be relegated to the far western U.P. as the cells
die and collapse (similar to how we saw the severe winds over the
eastern U.P. yesterday afternoon). Given the sharp drop in precip
chances as the cold front moves eastwards tonight, I`ve reduced the
chances across the central and eastern U.P. to chance wording (30-
40%). However, this may need to be lowered further as the most
recent CAMs seem to amplify the lack of rainfall late tonight.

&&

.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
Issued at 354 PM EDT Tue Jun 18 2024

Light rain showers and maybe a stray thunderstorm or two could pop-
up over the central and east Wednesday as the cold frontal boundary
slowly stalls out. With CAMs showing only scattered light convective
coverage continuing over the central and east on Wednesday, expect
precipitation amounts to be light. By Wednesday evening, expect the
rain showers and thunderstorms to generally be finished over the
area. That being said, as the flow becomes zonal across our area by
Wednesday night and Thursday, we get weak ridging that sets up over
Lake Superior. At the same time, weak troughing looks to set up over
Wisconsin. With the ridging and inverted troughing fighting one
another around our south central, we could see some rain showers
continue across this area, as well as a few thunderstorms. As warm
frontogenesis starts to develop over our area late this week, the
rain chances begin to crawl northwards across the rest of the U.P.
late Thursday into this weekend. We could see some heavy rainfall
come late this week into early this weekend along the strengthening
warm front, as ensembles show PWATs near the max of modeled
climatology (nearly 2")! With training very possible along the front
given it`s slow movement northwards, we may need to keep an eye on
flooding concerns across our area, particularly over the west half
where the higher rainfall amounts are currently predicted. Once the
low creating the warm frontogenesis moves through Lake Superior
Saturday afternoon, expect a break in the rainfall before a
secondary Clipper low moving over our area Saturday night and
Sunday brings rainfall chances back across our area.

Moving into early next week, expect ridging and finally some drier
weather as a high pressure moves from the Plains through the
Midwest. Overall, expect temperatures to be near normal for the
extended period, with some days showing below normal high
temperatures (such as Thursday, Friday, and Sunday). Outside of the
rain and storm chances throughout the next week, the only other
thing worth mentioning is the possibility for localized river
flooding along the Chocolay River near Harvey. With much of the
basin having received between 2 to 3.5 inches of rainfall over the
past 24+ hours, and the Observation Program Leader having gone out
to the Chocolay near Yelden (around Skandia) and seeing the river
already up to the bridge, there may be some isolated spots along the
river near Harvey that could see some river flooding issues that are
more typical to the Spring-time (water in basements, etc.) This
situation will continue to be monitored by the staff here at WFO
MQT, as well as the NCRFC while the water from the recent rainfall
slowly exits the Chocolay River Basin into Lake Superior.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 720 PM EDT Tue Jun 18 2024

Shra/tsra ahead of an approaching cold front will reach western
Upper MI this evening then weaken thereafter. Over about a 1-2hr
period, IWD/CMX will be impacted with gusty winds to 35+kt and MVFR
to IFR. LLWS will follow the storms. Cigs at IWD/CMX will fall to
MVFR/IFR around the time of fropa late night, then will improve to
VFR early Wed aftn. At SAW, confidence is lower that any shra/tsra
will reach the terminal. Only VCTS and VCSH were included in fcst.
LLWS will also develop at SAW this evening. Expect a period of MVFR
cigs at SAW Wed morning with VFR for the aftn.

&&

.MARINE...
Issued at 421 PM EDT Tue Jun 18 2024

Southerly winds of 20 to 30 knots across the southern nearshores and
over the eastern lake this afternoon, with a few gale force gusts up
to 35 knots possible along the shoreline from Marquette to Whitefish
Point, weaken tonight before southwesterly winds of 20 to 30 knots
moves across the western half of the lake late tonight into
Wednesday morning as a LLJ passes through. Winds weaken to 20 knots
or less again by Wednesday as ridging builds in over Lake Superior
behind the decaying cold front boundary. The light winds look to
remain over Lake Superior until possibly Saturday and again Sunday,
when a Colorado low lifts through the lake in the afternoon and a
secondary Clipper follows behind it, respectively.

The other mentionable hazard over Lake Superior for the next several
days is thunderstorms, particularly this evening over the west as
some severe weather is possible. Some large hail, damaging and
erratic winds, and an isolated waterspout are possible over the
western lake this evening. As the thunderstorms move into the
central and eastern lake late tonight, the severe weather threat
dissipates, with the thunderstorm activity diminishing as well.
Thunderstorms are still possible over the eastern lake Wednesday
until the evening hours. Thunderstorms do become possible again
Friday as a warm front lifts into the area. The thunderstorm
activity could continue until after the low passes through Saturday
afternoon.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
  Beach Hazards Statement until 10 PM EDT this evening for
     MIZ014.

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

&&

$$

SHORT TERM...TAP
LONG TERM...TAP
AVIATION...Rolfson
MARINE...TAP