104
FXUS63 KMQT 160648
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
248 AM EDT Mon Sep 16 2024

.KEY MESSAGES...

- Isolated non-severe showers and storms into early evening
  along a narrow corridor from Iron through Baraga and western
  Marquette counties.

- Extended stretch of well above normal temperatures continues
  through at least Saturday with highs mainly in the upper 70s
  and 80s.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 331 PM EDT Sun Sep 15 2024

Despite large scale high pressure dominating much of the Great Lakes
and northeast CONUS, water vapor imagery does show a connection to
Gulf of Mexico/Atlantic moisture into the Upper Great Lakes
region this afternoon. This moisture connection has allowed
surface dew points to climb into the mid 60s across much of the
west half of the U.P. this afternoon. MLCAPE values near 1000
j/kg and minimal to no capping noted on soundings has led to the
initiation of a few showers and isolated t-storms over central
Iron County early this afternoon at the nose of the sfc theta-e
ridge. A few of the CAMs suggest isolated showers could continue
into early evening along a fairly narrow low-level convergence
zone and theta-e ridge axis extending from Iron into Baraga and
nw Marquette counties. With weak wind shear, none of these
storms will become strong or severe but could produce brief
heavy downpours.

After showers die out over central Lake Superior tonight with loss
of diurnal heating, much of the rest of the night should be quiet
under the dome of high pressure. Models hint that some convection
could reinitiate into north central MN at the nose of a weak LLJ
this evening, and then possibly advect into the western U.P. toward
12Z Monday, but given model uncertainty with this happening only
have slight chc pops barely reaching into the far western U.P.
toward sunrise. Given high dew points over the area it`s also not
out of the question that patchy fog could form at a few locations,
especially where showers occur.

Expect min temps tonight ranging from the mid 50s to mid 60s under
partly cloudy skies.

&&

.LONG TERM /TONIGHT THROUGH SUNDAY/...
Issued at 247 AM EDT Mon Sep 16 2024

A rex block over the eastern U.S. allows us to receive warm
southerly air for most of this week, before the troughing over the
western U.S. finally is able to fight its way into the Upper Great
Lakes and bring some much needed rainfall to the U.P. this weekend
and early next week. While the strength of the ridging from the rex
block to our east will decay with time this week, the anomalously
warm air could allow us to bring the high max temperature record on
Tuesday and possibly the high min temperature record a few evenings
late this week into early next week as cloud cover increases. We may
also finally see some much needed rainfall re-enter Upper Michigan
late this week into early next week.

The last of the showers and thunderstorms associated with the
shortwave activity early this week leave the western half of the
U.P. tonight as the last of the shortwaves lifts away. As this
occurs, the clear skies overnight will allow the low temperatures to
sink into the mid to possibly even lower 50s across the interior
areas, especially over the central. Overall, expect any rainfall we
do receive over the west half to be pretty light (a tenth of an inch
or less), with the east half pretty much slated to receive nothing.
There may be some patchy fog that develops over the south central
late tonight. Should it form, low temperatures may be warmer than
what is currently predicted.

Expect sunny skies from Tuesday to around Thursday as ridging over
us slowly decays while a vertically-stacked low lifts from the
Intermountain West into the Canadian Prairies. With warm southerly
air continuing to flow into our area Tuesday, we could see a few of
the high daily max temperature records broken across the area,
particularly in the downslope areas near Lake Superior. While
Wednesday and Thursday aren`t looking to be as warm, we can still
expect high temperatures in the upper 70s to lower 80s across the
area, which means some spots could flirt with tying or breaking the
max high temperature record even on those days. As for fire weather
concerns, it does look like we could flirt with some limited
concerns on Tuesday as the min RH in the interior south central
could get into the lower 30 percents. However, with winds being
light, not much concern is warranted at this time. Min RHs are
expected to be a little higher Wednesday and Thursday, although the
continued drying of fuels may be something that still needs to be
monitored.

While model spread increases from this weekend into early next week,
the differing suites do agree that cloud cover and possibly even
rainfall look to move over us late in the extended period. As the
cloud cover increases Thursday night onwards, the European ensemble
highlights min temperatures being anomalously warm for this time of
year. Thus, we may see some high min temperature records broken from
Thursday night onwards as the cloud cover could provide extra
insolation and cause low temperatures to struggle to make it down
into the mid to upper 50s. As the aforementioned low over the
Canadian Prairies continues to lift towards Hudson Bay Thursday
night into Friday, a cold front weakening with time looks to move
into our neck-of-the-woods around that same time. This cold front
could bring our first rainfall back across the area since
today/tonight. Additional chances for rainfall look possible this
weekend into early next week as another low lifts from the Desert
Southwest towards the Upper Midwest.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 140 AM EDT Mon Sep 16 2024

VFR conditions to persist with Upper Michigan under the influence of
high pressure.  The exception will be some possible MVFR fog at SAW
early this morning, but this is low confidence especially without
any rain showers yesterday evening.  In addition, confidence remains
too low to mention re-developing rain showers at IWD early this
morning, but will carry VCSH mention at CMX this afternoon with
some assistance from diurnal heating. Again though, impacts
will be negligible on flight categories.

&&

.MARINE...
Issued at 247 AM EDT Mon Sep 16 2024

Light winds of 20 knots or less continue over Lake Superior this
week as high pressure ridging over the eastern U.S. influences our
weather pattern for the next several days. Nevertheless, some
showers and thunderstorms are possible today and tonight as a
shortwave low rides along the ridging overtop us.

&&

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

&&

$$

SHORT TERM...Voss
LONG TERM...TAP
AVIATION...TDUD
MARINE...TAP