549
FXUS63 KMQT 121844
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
244 PM EDT Sun May 12 2024

.KEY MESSAGES...

- Scattered thunderstorms develop this afternoon into early
  evening, especially south central. There is a slight risk
  (15%) of large hail and/or damaging winds south central.
- Dry weather returns by Monday, continuing through Wednesday afternoon.
  Next chance for rain will be Wednesday night into Thursday.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 316 AM EDT Sun May 12 2024

As a shortwave over northern Manitoba heads into northern Ontario
this morning, strong theta-e advection and a low-level jet at 35 to
45 knots is bringing some sprinkles across the area early this
morning over the western U.P. As cloud cover and warm air advection
increase over the area early this morning, we`ve seen temperatures
across the area stabilize and slightly rise. Therefore, we`ve almost
certainly hit our low temperatures already, ranging from the mid 30s
over the interior east to the mid 50s over the far west.

As the sprinkle activity moves into the eastern U.P. after dawn this
morning, expect to see a little bit of clearing over the west and
central. This will allow the sunlight to increase the temperatures
at the surface while dewpoints remain generally steady, creating a
strong inverted-v sounding near the surface. This is most pronounced
over the south central, where RHs could fall down to around 30%. We
could (40% chance) see a spot or two in the south central hit
elevated fire weather conditions as the highs today look to get to
around 80F and winds could gust up to as high as 20-25 mph from the
southwest before a cold front moves through this afternoon. However,
given the likelihood and possible coverage of the potential elevated
fire weather conditions, no notification will be sent this morning.

However, fire weather isn`t the only concern over the south central
today. With CAMs model soundings showing convection becoming surface-
based over the south central this afternoon up to around 1200 J/kg
and 0-6 km bulk shear vectors being around 35 to 45 knots
perpendicular to a lake-breeze aided cold front moving through Upper
Michigan this afternoon, we could see marginally severe wind and
hail this afternoon into early this evening across the south central
(5% chance). Hail chances are aided by the wetbulb zero heights
being in the 7-9 kft range and severe wind chances are increased by
the strong lapse rates and evaporation near the surface ahead of the
cold front. Thinking the storms will remain fairly discrete this
afternoon into this evening over the central and east, but they will
mainly be restricted to the cold front as it passes through Upper
Michigan. Therefore, we could see the storms congeal into a more
linear state late this afternoon into early this evening. As the
cold front continues to push south and east out of area this
evening, expect the showers and thunderstorms to roll out of area
with it. Therefore, the severe weather threat looks to end before
midnight tonight, with skies clearing out behind the cold front. Due
to the clear skies tonight, expect low temperatures to be around 40,
save for around Menominee where lows look to be a few degrees
warmer.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 243 PM EDT Sun May 12 2024

A couple beautiful weather days are forecast to start off the coming
work week. Behind tonight`s cold front, drier and cooler air will
filter into the region as high pressure at the surface and mid-level
ridging gradually build across the region. Before then though, a
weak mid-level shortwave moving through from the west and another
system moving eastward well south of us may support some cloud cover
late Monday into Tuesday. Otherwise, ridge axis moving through on
Tuesday should support mostly clear skies. Under mostly northerly
flow, lakeshore areas both days should top out near 50F with low-mid
60s across central and southern portions of the forecast area.
Overnight lows both days look to be in the 30s for most of the area.
Best places for bottoming out in the 40s will be the southern
portions of Menominee County.

Upstream smoke observed on GOES 16 imagery and surface cameras in
Minnesota, is expected to filter into the region behind today`s cold
front. The HRRR Vertically Integrated Smoke product does suggest
some of this may produce a hazy sky Monday.

An upstream shortwave will press closer to the region on Wednesday
while a surface low moves into western Minnesota, allowing for
increasing cloud cover from west to east. By Wednesday night, the
low looks to press into western Wisconsin, allowing weak theta-e and
moisture advection to eventually spread showers into the region. By
Thursday, increasing left exit jet dynamics may support more
widespread shower activity, but notable timing differences can be
seen among the deterministic suite, suggesting the showers may be
confined to the west half until Thursday night/Friday morning.
Another wave looks to press into the region Friday night/Saturday.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 125 PM EDT Sun May 12 2024

A cold front will sweep across the area this afternoon and tonight.
Shra/tsra developing along and ahead of the front will occur to the
e of IWD. VFR will prevail at IWD thru this fcst period. At CMX,
there will be passing shra in the vcnty for the next 2-3hrs. If a
shra does pass over the terminal, do not expect conditions to drop
out of VFR. VFR will prevail thru the fcst period at CMX. At SAW,
developing shra/tsra will likely impact the terminal btwn 20-22z,
bringing potential of gusty winds to 45kt and MVFR conditions.
Otherwise, VFR will prevail at SAW thru this fcst period. Gusty
winds to 20-30kt at all terminals this aftn will diminish early this
evening.

&&

.MARINE...
Issued at 243 PM EDT Sun May 12 2024

Warm sector draped across central Lake Superior this afternoon is
producing winds of 25-30 knots is some places. Some of this appears
to be a mix of outflow/downdrafts from lingering showers in the east
and a stronger low level jet overhead behind the warm front then
every model suggested. A cold front is currently stretched
southwestward across western Lake Superior. Ahead of this front,
some showers and some lightning have been observed mainly north of
the Keweenaw, but much of this isn`t likely reaching the surface. As
this front pushes east this afternoon/evening, winds should shift to
northwest post frontal, but a significant wind increase isn`t
expected unless there`s thunderstorms. Thunderstorm development
should be confined to the interior portions of Upper Michigan and
into Lake Michigan, but if something develops over Baraga/Marquette
County this afternoon, its possible this may stretch into Lake
Superior east of Marquette near the lakeshores. Stronger storms will
be capable of producing erratic winds and some hail. Behind the
front, high pressure will settle over the lake, supporting a few
days of mostly 20 kts or less over the lake through at least
midweek.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Small Craft Advisory until 3 PM EDT this afternoon for LSZ244-
     245.

  Small Craft Advisory until 6 PM EDT this evening for LSZ250-
     251.

Lake Michigan...
  Small Craft Advisory until 8 PM EDT this evening for LMZ221.

  Small Craft Advisory until 11 PM EDT this evening for LMZ248-
     250.

&&

$$

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