642
FXUS63 KMQT 030942
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
542 AM EDT Fri May 3 2024

.KEY MESSAGES...

- Active pattern continues through next week as a series of low pressure
  systems track across the U.S. and affect Upper MI. Above
  normal precipitation expected, including chance of
  thunderstorms at times.
- Mostly above normal temperatures expected, generally 5 to 10 degrees
  above normal on the majority of days thru the middle of next
  week.

&&

.SHORT TERM /TODAY/...
Issued at 504 AM EDT Fri May 3 2024

Current water vapory imagery/RAP analysis highlight a well-defined
shortwave rotating over the MN/Canada border with its associated
occluded front already well into Upper Michigan. As expected,
showers have quickly tapered off with frontal passage with the only
activity on latest radar mosaic concentrated over the easternmost
portions of the UP.  And, even these should taper off by mid-
morning.  So far, convective activity has been non-existent, but
still cannot rule out a few rumbles of thunder over the far eastern
counties after sunrise.  Most of the forecast area will be sunny
this morning as forecast soundings trend toward a dry column.  The
exception will be the eastern third of the UP where it will take a
bit longer for the moisture/cloud cover to clear out.  Gusty
southwest winds in the 20 to 30 mph range, especially across the
western UP will contribute to rapidly falling dew points and
temperatures climbing into the upper 60s/low 70s (inland).  Recent
rainfall will, however, mitigate today`s fire weather threat.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 542 AM EDT Fri May 3 2024

Overall, the first half of the extended period (tonight through
Monday night) is mostly dry and sunny as high pressure tracks across
the area with just a brief chance for rain showers on Saturday.
Elevated fire wx conditions may occur each day Sat - Mon, but are
more likely on Sunday and Monday when sunny skies help us dry out.
On the other hand, we return to a pattern with frequent rain chances
for the Tuesday thru Friday time frame as a broad area of low
pressure spins across the region. There are early signals for a
prolonged stretch of drier weather starting the weekend of May
11/12, but temperatures appear to average near normal at this time.

Starting with tonight, weak surface ridging to our east results in
light southerly flow with upper level cloudiness spreading across
the western UP overnight. Mostly clear skies across the east should
allow for good radiational cooling into the upper 30s away from
downsloping along the Lake Superior shoreline. The next weather
maker approaches Saturday morning and most guidance suggests a weak
but deepening surface low. Rain chances spread across the western UP
during the morning which keeps high temps cooler (around 60F)
compared to the central and especially the east where highs
approaching 70F are forecast. Warmer temps/deeper mixing across the
east within the dry pre-frontal air mass suggests potential for
locally elevated fire wx conditions. It`s worth noting that both NAM
and GFS soundings show single digit RH values in the mid-level dry
layer that we`ll be mixing into. Increasing cloud cover should limit
mixing potential, but conditions appear to be trending more volatile
across the east ahead of Saturday`s rain chances. The cool front and
associated rain chances spread across the central and eastern UP
during the afternoon and evening, respectively. The NAM-3km even
delays precip at Newberry until around midnight or 3-5 hours later
than the GFS. HREF ensemble mean MUCAPE remains less than 100 J/kg,
but HRRR simulated radar indicates an increasingly convective
pattern as showers track east across the area. Overall, the forecast
may still exaggerate the rain potential with this system since model
soundings only show a 3-6 hour window of rain chances at any one
location. Limited instability and duration indicate light amounts
are most likely.

Dry high pressure settles across the area on Sunday allowing sunny
skies to spread across the area during the morning hours. In fact,
CAMs suggest potential for fog resulting from moisture lingering in
a boundary layer inversion beneath clearing mid/upper level clouds.
A more straight-forward radiation fog setup could materialize Sunday
night under high pressure, clear skies and light winds. Otherwise,
fire weather is the primary concern for the Sunday-Tuesday period.
Sunday and Monday are both likely to see min RH dipping below 30%
across the interior, but light winds temper the fire wx threat.
Stronger winds are expected on Tuesday and if the dry air mass
lingers a bit longer then Tuesday likely represents a more volatile
combination of low RH and winds. However, that possibility depends
on rain chances being delayed until late in the day which current
model blends do not indicate.

Late week rain chances are associated with a deep closed low
developing across the Northern Plains late on Monday that slowly
spins eastward over the subsequent week. Moderate rainfall and
embedded thunderstorms are again possible with the warm front
passage Tuesday/Wednesday followed by spottier showers
Thursday/Friday. A cold core upper low suggests a large diurnal
component to the late week shower activity.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 124 AM EDT Fri May 3 2024

IFR/LIFR conditions will continue overnight. Easterly upslope flow
at SAW and CMX will result in LIFR prevailing longer than IWD.
Expect improvement to VFR at all terminals as a west-southwest wind
develops in the wake of the system`s cold front moving across the
area. First will be at IWD by later tonight and by morning at CMX
and SAW.

&&

.MARINE...
Issued at 542 AM EDT Fri May 3 2024

Light winds, mainly out of the south-southeast are currently being
observed across Lake Superior and winds are expected increase while
veering southwesterly today. While gusts up to 25kt are expected
over western Lake Superior this afternoon, winds diminish to less
than 20kt tonight. Expect winds mostly below 20kts across Lake
Superior this weekend, but northwesterly winds increase to around 20
knots Saturday night behind a cold front before becoming light again
on Sunday. High pressure that arrives over the Upper Great Lakes
late this weekend shifts eastward on Mon while a deep low pressure
emerges over the western Dakotas. This will result in increasing
easterly winds late on Mon into Tue when gusts up to 30kts are
expected.

Patches of locally dense fog are occuring over western Lake Superior
this morning, which is expected to push mainly into Canadian waters
as south/southwesterly winds increase today. If fog does not clear
off of the lake today then additional rain chances on Saturday may
result in increasing fog coverage.

&&

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

&&

$$

SHORT TERM...TDUD
LONG TERM...EK
AVIATION...07
MARINE...EK