342
FXUS63 KMQT 031739
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
139 PM 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 /THROUGH TONIGHT/...
Issued at 139 PM EDT Fri May 3 2024

Calmer weather is being seen this afternoon as the last of the cloud
cover has lifted away from the far east. With sunny skies being
overhead the rest of this afternoon and with subtle warm air
advection continuing, highs today could get into the mid 60s to low
70s before this evening; some spots, including Watson, Marquette,
and L`Anse, have gotten to 68F already. Otherwise, gusty WSW`rly
winds across the western half continue the rest of this afternoon
before dying down this evening as deep mixing takes place across our
region. Moving into tonight, cloud cover looks to return to the west
half late as another low pressure system from the Central Plains
looks to lift towards the U.P.. As it does so, we could see a few
sprinkles late tonight from time to time across the west. Therefore,
while skies will be mostly clear for tonight, the western half`s low
temperatures tonight will be a few degrees warmer due to the
incoming cloud cover; temperatures are expected to get down to the
mid 40s near Lake Superior, the low 40s over the western interior,
and upper 30s in the interior east tonight.

&&

.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 /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 109 PM EDT Fri May 3 2024

VFR conditions continue through most, if not the rest of the TAF
period as weak ridging moves over us the rest of this afternoon.
Starting late tonight, another low pressure currently over the
Central Plains lifts northeastward towards the Upper Midwest and
brings more rainfall to the west as soon as Saturday morning
(although some sprinkles could be seen here and there tonight). This
incoming rainfall could bring MVFR and possibly lower conditions
back across KIWD by the end of the TAF period. Meanwhile, expect the
gusty WSW`rly winds to die down later today as the sun sets. While
we could see some marginal LLWS over the TAF sites (namely KCMX),
the chance is only around 20 to 30%. Therefore, LLWS was not put
into the KCMX TAF at this time.

&&

.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...
  Small Craft Advisory until 5 PM EDT this afternoon for
     LSZ242>244-247.

Lake Michigan...
None.

&&

$$

SHORT TERM...TAP
LONG TERM...EK
AVIATION...TAP
MARINE...EK