076
FXUS63 KMQT 052006
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
406 PM EDT Sun May 5 2024

.KEY MESSAGES...

-Pleasant weather through Monday with dry conditions, little
 cloud cover and seasonable temps.
-Dry Monday, but fire concerns low given low winds and recent
 above normal precipitation.
-Complex weather pattern with rain chances increasing on
 Tuesday and multiple passing low pressures keeping rain in the
 forecast through the end of the week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 239 PM EDT Sun May 5 2024

Confluent flow ahead of a mid-upper level ridge stationed over the
Plains has resulted in building sfc high pressure and dry conditions
across the Upper Great Lakes today. Other than fair weather cumulus
clouds over the interior west and central, plenty of blue sky today.
Under lake breeze circulations, temps have ranged from the 50s
across the north to lower 60s south.

Under clearing skies, light winds and fairly ideal radiational
cooling conditions, went maybe a hair under the model blend
guidance for min temps tonight. Generally expect mid 30s temps
over the interior with upper 30s to lower 40s readings near the
Great Lakes. Also, wouldn`t be shocked to see some patchy fog
form over the interior as we radiate through crossover
temperatures of 37-38F.

&&

.LONG TERM /MONDAY THROUGH SUNDAY/...
Issued at 403 PM EDT Sun May 5 2024

Ridging aloft continues to build overhead through Monday afternoon
with surface high pressure shifting over to Lake Huron. Besides a
FEW layer of fair weather cu, Monday is another dry, clear day.
Soundings show a slightly shallower mixed layer relative to today,
with mixed heights only up to around 5kft. RHs look to fall to the
mid-20% range across much of the interior as a result. However, with
mostly light winds below 10 mph gusting to 15 mph expected, along
with prior rainfall, fire weather concerns should be fairly low. The
wind direction may be locally variable around lake breezes, which
CAMs resolve off of both lakes.

Opposed to the ridging aloft on Monday is a deep, negatively tilted
trough just on the lee side of the Rockies which becomes an
anomalous closed low over the Dakotas late Monday. This stacked low
will be stalled over the Dakotas Tuesday through Wednesday morning,
but a shortwave rotating around the base of the low will be the
focus for the weather pattern heading into the midweek. This
shortwave will get jet support as it becomes coincident with a right-
entrance region of a ~125 kt 300mb, giving enough synoptic support
for showers over the UP beginning Tuesday morning in the west and
overspreading the UP by the end of the day. Thunderstorm probability
has decreased some as instability trends have been downward with the
past 24 hours of ensemble guidance. Some more clarity will be
provided by tomorrow afternoon as the CAMs begin to describe this
time period, but the current forecast will only reflect a slight
(~20%) chance of thunderstorms along the MI/WI state line and along
Lake Michigan Tuesday.

The pressure falls associated with the shower activity Tuesday will
become a discrete surface low pressure by Wednesday morning and
depart the region by the afternoon. As it does, the original closed
low over the Dakotas will weaken from a peak strength of near 980mb
Tuesday morning to near 1000mb by midday Wednesday as it slides
southeast. As it does, it will phase with another weak lee cyclone
off the Rockies, with ensembles tracking this new low generally
around Lake Michigan and Illinois by overnight Wednesday into
Thursday. Precip will be the forecast if the northern clusters
verify, but the UP could be high and dry if a more southern solution
materializes. By Friday, anomalous ridging over coastal British
Columbia will be contrasted with anomalous troughing over the Lower
Great Lakes, putting the UP in a northwesterly flow regime. Some
deterministic and ensemble guidance suggests a clipper-type low late
in the week into the weekend, keep PoPs in the forecast, though
uncertainty is high in any specifics as the complex setup has a lot
of variables to work out first. Confidence is increasing that this
ridge will shift over the Great Lakes by the midweek of next week,
warranting the CPC to favor below normal precipitation for the
second half of May.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 120 PM EDT Sun May 5 2024

VFR to prevail for the duration of the TAF period as high pressure
strengthens over the region. Lake breezes will dominate this
afternoon and west-northwest winds could be gusty at IWD and
CMX with gusts possibly exceeding 20 knots until winds die down
toward sunset.

&&

.MARINE...
Issued at 403 PM EDT Sun May 5 2024

With high pressure remaining over the Upper Great Lakes, winds are
forecast to be below 20 kt through Monday night. Tuesday morning,
approaching low pressure will force easterly and northeasterly
winds to funnel over the western reaches of Lake Superior to 25
knots by noon Tuesday. Model guidance suggests around a 40%
chance of a brief gale over far western Lake Superior Tuesday
afternoon. However, with the majority of guidance sub-gale and
the short duration of the highest winds, no Gale Watch is
hoisted at this time. Winds across the rest of the western half
of the lake increase to around 25 knots Tuesday evening, with a
brief break in 20+ kt winds overnight into Wednesday. Periodic
chances for winds in the 20-30 kt range dot the forecast through
the rest of the week as multiple weak low pressure systems pass
through the Upper Great Lakes region, but uncertainty increases
with each passing system.

&&

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

&&

$$

SHORT TERM...Voss
LONG TERM...GS
AVIATION...Voss
MARINE...GS