665
FXUS63 KAPX 270924
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
524 AM EDT Mon May 27 2024

.KEY MESSAGES...

- Cool, brisk and wet Memorial Day.

- Quick moving disturbance brings chances for showers and
  storms again Tuesday.

- Potential for frost Wednesday and Thursday nights?&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 249 AM EDT Mon May 27 2024

Pattern Synopsis/Forecast: Several shortwave troughs embedded in
larger scale troughing across the nation`s midsection early this
morning. These waves will pinwheel across the western Great Lakes
today through tonight. At the surface, low pressure over central
Lake Michigan will trek northeast across the forecast area through
the day today, centered over southern Ontario by this evening.
However, broad low-level cyclonic flow with wrap around moisture on
the backside of departing low pressure will dominate the night ahead.

Forecast Details: Most numerous shower activity ongoing early this
morning is across northern Lake Michigan, parts of northwest
lower and the eastern U.P. with more isolated activity dotting
the map across north-central and northeast lower. Much more
widespread activity upstream over the central U.P. and
northeast WI, which current trends support rotating into the
forecast area through the morning/midday hours -- favoring
north of M-55 for the most widespread shower activity today.
Suppose some embedded thunder still can`t be ruled out through
the morning hours with up to ~500 J/kg elevated instability.
Some locally impressive rain totals possible today as well,
especially between the M-32 and M-72 corridors in northwest
lower where time-lagged ensemble probabilities exceed a 70%
chance for greater than 1 inch of QPF, with some localized
30-50% probabilities for 2+ inches. These higher end totals
certainly have a better shot of materializing if we can muster
embedded thunderstorms and heavier rain rates.

Rain chances continue into tonight as wrap around moisture pinwheels
northeast to southwest across northern Michigan. Some uncertainty in
how fast this precip exits for the second half of the night with
latest trends supporting slow drying from north to south after 06z.

Otherwise, breezy west-northwest winds in place by this afternoon
with gusts as high as 25-30 mph. Some gustiness continues through
tonight. Highs today in the low 60s for many and into the mid-60s
near Saginaw Bay...only made to feel cooler with apparent temps in
the 50s thanks to gustiness and damp conditions. Lows tonight
generally ranging from the mid-40s to mid-50s.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 249 AM EDT Mon May 27 2024

Pattern Synopsis / Forecast:

Longwave troughing set to dominate through midweek, sending a series
of waves into the Great Lakes region. First wave will commence on
Tuesday as low pressure dives south and east from Manitoba, bringing
a chance of showers to the region highs largely in the 60s. Primary
trough axis swings through Wednesday, scouring out stubborn moisture
as surface high pressure moves overhead on its heels. This will open
the door for calming winds and clearing skies, and thus potential
for frost Wednesday night, and possibly again Thursday despite
temperatures moderating into the 60s and 70s. High pressure
dominates the remainder of the week as a robust ridge builds into
the Great Lakes ahead of a trough digging into the northern Plains.
Result will be a quick return of mid-summer like warmth Friday and
Saturday, with highs peaking in the 70s and 80s. Next trough set to
(somewhat) intrude some time into the weekend as the ridge axis
clears the region, setting up a more zonal flow that would be more
conducive for waves (perhaps convectively charged?) to move into the
region as we progress through the upcoming weekend.

Primary Forecast Concerns:

Tuesday Precip: Rain Tuesday morning will be on the downswing as an
initial wave moves to the east. On its heels, the second wave will
make its approach through the day Tuesday. As stated by the previous
forecaster, the gap between these two disturbances could lead to
some clearing developing, which should provide a modest boost of
surface temps into the 60s for most. With relatively steep lapse
rates, could see CAPE blossom in the order of 500-1,000 J/kg,
particularly across NE lower. Result will be potential for thunder
after noon, primarily east of a Cheboygan to Cadillac line,
where surface temps may approach or even exceed 70, helping to
drive greater surface instability. Severe potential continues to
remain marginal at best, though any storm could be locally
gusty with some hail, particularly across NE lower.

Frost Potential: Still watching frost potential across interior
locales Wednesday night and maybe again Thursday night. Drier air
moving into the region will lead to more diurnal cooling responses
with clearing skies and calming winds. Will have to see how much
rain falls to influence low level moisture... but if rain can be on
the lighter side, drier soil conditions will allow for more
efficient mixing to transpire, scouring out low level moisture
(dewpoints may drop well into the 20s Wednesday afternoon and
perhaps Thursday too?). Could be conducive for frost as temps drop
well into the 30s across the interior regions Wednesday night. Could
see it happening again Thursday night (albeit probably more
localized) as high pressure moves directly overhead, and drier air
scours out more low level moisture.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 523 AM EDT Mon May 27 2024

Low pressure currently making headway into western lower Michigan,
which will continue northeast across the state today...centered over
southeast Ontario by this evening. Periods of showers and some
embedded thunderstorms likely at times through the TAF period...most
widespread later this morning through this evening. Any lingering
VFR CIGs early this morning expected to fall to MVFR area-wide
through the TAF period. Medium probabilities (50-60%) for periods of
IFR CIGs today/tonight with lower chances (15-25%) for LIFR.

Winds this morning in the process of turning out of the west-
northwest, becoming breezy at times this afternoon through
tonight.&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 2 AM EDT Tuesday for LHZ345.
     Small Craft Advisory from 6 PM this evening to 8 AM EDT
     Tuesday for LHZ347>349.
     Small Craft Advisory until 2 AM EDT Tuesday for LMZ341-342.
     Small Craft Advisory from 11 AM this morning to 2 AM EDT
     Tuesday for LMZ323-344>346.

&&

$$

SHORT TERM...MJG
LONG TERM...HAD
AVIATION...MJG