321
FXUS63 KAPX 280738
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
338 AM EDT Tue May 28 2024

.KEY MESSAGES...

- Chance for a few showers and t-storms today.

- Potential for frost Wednesday and Thursday nights?

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 317 AM EDT Tue May 28 2024

Pattern Synopsis / Forecast:

Great Lakes region will continue to be under the influence of
upper-level troffing through the period, leading to unsettled
weather (especially during peak heating today) and cooler than
normal temperatures.

Showers that had been over the area for much of yesterday into
the nighttime hours are finally exiting the area to the east
early this morning. These shower are associated with a weakening
impulse within the mean long-wave trof over much of eastern
North America. Another impulse is currently dropping into the
mean trof across the extreme upper Midwest. The forcing with
this feature will arrive later this afternoon into this evening.
The thermal troffing aloft associated with this feature,
combined with diurnal heating will result in several hundred
J/kg of CAPE this afternoon (especially NE Lower MI). This
should result in showers and a few thunderstorms, but strong
storms are not anticipated. Precipitation chances wane tonight
as the disturbance shifts to the east later tonight and diurnal
instability is lost.

Temperatures today will top out warmer than yesterday (mainly in
the 60s), but still be a few degrees cooler than normal. Look
for overnight lows in the 40s, which is about where they should
be for late May.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 317 AM EDT Tue May 28 2024

Pattern Synopsis / Forecast:

Primary longwave trough axis will pass through the region, as
longwave troughing as a whole centered over northeastern North
America is forced eastward by an amplifying ridge ahead of another
digging trough intruding into the northern Rockies. Result will be
ample subsidence building into the Great Lakes region midweek and
beyond as the ridge axis moves overhead by Friday. Closer to the
surface, a stout area of high pressure will slowly move between Lake
Superior and Hudson Bay, providing a very dry northerly flow
initially Wednesday and Thursday before winds turn more southerly.
This will lead to a climb in temperatures as we progress into the
weekend, starting in the 50s and 60s Wednesday, reaching into the
70s by Friday, and perhaps into the 80s across northern lower by
Sunday. Dry airmass and lowering dewpoints may contribute to a
handful of chilly nights Wednesday night and Thursday night, where
interior locales may drop well into the 30s. Precipitation chances
leak back into the picture as the aforementioned trough more or less
stalls over the Canadian Prairies, bringing about more of a zonal
flow to the region by the end of the weekend. Potential for any
convectively charged waves to eject east of the Rockies into this
corridor of quicker flow may bring about chances for showers and
thunderstorms, though the intensity / coverage remains in question
at this time.

Primary Forecast Concerns:

Frost Potential: Will have to pay close attention to dewpoint trends
through the day Wednesday, as subsidence is set to scour out low
level moisture in pretty quick fashion through the morning into the
afternoon. Latest guidance has dewpoints falling into the upper 20s
(some more aggressive guidance even mixes dewpoints into the lower
20s across northeast lower) by late Wednesday afternoon as the low
level cloud deck erodes from north to south. Presence of high
pressure leading to calming winds and clear skies at night will
allow for rapid onset of radiational cooling processes to commence.
Most guidance has temperatures dropping well into the 30s across
interior locales across both northern lower and eastern upper
Michigan Wednesday night into Thursday morning. Still somewhat of
an uncertainty to see how much the recent rainfall supplies low
level moisture responses that could cause temps to hit a wall, but
given the aggressiveness of the drier air intrusion and daytime
temps in the 50s and 60s, the effort to get temps below 36 degrees
across the interior will be lesser. As far as Thursday goes, more
low level moisture should be scoured out by the presence of high
pressure, though the lack of wind may keep soil moisture relatively
high in wooded areas. Regardless, another clear and calm night could
lead to a localized frost threat across the interior locales. Still
a ways away, but it is entirely possible for Frost Advisories to be
hoisted Wednesday night across the interior.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1145 PM EDT Mon May 27 2024

Ongoing rain across the Tip of the Mitt and northeast lower will
continue to work southeast across the area tonight, and is expected
to exit Tuesday morning. CIGs have lifted over the last several
hours, and VFR conditions are anticipated across most TAF sites
through the issuance period. The exception may be APN where IFR/MVFR
CIGs may linger for a few hours after 06Z. Otherwise, northwest
winds will gradually increase Tuesday morning into the
afternoon.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 5 AM EDT early this morning for
     LSZ321.

&&

$$

SHORT TERM...PBB
LONG TERM...HAD
AVIATION...DJC