623
FXUS63 KAPX 051448
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1048 AM EDT Sun May 5 2024

.KEY MESSAGES...

- Patchy frost possible tonight, especially inland areas.

- Thunderstorm potential Tuesday into Wednesday.

- Cooler late week.

&&

.UPDATE...
Issued at 1046 AM EDT Sun May 5 2024

Current forecast remains on track as low clouds continue to
aggressively clear this morning with quiet weather expected into
Tuesday. For details, please see the short term forecast below.

&&

.SHORT TERM /THROUGH TONIGHT/...
Pattern Synopsis/Forecast: Upper-level trough axis is in the process
of crossing northern Michigan this morning. Attendant surface cold
front tied to low pressure near James Bay following suit...working
its way across the eastern third of the forecast area. Both upper
level wave and surface reflection expected to quickly race east
early this morning with slowly rising heights aloft and surface high
pressure becoming the rule through tonight.

Forecast Details:

Any lingering pre-dawn showers and morning low clouds expected
to give way to plentiful afternoon sunshine across northern
Michigan. Cooler temperatures on the heels of northwest winds
when compared to yesterday -- topping out in the 50s far north
and through the 60s across much of northern lower MI.

High pressure centers squarely overhead tonight, which should yield
ideal radiational cooling conditions with clear skies and winds
becoming calm. Potential continues to increase for a 30+ degree
diurnal temp swing with at least patchy frost development, especially
away from the immediate lakeshores. While probabilistic guidance
suggests chances are fairly low, raw statistical guidance
that`d typically handle these clear/calm nights well suggests
localized temps falling into the upper 20s in the typical icebox
locales. Certainly something that`ll be monitored today for
potential frost advisory consideration.

&&

.LONG TERM /MONDAY THROUGH SUNDAY/...
PATTERN SYNOPSIS/FORECAST:

Trough axis and attendant surface cold front swinging through the
Upper Great Lakes early this morning...with ridging building across
the northern/central Plains...as anomalous troughing (-3 standard
deviations from the mean) digs into the West Coast. Surface high
over the central US...with cold front stretching along the perimeter
from the Upper Great Lakes down through the Mid MS Valley into
TX/OK, where best convection continues amid deeper moisture and
weaker stability. Aforementioned anomalous troughing resulting in a
very dynamic system over the Intermountain West, which will be the
item of note for the first half of the week.

Ridging builds into the area tonight...and expecting resultant
surface high to only slowly meander out of the region Monday into
Monday night, leading to a dry and pleasant day, with overall light
winds. As the western system plows its way into the central
US...will look for a warm front to slip northward into the Upper
Great Lakes through the day Tuesday. Current expectations have this
front largely stalling out somewhere over Michigan...most likely
over northern/central Lower...with an attendant cold front likely to
swing across southern Lower Tuesday night. As primary upper low
retrogrades across the Plains Tuesday night into Wednesday, will
look for col region to set up over the Upper Midwest...with
annoyingly dreary conditions possible for midweek.
Eventually...looks like the broader trough begins to eject eastward
across the region, save for a piece of cutoff energy over the SW
US...with another surface wave slipping through the Ohio Valley
Thursday. Signals then point toward longwave troughing settling into
the eastern CONUS for the latter portion of the week, and perhaps
beyond...though exact details are still a bit unclear, depending on
how broad and where the trough axis ends up setting up, though the
bottom line is that there is potential for a cooling trend in the
region going into next weekend and beyond (which, from an
agriculture weather standpoint, is not good).

Primary Forecast Concerns:

Tstorm potential Tuesday into Wednesday...Think the drier conditions
expected Monday will be enhanced as southeasterly flow ramps up
ahead of the warm front Tuesday morning, which should (in theory)
slow precip onset as it moves in from southwest to northeast ahead
of the warm front Tuesday. However, it does appear that things will
moisten up fairly quickly once it gets going, so the latter half of
the day Tuesday will likely be on the dreary side...though some
guidance is even slower yet with bringing the rain in Tuesday
afternoon/evening. Not sure how far into the warm sector we will
get...as guidance is still struggling with this attm...and if we do
remain north of the warm sector, it`s possible temps may need to be
lowered for Tuesday.

As mentioned last night, better parameters for severe weather are
favored across southern Lower and points south...where better shear
is expected to overlap with greater instability in the warm sector
ahead of a cold front that should swing through Tuesday night. (Not
sure that the cold front will make it up into our region.) We do
have a shot at some elevated instability, though, which should keep
the thunder threat in the forecast, as well as perhaps sneak in some
small threat of at least small hail? Will have to monitor going
forward...but noting the strong inversion in soundings, think that
hail would be the primary threat if anything were to strengthen.
Otherwise...with better pwats ramping up to around an inch or better
through the day...and a bit of a pivot point over northern Lower/the
Straits...think there is some chance we could see some decent
rainfall, though forcing does seem to get a bit nebulous as the
boundary washes out over us...and we get a bit col-y. (Depending on
exactly where that col region focuses, it`s also possible it could
aid in a deformation band...but we`ll see...) Otherwise, with the
weak boundary lingering into Wednesday morning...along with boundary
layer moisture...will look for dreary conditions to hang on into
midweek.

Cooler late week...signals point toward troughing trying to settle
into the Upper Great Lakes/eastern CONUS toward the weekend and
beyond. For now, not going too aggressive on the cold idea in the
forecast, but do have highs and lows running near normal, or perhaps
slightly below. Noting that lows in particular are generally in the
mid to upper 30s to around 40 by this time of year, and considering
where plants are at even up here in the interior...think we will
need to keep an eye out for additional frost concerns going into mid-
month, especially depending on exactly how the pattern sets up. Stay
tuned.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Lingering MVFR/IFR CIGs early this morning should rather quickly
burn off by midday with sun-filled skies this afternoon. Northwest
winds today become calm tonight.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

UPDATE...DJC
SHORT TERM...MJG
LONG TERM...FEF
AVIATION...MJG