858
FXUS63 KAPX 081443
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1043 AM EDT Wed May 8 2024

.KEY MESSAGES...

- Lingering rain this morning.

- Patchy frost possible Thursday night.

&&

.UPDATE...
Issued at 1038 AM EDT Wed May 8 2024

Mostly light rain, low clouds, and some patchy fog seen this
morning via satellite, radar, web cams, and surface
observations. These conditions will linger for eastern upper
through mid day, with chances for conditions lingering through
early afternoon for the tip of the mitt and NE lower as the
system exits east today. Winds have turned northwest to
northerly and diminished to mostly light (with some exceptions
over the NE lower near shore waters). Clouds should hang around
for most of the day today, with chances for fog returning
tonight over some areas.


&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 329 AM EDT Wed May 8 2024

Pattern Synopsis/Forecast: Developing surface low pressure currently
centered over the Straits region early this morning with textbook
comma head of precipitation pinwheeling over eastern upper, northern
Lake Michigan into northwest lower. This low pretty quickly
ejects east this morning, pulling associated showers along with
it. Attention then shifts to another area of low pressure
progged to trek across the mid-MS Valley late tonight into the
Ohio Valley on Thursday, which latest trends over the last 24
hours suggest much, if not all, notable precipitation associated
with that system remains to our south.

Forecast Details:

Focus for additional rain showers this morning largely exists near
and north of M-72 with the highest probabilities and associated
greatest additional QPF near and north of M-32. Chances wane from
northwest to southeast later this morning through early afternoon
with even some late day peeks of sun anticipated, especially over
the southern half of the forecast area. Highs ranging from the 50s
far north to near 70 degrees close to Saginaw Bay.

While by and large, a general lull in precipitation is anticipated
this evening and overnight, suppose there`s just enough mid-level
energy and low-level moisture support for a few additional isolated
showers to percolate at times. Pretty tough to say with much
certainty if and where these showers actually develop -- current
confidence is highest across the U.P., Straits and tip of the mitt --
and as a result, it`ll be hard not to have some splotchy low PoPs
from time to time later today into tonight in those areas. By very
late tonight, focus transitions to low pressure to our southwest
with an expected area of associated rain trekking across northern IL
and southern WI. This tries to make inroads into far southwest
sections by 12z Thursday, but latest trends favor that precip
remaining across southern lower Michigan. Lows tonight pretty
close to normal for early May -- largely in the 40s area-wide.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 329 AM EDT Wed May 8 2024

PATTERN SYNOPSIS/FORECAST:

Almost a blocky pattern setting up over the central continent...with
anomalous easterly flow north of the Canadian border between
elongated anomalous low centered over the Dakotas (attendant 987mb
surface low here)...and ridging over central/northern Canada. Sharp
trough axis swinging through the Upper Great Lakes...driving surface
cyclogenesis over northern Lake MI attm...well north of the warm
front that led to severe weather across the southern portion of the
state. Moisture axis still holding on across the EUP and parts of
northern Lower attm.

Blocky pattern doesn`t appear to last long...with trough energy
riding over the western ridge...helping punt overall troughing out
of the Midwest for a time, though not before driving a surface low
across the OH Valley. Shortwave ridge axis slips in for Thursday
night and Friday, bringing seasonably pleasant conditions (minus
threat of frost Thursday night) to the region. Aforementioned trough
energy drops into the Upper Great Lakes Friday evening/night with
clipper-type vibes to keep the dreary/rainy idea in play into the
start of the weekend. High pressure may try to sneak in
Saturday night, but it appears another clipper-like system slips in
for later Sunday into Monday. A fair bit of uncertainty in the
evolution of the pattern for early next week, as guidance is
struggling to nail down how amplified troughing may end up over the
Great Lakes region...though attm, signals seem to be trending a
little less dramatic on the cold (which, to be honest, is probably
just as well for agricultural interests and everyday gardeners this
time of year).

Primary Forecast Concerns:

Patchy frost possible Thursday night...
Latest guidance coming in early this morning seems to be trending
further south and east with the wave riding up into the OH Valley
Thursday. Aside from diminishing precip chances across most of the
region north of M-55...this idea could have an impact on overnight
lows for Thursday night. If high pressure is a little quicker to
move in Thursday during the daylight hours, it could mean clearer
skies and perhaps lighter winds that would be more conducive to
overnight temps approaching the freezing mark. For now, I have
trended things a little more toward this idea, with coolest temps
likely the further north and west you go, as there should be less
clouds from the OH Valley system up there, and a greater shot at
decoupling winds overnight. Highs in the upper 50s to around 60
Thursday would, with a standard diurnal temp swing for early May,
suggest lows in the mid 30s would be possible...with a risk area
potentially in the portion of our CWA most sensitive to frost.
However...there are some caveats that need mentioning...
1) There are some signals that winds may not fully decouple Thursday
night, which, if it were to come to fruition, would mean more mixing
and warmer overnight lows that could preclude most temperature
issues.
2) There are also signals there could be enough boundary layer
moisture around to either a) keep some clouds around overnight and
preclude best radiational cooling... and/or b) keep temperatures
from bottoming out as low as they could if we had a drier airmass in
place. This latter idea is particularly worth noting given the
recent 1+ inch rainfall...though for better or worse, given that a
lot of the soil up here is sandy, it may not take long to lose some
of the moisture that might otherwise hang around and lead to warmer
lows (and perhaps fog).

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 534 AM EDT Wed May 8 2024

Low pressure continues to cross northern Michigan with the most
numerous lingering rain showers north of a line from TVC to APN.
Those shower chances diminish through the morning and midday.
MVFR to IFR CIGs associated with these showers expected to
slowly improve to VFR through the afternoon and evening. Winds
largely out of the northwest today -- gusty at times this
afternoon, before veering out of the northeast tonight.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 4 PM EDT this afternoon for LHZ349.

&&

$$

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