603
FXUS63 KAPX 210150
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
950 PM EDT Thu Jun 20 2024

.KEY MESSAGES...

- Isolated to scattered showers and storms through Friday.

- Widespread showers through Saturday night.

- Locally heavy rainfall possible Friday night into the first half
  of Saturday night.

- Showery and mostly cool conditions expected next week.

&&

.UPDATE...
Issued at 950 PM EDT Thu Jun 20 2024

Surface front is hung up over northern OH and central IN/IL.
Weak high pressure is feeding cooler low-level air into northern
MI. And reasonable return flow aloft will remain w of Lake MI
thru morning. But our deeper airmass is very moist (00Z APX Pwat
1.67"). Any little ripple arriving aloft from the west will act
to generate mid-level fgen forcing, and steepen lapse rates
aloft to result in precip. CAMs are all over the place in
regards to when/where/if that happens tonight, but far northern
lower MI seems like the most common spot to be impacted. Will
continue to have the highest pops late tonight (toward or after
dawn) between M-32 and the Straits.

Before then, just some sct light showers, especially early on.
Min temps mid 50s to low 60s.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 243 PM EDT Thu Jun 20 2024

Pattern Synopsis and Forecast:

Sfc high pressure will remain to the north-northeast of the region
tonight into Friday. However, moisture remains trapped across the
region with scattered showers and storms possible. Additionally,
ridge across the southeast shifts slightly to the south on Friday,
with a mid level perturbation pushing into the middle portions of
the country later on Friday. Response is for lowering of heights
across N MI into Friday. Low pressure associated with this
disturbance will be the feature of focus this weekend.


Primary Forecast Concerns:

Moderate moisture (I suppose it`s a quite a bit more than moderate
w/P Dubs & Dews ~>= daily 90th percentile) will continue through
tonight, and even increase on Friday especially across southern
portions of northern lower Michigan. Thus, we`ll keep the chance for
showers & storms in the fcst from tonight into Friday. Could be
another band of showers later tonight in the vicinity of the Tip of
the Mitt as progged by latest 12Z guidance. CAMs are hinting at this
potential  meanwhile the ECMWF shows another healthy batch of rain
possible (which it did yesterday as well if I recall). Additionally,
looks like a pretty good chance for showers and thunderstorms Friday
afternoon roughly south of M-32 where the better moisture pools, but
lapse rates and thus instability is generally overall a little
underwhelming in regards to severe weather. That being said, any
more robust thunderstorms will definitely have the chance to
produce heavy rains (for reference, almost an inch and a half of
rain fell in Alpena in a relatively short period of time due to
the anomalously moist environment earlier this morning) and
perhaps some gusty winds. Despite this, winds do increase with
height and although CAMs are not too impressed (with severe),
might be worth keeping an eye. Temperatures generally in the 70s
and 80s once again with generally light winds again Friday.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 243 PM EDT Thu Jun 20 2024

No major changes to the long term forecast. The upper level ridge is
still shown to eventually retrograde westward which will set up shop
to our southwest. Before that occurs, tropical moisture moves
northward into the Great Lakes this weekend. At the same time,
northern stream short waves top the ridge and move across the area.
This is all expected to result in widespread showers and embedded
thunderstorms Friday night into the first half of Saturday night.
Localized heavy rainfall is expected with models indicating some
spots could see 1 to 2 inch amounts with even higher amounts
possible. The heaviest rainfall Friday night is expected to be
concentrated across eastern upper and far northern lower with the
heavier rainfall slowly shifting to the south into the remainder of
northern lower on Saturday. Ponding of water on area roadways is
likely. The northern jet stream is then expected to be the dominant
feature up here Sunday into much of next week (but with small
deviations in the flow as short waves disrupt the flow). There will
be periodic chances for showers and possibly embedded thunder next
week. Temperatures are expected to be near to perhaps even slightly
below normal for the most part (with the exception of Monday when
the warmer air tries to briefly surge northward).

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 641 PM EDT Thu Jun 20 2024

Mixed VFR/MVFR conditions.

Weak high pressure over Lk Superior has pushed cooler air into
the region. That will be temporary, as the high weakens, and a
warm front pushes north into the southern and central lakes on
Friday. There are good chances for showers thru the period,
especially late tonight, and again on Fri afternoon. MVFR will
be most prevalent late tonight and Sat morning, otherwise a mix
of VFR and MVFR conditions are expected.

Light winds.

&&

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

&&

$$

UPDATE...
SHORT TERM...JLD
LONG TERM...AJS
AVIATION...JZ