FXUS63 KAPX 211757

Area Forecast Discussion
National Weather Service Gaylord MI
157 PM EDT Thu Sep 21 2023

.NEAR TERM...(Through Tonight)
Issued at 153 PM EDT Thu Sep 21 2023

High Impact Weather Potential: Minimal. Perhaps some dense fog in
places tonight.

Pattern Synopsis/Forecast:

Mid/upper level ridge continues to slowly mature across the western
Great Lakes early this afternoon. Weak shortwave trough tucked
within this expanding ridge...sliding east across central Illinois.
Center of large area of surface high pressure now well east of the
region...with ridging extending back west across northern Michigan.
A well modified airmass and continued weak return flow again
allowing another warm day as we round out the end of the summer
season...with current readings punching well up into the 70s across
most of the area.

Really not a whole lot of change expected tonight as deep layer
ridging remains centered across the Northwoods.

Primary Forecast Concerns/Challenges:

Addressing any isolated shower/storm potential the remainder of this
afternoon and overnight temperature trends/fog concerns.


Suppose a few showers and thunderstorms remain possible the
remainder of this afternoon as lake breeze driven low level
convergence axes interact with terrestrial mixed layer cape values
at or below 1k Joules/kg. Expect any activity to be largely confined
to north central and northeast lower Michigan where surface-based
convergence will be maximized. Any showers/storms come to an end
quickly this evening as instability support is lost. Mostly clear to
partly cloudy skies expected overnight with seasonably mild
temperatures only dropping into the mid and upper 50s. Rather
abundant low level moisture and light/calm winds again supports fog
formation...some of which could become locally dense. Most
widespread fog looks to occur across interior eastern upper


.SHORT TERM...(Friday through Sunday)
Issued at 153 PM EDT Thu Sep 21 2023

High Impact Weather Potential: Isolated thunderstorms possible
Friday afternoon.

Pattern Forecast: Split flow expected to remain evident across the
CONUS Friday into the upcoming weekend. Within this pattern, closed
upper level low is expected to drift from the Pacific Northwest into
the northern Plains this weekend while troughing down the eastern
seaboard prevails. Northern MI lies in the middle ground between
these two features with a fairly nebulous surface pattern overhead
as some semblance of high pressure dominates -- although not without
its complications.

Primary Forecast Concerns: Low precip potential.

Little in the way of sensible weather anticipated at the start of
the period Friday morning with any early fog giving way to partly to
mostly sunny skies. Warming temperatures remain the rule with
afternoon highs headed to the upper 70s to low 80s area-wide.
Complications arrive Friday afternoon, mainly revolving around
potential isolated to scattered shower/storm development. Not a ton
of confidence in this occurring given capping aloft, but enough low-
level moisture and low-level convergence from inland penetrating
lake breezes may prove to be enough to kick off some isolated
activity. Deep layer shear under 15 kts should limit storm
organization, but a rogue stronger pulse storm with briefly heavy
downpours, small hail and gusty winds not entirely out of the

Not much change to the overall pattern locally through the upcoming
weekend with another mild day expected on Saturday with highs
spanning the 70s area-wide. Minimal support for organized
convection, but another afternoon where a pop-up shower and storm
can`t be ruled out. Latest trends support a moisture-starved
backdoor cold front sliding into the forecast area from the
north/northeast late Saturday/Saturday night before essentially
washing out overhead. This sets the stage for what`ll likely be a
cooler, but dry Sunday. Highs in the 60s to low 70s.


.LONG TERM...(Sunday night through Thursday)
Issued at 153 PM EDT Thu Sep 21 2023

High Impact Weather Potential: Minimal.

Eventual pattern change looks to be on tap next week with cutoff
upper-level low pressure over the upper MS Valley Sunday night slow
to move east across the Ohio Valley/Great Lakes through the middle
of next week. However, once this does occur, a more typical longwave
pattern looks to follow with ridging across the nation`s midsection
sandwiches between troughing over the western and eastern tiers of
the CONUS.  Not a ton in the way of sensible weather anticipated
locally as latest ensemble trends support expansive high pressure
building across eastern Canada into the Great Lakes region for much
of next week. Cooler/more seasonable temperatures anticipated with
highs largely in the 60s. Perhaps some patchy frost concerns for any
clear/calm nights as well.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 118 PM EDT Thu Sep 21 2023

Only concern is the expected development of fog/br and stratus
later tonight into early Friday morning. Most impactful weather
expected at KPLN, KCIU, and KAPN. Expect these sites to see IFR
visibilities and cigs developing later tonight. Current trends
support less aggressive conditions at the remaining locations.
Quick improvement expected across the area after sunrise on
Friday. Light winds through the period.


Issued at 153 PM EDT Thu Sep 21 2023

Trends continue to support sub-advisory winds and waves through at
least the weekend. Overall dry and mild conditions are expected,
with just small chances for showers at times.





NWS APX Office Area Forecast Discussion