356
FXUS63 KAPX 170945
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
545 AM EDT Thu Jul 17 2025

.KEY MESSAGES...

- Rain, some heavy, will decrease in coverage into the morning.
  Greatest potential for flooding favors portions of northeast
  lower Michigan.

- Chilly and rain free into this afternoon, outside of some
  drizzle / light rain potential across northwest lower.

- Next rain chance comes Saturday, with warming temperatures and
  additional rain chances into next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 234 AM EDT Thu Jul 17 2025

Current Overview / Pattern Synopsis:

Mesoscale convective vortex (MCV) progressing eastward through the M-
55 corridor at this time, with saturated airmass well in place...
PWATs generally pushing 2.0. Ample stratiform rain shield surrounds
this feature, with some subtle convective elements ahead of it. As
such, some efficient to even torrential rainfall is ongoing across
the M-72 corridor in conjunction with the main MCV circulation.
Concerns for flooding are currently highest in an active Flood
Warning, particularly across northern Crawford County, where radar
estimates are depicting a total of 7"+ of rain since yesterday
morning southwest of Frederic. Elsewhere, weaker forcing is leading
to lesser, but still efficient stratiform rainfall. This feature is
riding along a stationary frontal boundary, and is drawing in a much
cooler airmass in its wake, which is helping to force this frontal
boundary through the region by later this morning. As such, will
eventually see subsidence overtake the area, with lesser moisture
content allowing for clearing skies amid a breezy NW flow courtesy
of a pinched pressure gradient on the backside of the system, along
with cold air advection processes aiding in efficient mixing.

Forecast Details:

Most prolific feature for the short term period will be the
departing effects of the MCV as it exits stage right early this
morning. Rain shield from this system will continue its northwest to
southeast departure, leaving the greatest remaining rainfall amounts
to favor northeast lower, particularly east of a Lake City to Rogers
City line, which remains in close proximity to the best forcing from
the MCV... though may become more sporadic the closer one gets to
Saginaw Bay. Of particular concern, will be that Grayling to
Harrisville corridor, which may see an additional 1.00-2.50" of rain
by daybreak... certainly leading to potential for some localized
flooding concerns. With the anticipated departure of this system,
expecting the flood threat to lower quite considerably once this
feature departs off Lake Huron, as the heavier rainfall rates will
be on their way out.

Aforementioned frontal boundary is set to clear the area, and in its
wake, a much chillier NW flow builds across the Northwoods. Will be
quite the contrast to the recent run of warmth and humidity the area
has been dealt. Lingering cloud cover and that flow of chillier
Canadian air will lead to temperatures generally 5 to perhaps 15+
degrees below normal in some places, as highs generally top out 64 to
74 degrees (warmest Saginaw Bay up to Alpena). In addition, that
stubborn low level moisture may lead to some orographic
influences contributing to drizzle / light rain shower potential
across the terrain of northwest lower. Will be quite the breeze
for July... sustained winds generally 10 to 15mph with some
gusts pushing 30mph at times this afternoon, especially near the
lakeshores. As such, probably a bit choppy on the Great Lakes
and inland lakes as well. High pressure works closer into the
overnight hours, and as such, anticipating with clearing skies
and drier air intrusion, along with decoupling winds...
expecting lows to tumble well into the 40s inland and mid 50s
near the coasts. With all the recent rain, certainly possible
for some fog development tonight as that cooler air overlaps the
recent warm rainfall.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 234 AM EDT Thu Jul 17 2025

Surface high pressure maintains a dry day Friday, with pleasant
temperatures in the 70s. Another wave approaches for Saturday, which
will return shower and storm chances. Initial look at this wave
comes back unimpressive, but nonetheless with just enough moisture
return, poses a scattered shower or storm chance. Quick moving wave
clears into Sunday, which will return drier conditions. Pattern
turns warmer and potentially more active as we progress into next
week. Above normal temperatures and muggier conditions set to
prevail as a robust thermal ridge develops across the Plains and
into the lower Great Lakes. This will place northern Michigan right
on the edge of this feature, which will lead to a progressive NW
flow around the ridge. This pattern tends to be favorable for
convective complex development, and latest long term guidance does
hint at a quicker jet max developing across the northern Plains,
which from a synoptic standpoint is vital in developing these
complexes. Obviously will have to see how that pattern evolves, but
definitely potential for things to turn active across the Great
Lakes... just a question as to where things go. More details to
come!

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 543 AM EDT Thu Jul 17 2025

Widespread IFR to MVFR producing low clouds expected early this
morning. Very slow improvement expected through the morning,
with more aggressive clearing expected heading into the
afternoon and early evening. North to northwest winds become a
bit gusty today, with winds going quickly light this evening.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through this evening for MIZ020-025-
     031-099.
MARINE...Small Craft Advisory until 5 PM EDT this afternoon for LMZ323-
     342-344>346.
     Small Craft Advisory until noon EDT today for LMZ341.

&&

$$

SHORT TERM...HAD
LONG TERM...HAD
AVIATION...MSB