738
FXUS63 KAPX 161727
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
127 PM EDT Sun Aug 16 2026

.KEY MESSAGES...

- Shower/storm chances this afternoon with best coverage
  expected across the far eastern U.P. and northeast lower.
  Severe storms are not anticipated.

- Dry start to next week with rain chances returning on Tuesday.

- Trending cooler after midweek with highs ranging anywhere from
  the lower 70s to upper 70s

&&

.DISCUSSION...
Issued at 117 PM EDT Sun Aug 16 2026

Double barrel shortwave setup traversing the broader Great Lakes and
Ohio Valley regions... a primary synoptic shortwave and associated
occluded surface low progressing east across northern Ontario, and a
second, convectively charged wave currently sparking deep convection
within a mesolow complex across northern Ohio. Deeper moisture to
subtly intrude over the next few hours following the passage of a
surface warm frontal boundary (which has sent surface dewpoints into
the upper 60s-lower 70s across the board).

Next piece of the puzzle is ongoing destabilization across the
region, aided in part by partial clearing just ahead of a surface
cold frontal boundary draped from roughly the Soo, south and west to
Green Bay through Dubuque, IA. Anticipation is that another
convective response is to manifest across the region... and
convective showers are already trying to fester over eastern
upper and far northern lower. Peak heating (1,000-1,500 J/kg
CAPE) coupled with ample moisture (PWATs spiking over 1.75")
will yield efficient rainmakers, though with bulk shear
generally holding sub 30kts, organized severe storms seem
unlikely. Predominant storm mode is likely to be a disorganized
multicellular mode, with the only risk being sub-severe hail and
some gusty winds (if deeper convection can materialize),
particularly across northeast lower, where the aforementioned
meteorological parameters are overlapped and maximized. Given
the atmosphere in place, can easily see localized 1.00"+
rainfall amounts, most prevalent across NE lower. The farther
west one goes in northern lower, the overall chances of seeing
rainfall in any given location decrease considerably, especially
once one gets west of I-75.

Convective processes to dwindle through the evening, with slow
clearing overnight as low level moisture holds steadfast, while we
dry in the upper levels. As surface high pressure moves to our
southwest tomorrow, low level moisture will scour out considering
reinforced NW flow. Result is a dry Monday with highs in the 70s
west into eastern upper, and highs in the upper 70s to lower 80s in
northeast lower (with much lower relative humidity!). Dry weather
will be short lived as another wave progresses through the region
later Tuesday, bringing the next chance for some scattered showers
and thunderstorms. Again I state... this is not a widespread
rainfall setup either, so not everyone is going to see rain! In the
wake of this system, a deeper longwave trough builds into the
northeastern part of North America, with the Great Lakes right on
the western edge of the feature. Result will be a cooler area of
high pressure settling in to end the week... and with limited
moisture return, rain chances will be few and far between through
the upcoming weekend, amid a stretch of temperatures holding in the
low to upper 70s Wednesday through Friday, moderating into the upper
70s-low 80s by the weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 125 PM EDT Sun Aug 16 2026

Low level CIGs with VCTS and VCSH will continue this afternoon
followed by winds veering to the northwest. Breezy winds will
subside tonight along with cloud cover returning to VFR at all
TAF sites. Some patchy BR development and low level CIGs remain
possible after 0600Z, especially at KCIU, KPLN, and KMBL. Any
BR development that does occur will quickly clear Monday morning
as VFR is expected through the remainder of the forecast
period.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until midnight EDT tonight for LHZ345-346.
     Small Craft Advisory until 5 AM EDT Monday for LHZ347>349.
     Small Craft Advisory until midnight EDT tonight for LMZ323-341-
     342-344.
     Small Craft Advisory until midnight EDT tonight for LSZ321-322.

&&

$$

DISCUSSION...HAD
AVIATION...SJC