370
FXUS63 KAPX 190531
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
131 AM EDT Thu Jun 19 2025

.KEY MESSAGES...

- Lingering showers and a few thunderstorms into tonight. Heavy rain
concerns continue.

- Periodic shower/storm chances and an aggressive warming trend
  expected into next week.

- Potential for some heat-related health concerns early next
  week.

&&

.SHORT TERM /THROUGH THIS AFTERNOON/...
Issued at 213 PM EDT Wed Jun 18 2025

Pattern Synopsis/Forecast:

Shortwave trough working steadily east into the western Great Lakes
this afternoon, with its attendant weak surface reflection pivoting
northeast along the ridge/trough interface into Illinois (helped
along by one impressive mesoscale convective induced vortex).
Stationary front working northeast from this low into southern lower
Michigan, with sustained warm and moist advection along and north of
it kicking off rounds of mostly light showers and sprinkles across
parts of northern lower Michigan. Warm sector locked south of that
stationary front, and that is where primary severe threat remains.

Shortwave trough will cut across our area tonight/Thursday morning,
exiting off to our east Thursday afternoon. Weak surface response
and that MCV will continue to ride up lower Michigan baroclinic
axis, reaching vicinity southeast Ontario by Thursday morning.

Primary Forecast Concerns:

Shower/storm evolution into early Thursday. Heavy rain and severe
threat will need addressing as well.

Details:

Simple extrapolation and current observation trends support little
northward movement to central/southern Michigan frontal zone the
remainder of this afternoon into this evening, keeping the much more
unstable warm sector locked across southern Michigan. Accordingly,
best severe storm potential will reside in that area and points
south. Still can`t rule out a few stronger/marginally severe storms
across at least southern sections of our area, but definitely not
expecting anything widespread. Localized areas of heavy rain (inch
or greater) also remain possible with deep available moisture
(precipitable water values up and over 1.50 inches) and persistent
convergence/hints of transient frontogenetical responses north of
that stationary front later this afternoon into the early
overnight...especially along and southeast of a line extending from
Alpena to Cadillac. Again, heaviest rain rates likely to remain with
much deeper convection to our south, so current thought is any
potential for worrisome widespread rainfall totals looks
minimal...although some local impacts are indeed possible. Shower
threat to continue right into early Thursday morning with approach
of primary upper level support. Threat for any stronger storms and
heavy rain will however likely end by early morning.

Lingering showers into Thursday morning, expecting the afternoon to
trend dryer as wave pivots off to the east and mid level heights
begin to rebound some. Near normal temperatures Thursday, with highs
largely ranging through the 70s.

&&

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
Issued at 213 PM EDT Wed Jun 18 2025

Pattern Synopsis/Forecast:

All systems still a go for much warmer (downright hot) temperatures
to spread into the Great Lakes later this weekend into early next
week. Expansion of southeast Conus centered upper level ridge and
digging west coast troughing places our area in the cross-hairs of
deep layer southwest flow, with that flow having a direct connection
to southern Plains heat dome. Ridge/trough interface across the far
western Great Lakes into southern Canada will also lead to what
looks to be cyclic development of convective complexes...some of
which will likely impact our area at various times. Heat
dome/subtropical ridge does look to relax some as we head into the
middle and latter portions of next week.

Primary Forecast Concerns:

Temperature trends (just how hot it becomes) and additional
shower/storm concerns through the period.

Details:

First order of business is the increasing heat. Simple use of
top/down thermal progs and pattern recognition continue to support
some downright uncomfortable warm (perhaps dangerous so)
temperatures, especially by Sunday and Monday when highs look to
easily top 90 degrees across much of northern lower Michigan, with
mid 90s easily attainable across downslope favored areas of
northeast lower Michigan. Low level environment will also be a
moisture-rich one, with current trends supporting dewpoints in the
60s through the period. This will not only make it feel even more
uncomfortable during the daylight hours, but likely keep overnight
lows from falling too much...with current expectation that lows will
remain in the 60s and 70s Saturday night through Monday night.
Combination of all the above may eventually require the need for
some heat related headlines. Much too early for that of course, but
definitely something to monitor as we head into this weekend and
early next week.

Uncertainty is much higher with regards to additional shower and
thunderstorm chances through the period. Again, pattern recognition
strongly supports periodic bursts of deep convective to develop to
our west and northwest along strong instability gradient and
episodes of enhanced low level jet support. Instability gradient is
in a favorable position to allow at least some of this activity to
ride east/southeast into our area at times Thursday night into the
start of the weekend. Quick hitting shot of mid level support and
attendant significant ramp-up of low level jet looks to bring the
best potential of a more organized and intense convective complex
Friday night into Saturday morning (timing subject to change of
course). Latest SPC Day 3 outlook has nearly half of our area in a
marginal risk for severe storms during that period...although they
do mention quite a bit of uncertainty...both with storm organization
potential and eventual propagation of any convective complex.

Current trends support active instability gradient to bow north into
Canada with time Saturday night into Sunday night...perhaps
retreating south again Monday as western trough begins to exert more
influence. Cooler weather looks to return on Wednesday as a cold
front works through the region. Plenty of time to monitor how this
unfolds in the coming days.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 131 AM EDT Thu Jun 19 2025

Showers and rain continue over northern MI overnight, as a
system passes to our south. Rain gradually exits Thursday
morning. MVFR to perhaps IFR conditions will become widespread
by Thu morning, with gradually improvement during the day.

Light nw winds develop Thursday.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until noon EDT today for LHZ348-349.

&&

$$

SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JZ