454
FXUS63 KAPX 071041
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
641 AM EDT Fri Jun 7 2024

.KEY MESSAGES...

- Isolated/scattered showers and cool temperatures today.

- Another round of showers Saturday into Saturday night. Some
  thunder possible south.

- Next chance of rain and perhaps some thunder Tuesday night
  into Wednesday.

- Warming temperatures through the course of next week into next
  weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 343 AM EDT Fri Jun 7 2024

Pattern Synopsis:

Strong troughing draped across the Great Lakes will continue to
pivot east over New England today. Low-amplitude ridging on the
backside of said troughing will slide overhead later this evening
and tonight. A broad surface cyclone will also spin over southeast
Canada as relatively high pressure noses into the Great Lakes as
aforementioned ridging works overhead.

Forecast Details:

Isolated/scattered showers, cool temps today -- West to northwest
winds will prevail today as the aforementioned system continues to
work to our east. Ongoing isolated to scattered showers are also
expected to continue at times across parts of the area into this
afternoon. Rain chances will gradually wane with time as a drier low-
level airmass is advected in and favorable forcing becomes
increasingly displaced from the region. Cloud cover also looks to
clear as high pressure works into the Great Lakes this evening and
tonight. Otherwise, temperatures are expected to stay cool today
with highs in the upper 50s to mid 60s. Lows should cool into the
mid to upper 40s away from the immediate lakeshores tonight.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 343 AM EDT Fri Jun 7 2024

Pattern Synopsis / Forecast:

Rotund area of retrograding longwave troughing set to pivot south
and east from the Dakotas through the upper Great Lakes Saturday
into Sunday as closed area of surface low pressure is slowly forced
eastward by amplifying ridging west of the Plains. The result
will be a continued period of occasional showers (with perhaps
a rumble of thunder) through the first half of the weekend.
Surface high pressure will finally work into the region as some
500mb ridging moves into the Great Lakes by Tuesday, drying
things out for the most part. This area of high pressure slowly
sags south and eastward into the Outer Banks of North Carolina,
directed by the lingering NW flow on the backside of longwave
troughing over Atlantic Canada. This will eventually lead to
warming temperatures, potentially quite on the warm side,
heading into next weekend as a 500mb thermal ridge flexes over
the central Plains and return flow draws warmer air into the
region.

Primary Forecast Concerns:

Saturday - Sunday: Embedded vort max within the longwave troughing
looks to pass through Michigan Saturday, though with such cool
temperatures and lacking steeper lapse rates, not looking at an
overly optimistic outlook for thunder. Rain will probably struggle
to move into the region initially as dry air aloft holds off
saturation, but eventually expecting showers to pass through the
region... with northern lower Michigan having the best chance of
showers, and lesser chances the closer one gets to the Soo. Wild
card could be enough diurnal heating just to the south of the vort
max drumming up a few hundred joules of surface based CAPE leaking
into the southern reaches of the CWA, but much of this instability
is progged to remain south of US 10 at this juncture. Wave passes
through. Looks like Sunday probably holds more dry than not for now,
though some lingering energy from the passing longwave may be enough
to spark some diurnal showers before moisture gets scoured out and
drier air moves in by Monday with the approach of surface high
pressure. Temps set to be rather chilly by early June standards,
largely getting stuck in the 60s to near 70 (perhaps mid 70s closer
to Lake Huron Saturday owing to a later onset of rainfall).

Rest of the Period: Next item of interest will be a shortwave riding
a zonal flow regime around the ridge overhead, which will bring the
next chance for shower and thunder later Tuesday night into
Wednesday. Suboptimal timing of this feature passing through leads
me to believe this will mainly be showers. Somewhat of a subtle
convective wave signal building in for Wednesday night into
Thursday, which could have some thunder with it if it indeed does
originate as an MCS in the Plains, but still a bit far out to get
into any more specifics. Thermal ridge axis peaks over the Plains by
the end of the forecast period, leaving northern Michigan on the
periphery of the larger ridging complex. While the core of the heat
and surface moisture will be suppressed well to the south and west,
surging 850mb temps suggest that we will indeed be seeing
temperatures rise into the weekend... starting in the 70s Tuesday,
rising well into the 80s by the weekend for most.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 641 AM EDT Fri Jun 7 2024

IFR CIGs look to stay in place over the eastern U.P./CIU into the
early afternoon before lifting to MVFR. Otherwise, MVFR CIGs are
expected to persist at PLN and APN into the afternoon while TVC and
MBL stay VFR through the period. Otherwise, isolated to scattered
showers are expected to move across northern Michigan at times
through this afternoon before tapering this evening. West-northwest
winds around 10 kts will gust to 20-25 kts at times through
this evening before weakening near 5 kts later tonight.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 8 AM EDT Saturday for LHZ345>349.
     Small Craft Advisory from noon today to midnight EDT tonight
     for LMZ341-342.
     Small Craft Advisory until 5 AM EDT Saturday for LSZ321-322.

&&

$$

SHORT TERM...DJC
LONG TERM...HAD
AVIATION...DJC