265
FXUS63 KAPX 070744
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
344 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 troughing west of the Plains. The result will
be a continued period of occasional shower (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 /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1145 PM EDT Thu Jun 6 2024

Deep upper level troughing/convergence combined with ample low
level moisture will continue to generate sct/nmrs showers overnight
into Friday across much of Michigan. Prevailing conditions will
remain low VFR/MVFR. Surface winds will remain from the W/NW at
10 to 20 kts thru Friday.

&&

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

&&

$$

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