628
FXUS63 KAPX 161328
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
928 AM EDT Thu May 16 2024

.KEY MESSAGES...

- Shower and storm chances return late today into tonight.

- Periodic rain/storm chances continue at times Friday into
  next week.

- Patchy fog Friday night.

&&

.UPDATE...
Issued at 928 AM EDT Thu May 16 2024

An initial push of cirrus into the area doesn`t seem to be doing
too much to hold back heating. After another cool start, temps
are zipping thru the 50s and into the lower 60s. Clouds will
thicken up further this afternoon in western and northern areas.
But with weak warm advection also getting started ahead of our
next system, the current warmish forecast max temps still seem
reasonable. That`s mostly 70s in northern lower MI (60s near Lk
Huron), as well as 60s in eastern upper.

CAMs remain in reasonably good agreement that convection (or
the remnants thereof) could make a run at western areas after
5pm. Small pops for the nw lower MI coast, Beaver Isl, and
western Mack Co only need minor fine tuning.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 324 AM EDT Thu May 16 2024

Pattern Synopsis/Forecast: Mid-level shortwave ridging overhead
tonight shifts off to the east the day ahead...replaced by steadily
lowering heights as shortwave troughing rotates from the mid-upper
MS Valley into the western Great Lakes by this evening. Associated
area of surface low pressure currently over western MN will follow
suit and slide northeast to north of Lake Superior tonight. An
occluded front likely to trek west to east across the area early
Friday morning with increasing chances for pre-frontal showers and
perhaps some rumbles of thunder late today into tonight.

Forecast Details: Increasing clouds will be the rule today,
especially this afternoon with otherwise filtered sunshine aiding to
boost temperatures into the low-mid 70s for many inland areas.
Cooler across the eastern U.P. and near the Great Lakes -- generally
spanning the 60s in those areas.

Moisture slow to increase through the day, but steadily improves
from southwest to northeast by late this afternoon with PWS progged
near 1.15" area-wide overnight. Latest trends support initial
scattered shower and perhaps a few non-severe thunderstorms arriving
into far northwest lower after 21z before steadily working east
through the evening hours. Not sold one bit on how numerous these
showers will be with some rather concerning trends in hi-res
guidance that many locations struggle to receive much, if any, rain.
Additional isolated to scattered showers chances may percolate
through the overnight hours, but again coverage may really struggle
with this activity as well. Lows tonight ranging from the mid 40s to
mid 50s.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 324 AM EDT Thu May 16 2024

SW-NE oriented trough axis/deformation zone across the central
US...ahead of ridging over the West Coast. PV maxima over SD with an
additional niblet ahead of it lifting through MN; looking at
strengthening height falls in this region under better
dynamics/difluence and deepening moisture (pwats around 1in).
Largely meridional BCZ stretches from this down into KS/OK, where
another niblet aids in development of a surface low...and where best
convection is on going as of 4z/16 along a theta-e ridge ahead of a
surface cold front. Here in the Great Lakes...high pressure holding
on to our northeast...with dry easterly background flow still
holding firm over the region. Upstream moisture trying to sneak
in...but struggling against our current dry air mass, noted by pwat
of 0.43in from the 0z/16 sounding....with a decent dry layer below
about 700mb, reflected by dewpoints in the mid 30s overhead as of
4z.

Upstream trough axis to swing through the region
today/tonight...with some lingering impacts into Friday.
However...will look for ridge axis to build over the region in its
wake...ahead of the next system that should be on the horizon for
Saturday. Currently expecting this next PV niblet to lift through
with an attendant surface system late Saturday into Saturday night,
though not before a bit of a toasty start to the weekend beneath
that shortwave ridge axis. This boundary looks to wash out over us
Sunday, with ridging again building into the region...keeping the
warmth and pleasant conditions in the area for a time. As next, more
potent, trough develops upstream early next week...will watch for
some kind of warm advection activity ahead of the primary system for
the first part of next week. Do expect things to remain warm ahead
of the primary system for the start of next week, with increasing
shower/storm chances as it swings into the region at some point
between Monday night and Tuesday. Right now...looks as though this
system will try to stick around for midweek or so, though there is
uncertainty in how deep over us this will end up, which could have
impacts on temperature forecasts for the latter half of next week,
going into Memorial Day weekend...though details are far from being
clear attm.

Primary Forecast Concerns:

Periodic rain/storm chances Friday into next week...Think we will
still be dealing with the tail end of the initial round of
showers/storms Friday morning, especially over northeast Lower, but
perhaps as far west as the I-75 corridor as the front slips in, as
some convective instability should still be around. In fact, focus
for any lingering precip through the day Friday should be over NE
Lower...where there are some signals for the front to kind of
stall/wash out during the day...though I do have to wonder if it may
become reinforced by lake breeze development if lake breezes are
able to crop up, esp off Lake Huron. Steep lapse rates aloft support
upwards of 500 J/kg of MUCAPE, especially in the afternoon, though
there is some question as to whether or not we`ll get enough diurnal
heating/forcing to be able to bust through a cap expected to develop
around 850/800mb. Again...best shot at this would be over northeast
Lower...but a lot of questions as to how this will play out for
sure...especially with drier air advecting in, which should work
against cap-breaking Friday afternoon. Think the primary threats
with any storms will be wind/downbursts and hail...though shear
isn`t overly impressive, which currently suggests widespread strong
storms aren`t likely attm.

Some nebulous potential for showers/storms Sunday afternoon as a
front washes out in the region...but better rain/storm chances could
return as early as Sunday night into Monday with aforementioned warm
advection. Broadly...setup appears favorable for showers and storms
to impact the Upper Midwest/Upper Great Lakes into midweek next
week, though details may not be totally sorted out until we get much
closer...as it`s possible the forecast will be altered/impacted by
any of the rounds of convection that develop. Stay tuned.

Patchy Fog Friday Night...Given light/nebulous winds Friday into
Friday night (actually, through much of the weekend, for what it`s
worth)...and the rain from tonight into Friday...think there is some
potential for patchy fog to develop Friday night. Have added this to
the forecast for now, though will have to see if the atmosphere is
able to dry out enough during the day to keep it from forming after
sunset. Not impossible we could see a little fog again Saturday
night, though less certainty in this idea attm.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 627 AM EDT Thu May 16 2024

While cloud cover will slowly be on the increase today, VFR
conditions are expected to prevail through much of the period.
Scattered shower and isolated thunderstorm chances increase
early this evening at MBL/TVC and at the remaining terminals
during the mid-late evening through the overnight hours. This
activity should remain pretty hit and miss with very low
probabilities for widespread precipitation. Chances for MVFR to
IFR CIG restrictions do increase from west to east by late
tonight. No wind concerns through the TAF period with afternoon
lake breezes likely, most prominently off of Lake Michigan.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

UPDATE...JZ
SHORT TERM...MJG
LONG TERM...FEF
AVIATION...MJG