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000
FXUS63 KAPX 181045
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
645 AM EDT Sun Jul 18 2021

.NEAR TERM...(Today through Tonight)
Issued at 342 AM EDT Sun Jul 18 2021

...Mostly clear and continued quiet thru tonight...

High Impact Weather Potential...None.

Pattern Synopsis/Forecast...Large area of strong high pressure
remains centered over the Upper Mississippi Valley and the Western
Great Lakes region early this morning...maintaining dry wx and
mostly clear skies across all of Northern Michigan. Clear skies and
light/calm winds have allow temps to drop into the 50s early this
morning as expected. Upper level ridge axis also extends into the
Western Great Lakes. Weak impulses of energy continue to ridge along
the northern periphery of this upper level ridge axis...producing
some spotty cloud cover over Lake Superior and Ontario.

As we head into today...some of this spotty cloud cover may spill
into northern sections of our CWA...but likely not enough to
preclude another mainly sunny day across our Northwoods. Vigorous
low level mixing will allow for some warm breezes again this
afternoon as high temps warm into the 80s. Expect another mainly
clear and cool night as low levels decouple after sunset. Overnight
lows will cool back into the upper 50s and lower 60s.

&&

.SHORT TERM...(Monday through Tuesday)
Issued at 342 AM EDT Sun Jul 18 2021

High Impact Weather Potential: Minimal attm...

Pattern Synopsis/Forecast:

Monday morning...troughing off the coast of British Columbia will be
holding strong...with anomalously strong ridging ahead of it through
the western US/Canada. Downstream of that...we here in the
Northwoods will be sitting pretty under a shortwave ridge axis which
should keep us toasty into the start of the workweek. Troughing to
our north in the vicinity of Hudson Bay will throw a niblet of
energy our way Monday night into Tuesday...allowing for troughing to
take hold of our fair state for the latter half of the short term.

Primary Forecast Concerns: Rain/storm chances Monday night into
Tuesday...

Model guidance seems to want to bring some mid-level moisture into
the area during the day Monday...well in advance of troughing to our
north...though they all keep the bulk of it to our northeast, closer
to better dynamics with the system itself near James Bay. Given that
there seems to be a trend tonight of model guidance overdoing mid-
level moisture...will therefore side with drier guidance and
tend to keep things dry during the day Monday. Considering that
we`ll still be pretty firmly underneath the ridge axis much of
Monday...and a decent amount of low-level dry air should be in place
given northerly flow over the last few days...this seems like a
decent bet. With surface high pressure drifting pretty close to
overhead Monday...will look for diurnal cu development to be about
the extent of things, especially along the lake breezes. Wouldn`t be
entirely out of the question to pop something along the lake
breezes...particularly along the Lake Huron lake breeze...where
convergence will be maximized...and low levels will have warmed the
most...lending to a chance at surface based instability,
perhaps...so I have added low end slight chance wording to the
forecast. Would not be surprised if we stayed dry, though.

Things are somewhat less straightforward going into Monday night and
Tuesday...with some uncertainty in the timing and position of the
front and its parent shortwave aloft as it drops southeastward along
the flow. If the front is able to slip in quicker Tuesday...highs
may be a touch cooler, CWA-wide, than if the front is slower to
move in. Did trend highs down a smidgen to account for this idea.
Additionally...if fropa is quicker...will look for the best
forcing to be primarily out of the area by peak heating...which
would lead to somewhat minimized instability. As it stands...we`ll
be on the tail end of the front...and will likely be removed from
the better moisture and dynamics for much of any substantial rain or
storm concerns for our area. Even so...thunder is still on the
table, as there should be some instability along and ahead of the
front as slightly cooler air aloft slides into the region.

.LONG TERM...(Tuesday night through Saturday)
Issued at 342 AM EDT Sun Jul 18 2021

High Impact Weather Potential: Minimal attm...

Beyond Tuesday`s system...there is a fair bit of uncertainty in
the exact evolution of the pattern...though there seems to be some
semblance of overall agreement on the general idea. Baroclinic zone
lingering somewhere in the area from Tuesday`s system will likely
play a role in focusing impacts from various embedded shortwaves
diving down through the flow. The first of these should trek in
Wednesday night into Thursday...bringing us the next chance for
precipitation...which attm looks like it could be slightly more
favorable than Monday night/Tuesday`s chances...but we`ll see. As
mentioned in last night`s discussion...will be looking for the pesky
troughing over the west coast of North America to get booted out
late in the week...and trek across the top of the ridge. This should
serve to flatten the ridge across the northern Plains/Canadian
Prairies...and perhaps lend to additional precipitation chances going
into the end of the week...though there are still a lot of details
to work out between now and then.

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 645 AM EDT Sun Jul 18 2021

Strong high pressure and dry air thru the column will maintain
solid VFR conditions at all Northern Lower Michigan TAF sites thru
Monday morning. Light NW winds will allow for lake breeze
development again today.

&&

.MARINE...
Issued at 342 AM EDT Sun Jul 18 2021

Winds and waves will remain below SCA criteria into the first part
of our workweek as high pressure dominates our wx. No precip and
plenty of sunshine is expected thru Monday. Our next chance of
precipitation will develop Monday night as a weak cold front drops
into Northern Michigan.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

NEAR TERM...MR
SHORT TERM...FEF
LONG TERM...FEF
AVIATION...MR
MARINE...MR