000
FXUS63 KAPX 011005
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
605 AM EDT Mon Jun 1 2020

.NEAR TERM...(Today through Tonight)
Issued at 237 AM EDT Mon Jun 1 2020

Impactful weather: Showers likely, mainly tonight with thunderstorms
possible in GTV Bay region. Severe storms not anticipated.

Pattern synopsis and forecast:

Still a fairly amplified pattern out there, with upper level
troughing over both coasts, and ridging through the Plains. Low
pressure was in Saskatchewan, out ahead of a vigorous shortwave seen
on latest water vapor loop, with a warm front that extended SSE
through the Dakotas and NE, and a cold front that extended back
through MT/WY. Scattered convection is seen ahead of the warm front,
in a theta-e convergence zone on the nrn/eastern edge of an axis of
higher PWAT air (greater than 1.50") from the Dakotas into IA. Nrn
Michigan still had pretty strong NW flow aloft, with very dry air in
place (less than 0.45" PWAT). Skies were mostly clear here, with
just some advection of higher level moisture seen as cirrus across
the western CWA.

The upper air pattern de-amplifies a bit heading through the day, as
the aforementioned vigorous shortwave and associated sfc low rounds
the top of the ridging in the Plains, and heads into Manitoba. This
pulls the warm front to a position from Manitoba down into WI/nrn
IL. A weaker wave is analyzed to cross WI and into Lake Michigan at
the same time, and strong LLJ (30-40kts) points the leading edge of
the theta-e convergence on the NE edge of the higher PWAT axis, into
our neck of the woods. Hardly any instability at this point, but the
modest deep layer -divQ is likely to result in showers moving
in/developing late in the day, at least over the western CWA,
generally along and west of I75. Would tend to think that the
development of showers would only be a touch slower (as it seemingly
usually is), when you try to saturate an initially very dry
atmosphere.

The best forcing is more focused during the evening, at least when
considering the entire CWA. This is when the warm front will be
pushing through nrn Michigan, and the atmosphere really saturates
well, in conjunction with the arrival of strongest LLJ theta-e
convergence. A swath of showers is expected to bring rain to just
about everyone, with instability growing on the western/srn edge of
this convection, aided by a pocket of potential upper divergence.
This more focused from Charlevoix to HTL, with the greatest
instability over the GTV Bay region, where MUCAPE can be as high as
1000-1500 j/kg, but most of this develops after the greatest
precipitation is moving off to the SE. A corridor of heavy rain is
definitely possible here though, and with a high water table and
creeks and streams running high, flooding may be an issue again if
all of the above play out as stated. No severe storms expected.
Despite impressive 0-6km bulk shear of greater than 50kts, showers
and potential storms are mostly gone when the greatest instability
develops.

Highs today will be a little bit warmer today, mostly in the low to
mid 60s. Lows tonight will largely be in the lower half of the
40s.

&&

.SHORT TERM...(Tuesday through Wednesday)
Issued at 237 AM EDT Mon Jun 1 2020

...More thunder chances Tuesday with warm temperatures...

High Impact Weather Potential: Minimal

Synopsis/Forecast: An amplified upper level pattern exists over the
CONUS currently, with sharp troughing across New England and strong
ridging through much of the Plains and Midwest. A shortwave sweeping
out of the Pacific Northwest overtops the ridging through southern
Canada and dives through Ontario on Tuesday. This pushes a cold
front across Michigan through the day, producing more scattered
shower and storm chances. Another wave hot on its heels sweeps
through southern Canada...nearing the Great Lakes and potentially
impacting our weather for midweek.

Details: Early Tuesday morning we may still be dealing with
lingering showers from the overnight passage of a warm front. But as
the warm front lifts northeast showers move out. Believe the
leftover stratus will mix out by midday with boundary layer winds
nearing 20 knots. We slowly warm into the 70s with generally
southwest winds...The big question is whether or not we can reach
the convective temperature, otherwise we`ll have to wait on the
front to help out with storms given the weak midlevel cap. As of now
guidance has plenty of moisture (with PWATs around 1.3"), 40-50 kts
of effective shear and steep lapse rates nearing 7 deg/Km spreading
into the area in the afternoon and evening...All of which will be
sufficient to produce some stronger updrafts if storms can get
going. The cold front sinks down from the northwest...attached to
that same low treking through Ontario, and looks to move through
northern Lower in the early evening, a little after peak
instability.

The storm threat lasts through the evening as sufficient
instability, shear, and moisture is left over from the day. One area
of focus could also be a southward-sinking instability gradient in
the evening. Any convection that does try to fire on this will be
fighting weak subsidence behind the passing shortwave. This will
lead to a relative lull in the action in the first half of the
night. The wee hours of the morning bring a fresh wave of potential
showers and storms as another surge of moisture coincides with lift
and shear ahead of another wave sinking through western Ontario.
Some guidance is heavily hinting at our southwest counties getting
clipped by an MCS moving out of southern Wisconsin Wednesday
morning. Heading into the afternoon/evening conditions dry out and
become a little less muggy as weak high pressure move in. Can`t rule
out a stray pop up shower through the late afternoon/evening thanks
to the weakening wave sliding through the region, but chances look
lower on Wednesday than on Tuesday.

.LONG TERM...(Wednesday night through Sunday)
Issued at 237 AM EDT Mon Jun 1 2020

A series of weak waves moves through the flow the upper level jet
remains fairly zonal across the US-canadian border late week. This
will continue the scattered shower trend mainly for Friday. The next
pattern shift comes from a deep upper level low moving onshore in
the Pacific Northwest this weekend. This will pump up ridging once
again across the Plains and Midwest. Rising heights and surface high
pressure will likely lead to a fairly warm and dry weekend.
Temperatures remain slightly above normal for early June with highs
running in the 70s and lows in the low to mid 50s.

&&

.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 601 AM EDT Mon Jun 1 2020

High pressure across the srn Great Lakes departs SE today, while low
pressure tracks from the western provinces of Canada to Ontario
tonight. A warm front moves into nrn Michigan late today through
tonight, saturating the atmosphere from the upper levels to the
lower levels, and also resulting in showers and thunderstorms with
MVFR/IFR CIGS and some reduced VSBYS. Winds turn more out of the
SW today and become a bit gusty, before weakening and turning
more out of the south through tonight.

&&

.MARINE...
Issued at 237 AM EDT Mon Jun 1 2020

High pressure across the srn Great Lakes departs SE today, while low
pressure tracks from the western provinces of Canada to Ontario
tonight. This will tighten the pressure gradient today, resulting in
low end advisory wind speeds across the Lake Michigan nearshore
waters of NW lower for this afternoon and this evening. In addition,
the sfc low will have a warm front that moves into the region
tonight. Showers and potential thunderstorms move in late today, but
especially tonight. Some localized heavy rainfall is possible. The
warm front blows through by Tuesday morning, with the system cold
front moving through Tuesday afternoon into Tuesday evening.
Additional showers and thunderstorms looks to prove difficult attm,
but better total rainfall arrives later Tuesday night as a
disturbance aloft arrives. No further advisory level winds are
expected after Tuesday evening.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY from 8 PM this evening to 1 AM EDT Tuesday
     for LMZ323-342.
     SMALL CRAFT ADVISORY from noon today to 1 AM EDT Tuesday for
     LMZ344>346.
LS...NONE.
&&

$$

NEAR TERM...SMD
SHORT TERM...STJ
LONG TERM...STJ
AVIATION...SMD
MARINE...SMD

NWS APX Office Area Forecast Discussion