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000
FXUS63 KAPX 292027
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
427 PM EDT Mon May 29 2017

.NEAR TERM...(Tonight through Tuesday)
Issued at 354 PM EDT Mon May 29 2017

...Scattered showers again on Tuesday...

High impact weather potential...Minimal. Chance for a few
thunderstorms through early this evening.

Pattern Synopsis/Forecast...Deep closed low continues to spin over
northern Lake Superior with cyclonic flow entrenched over the Upper
Great Lakes region. Somewhat of a wrapped-up dry slot stretches from
the lower Ohio Valley to Lake Huron and back to the center of the
low, as evident on visible and water vapor satellite imagery. Deeper
moisture is located off to our west, as evidenced by GRB and MPX 12Z
soundings and more extensive cloud cover over Wisconsin and
Minnesota. A couple lobes of vorticity rotating across northern
Michigan have interacted with ample low level instability (courtesy
of strong low level lapse rates up to 9.5 C/km near Saginaw Bay) to
generate isolated to scattered showers and storms at times. Some
better 0-6km wind shear of 40-50 knots allowed for a few better
organized cells around Alpena earlier this afternoon. As daytime
heating wanes towards early evening, expect these diurnally driven
showers to largely dissipate across most of northern Lower, with
shower chances overnight focusing more over eastern Upper and the
Tip of the Mitt. Due to the strong low level lapse rates and
resultant boundary layer mixing, southwest winds have been gusty
this afternoon south of M-72. The gustiness will also diminish
towards sunset.

Fairly quiet night ahead. Cloud cover expected to gradually increase
tonight as the upper low slowly wobbles farther northeast and drags
some of the deeper moisture over WI/MN into northern MI. However, it
may take some time for the cloud cover to thicken up/congeal if the
loss of daytime heating results in some erosion of the daytime cu
field. Regardless, clouds will be more extensive across eastern
Upper and northwest Lower than down towards Saginaw Bay. Ongoing
cold air advection will cause temperatures to drop into the mid 40s
to low 50s across the area by Tuesday morning.

For Tuesday, expect more diurnally-driven scattered showers once
again as the upper low drifts towards James Bay. Chances will be
highest across eastern Upper, with only slight chances for northern
Lower. Cooler temperatures and lower dewpoints due to ongoing CAA
will result in even less daytime instability, so not anticipating
thunderstorms. It will again be breezy with SW winds gusting to
around 25 mph over northern Lower in the afternoon. Highs will range
from the 50s over eastern Upper to upper 60s near Saginaw Bay.

&&

.SHORT TERM...(Tuesday night through Thursday)
Issued at 354 PM EDT Mon May 29 2017

...Cooler and less active...

High impact weather potential: None.

Pattern forecast: By Tuesday night, vertically stacked low pressure
centered near James Bay that has plagued northern Michigan with
occasionally unsettled weather over the second half of the holiday
weekend will slowly shift northward through the midweek timeframe.
Low pressure re-energizes and drops southward across the northern
Great Lakes late this week into next weekend...potentially bringing
another round of unsettled weather. Sandwiched in between the two
periods of unsettled weather will be an expansive area of high
pressure expected to drop from southwest Canada into the northern
Plains before gradually expanding eastward Wednesday-Thursday,
ultimately driving our sensible weather (or lack thereof) during the
midweek time frame.

Primary forecast challenges/concerns: Main concerns revolve around
lingering PoPs Tuesday night into early Wednesday along with
temperature trends throughout the period.

Broad troughing overhead continues Tuesday night with aforementioned
low pressure spinning across central Canada. With an absence of true
forcing, any lingering showers Tuesday evening should gradually
diminish beyond sunset with a loss of diurnal processes. Despite
mostly cloudy skies overnight, weak cold air advection is expected
to aid in temperatures falling to the low-mid 40s for overnight lows.

The bulk of Wednesday is expected to be dry, although one last
disturbance pinwheels around the parent low. This is expected to
provide just enough support when combined with renewed diurnal
components to produce a few isolated showers across the area. Any
precip should  be far from widespread with the majority of northern
Michigan remaining dry, thus only supporting low end/slight chance
PoPs. High temps several degrees below normal...ranging from the
mid-upper 50s north of the bridge to the low-mid 60s south.

High pressure begins to expand from the west Wednesday evening
bringing any lingering shower threat to an end. Little of concern on
Thursday, except for another slight chance of showers across eastern
Upper, with the rest of the area expected to feature partly to
mostly sunny skies and high temperatures climbing back to near-
normal.

.LONG TERM...(Thursday night through Monday)
Issued at 354 PM EDT Mon May 29 2017

Long range models are varying greatly, lowering confidence through
this forecast period. The forecast period will begin with some
showers and possibly even a thunderstorm over northern lower
Thursday night through Friday afternoon with a weak area of low
pressure overhead along with an upper level wave and ample moisture.
Too many uncertainties past this point, but believe it`s safe to say
there will be periods of mostly cloudy to cloudy skies throughout
the period with best chances of rain being Sunday as models have
either a surface low over southern lower Michigan or troughs
associated with a low pressure system over the New England area
stretching over northern Michigan. Highs will generally be in the
mid to upper 60s, while lows will be in the mid to upper 40s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 201 PM EDT Mon May 29 2017

Scattered showers and thunderstorms are popping up across the
Upper Great Lakes region as several disturbances rotate around an
upper low centered north of Lake Superior. This activity will
continue through the afternoon, diminishing towards evening as
daytime heating wanes. Brief localized heavy rain, MVFR
visibilities, and possibly some gusty winds may occur with the
stronger cells. Otherwise VFR conditions expected for the rest of
today with gusty SW winds (up to 25 knots) diminishing this
evening.

There are some models hinting at possible MVFR ceilings
developing late tonight as the upper low wobbles east and pulls
the more extensive cloud cover currently over WI/MN into northern
Michigan. This would affect mainly PLN, APN, and possibly TVC
which will be nearer to the low. Clouds expected to be more
widespread on Tuesday with another chance for scattered showers
(no thunderstorms expected) and breezy SW winds developing midday.


&&

.MARINE...
Issued at 424 PM EDT Mon May 29 2017

Today`s gusty winds are expected to diminish this evening over
the nearshore waters, so have trimmed back the SCA expiration for
Lakes Michigan and Huron to 8 PM this evening.

Low pressure just north of Lake Superior will continue to result
in gusty winds at times through Tuesday, mainly during the
daytime hours. Gusts may marginally reach small craft advisory
criteria on Lake Michigan Tuesday afternoon. Showers and storms
late this afternoon will diminish through evening. Scattered
showers are possible again on Tuesday.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY until 8 PM EDT this evening for LHZ348-349.
LM...SMALL CRAFT ADVISORY until 8 PM EDT this evening for LMZ323-342-
     344>346.
LS...NONE.
&&

$$

NEAR TERM...MEK
SHORT TERM...MJG
LONG TERM...TJL
AVIATION...MEK
MARINE...MEK