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000
FXUS63 KAPX 142353
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
753 PM EDT Fri Jul 14 2017

.NEAR TERM...(Tonight through Saturday)
Issued at 253 PM EDT Fri Jul 14 2017

...Much warmer Saturday with some late day thunderstorm concerns...

High impact weather potential...Parts of the area remain under a
marginal risk for severe thunderstorms Saturday afternoon and
evening.

Pattern synopsis/forecast...Unseasonably cool northwest flow
continues across the northern Great Lakes (talk about stating the
obvious...huh) as mid level trough axis responsible for such slowly
departs. Aggressive drying on the backside of this departing trough,
evident by decreasing drizzle/light shower activity and clearing
skies spreading in from the north. Low level environment will
continue to go through aggressive drying tonight as surface high
pressure builds into the region. Despite these changes, deep layer
northwest flow will continue as large scale troughing dominates.
Next shortwave trough, just now rounding top of Intermountain West
ridge over southern Saskatchewan, will race southeast within this
flow regime, bringing our next shower threat as early as later in
the day Saturday.

Primary forecast concerns/challenges...Just how fast to clear skies
this evening and addressing that late day shower/thunderstorm threat
on Saturday.

Details...Simple satellite trends suggest any lingering
drizzle/light shower threat will end quickly heading toward evening.
Skies will also clear, with all areas becoming mostly clear during
the overnight. Will need to watch for the development of some
fog/low stratus toward morning over the higher terrain areas, but
amount of down low drying does suggest otherwise.

A mostly sunny start to the weekend gives way to increasing clouds
from the north later on Saturday as that next wave and attendant
cold front begins to approach from Canada. Pre-frontal southwest
winds and sunshine will sure do a number on temperatures, with
readings on Saturday likely to make a run into the lower 80s across
northeast lower Michigan, and just a few degrees cooler elsewhere.
Moisture return is brief and minimal at best, with the "best"
focused across northwest lower and points southwest by evening. Just
enough forcing/moisture to kick off some scattered convection late.
Best instability stays back across Wisconsin and this is likely
where better shower/storm coverage will reside. Still expect some
scattered activity to impact eastern upper and northwest lower
Michigan by evening. Latest SPC Day 2 Convective Outlook has scaled
back the severe risk, removing slight risk wording completely,
placing just portions of north central and northwest lower Michigan
under a marginal risk. This makes sense given best severe weather
ingredients remain to our west, with mean layer cape profiles
dropping off quickly into northwest lower Michigan. Just enough
cape/effective bulk shear (approaching 35 knots)/downdraft cape to
warrant marginal wording, but feel any such activity will be widely
scattered at best (if it occurs at all).

&&

.SHORT TERM...(Saturday night through Monday)
Issued at 253 PM EDT Fri Jul 14 2017

Perhaps a shower or thunderstorm (slight chance) Saturday evening as
a surface cold front moves across the region. Overall, not a lot of
moisture or instability to produce much activity so chances are on
the low side. Breezy and cooler conditions Sunday as high pressure
begins to build in from the west. In addition, model soundings and
cross sections show abundant moisture trapped below a subsidence
inversion. So expect low clouds and possible drizzle to be slow to
exit during the day. Becoming clear and chilly Sunday night with
sunny and comfortable conditions expected on Monday as high pressure
is in control. Lows Saturday night in the mild middle 50s to lower
60s. Cooler Sunday with highs in the middle 60s to around 70. Chilly
Sunday night with lows in the middle 40s to lower 50s. Highs Monday
in the middle 70s to near 80.

.LONG TERM...(Monday night through Friday)
Issued at 253 PM EDT Fri Jul 14 2017

...Scattered thunderstorms midweek...

High impact weather potential...Cold front moving through descent
instability late Tuesday/early Wednesday.

Upper ridge axis moves through the region late Tuesday. Upper flow
then flattens across the northern states as the high drifts into the
southern parts of the country. At the surface, high pressure
dominates through midweek. Models bring cold front into the region
Tuesday night into Wednesday time frame. Front then slows as it
encounters upper ridge. Waves of energy moving along the front
across Michigan.

The ridge and surface high will push temperatures to near or above
normals Tuesday. Moisture and instability increases Tuesday ahead of
the cold front with an open Gulf. Expect thunderstorms to develop
ahead of the cold front Tuesday night and Wednesday. Rest of the
week becomes a bit more nebulous. Waves moving along the slowing
front could bring us the chance of more precipitation depending on
where the frontal boundary sets up. Right now it looks like better
chances across southern Michigan late Wednesday and Thursday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 753 PM EDT Fri Jul 14 2017

Dry air is finally making inroads into northern lower Michigan
early this evening...eroding our pesky stratus. TVC/MBL/PLN have
returned to VFR conditions. APN also...although satellite imagery
and nearby OBS suggest brief MVFR cigs remain a possibility there
through early evening.

VFR conditions will largely prevail tonight and through the
Saturday. Some VSBY reductions with fog/mist are possible later
tonight at the more fog prone locations (PLN/MBL)...but widespread
fog is not anticipated.

Lighter winds to start the day Saturday. Winds turn SW and
increase for the afternoon with some gusts into the 20 knot range.

&&

.MARINE...
Issued at 253 PM EDT Fri Jul 14 2017

Light winds tonight becoming increasingly gusty out of the
southwest on Saturday as another cold front approaches the northern
Lakes. Small craft advisories may be required Saturday, especially
across portions of northern Lake Michigan. Winds turn north behind
the front Saturday night and Sunday, staying a bit gusty in the
process. Will need to watch for a few thunderstorms later Saturday
afternoon into Saturday evening, any of which could produce brief
gusty winds and enhanced wave action. Greatest threat for this to
occur will once again be on Lake Michigan.


&&

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

$$

NEAR TERM...MB
SHORT TERM...AS
LONG TERM...KF
AVIATION...BA
MARINE...MB