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Area forecast discussion 
National Weather Service Gaylord Michigan
405 PM EDT Sat Aug 23 2014

issued at 405 PM EDT Sat Aug 23 2014

High pressure to our east will provide for light southerly
breezes...and increasing warmth and humidity through Monday. For the
most part the weekend looks dry...but showers and thunderstorm
chances will increase on Monday...ahead of a weak cold front that
will enter northern Michigan Monday night.


Short term...(this evening through tonight)
issued at 405 PM EDT Sat Aug 23 2014

Sharp middle level ridge axis continues to poke up into the western
Great Lakes roughly from eastern Wisconsin up through central
Upper Michigan...downstream of strong short wave troughing across
the northern rockies into the northern plains. Broad low pressure across the
Central Plains with a surface warm front draped across Missouri into
the Ohio River valley. Elevated warm front and Theta-E plume
has spread northward across the Midwest into the lower Great
Lakes and continues to be the main weather focus with yet another
round of convection working across the Midwest this afternoon.

Across the northern Great Lakes...weak high pressure is draped across
northern Michigan. But...subtle low-middle level trough axis analyzed
across western/central Upper Michigan along NE fringe of deeper
moisture gradient...where RUC analysis continues to depict a
strong low-middle level deformation axis stretching from Northern Lake
Michigan up through central Upper Michigan. This has/is generating
a band of showers up through that area particularly around the
Escanaba area (terrain influenced) trying to bleed across Northern Lake
Michigan although precipitation appears to finally be winding down. Some
heating induced convection also ongoing in NE Wisconsin within the
better moisture field. Across northern lower Michigan...stubborn lake
stratus in eastern upper and NE lower Michigan has mostly mixed
out into a flat cumulus field. No signs of any precipitation. But solid lake
stratus remains locked across Western Lake Huron into The
Straits...signs of things to come I think. precipitation as main focus will remain west-through-south of
northern Michigan. Will enjoy a few hours of clear to partly cloudy skies
this evening as heating induce cumulus/stcu deck fades away. But with
persistent easterly flow just off the deck...veering southeast
overnight...suspect marine layer/lake stratus and fog out across
Lake Huron will once again get scooped into eastern Upper Michigan
and northeast lower Michigan during the overnight hours. Have
tailored the forecast that way along with patchy to areas of fog
overnight. A repeat on temperatures with a bit of a muggy night
(relatively speaking) and lows in the upper 50s to middle 60s.


Long term...(sunday through saturday)
issued at 405 PM EDT Sat Aug 23 2014

..warm start...Cooler finish to the upcoming week...

High impact weather potential: minimal. Some thunder potential at
times this week.

Pattern synopsis/anticipated evolution: amplified pattern Soo talked
about the last several days looks to reach maturation Sunday...when
most impressive ridge axis/heat dome of this Summer builds directly
overhead and up into southeast Canada. Western troughing
continues...with lead ejecting rather robust shortwave looking to
put a kibosh on further ridge amplification heading into the start of
next work week. Pattern there-on-after looks to become an
increasingly flatter one as strongest cores of upper level jet energy
slice west/east across southern Canada. A changeable pattern for
sure...and one that simple forces another extended stretch of low
confidence shower and storm forecast evolution.

Primary forecast concerns/challenges: just how warm to go
Sunday/Monday and addressing what initially looks to be multi-period
shower and thunderstorm chances right through the week.

Details: take today's weather...tack on a few degrees...sundays
weather done! More significant changes take place Monday as ridge
apex pushes east and earlier mentioned shortwave punches up into south
central Canada. Southwest flow ramps up in response...driving a good
chunk of current Southern Plains heat dome along with it. 800 mb temperatures
make a run into the upper teens...readings not yet seen around these
parts this Summer. Increasing pressure gradient on front side of
approaching/albeit steadily decaying/cold front should only help the
surface warming cause. Temperatures well into the 80s a sure bet for
areas south of the big bridge...and not out of the realm of
possibility a few favored downslope areas of northeast lower make a
run a 90. Now...that same front may bring a shower and storm threat
along with it. Definitely not entirely sold on this idea given far
removed middle level support and quickly decaying forced surface
convergence. Atmosphere also has the look of being rather
caped...with noted 800 mb warm nose. While overall airmass becomes
increasingly moist...set-up screams of decent low level mixing out
of moisture...and starting to wonder if prognosticated upper 60 dewpoints
are several degrees too high. No doubt above leaves plenty of
opportunity for a dry late Monday frontal passage. Inherited low
chances will do for now...but truly believe many will see
little...if any...rain.

Said front looks to significantly slow its south progress Monday
night through Tuesday night as it becomes increasingly aligned with
deep layer westerly flow. Just where it stalls out is open to plenty
of debate...but given breadth of prefrontal warming and total
detachment of any middle level support...kinda feel it may struggle to
clear our southern counties until sometime Tuesday night. Now...that
leads to a tricky temperature and shower forecast right through middle
week. As for temperatures...Tuesday has the potential to be
downright warm...especially for areas near Saginaw Bay...where
temperatures may once again reach into the middle and upper 80s. Cooler
air arrives Wednesday...with highs mostly in the 70s (all dependent
on that whole frontal timing thing of course). Nearly all guidance
remains steadfast on additional shower/storm development along and
north of the surface front as weak middle level impulses ride along it
Monday night right into Wednesday. Any decent support is far from
certain...and just not buying this wet look in guidance. Much like
Monday...lower probability of precipitation the way to go for now...with plenty of time to
work on better temporal and spatial resolution of shower/storm
chances in the coming days.

Some hints what is left of western troughing gets shunted east late
in the week...forcing front back north and drumming up additional
rain chances to start next weekend. Timing will change...and a
simple consensus blend approach will be utilized for now....which
indeed holds off next mention for showers/storms until Friday night
and Saturday.


Aviation...(for the 18z tafs through 18z Sunday afternoon)
issued at 132 PM EDT Sat Aug 23 2014

Stubborn stratus deck flowing off Lake Huron on easterly winds
continues to bring MVFR flight conditions to pln/apn...although
stratus deck has/is slowly eroding. Clouds should scatter out by
middle to late afternoon at those sites leaving a period of VFR
conditions heading into the evening. VFR conditions at tvc and mbl
will persist.

Tonight...fear cycle will repeat as marine stratus once again
redevelops off the lake into NE lower Michigan...later this
evening and for the overnight hours within persistent east/southeast flow.
Thus...have IFR ceilings and low visibilities once again taking off at
apn/pln through the course of the night while tvc/mbl remain
largely VFR with some minor reductions to visibility due to light fog.

Winds...light easterly today...calm tonight and light southeast on


issued at 405 PM EDT Sat Aug 23 2014

Abundant marine stratus and fog will continue to impact the nearshore
areas of Northern Lake Huron into the Saint Marys River system...tonight
into Sunday before stronger southerly winds develop later Sunday
into Monday and finally scours out the stratus/fog.

Otherwise...light easterly winds tonight will veer more southeasterly
then south on Sunday...increasing Sunday night into Monday. May
develop enough gustiness to warrant small craft advisories for
parts of Northern Lake Michigan by Monday morning...although lake
stability may keep winds/waves in check.


Apx watches/warnings/advisories...


short term...Adam
long term...msb

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