Area Forecast Discussion
Issued by NWS Gaylord, MI

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838
FXUS63 KAPX 291045
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
645 AM EDT SUN MAY 29 2016

.SHORT TERM...(Today and tonight)
Issued at 401 AM EDT Sun May 29 2016

Overview: Progressive short wave trough axis is swinging through
the upper Midwest and into the far western Great Lakes region
this morning. Broader area of surface low pressure is across the
upper Midwest with some semblance of pre-frontal troughing working
into lower Michigan. Main cold front resides from western
Wisconsin down through Iowa. Deep S/SW flow ahead of this system
has maintained a fairly moist boundary layer across the Great
Lakes with sfc dewpoints currently holding in the 59 to 65 degF
range, and we still have a fair amount of MLCAPE out there this
hour (several hundred J/KG across NE lower MI per SPC meso
analysis page) although a good amount of CINH as well given the
time of day.

Meanwhile, sharply defined dry slot has punched up into the western
Great Lakes ahead of the parent upper low. Combined with daytime
heating on Saturday, helped to spur on the earlier line of convection
from Wisconsin into Illinois. That activity died quickly upon reaching
Lake Michigan. But there is yet another thin line of showers that
has spread up from SE lower Michigan through Saginaw Bay area and
up along the Lake Huron coast into NE lower MI apparently along
that axis of modest instability nosing up through the area.

Today: Convective development late morning through the afternoon
is of course the main forecast issue. But first off, will have to
account for remnant showers rolling up along the Lake Huron
coastline. Not a big deal, but will has some low end chance pops
through early morning.

Then, upper level short wave trough still expected to swing
through the region late this morning through the afternoon, with
the strongest upper level height falls taking shape across Upper
Michigan/Lake Superior. Attending surface low advances across Lake
Superior and into Ontario by evening with the surface cold front
slipping through the region this afternoon. We should have a
decent amount of instability to work with this afternoon
especially across NE lower MI where warmest temps (back into the
lower 80s) and highest dewpoints will be found, with forecast
soundings suggesting 1000-1500 MLCAPE across NE lower michigan
assuming we can keep those dewpoints up around 60F. But, overall
QG-forcing for ascent is rather unimpressive this afternoon while low
level convergence with the front itself gets a bit muddied as
winds turn a bit more SW behind our pre-frontal trough. Still,
cannot rule out the chance for showers/thunder just about
anywhere in the CWA this afternoon. But I have focused the better
chances across NE lower Michigan and particularly along the Lake
Huron coast where added low level convergence off the lake will
be had.

Severe weather threat: I`m not wowed. But the combination of
decent instability, some modest 0-6 KM bulk shear values pushing
40 knots and freezing levels largely under 11K feet does support a
marginal severe storm threat across NE lower MI as depicted by
Day 1 SPC outlook.

Tonight: Upper trough and attending surface low continues into
Ontario. Wrap around/deformation forcing/precip (currently across
northern Minnesota) will be sliding through Upper Michigan and
parts of far northern lower Michigan through the evening. Thus
will maintain chancy pops for showers across those areas before
ending precip overnight.

.LONG TERM...(Monday through Saturday)
Issued at 401 AM EDT Sun May 29 2016

...Dry early part of the week then turning wetter for midweek...

High Impact Weather Potential: Minimal through Wednesday.

Pattern Synopsis/Forecast: Split pattern continues across North
America...with an active southern branch with short wave troughing
over southern California and moving into the midwest...with tropical
cyclone "Bonnie" getting funneled toward South Carolina.  To the
north of the tropical storm is an upper level ridge extending
northwest from the Atlantic up across the Great Lakes and into
northern Canada.  Northern branch upper low spinning over British
Columbia...pinched between the aforementioned ridge axis and another
closed high over Alaska.  Short wave trough moving into the midwest
has an associated surface low over southern Minnesota...with a
trailing cold front back into the southern Plains.

Midwest short wave trough will track across the Great Lakes over the
next 24 hours...while trough over British Columbia will advance very
slowly east into the northern plains by midweek and eventually
reaching the upper Lakes in the Thursday time frame.  A cold front
will be draped across Lake Superior and adjacent portions of Ontario
Monday...and will likely sag into Michigan Monday night into Tuesday
as a short wave trough ripples by the forecast area to the north.

Primary Forecast Concerns: Increasing rain chances toward midweek.

Monday...A drop in boundary layer humidity is expected for Memorial
Day Monday with dew points expected to fall into the 50s. Should be
a decent bit of sunshine with highs expected to range from the upper
60s over parts of eastern upper to the lower 80s over northeast
Lower. Height falls passing by to the north of the forecast area
will push a cold front south and into northern Michigan Monday night
into early Tuesday.  Not expecting much with this feature
initially...with generally clear to partly cloudy skies expected
Monday night and lows ranging from the mid 40s to lower 50s.

Tuesday...Short wave trough will move into the northern/central
plains states Tuesday...with some short wave ridging out ahead of
this feature.  Cold front will likely lie across lower Michigan
though instability looks pretty thin and think we can squeeze out
another dry day and will maintain that forecast trend.  A little
uncertain as to how quickly rain chances will increase across
northern Michigan as upstream short wave trough will make only slow
progress toward the upper Midwest/upper Great Lakes.  Will bring
chance PoPs into much of the area Tuesday night for the time being.

Extended Forecast (Wednesday through Saturday)...Upstream short wave
trough will still be...well...upstream of Michigan Wednesday though
associated cold front will probably be inching into the forecast
area Wednesday night.  So will continue with shower/thunderstorm
chances for Wednesday and will probably be a warm and sticky day.
Will keep precipitation chances in for Thursday given uncertainty
regarding frontal timing across lower Michigan (it is possible that
Thursday could end up being dry).  Will dry things out for
Friday/Saturday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 645 AM EDT Sun May 29 2016

Low pressure over the western U.P. will advance into Ontario by
this evening, dragging a cold front through northern lower
Michigan. Warm and a somewhat unstable airmass ahead of the front
will lead to the threat of showers and some thunderstorms for
northern lower Michigan today, mainly this afternoon and with the
best chances impacting the APN terminal site. Otherwise, overall
VFR conditions will persist through the day, except where
showers/storms roll through any particular location.

Tonight, high pressure and drier air will begin to build into the
region. But some lingering showers will impact PLN this evening
and there may be a period of MVFR cigs there.

Winds will becoming gusty from the SW today, veering westward
tonight and diminishing.

&&

.MARINE...
Issued at 401 AM EDT Sun May 29 2016

Some gustier SW winds will be found across the region today
particularly from Manistee up through Sleeping Bear Point. May
need to hoist another SCA for that area today. Otherwise, winds
and waves should largely remain under headline criteria. Winds
turn a bit more westerly tonight through Monday and again with
perhaps some gustiness. But no headlines are anticipated at this
time.


&&

.APX Watches/Warnings/Advisories...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...Adam
LONG TERM...JPB
AVIATION...Adam
MARINE...Adam



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