Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 301124

Area Forecast Discussion
National Weather Service Gaylord MI
724 AM EDT MON MAY 30 2016

.SHORT TERM...(Today and tonight)
Issued at 413 AM EDT Mon May 30 2016

...Drier and cooler today/tonight...

High impact weather potential: None.

Broad troughing remains across the Great Lakes this morning with
a couple short waves rolling through the region. One wave moving
out of eastern upper Michigan, a second piece moving through
southern lower Michigan and third pushing through eastern
Wisconsin. Just enough to keep sct-bkn mid clouds and some very
spotty showers going through the overnight hours. Some lower
clouds (sub 2K feet) have developed and are sliding through
eastern upper MI and skirting the tip of the mitt.

At the surface, low pressure is migrating up through the southern
James Bay region with an ill-defined cold front stretching down
through the eastern lakes and into the Ohio Valley. Not a huge
airmass change, but enough to suppress some of the warmer temps
and higher dewpoint air to our south/east.

Today: Trailing short wave will exit the region by midday followed
by surface high pressure building into the northern lakes, and
further boundary layer drying continuing as we go through the
day. Cannot fully rule out the possibility of spotty showers
slipping through the CWA this morning as the trailing wave moves
through. But the chances are looking low at this point and I plan
on having a dry forecast to start the day (unless something
changes by 6 am).

For the afternoon, E/SE counties and down into southern lower MI
will hang on to some warmer temperatures/higher dewpoint air for
a time. Unmodified forecast soundings generate a few hundred J/KG
MLCAPE and at least suggest the notion of a few showers popping in
those areas before better mixing/drying takes hold. But in typical
fashion, model boundary layer moisture/resulting instability is
probably overdone. We will likely see some diurnal cu development
particularly across those E/SE areas but I won`t put any explicit
showers in the forecast at this point.

Tonight: Anticipate a mainly clear and quiet evening. Another
short wave along the Manitoba/Ontario border this morning is
forecast to dip through the far northern Great Lakes overnight
pushing another weak/ill-defined front into northern Michigan. No
precip expected although there will be some increase in cloud
cover across the northern areas. Otherwise, a cooler night is on
tap with lows dipping into the middle 40s to lower 50s.

.LONG TERM...(Tuesday through Sunday)
Issued at 413 AM EDT Mon May 30 2016

...More wet weather likely for the midweek period...

High Impact Weather Potential: Thunderstorms possible Wednesday...
severe risk at this point appears minimal though within SPC Day 3
Marginal risk.

Pattern Synopsis/Forecast: Large scale pattern still exhibiting a
bit of a split with a more-or-less zonal pattern in the northern
branch of this split...with one short wave trough moving through the
Great Lakes and another over the Pacific northwest/British Columbia.
Southern branch flow is weaker with a short wave trough over
southern California and some weakness in the height pattern over
Florida and the Caribbean which spawned former Tropical Cyclone
"Bonnie".  Surface low pressure was located near the southern tip of
James Bay with a cold front extending south across the lower Great
Lakes.  A new front was developing to the west of this low into the
southern Prairie provinces.  West-east moisture gradient extends
from the Great Lakes back across the upper midwest and into the
Dakotas with drier air upstream.

Short wave trough over the Pacific northwest will be on the move
early this week...into the northern Plains by Tuesday but will inch
its way into the upper Midwest and eventually into the upper Great
Lakes in the Thursday time frame.  Developing cold front across
southern Canada will sink south into the upper Lakes Tuesday and
probably get hung up across northern Michigan/Wisconsin.  Slowly
approaching height falls will push an associated cold front into
Wisconsin/Upper Michigan Wednesday...which should cross lower
Michigan Wednesday night/early Thursday.

Primary Forecast Concerns: Evolution of rain chances will
approaching short wave trough/cold front for midweek.

Tuesday...Tuesday dawns with the cold front dropping in from the
north draped across the Straits region...and a short wave ridge axis
that will drift east across the forecast area as the day progresses.
Low level theta-e ridge axis across the midwest will likely help
drive an area of showers/thunderstorms across parts of Minnesota/
Wisconsin and into upper Michigan Tuesday morning.  Think the
probability of any of this activity getting into eastern Upper is
pretty small...though debris clouds will likely spread into northern
portions of the forecast area.  Precipitation focus should remain
upstream across Wisconsin/western Upper into Tuesday afternoon...
aside from the GFS attempting at bringing lower-mid 60s dew points
into northern Lower during the afternoon and generating some
convection (which seems unrealistic especially given the trouble the
"new" GFS has been having with boundary layer moisture).  Will carry
a north-south cloud cover gradient for Tuesday (more clouds
north/more sun south) and play on the assumption that there won`t be
enough instability around for stalling boundary to tap into.  Highs
for Tuesday afternoon expected to be around 70 across eastern Upper
(though will be conditional on cloud cover) and more widespread
70s/around 80 for northern Lower.  Main precipitation focus Tuesday
night still looks to be west of Lake Michigan along a low level
theta-e axis and south-southwest low level jet across Wisconsin/
Upper Michigan.  But a little too close to not carry at least chance
PoPs across eastern Upper and perhaps into northwest Lower Michigan.

Wednesday...A slow eastward progression of the cold front moving
into the upper Lakes and its parent upper level disturbance should
eventually push better precipitation chances into lower Michigan.
There will likely be a band of showers/thunderstorms along/ahead of
the cold front within an axis of increasing deep layer moisture
(precipitable water values approaching 1.50 inches)...with the
possibility of additional development ahead of the front where some
destabilization may take place.  Marginal severe risk depicted
across northern Michigan in the Day 3 SPC outlook...and does indeed
look pretty marginal as overall instability looks pretty thin.
Frontal precipitation band expected to cross northern Michigan
Wednesday night...could be a decent little rain producer with
greater than one-half inch rainfall amounts in spots.

Extended Forecast (Thursday through Sunday)...Short wave trough will
be moving through Michigan Thursday...and may still be hanging in
the vicinity on Friday.  Upper level ridging is forecast to build by
the weekend across the western half of North America...which in turn
will lead to lower heights over the Great Lakes though the details
are uncertain this far out.

Thursday looks mainly dry provided cold front timing is correct...
though some diurnally driven showers possible across Upper Michigan
in proximity to an upper level cold pool.  Next chance of more
widespread rain may come during the latter half of the weekend
though as mentioned above there is plenty of uncertainty in that
time frame.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 724 AM EDT Mon May 30 2016

High pressure and less humid air will build into the region
today providing solid VFR conditions at the terminal sites. Some
heating induced clouds are expected for the afternoon particularly
across NE lower michigan (APN terminal site). Becoming clear this
evening, although some cloud cover will begin to spread back into
the region toward Tuesday morning.

Westerly winds today with some gusts near 20 knots. Winds become
calm tonight.


Issued at 413 AM EDT Mon May 30 2016

Westerly winds will be the rule today with some afternoon gusts
into the teens to near 20 knots. But conditions should remain just
under small craft advisory headlines today. Light winds/waves
tonight into Tuesday. But southerly winds increase Tuesday night
ahead of another area of low pressure that will move through the
Great Lakes midweek. Small craft advisory headlines may ultimately be
needed Tuesday night or for Wednesday.


.APX Watches/Warnings/Advisories...


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