Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 261844
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
244 PM EDT THU MAY 26 2016

.SHORT TERM...(This evening and overnight)
Issued at 244 PM EDT Thu May 26 2016

Morning low clouds have mixed into a sct/bkn CU deck across our CWA
this afternoon...with some additional cirrus still drifting
overhead. Instability is still in the process of recovering in
response to diurnal heating aided by the development of significant
breaks in the low clouds. Latest NAM12 boosts MUCAPES to near 3000
J/kg later this afternoon...while the RAP13 comes in with a slightly
more modest 2000 J/kg. Both quickly diminish instability with sunset
as would be expected with mainly diurnally-driven convective
situation. Both directional and speed shear strengthen during this
time as well along the warm front...which will certainly aid in the
organization of any convection that does develop. Speed shear is a
bit stronger than direction...so at this point...expect the main
severe wx threat will be strong/damaging winds. In agreement with
latest day 1 SPC outlook...any severe threat should be marginal...
with the potential for isold winds gusts to 60 mph and hail around
an inch in diameter. With respect to POPs...Will certainly keep
chance pops in the forecast thru this evening...especially across
North Central and NE Lwr Michigan where highest instability will
likely develop.

Convection will steadily diminish in both areal coverage and
intensity with sunset and loss of diurnal instability. Cannot
completely rule out the slight chance of a shower or thunderstorm
during the remainder of the night...thus have kept a slight chance
in the overnight forecast. Expect areas of fog will again develop
within the soupy airmass...further reinforced by late
afternoon/evening precip. Should be a relatively mild night...with
overnight lows falling into the mid 50s across Ern Upr Michigan and
to a degree or two either side of 60 across Nrn Lwr Michigan.

.LONG TERM...(Friday through Thursday)
Issued at 244 PM EDT Thu May 26 2016

Friday through Sunday...The holiday weekend is shaping up to be very
summer-like, complete with warm and humid conditions and afternoon
and evening convection.

At upper levels...500mb ridge in place over the Great Lakes to end
the work week, will slowly strengthen through the first half of the
weekend as an upper trough organizes over the central Plains. This
trough will eventually lift into the Great Lakes Sunday. 850mb temps
in this pattern will be around 15c/16c Friday and Saturday, before
cooling to around 10c Sunday as the upper trough pushes east across
the state.

At the surface, a nearly stationary pattern to persist across the
eastern half of the country, with large area of high pressure
anchored over the Atlantic while a storm system organizes over the
Plains. The warm front that lifted north across the state Thursday
will remain well north of the Great Lakes through the weekend,
before the Plains storm system finally pushes across the state
on Sunday.

The overall airmass this weekend will be conducive to the typical
afternoon and evening summer-time showers and thunderstorms. Plenty
of moisture and instability will linger over northern Michigan
Friday through Sunday, with sfc dew pts in the 60s, 850mb dew pts
between 12c and 16c, 0-3km most unstable cape values each afternoon
around 2500 to 3500 j/kg and 850/500mb lapse rates around 7 c/km.
Forcing each day will be enhanced by old thunderstorm outflow
boundaries, along with afternoon lake breeze boundary as northern
Great Lakes water temps remain around 50 degrees and synoptic
southern winds remain below 10 mph. Currently, the best chances for
non-diurnal widespread pcpn this weekend will be Sunday, as
850/700mb qvectors show convergence increasing across the area in
advance of approaching sfc and upper lvl storm systems.

Extended (Sunday night through Thursday)...

A somewhat less active extended period is expected late in the
Memorial Day weekend into next week as energy from northwest Canada
spills into the northern Plains, aiding in rising heights and
associated surface high pressure across the Great Lakes region.
Details become a little more muddy toward the end of the extended
with several possible solutions in regards to a cold front progged
to slide across the Midwest/Great Lakes and resulting precip
potential and temperatures. While temps will generally be trending
cooler throughout the extended, a blended guidance approach suggests
highs back near normal (lower 70s) by the end of the extended, but

Gillen

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 117 PM EDT Thu May 26 2016

Scattered showers and thunderstorms will redevelop across Nrn Lwr
Michigan later this afternoon and this evening as CAPES increase
to near 2500 J/kg thanks to diurnal heating. Modest wind shear
thru the column could produce an isold strong/marginally svr
storm. The best chance of precip will be across North Central and
NE Lwr Michigan...including APN. Will handle with VCTS for a
portion of the afternoon and early evening. Will leave the rest of
our TAFs (PLN/TVC/MBL) dry for now and update if needed.
Southerly winds around 10 kts this afternoon will become
light/variable tonight and then shift to the SE on Friday.

&&

.MARINE...
Issued at 244 PM EDT Thu May 26 2016

Winds and waves will remain below SCA criteria thru Saturday thanks
to a relatively weak pressure gradient remaining overhead. The
chance of showers and storms will remain in the forecast thru the
weekend...especially during the afternoon and evening as convection
is enhanced by daytime heating/instability.

&&

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

$$

SHORT TERM...MLR
LONG TERM...SWR/Gillen
AVIATION...MLR
MARINE...MLR


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