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000
FXUS63 KAPX 241047
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
647 AM EDT Sat Sep 24 2016

.SHORT TERM...(Today and tonight)
Issued at 250 AM EDT Sat Sep 24 2016

One amplified large scale pattern out there at this early hour, with
Mississippi River Valley/Canadian Prairie centered upper level ridge
bookended by just as impressive northeast Canada and Intermountain
West centered trough axes. Sprawling surface high centered where it
should be in such a pattern, stretching out across Ontario into the
Great Lakes on downstream side of the upper level ridge axis. Above
combination resulting in deep layer subsidence across our area, with
just some passing thin high clouds and a few Lake Huron induced
strato-cu. A seasonably chilly night, with much of the area already
dropping down into the 40s.

While amplified, pattern actually remains somewhat progressive,
forcing that upper level ridge to build directly overhead by early
Sunday morning. Center of surface high also pivots off to the east,
although due to its size, will continue to influence our weather
right into Sunday morning. Add it all up, and the stage is set for a
rather pleasant northern Michigan fall weekend. Get out and enjoy it!

Really, just not a whole lot to talk about today and tonight as deep
layer high pressure dominates. Still looking at some passing high
and mid clouds today, especially for southwest areas. May also see
some lingering Lake Huron clouds for a few hours this morning across
northeast Lower, as well as the development of afternoon shallow cu
across the area. While low level thermal advection is nearly
neutral, that sun will help temperatures push well up into the
60s...a few degrees above specific normal values for today`s date. A
few mid and high clouds tonight, but still looking at generally
partly cloudy to mostly clear skies. Temperatures have a window to
tank rather quickly this evening, before perhaps stabilizing some
during the early morning hours. Don`t think conditions get too
chilly, but would expect to see some areas down near 40 in the
traditional colder location in the Au Sable River valley.

.LONG TERM...(Sunday through Friday)
Issued at 250 AM EDT Sat Sep 24 2016

High Impact Weather: Waterspouts Monday? and then Tuesday into
Wednesday?

(9/25)Sunday...During the day, the 500 mb ridge axis moves through
the forecast area, and is east of the region by 00z. At the same
time, the sfc high moves into New England, pulling the dry air with
it. In the meantime, the cold front, by 00z, runs from roughly the
Keweenaw Peninsula through eastern Wisconsin and NE Illinois. All of
the models have very similar timing as the qpf looks to barely get
to E Upper and the shore of NW Lower. Have slowed the timing down to
this idea for the day. In the evening, the rain begins to spread
across the region with the models in pretty good agreement in the
timing and the amounts. Models keep the heaviest rain north of M-32
closer to the sfc low which by 06z will be in N Ontario. Was going
to show some differences in the ECMWF and GFS, however with the
latest ECMWF (00z run) having come in while typing this, it too, now
cuts off the 500 mb lower over the Upper Great Lakes by 12z

(9/26)Monday...Models are slow to push this cut off out of the Great
Lakes, with it still over the region by 06z at night. The 850 mb
temperatures fall to around +1C in NW Lower by that time, and with
the water temperatures around 21C, will expect good instability over
the water. With the winds in the mixed column between 30 and 35
knots, it looks like waterspouts could be an issue over N Lake
Michigan, and maybe Lake Superior during the day. At night the 850
mb winds are expected to increase to better than 40 knots, so the
likelihood of the waterspouts will begin to trail off.

Extended (Tuesday through Friday)...with the addition of the 500 mb
cut off low over the Upper Great Lakes to start the extended period,
this delays the expected warm up until after the low moves off the
east coast Wednesday night into Thursday (GFS). Although the new
ECMWF run, continues the cut off low into Friday, and pushes it
south into the Southern Appalachians. This would leave us at or
below normal, looking at the 850 mb temperatures (around 6C on the
ECMWF). So have little confidence even in the trends portion of this
forecast as the ECMWF has gone completely into another direction
with this solution.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 645 AM EDT Sat Sep 24 2016

VFR conditions through this taf period, with just passing high
based clouds and no vis restrictions. Light east winds today,
becoming calm tonight.

&&

.MARINE...
Issued at 250 AM EDT Sat Sep 24 2016

No headlines anticipated through Sunday. High pressure will continue
to bring dry weather to the Great Lakes into Sunday. East to
southeast winds, at times a bit gusty, will continue today and
tonight, with winds taking on a decidedly more southeast direction
Sunday as center of high pressure pushes further east. Some threat
for SCA conditions heading into Sunday night as southeast to south
flow continues to strengthen within tightening pressure gradient
regime ahead of approaching cold front. This front will bring a good
chance for more rain later Sunday, and especially Sunday night into
Monday. Gusty west winds are expected to develop behind this front
for later Monday into Tuesday.


&&

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

$$

SHORT TERM...MSB
LONG TERM...JSL
AVIATION...MSB
MARINE...MSB