Area Forecast Discussion
Issued by NWS Gaylord, MI

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FXUS63 KAPX 260338

Area Forecast Discussion
National Weather Service Gaylord MI
1138 PM EDT Tue Oct 25 2016

Issued at 946 PM EDT Tue Oct 25 2016

Pretty quiet out there tonight with an axis of sfc high pressure
bisecting nrn Michigan. A weak northerly flow was going light
and lake clouds have kinda of dissipated or lingered out over mid
lake. Still a bit of stronger low level wind over Lake Huron where
more bona fide lake induced clouds were. As the sfc high works
east, winds will turn easterly and likely bring these clouds back
in across NE lower. This was in the ongoing forecast already.
Otherwise, high level cirrus was making it`s way toward nrn
Michigan, from an upstream wave and low pressure in the central
plains. No significant changes to the forecast for the overnight.


.SHORT TERM...(This evening and overnight)
Issued at 313 PM EDT Tue Oct 25 2016

Strong surface ridge axis remains over Michigan this afternoon. A
few light lake effect rain showers continue to hold on across some
locations in NW Lower Michigan despite strengthening subsidence...
dry air and lowering inversion heights. Over-lake instability seems
to still be winning out over an increasingly more hostile synoptic
environment...but this is and will continue to give way to high
pressure as well as loss of diurnal heating/instability as we head
toward evening. Most locations warmed into the 40s today...even a
few lower 50s along the Lake Michigan shoreline. Clearing skies
tonight will lend to a descent diurnal temp drop...with most
locations falling into the upper 20s and lower 30s tonight.

Attention now turns to the developing storm system to the lee of the
Rockies. Mid/high clouds will begin to increase from SW to NE late
tonight in advance of this system. Light/calm winds during the
evening hours will increase just a bit overnight as well in response
to some tightening of the low level pressure gradient. Expect temps
will begin to slowly warm before sunrise as a result. Still expect
temps should warm to above freezing before deep moisture arrives and
any precip develops. No doubt...widespread precip will develop on
Wednesday from SW to NE across our entire CWA as deep moisture
surges northward ahead of the low. Again...expect precip should be
all liquid on least until very late afternoon/early
evening when some colder air begins to wrap around the northern
periphery of the surface low tracking south of our CWA. Diurnal
heating will also begin to wane by this time. NAM BUFR soundings
still show precip becoming mixed with snow by around 22Z or so. High
temps Wednesday afternoon will only warm into the low to mid 40s
thanks to thick cloud cover...precip and some low level CAA
beginning late in the day.

.LONG TERM...(Wednesday through Tuesday)
Issued at 313 PM EDT Tue Oct 25 2016

Wednesday night through Friday

High impact weather...Snow Wednesday night in higher elevations.

Jet currently punching into the PAC NW helps spin up fairly vigorous
surface low that reaches MI Wednesday. Low track takes it across IA
and then along the MI/IN border Wednesday night and then into Lake
ON Thursday. 40-50kt 850mb jet just ahead of the low will advect
moisture/warm air north over boundary in southern part of the state.

Low tracks south of the area but strong warm advection/isentropic
lift early Thursday morning with 40-50kt 850mb jet moving in ahead
of the surface low. We are far enough north to be in the colder air
for a mix or change to snow in higher elevations Wednesday night.
Warm advection strong enough to change everyone back over to rain
maybe as early as before daybreak Thursday.

Deeper moisture to the south so QPF will be on the light side but
isentropic lift quite strong. PWAT values generally 0.5 north to
0.75 south. Storm total QPF values should range from around 0.10
north to 0.60 south between 18z Wednesday and 00z Friday.

Temperature profile shows cold enough air for snow just above the
ground. 850mb temps in the 0 to -4C range Wednesday night. Problem
is depth of above freezing air near the surface. Right now it looks
like the chance of precipitation mixing with or changing to snow
will have to be in the higher elevations inland and the UP overnight
Wednesday night. Strong lift in advance of the 850mb jet will help
the changeover to snow between midnight and daybreak with maybe some
bursts of low visibility large-flake snowfall.


Pattern looks to remain active through the extended period. Rain
chances will carry through the weekend as a pair of occluding, weak
lows move through the region. A more robust system will be in the
area early next week, but confidence is quite low as to where it
will pass. The current storm track varies from well north of us to
tracking through the U.P., with the more southern track bringing
some decent rainfall. Temperatures will be above normal through the
period, and any precipitation will be of the liquid variety.



.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1138 PM EDT Tue Oct 25 2016

Winds have gone calm or turned light out of the east behind
departing high pressure. As a result, and in part by continued
overlake instability, low end VFR lake clouds were already coming
back toward NE lower off Lake Huron. APN can expect these clouds
later tonight and into Wednesday. Low confidence that CIGS could
be MVFR. Otherwise, skies will increase in clouds in the high
levels ahead of advancing low pressure. This low pressure will
bring lowering cloud heights and rains through the day and
Wednesday evening. There is even an outside shot at some snow
mixing in.

Winds increase substantially above the sfc Wednesday evening,
which will bring some low end LLWS.


Issued at 313 PM EDT Tue Oct 25 2016

Winds and waves will remain below SCA criteria thru tonight and into
early Wednesday as the surface ridge axis overhead slowly begins to
give way to an approaching low pressure system. Low level pressure
gradient will begin to tighten by mid Wednesday morning...which will
likely boost winds and waves into SCA criteria across most of Lake
Michigan for the rest of Wednesday and likely into Wednesday night
as well. Widespread rain showers will develop from SW to NE across
Northern Michigan on Wednesday as deep moisture surges northward
ahead of this system. Precip will become mixed with snow across
Eastern Upper Michigan and within the higher elevations of Northern
Lower Michigan by Wednesday night.


LH...SMALL CRAFT ADVISORY from 8 AM Wednesday to 8 AM EDT Thursday
     for LHZ345>349.

LM...SMALL CRAFT ADVISORY from 8 AM Wednesday to 8 AM EDT Thursday
     for LMZ323-341-342-344>346.

LS...SMALL CRAFT ADVISORY from 8 AM Wednesday to 8 AM EDT Thursday
     for LSZ321-322.



LONG TERM...Farina/Mayhew
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