000
FXUS63 KAPX 150326
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1126 PM EDT Thu Sep 14 2017

.UPDATE...
Issued at 959 PM EDT Thu Sep 14 2017

Evening surface analysis reveals elongated high pressure across
the eastern third of the CONUS edging back into the western Great
Lakes. Low pressure is over the central plains with an inverted
trough/stationary front stretching northeastward up into the far
western Great Lakes. Lots of convection/lightning along the front
from northern Minnesota and just into western lake Superior that
should largely remain just north of the U.P. overnight into
Friday...although midnight crew will need to keep an eye on that.

Otherwise...another night of largely cosmetic changes to the
forecast. Shallow fog has already developed in some areas with
temperatures very quickly dropping in the last few hours. Looking
like a bit of a repeat of last night with fog potentially
lingering through mid morning Friday. That said...we will start to
see a subtle increase in southerly flow late overnight into Friday
which could thin out fog just a bit faster.

&&

.NEAR TERM...(Tonight through Friday)
Issued at 328 PM EDT Thu Sep 14 2017

...Some fog tonight; quiet again on Friday...

High Impact Weather Potential...Minimal.

Pattern Synopsis/Forecast...Positively tilted upper ridge will
remain over northern Michigan as remnants of Irma lift into the
Northeast. Plenty of smoke aloft from Western wildfires will linger
into tonight with very weak flow throughout the atmospheric column.
Looking upstream, a surface low is slowly organizing over the
Northern Plains with an associated quasi-stationary front extending
northeast out over Lake Superior. Nearly zonal flow aloft over
southern Ontario is keeping convection triggered by weak passing
shortwaves well north of eastern Upper. Not much of a pattern change
expected through Friday, though 500mb heights over northern Michigan
will continue to rise as the heart of the ridge builds over the
region. Temperatures will dip into the 50s overnight and climb into
the mid/upper 70s (eastern Upper) to around 80 (northern Lower) on
Friday.

Primary Forecast Concerns...Areas of fog developing tonight.

Expect diurnal fair weather cu field over northern Lower to
diminish quickly this evening, while stratocu around Manistee will
linger a bit longer. Should be a favorable radiational cooling setup
again overnight with very light or calm winds. Any passing cirrus
should be thin enough to not have any impact on cooling overnight.
Thus, areas of fog are likely, but the main question revolves around
how widespread and thick it may become. Last night`s fog was dense
in spots, but with today`s mixing expect tonight`s low level
moisture to be a little less and shallower off the surface. Evening
shift will have to monitor latest trends on fog potential.

&&

.SHORT TERM...(Friday night through Sunday)
Issued at 328 PM EDT Thu Sep 14 2017

...Above Normal Temperatures Continue...

High Impact Weather Potential: None.

A deepening trough over the inter-mountain west will induce
increased upper ridging across the Great Lakes into Saturday.  A
cold front will slide into the Great Lakes on Sunday, increasing
chances of showers and a few storms.  Temperatures will remain well
above normal as an 850mb thermal ridge remains anchored over the
Great Lakes.

Details:  Saturday will be the warmest of the weekend days for most
areas as southerly flow increases, helping to push temperatures well
into the 80s in many parts of the area.  A cold front pushes into
the Great Lakes on Sunday, resulting in more clouds and scattered
afternoon showers/storms.  Rather narrow axis of deeper
moisture/forcing along and just in advance of the boundary, which
should keep most of the precipitation confined to the afternoon
hours with fropa.   The clouds/pcpn will keep temperatures down a
bit in most areas compared to Saturday, with most locations in the
70s (still above normal).  Will have to watch southeast parts of the
area (closer to Saginaw Bay) on Sunday for a potentially very warm
day, as they warm well into the 80s prior to the front arriving.

.LONG TERM...(Sunday night through Thursday)
Issued at 328 PM EDT Thu Sep 14 2017

Models are in consensus of a cold front associated with a low
pressure system over western Ontario sweeping through northern
Michigan late Sunday night with much drier air and high pressure
building in behind the departing system. With this drier air you can
expect any lingering rains Monday morning to diminish quickly. Rain
chances remain at bay until Wednesday morning, when Gulf moisture
advects into the region on a southerly wind flow...rain chances
remain through Thursday as well. Temperatures will only be in the
upper 60s to low 70s Monday and will moderate a degree or two each
day through the remainder of the period...with Thursday in the low
70s over eastern upper and mid to upper 70s over northern lower.
Lows will generally be in the upper 40s to mid 50s.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1126 PM EDT Thu Sep 14 2017

Surface high pressure over much of the eastern CONUS and back into
the Great Lakes will maintain overall quiet weather across
northern lower Michigan through Friday. Fog has already developed
in spots and will be a nuisance overnight...with periodic MVFR
and possible IFR conditions.

Meanwhile upstream...low pressure is located in the central
plains with a surface trough/front stretching up into the far NW
Great Lakes. Showers and thunderstorms along and north of this
boundary will remain out of the region through Friday although
some thicker mid and high cloud will slowly edge into the region.
Otherwise...slightly stronger south/southwest surface winds will
develop on Friday across northern lower Michigan.

&&

.MARINE...
Issued at 328 PM EDT Thu Sep 14 2017

High pressure extending into the northern Great Lakes will keep
winds and waves below SCA criteria tonight through the end of the
week. Winds will generally remain southerly through Saturday,
aside from lake breezes developing Friday afternoon. Areas of fog
will develop tonight, otherwise skies will remain generally mostly
clear with dry weather continuing through Saturday.


&&

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

$$

UPDATE...BA
NEAR TERM...MK
SHORT TERM...JK
LONG TERM...TL
AVIATION...BA
MARINE...MK