FXUS63 KAPX 291127

Area Forecast Discussion
National Weather Service Gaylord MI
627 AM EST Wed Jan 29 2020

.NEAR TERM...(Today through Tonight)
Issued at 355 AM EST Wed Jan 29 2020

High Impact Weather Potential: Minimal.

Pattern Synopsis/Forecast: Split flow pattern in place across North
America with an active southern branch/Pacific wave train...and a
northern branch displaced north of 55N latitude except for a dip
over northern Quebec and Atlantic Canada.  Southern branch flow
features a short wave trough rolling through the lower Mississippi
Valley/northern Gulf of Mexico...with a lingering piece of energy
left behind over the eastern Dakotas/Nebraska/Kansas.  Another
splitting short wave trough wasn`t far behind moving through the
Intermountain West.   A lingering latent potential vorticity anomaly
lies along a deformation/col axis across the lower Great Lakes
northwest to north of Lake Superior...Michigan is mostly caught in
this weakness between the two branches...though still mostly under
the influence of the northern branch which is pushing very dry
air/large scale subsidence southward toward the region from
northeast Ontario.  00z APX sounding showing inversion height around
870mb/-11C...so still enough cold air around with lake water
temperatures averaging around 3C to allow for some shallow lake
convective processes to continue.

04z surface/composite analysis shows a 1028mb high centered north of
Lake Superior...ridging southwest into the upper Midwest.  Low
level flow becoming increasingly anticyclonic across the upper
Lakes...though still some flurries out there as low level flow has
become more northerly over northern Lower Michigan...and
northeasterly into eastern Upper.  Some clearing over northeast Lake
Superior and the adjacent shoreline...not getting across the St.
Mary`s River yet.  We`ll see if increasing subsidence and
downsloping easterly component to low level flow helps in this
regard over the next several hours.

Surface high to the north will continue to build east today toward
strongest low level cold advection/pressure rises...while short wave
ridging aloft slides across the region today.  Elongated potential
vorticity anomaly moving into the upper Midwest this morning will
get sheared out as it moves into Michigan tonight.

Primary Forecast Concerns: Pretty minimal other than the usual mid
winter cloud cover issues...and will not be optimistic on seeing sun
until I actually see it.  Long fetch easterly flow off Lake Huron
develops today...and still a good bit of cloud cover to the north
and northeast of a mostly ice-free Georgian Bay.  Shallow cold air
doesn`t really go anywhere today...so expect that lake convection
and diurnal processes will keep clouds in across northern
Lower...with the addition of high based AC and CI this afternoon
from the west. Can`t rule out some flurries over northeast Lower
today either...or maybe some freezing drizzle with saturation
flirting with temperatures around -10C.  Will probably stay on the
cloudier side across eastern Upper as well though there is a better
probability here for cloud breaks and some sun especially closer to
the St. Mary`s River/Drummond Island though even here mid/high
clouds will spread in from the west later today.

Short wave trough arrives tonight...but with a nice wedge of mid
level dry air which suggests that...from a synoptic point of
view...the precipitation threat appears limited.  But the upward
forcing and resultant dynamic cooling will lift inversion heights
once again (825-850mb) in light east/southeast boundary layer flow.
So we may see an uptick in flurries/light snow showers into far
northeast Lower and particularly into the Central/Southeast Chippewa
county zones overnight.  Will also see the same effect over northern
Lake Michigan into western Mackinac county and points west.


.SHORT TERM...(Thursday through Friday)
Issued at 355 AM EST Wed Jan 29 2020

High Impact Weather...None is expected.

Forecast Concerns...Light lake effect of off Lake Michigan?

The rather blah weather will continue across most areas through
Friday. However, marginal over lake instability in combination with
a weak southwest flow may churn up a few snow showers or flurries
off of Lake Michigan Thursday into Thursday night (the flow is
pretty light though so it may not be able to get much going). A weak
short wave moving across the area Friday could also produce a few
snow showers, especially across eastern upper. Overall, nothing too
exciting with mild temperatures continuing.

.LONG TERM...(Friday night through Tuesday)
Issued at 355 AM EST Wed Jan 29 2020

High Impact Weather...None is expected at this time.

Forecast Concerns...Pops through the period.

Rather quiet weather is expected for your Superbowl weekend, though
a short wave moving through the flow will likely produce a few snow
showers Saturday. Milder air streams in for Sunday into Monday with
some spots likely hitting the 40 degree mark. We will then be
monitoring an area of low pressure which is shown to be off to our
south Monday night into Tuesday. Extended models vary on if this
system will affect northern Michigan or not so we`ll keep an eye on
the situation over the coming days. In addition, a colder shot of
air looks like it will drop into the region toward the middle of
next week.


.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 626 AM EST Wed Jan 29 2020

A continuation of MVFR ceilings expected today and tonight at all
of the terminals...minimal precipitation outside of some flurries
at APN.


Issued at 355 AM EST Wed Jan 29 2020

Weak easterly pressure gradient expected through tonight as high
pressure slides east from north of Lake Superior into Quebec.  Winds
will slowly veer today through east to southeast...with more of a
southerly component tonight but overall winds are expected to remain
light through Thursday.





NWS APX Office Area Forecast Discussion