FXUS63 KAPX 271104

Area Forecast Discussion
National Weather Service Gaylord MI
604 AM EST Fri Jan 27 2023

.NEAR TERM...(Today through Tonight)
Issued at 356 AM EST Fri Jan 27 2023

...Accumulating and Blowing Snow Later Today...

High Impact Weather Potential: Accumulating/blowing snow and rapid
drops in visibility this afternoon and evening.

Pattern Synopsis:

Longwave troughing continues to encompass most of the CONUS east of
the Rockies through the end of the week as an embedded ridge quickly
slides overhead early this morning. An upstream shortwave will dig
from southern Canada over the upper Great Lakes this afternoon,
providing strong ascent aloft to support a near-990mb clipper that
will trek across the arrowhead of Minnesota and southern Ontario
through the period. An attendant cold front is expected to swing
across the area this evening.

Forecast Details:

The main forecast concern will be the expected accumulating snow and
visibility reductions produced along and ahead of the aforementioned
cold front, mainly this afternoon and evening. Strong southerly low-
level winds will bring the first chances for snow to western
Mackinac and Chippewa counties this morning with the potential for
light lake enhanced snowfall. Near-surface forcing providing by
prefrontal troughing is expected to generate a more concentrated
band of snow that will swing across northwest lower and eastern
upper Michigan beginning early this afternoon and into the early
evening hours. This timeframe -- from around 1 PM to 7 PM -- will be
the most likely time for heavier snowfall and rapid drops in
visibility. This aligns with latest HREF guidance that displays
enhanced probabilities for 1"/hr snowfall during this timeframe
with the best chances coming across western Mackinac county. While
these rates will be possible for a brief time, 0.5" to 0.75" per
hour rates are more likely across most of the area. Snowfall
accumulations of 1-3" are expected for most of northwest lower
Michigan with 2-4" with locally higher amounts possible for
western Mackinac and Chippewa counties due to potential lake

While higher snowfall rates will be possible, strong wind gusts are
anticipated to be the primary driver of impacts across the area --
specifically the counties included in the Winter Weather Advisory.
Wind gusts of 35-45 mph are expected this afternoon and evening
coinciding with ongoing snowfall. The combination of these two will
lead to rapid drops in visibility -- and even the potential for near
whiteout conditions for a time when the aforementioned band passes
through the area. Strong winds may lead to blowing snow across open
areas as well with ongoing/fresh snowfall. All in all, this is
expected to be a relatively transient event with the majority of
snowfall and impacts confined to a several hour period this
afternoon and early evening. However, this relatively brief period
will still bring the potential for hazardous travel to northern
Michigan during the evening commute -- especially those traveling
along US-2 later today.


.SHORT TERM...(Saturday through Sunday)
Issued at 356 AM EST Fri Jan 27 2023

...Lake Effect and Perhaps Some System Snow...

High Impact Weather Potential...Low for now.

Primary Forecast Concerns...Snow accumulations through the period.

Expect west northwest flow lake effect to be ongoing Saturday
morning with upwards of another couple of inches across the
snowbelts of eastern upper and perhaps up to an inch across
northwest lower. Attention then turns to a weak area of low pressure
passing by to our south Saturday night. Model have trended farther
north with this system so guidance has adjusted chances for snow
showers Saturday afternoon into Saturday night accordingly. Could
see an inch or two of accumulation across far southern counties by
early Sunday. Drier air then moves in on Sunday taking the snow with
it across northern lower (with the possible exception of some lake
effect snow showers across northwest lower). Across eastern upper,
snow showers should continue with another couple of inches of
accumulation possible. Colder with highs ranging from the upper
teens to mid 20s and lows ranging from the single digits above zero
north to the mid and upper teens south.

.LONG TERM...(Sunday night through Thursday)
Issued at 356 AM EST Fri Jan 27 2023

High Impact Weather Potential...Low at this time.

Well it looks like the polar vortex will take up temporary residence
over north central and northeast Canada. This places the Great Lakes
on the southern end of this feature. The extreme cold should remain
to our north but it still looks like the coldest air of the season
is on the way. Temperatures of a few degrees below average are
expected. It will be plenty cold enough for lake effect production
but a couple of factors may limit impacts in that regard. Dry air
from strong high pressure pressing in from the Plains and the
formation of a split jet stream flow with disturbances periodically
moving through the southern stream. Therefore overall not expecting
any long duration lake effect event. This is not to say we won`t get
some accumulating lake effect snow from time to time. Pinning down
exactly where and when is anyone`s guess as models have differing
viewpoints on the direction and strength of the mean flow as well as
the amount of available moisture. Hopefully we`ll get better model
consensus moving forward. Confidence in the colder temperatures is
high regardless.


.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 602 AM EST Fri Jan 27 2023

Main aviation concerns through the TAF period will be snowfall that
may be heavy at times accompanied by strong wind gusts today. Main
snow chances arrive early this afternoon from west to east with a
concentrated band that is likely to significantly lower visibilities
for a period of an hour or two -- potentially down to 1/4SM at
times. Otherwise, lighter snowfall surrounding this band may prevent
LIFR VSBYs for an extended period of time and remain in IFR/MVFR
conditions. South winds will quickly increase in speed today with
gusts of 30-40kts anticipated this afternoon and evening. Blowing
snow will also be possible at times given wind speeds and falling
snow. Winds will shift to westerly this evening and tonight
following a frontal passage.


Issued at 356 AM EST Fri Jan 27 2023

Southerly winds will quickly increase over Lake Michigan nearshore
waters and Whitefish Bay this morning as a clipper system moves
closer to the Great Lakes. Winds will increase over the Lake Huron
nearshore waters later this morning and afternoon. Gale force gusts,
including gusts in excess of 40kts, are expected over the nearshore
waters today with wave heights of 8-12+ feet. South winds will
become west winds tonight after a cold front passage, tapering in
intensity overnight into Saturday morning. Winds look to fall below
SCY criteria by Saturday afternoon.


MI...Winter Weather Advisory from noon today to 10 PM EST this
     evening for MIZ020-025-031-098.
     Winter Weather Advisory from 11 AM this morning to 7 PM EST this
     evening for MIZ086-095.
LH...Gale Warning until 10 PM EST this evening for LHZ345.
     Gale Warning from noon today to 7 AM EST Saturday for LHZ346>349.
LM...Gale Warning until 10 PM EST this evening for LMZ323-341-342-
LS...Gale Warning until 4 AM EST Saturday for LSZ321.
     Small Craft Advisory until 4 AM EST Saturday for LSZ322.



NWS APX Office Area Forecast Discussion