FXUS63 KAPX 121100

Area Forecast Discussion
National Weather Service Gaylord MI
600 AM EST Tue Nov 12 2019

.NEAR TERM...(Today through Tonight)
Issued at 245 AM EST Tue Nov 12 2019

...Accumulating lake effect snow showers continue...

High Impact Weather Potential...Accumulating N/NW flow lake effect
snow showers continue today...shifting to the W/SW tonight. Travel
will remain difficult due to rapidly changing visibilities and slick
roads. Locations hardest hit by lake snow showers will be along and
west of US-131 in Northwest Lower Michigan. Some blowing and
drifting snow is also possible.

Pattern Synopsis/Forecast...Michigan remains positioned between a
strong cold front now exiting SE away from the Ohio Valley and a
large area of very cold high pressure centered over the Plains. NW
edge of deep moisture and resulting synoptic snows that impacted
portions of NE Lower Michigan yesterday has exited our CWA. But
northerly flow lake effect snow showers continue to target locations
west of US-131 as well as some Lake Huron shoreline areas from PZQ
to APN to just north of OSC. Certainly the most robust lake snow
shower continue to pound our Lake Michigan shoreline areas from near
CVX to TVC to MBL where periodic heavy snowfall is still happening.
Land breeze development due to extremely cold temps over land kept
low level flow slightly offshore (N/NE)...thus pushing the heaviest
snowbands to our Lake Michigan shoreline. Low level flow is in the
process of shifting to a more N/NW trajectory...resulting in the
beginning of an inland shift of these shoreline bands.

As we head into today and tonight...low level flow will steadily
back to the N/NW this morning...NW this afternoon...W this evening
and then finally to the SW overnight in response to the pronounced
surface ridge axis sliding overhead and then shifting east of
Michigan late tonight. As a result...locations targeted for the most
persistent and heaviest lake snow showers will shift from along and
west of US-131 today to portions of Eastern Upper Michigan...the
Straits and the Tip of the Mitt by late tonight. Will definitely
keep all headlines in tact as we head into today...with an
additional 4 to 9 inches of snowfall thru today within the warning
and advisory areas. Building subsidence...drying low levels and
continually shifting low level winds will decrease snowfall coverage
and intensities tonight...with less than 2 inches of additional
snowfall expected tonight for our typical snowbelt areas.

Temps will remain unseasonably cold thru tonight as this arctic
airmass slides directly overhead. High temps today will only warm
into the upper teens to mid 20s. Low temps tonight will again fall
into the single digits above zero.


.SHORT TERM...(Wednesday through Thursday)
Issued at 245 AM EST Tue Nov 12 2019

High impact weather potential: Lake effect/enhanced snow. Possible
lakeshore flooding issues Wednesday with strong southerly flow.

850mb temperatures continue to remain cold...between -12 and -18C.
Winds will be backing to south-southwesterly Wednesday ahead of an
approaching cold front associated with a low pressure system near
Hudson Bay. This will bring deeper synoptic moisture to the region
and great snow producing delta t/s...this along with the cold 850mb
temperatures will be plenty enough to say there is a good chance for
some northern Michigan lake effect clouds and snow. As the cold
front and accompanying synoptic moisture approach Wednesday, the
snow will be enhanced by the lakes with delta t/s nearing 20+C for
favored south-southwesterly flow regimes. The greatest threat for
accumulating snow will be over western Mackinaw and Chippewa
Counties...where 4-6 inches...locally higher amounts may fall.
Behind the aforementioned cold front, winds will veer to more
westerly continuing the lake effect snow threat through Thursday
morning. A narrow ridge of high pressure and drier air then build in
for the second half of Thursday and the beginning of Friday...giving
a quick break of precipitation chances until yet another weak cold
front and accompanying moisture will return chances of lake enhanced
snows Friday afternoon. Highs will be in the low 20s Wednesday and
moderate to the low 30s for Thursday and Friday. Lows drop into the
upper teens to low 20s (with warmer temperatures near the shorelines
of the Great Lakes).

.LONG TERM...(Thursday night through Monday)
Issued at 245 AM EST Tue Nov 12 2019

High Impact Weather Potential: Snow showers.

Upper level flow finally becomes more zonal. Friday will see high
pressure and much drier air begin a retreat to the east as synoptic
moisture returns with a weak clipper system Saturday.
Several other disturbances look to take aim at the Great Lakes
region...producing precipitation chances throughout the rest of the
period. Highs will be in the upper 20s to low 30s Saturday and warm
to the mid to upper 30s by Sunday and last through the rest of the
period.High Impact Weather Potential: Snow showers.


.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 600 AM EST Tue Nov 12 2019

Heavy lake effect snow showers will continue to impact portions of
NW Lower Michigan today...with the most persistent and heaviest
snow falling along and west of US-131 (TVC and MBL). Conditions
will drop to IFR within these heavy snow showers. Low level winds
will gradually shift to the NW by afternoon...W this evening and
eventually SW overnight...shifting the trajectory of these snow
showers northward into the Tip of the Mitt and the Straits later
tonight. Building subsidence and drier air will diminish areal
coverage and intensity of the snow showers as they shift
northward. Away from the lake effect snow...overall conditions
will be VFR. Surface winds will be stronger along the
shorelines...gusting to 15 to 25 kts at times.


Issued at 245 AM EST Tue Nov 12 2019

Winds and waves will continue to reach SCA criteria today for much
of our nearshore areas. N/NW flow lake effect snow showers will
continue today...with the most persistent shower activity expected
across our Lake Michigan and far Northern Lake Huron nearshore
areas. Low level winds will shift to the west this evening and then
SW late tonight...shifting the focus of the most persistent snowfall
northward to Eastern Upper Michigan...the Straits and the Tip of the
Mitt by late tonight.


MI...WINTER WEATHER ADVISORY until 6 PM EST this evening for MIZ021-
     WINTER STORM WARNING until 6 PM EST this evening for MIZ020-025-
LH...SMALL CRAFT ADVISORY until 6 PM EST this evening for LHZ345>349.
LM...SMALL CRAFT ADVISORY until 6 PM EST this evening for LMZ323-341-



NWS APX Office Area Forecast Discussion