Clouds & More Clouds

Yesterday our high temperature was 37° and the low was 30°.

Today will be foggy in some areas with light drizzle, and perhaps a little freezing drizzle causing some slick spots in Central Michigan. Temperatures will trend milder through New Year’s Eve with continued cloudy skies and rain chances.  Arctic air may pour back in to ring in the New Year waking up the lake-effect snow machine.

---

Weather History

1985: Muskegon sets a daily snowfall record of 14.4 inches during a long stretch of snowy weather. The monthly total for December is 57 inches.

2001: A foot of lake effect snow piles up at Grand Rapids as a week-long snow blitz drops about 4 feet of snow at Grand Rapids.

On December 26, 2016, Detroit, Flint, and Saginaw set record highs of 57, 56, and 54 respectively.

Also on December 26, 2012, a large Gulf low lifted northeast along the Appalachian Mountains and clipped southeast Michigan bringing a widespread accumulating snowfall to the area. By the following morning, 4″ to 7″ had accumulated across the southeast half of the area, with higher amounts of 14″ in Lakeport and 11.1″ in Port Huron. Detroit and Flint measured storm total accumulations of 6.2″ and 5″ respectively. Further northwest, Saginaw received a glancing blow and measured only 1.5″.

Also, on December 26, 1914, the overnight temperature in Saginaw plummeted to -12 degrees, which is 30 degrees below the average overnight temperature.

---

Forecast Discussion

- Drizzle and Patchy Fog Today

Continued boundary layer moistening this morning is promoting areas
of drizzle and fog across West Michigan this morning as evidenced by
weak radar returns. Near and north of M46 surface temps remain at or
below freezing meaning patchy slick spots are possible this morning
from the fog/drizzle. Fog will also likely be dense at times in this
region given a still depleting snowpack adding additional moisture.
Have issued a Special Wx Statement to highlight the potential for
isolated impacts for the first part of the morning in this area.

Patchy fog and drizzle remain likely through the day as abundant low-
level moisture is supported by a secondary weak vort maxima. Though
with temperatures above freezing it appears to be relatively benign.
What will need monitoring is signals for more widespread fog across
Central Lower Michigan later today and tonight as higher dewpoints
advect over a dwindling snowpack.

- Warming With Rain Friday into Sunday

Southerly flow establishing itself across the region Friday drives a
notable warmup into the weekend. 850mb Ts around 5C send highs into
the 40s Friday and Sunday and even into the 50s for Saturday.
However, this warmup will not come without the promise of rainfall
for the region. Rainfall increases later Friday as a mid-level wave
swings through the area from the southwest driving an occluding low
in our direction. The rain continues into Saturday as the parent
trough swings through the region before diminishing Sunday as a weak
cold-front crosses the Upper Great Lakes. Impacts look to be low as
our warmer pattern ensures only rain with this system while on the
other end of the spectrum a lack of instability keeps thunder out of
the forecast.

- Colder Pattern And Precipitation Arrive Mid Next Week

Behind the weak frontal boundary Sunday conditions look to be dry as
we`re located in the col between our departing low and our next
system mid-week, with the colder air/polar jet remaining north
keeping highs in the 40s.

However, mid-week marks the beginning of a pattern change for the
region as a system ejects north out of the western US while a
northern stream wave slides southeast at the same time. The timing
and interaction between these waves will determine how this pattern
change unfolds. As the wave arrives, the associated forcing makes
precipitation likely Tuesday and Wednesday. The primary question
will be p-type. If the northern stream wave and associated colder
air can phase with the southern wave that will support more notable
snow potential in the Great Lakes or Northeast (which the EPS is
hinting at). If the colder air holds off until the southern wave and
associated low exit, rain will be dominant until the colder air can
arrive (which the GEFS/CMC suites lean towards). Once the colder air
associated with the northern stream arrives, temps fall and some
lake effect is possible given the very cold nature of the
airmass. Specifics as to which scenario will occur during this
changeover will become clearer in the coming days.