First Day of Astronomical Winter – Winter Weather Advisory

The winter solstice is the day with the fewest hours of sunlight in the whole year. In the Northern Hemisphere, it always occurs around December 21 or 22. (In the Southern Hemisphere, the winter solstice occurs around June 20 or 21.)  At the winter solstice, the Sun’s path has reached its southernmost position. The next day, the path will advance northward.

However, a few days before and after the winter solstice, the change is so slight that the Sun’s path seems to stay the same, or stand still. The Sun is directly overhead at “high-noon” on Winter Solstice at the latitude called the Tropic of Capricorn.

The day of the winter solstice is the shortest day of the year, meaning the one in which we experience the least amount of daylight in 24 hours; it is also the time when the Sun reaches its southernmost point in the sky.

Although this part of Earth is cooling, its great thermal mass still retains some heat from the summer and fall. As the gradual cooling process continues over the next two months, temperatures will continue to fall, and the coldest temperatures will be recorded. The same pattern holds true for the summer solstice in June, as the year’s highest temperatures are recorded later, in July and August (in the Northern Hemisphere).

Boy its gonna feel like winter as we move into a colder pattern.  A significant outbreak of arctic air will occur over the Midwest and Great Lakes region early next week, which includes Christmas day. A period of light snow as well as lake effect snow showers with some accumulations are possible this weekend into early next week as well.

Temperatures will become colder over this coming weekend but the bitterly cold air is expected Christmas Day through Wednesday of next week. High temperatures will likely only be in the teens and low temperatures in the single digits.

It is possible that low temperatures could drop below zero while high temperatures remain in the single digits, especially in areas that will have snow on the ground by next week. (We still have a couple inches of hard pack here at the station).  Wind chills will be below zero and could possibly be well below zero at times Monday through Wednesday.

Snowfall will be light through the weekend with the better chances on Christmas eve and Christmas day, but the air will be fairly dry. Maybe 1 to 3 inches of new snow on the ground for Christmas.

This is the NWS Discussion:

Will not be issuing any winter weather headlines at this time but we will need to watch for the possibility of some impactful light freezing rain or freezing drizzle developing tonight and Friday. A somewhat complicated scenario unfolding next 48 hours. First, for today, we have a very dry air mass below 700 mb so for much of the day any incoming precip will struggle to reach the ground. However later today some type of FGEN band of snow may try to develop north of a Ludington to Mt Pleasant line, related to a coupled upr lvl jet structure.

This feature could produce 1-2″ of snow this afternoon and evening but confidence remains low as to where (and if) this actually sets up, and how expansive it is. The other thing to watch for later today and this evening is for some light warm advection precip breaking out, mainly near and south of I-96. P-type with this should be a mix of light rain and snow given sfc temps in the mid to upper 30s but wet bulbing also occuring related to pre existing dry air mass. So little impact expected from this as well given above frzg sfc temps.

The soundings change however by later tonight, with the column become more saturated below 700 mb, but the DGZ becoming unsaturated aloft. The DGZ actually remains quite high up, above 10,000 ft, tonight into Friday. So it would appear that as low level moisture increases tonight and Friday but mid level moisture is lacking, we should be looking at predominately a drizzle/freezing drizzle scenario eventually setting up – at least for areas near and south of I-96. This could necessitate an advisory at some point if confidence increases.

Farther north tonight and Friday there is a better probability of ice present in the clouds due to deeper moisture, so there should be more in way of light snow with a lower risk of freezing rain/drizzle. Main precip threat ends Friday night as weak system moves out.

The GFS is still showing colder air and snow at the end of the first week of January – this model has been consistent through the past few days showing even colder air moving into the Midwest and Great Lakes region with a synoptic event and lake effect.  It will be interesting to see if this plays out as it would be the coldest air we have seen in several years.

Today: A slight chance of rain after 4pm, mixing with snow after 5pm. Cloudy, with a high near 37. East southeast wind 5 to 8 mph. Chance of precipitation is 20%.

Tonight: A chance of rain and snow before 11pm, then a chance of snow and freezing rain between 11pm and 1am, then a chance of freezing drizzle after 1am. Cloudy, with a low around 30. East wind around 8 mph. Chance of precipitation is 40%.

Friday: A chance of freezing drizzle before 11am, then a chance of drizzle. Cloudy, with a high near 36. East northeast wind 5 to 7 mph.

Friday Night: A slight chance of drizzle before 11pm, then a slight chance of freezing drizzle between 11pm and 1am. Cloudy, with a low around 28. Calm wind becoming west northwest around 5 mph after midnight.

Saturday: Mostly cloudy, with a high near 33. West northwest wind 6 to 10 mph.

Saturday Night: A 20 percent chance of snow showers after 1am. Mostly cloudy, with a low around 19.

Sunday: A chance of snow showers before 1pm, then snow likely after 1pm. Cloudy, with a high near 25. Chance of precipitation is 70%.

Sunday Night: Snow likely before 1am, then snow showers likely after 1am. Cloudy, with a low around 15.

Christmas Day: A chance of snow showers. Mostly cloudy, with a high near 20.

Monday Night: A chance of snow showers. Mostly cloudy, with a low around 11.

Tuesday: A chance of snow showers. Mostly cloudy, with a high near 17.

Tuesday Night: A slight chance of snow showers. Mostly cloudy, with a low around 10.

Wednesday: A chance of snow showers. Mostly cloudy, with a high near 21.

Afternoon Update:

WINTER WEATHER ADVISORY IN EFFECT FROM 3 PM THIS AFTERNOON TO
1 PM EST FRIDAY For:  Muskegon-Montcalm-Gratiot-Ottawa-Kent-Ionia-Clinton-Allegan-Barry-
Eaton-Ingham Counties

Mixed precipitation expected. The ice will result in
difficult travel conditions, including during the morning
commute on Friday. Total snow accumulations of up to one inch
and ice accumulations of up to one tenth of an inch are
expected. The precipitation will be heavier near and north of
I-96, with lighter amounts south of I-96.