Why we won't get much snow today.

The bottom line is, this would be a great low pressure system track and would give us a lot of snow, but temperatures are simply too warm for snow to fall. Eventually later this afternoon and early this evening, temperatures will get cold enough for snow, but by then the low pressure system will be moving out of the area, leaving us with only a few hours of snow. Therefore, my new snowfall map has toned down the projected accumulations a lot.

Saturday...first moderate accumulation of the season?

On Friday, a strong cold front will move through the area. Ahead of this cold front, heavy rain and embedded thunderstorms will occur all day Friday, and into Friday Night. Behind this cold front, temperatures will quickly fall. These falling temperatures, combined with a low pressure system forming over NW Ohio or SE Ontario and then strengthening as it moves Northeast, will likely allow for some moderate snow accumulation to occur on Saturday Night. The forecast models are still in disagreement about the track of this low pressure system, which could lead to changes in its strength and location, which in turn would lead to different snow accumulation forecasts. However, one forecast model, the NAM has been relatively consistent, and that is therefore what I am mainly basing my forecasts off of. The NAM shows a surface low forming in Ontario, and moving to the Northeast while strengthening. Snow would wrap behind this low and impact us starting late Saturday afternoon and ending in the wee hours of Sunday Morning.

Chance of Snow: 70%

Reasoning: If the surface low takes a track too far to the east, we would likely see no snow at all. Otherwise, we will see a period of at least light to moderate snow, perhaps heavy at times.

Chance of a Snow Day: 0%

Reasoning: The accumulations won't be anything major, and the timing of the system (Saturday Night) is poor for a snow day to occur.

Predicted Accumulation: 1-4 inches

Reasoning: At this time, the low pressure system's track would support several hours of moderate snowfall. However, this prediction is likely to change somewhat. If the low tracks further to the east than forecast, or much further west than forecast, we probably will see less than 1" of snow. Conversely, if surface low formation occurs earlier than expected, and then the low strengthens more than expected before reaching us, we could see more snow than forecast. So, check back here tomorrow morning when I will issue my update on this system.

Here is my preliminary snowfall map for SE Michigan:

Upcoming Systems

For now, the storm system Friday Night is expected to pass a little too far to the east for us to get anything. I will keep watching this system though, and have updates if the track adjusts further west.

The system to watch, in my opinion, will move through from Sunday Night to Monday Afternoon. It will be a fast-moving system dropping out of Canada (known as a clipper) and could bring us a quick 1-2 inches of snow Sunday Night and Monday Morning.

I'll have more updates on these two systems when I come home from school today.

Regardless of if either of these two systems come to materialize, we should see more snow showers throughout this weekend and early next week, which should result in more dustings of accumulation like the one we had last Sunday Night.

Light Snow possible tonight

A band of precipitation is moving into Southern Lower Michigan. If the precipitation doesn't dissipate before it reaches Lake Orion, we will see a period of light snow tonight, transitioning to rain tomorrow morning. There will be almost no accumulation (even less than with the snow showers Sunday Night).

Bottom Line: Just another sign that winter is slowly getting closer.

However, there is a really interesting pattern that the forecast models are showing. This pattern is that of a secondary system moving in after a strong cold front comes through on Friday. If this holds, we may see an inch or two of snow Friday Night. I'll issue a more elaborate discussion tomorrow, if necessary.

First light accumulation?

For the time being today, there shouldn't be much precipitation other than the lake effect rain band that's about to move through the area. What precipitation falls today will be rain, perhaps with some sleet mixing in in the stronger showers. Then, in the late afternoon, an upper level low and accompanying cold pool will move to the north of the area. This will allow for numerous showers to form. These showers will start out as rain, then mix in with snow overnight.
Tomorrow, the showers will continue to be numerous as the cold pool (along with a shortwave) provides sufficient instability to allow for showers to form. The showers will end up transitioning to all snow by Sunday Afternoon as a strong cold front will pass through the area overnight tonight.

Also, these snow showers will have some lake enhancement. The winds will mean that the heaviest snow will fall along and south of the Detroit area. However, that won't make a lot of difference in this event, as almost everyone should see some snow, and roads will be too warm for any accumulation.

Chance of Snow: 80%
Temperatures will be cold enough for snow by tomorrow afternoon, and possibly tonight and tomorrow morning. Precipitation coverage will be high, so therefore there is a high chance of snow with this event.

Chance of a Snow Day: 0%
The roads will be too warm for any accumulation. Even if they weren't, there wouldn't be enough snow for there to be any chance of a snow day.

Predicted Accumulation:
-On warm surfaces (Roads, etc.): None. They will still be too warm for any accumulation.

-On cold surfaces (Grass, Car roofs, etc.): 0.5 inches. Snow showers will likely be heavy enough for some light accumulations on cold surfaces. If Lake Orion gets a heavier snow shower, we may even see up to a quick inch of accumulation. I will be measuring snow accumulation on my car roof for this event.

Bottom Line: A chance for almost everyone in Southeast Michigan to see their first snow.

Snow on Sunday

Two cold fronts will come through in the next few days, bringing an abrupt end to our summerlike stretch in early November. Indeed, after the second cold front comes through on Sunday, rain showers will likely mix with snow showers by sundown on Sunday, with all precipitation likely falling as snow Sunday Night.

Chance of Snow: 50%
Reasoning: Precipitation should fall Sunday and Sunday Night, and as of right now, temperatures support the precipitation changing over to snow by sundown on Sunday.

Chance of a Snow Day: 0%
Reasoning: A little snow may accumulate on grassy surfaces, but none will accumulate on the roads. The only effect this snow will have may be to make the roads a little slippery for the Monday Morning commute.

Predicted Accumulation: Less than 1"
Reasoning: There should be some minor accumulations with these snow showers, especially the heavier ones, but accumulation will be limited to grassy surfaces.

Bottom Line: I know not all of Lake Orion saw their first snow with the October 27-28 system, so this is a chance for more people to see their first snow. Other than that, this system is nothing special.

Strong cold front, then snow???

Enjoy the weather early this week, as temperatures will be in the lower 70's. However, by the end of the week, a strong cold front will move through. The early effects of this cold front could be horrible weather for the Lake Orion - Romeo football game Friday Night, as temperatures right now look to be in the upper 30's for that game. However, the cold temperatures will be the least of the weather problems. There is about a 50% chance of rain for Friday Night, and it is almost certainly going to be windy as a cold airmass moves in behind the cold front.

Then by Saturday Night, temperatures could be cold enough to support light snow showers. IF snow falls, accumulations would likely be very light, if the snow even sticks to the ground at all. The snow forecast has a high potential for change, as a few degree swing in temperatures will be the difference between getting rain or snow behind the cold front. Stay tuned to the blog for updates.