On snow, frost, severe storms, and Halloween ...

Thoughts on a variety of topics after a weekend trip to western Maryland, where snow fell briefly Thursday afternoon ...

October freeze: The weekend cold snap produced the chilliest weather in the Carolinas this early in the season since 2006.

The low temperature Saturday morning in Charlotte was 27 degrees (which was colder than where I was, north of Frederick, Md.). That set a record for the date, and only once in Charlotte weather history -- on Oct. 26, 2006 -- has it been so cold this early in the season.

The 55-degree high temperature Friday was the chilliest maximum October temperature in Charlotte since a 53-degree high on Oct. 17, 2009.

Southeast snow: You probably saw where snow fell in the North Carolina mountains Thursday, and there were even minor accumulations for a while in some of the higher elevations.

You might not have realized, however, that more significant snow fell Thursday in the traditional "snow belt" areas along the Great Lakes. Several inches of very wet snow accumulated in the higher elevations southeast of lakes Erie and Ontario.

Deep low pressure to the north of the Great Lakes was funneling a strong supply of cold, unstable air into the United States. When that unstable air crossed the Great Lakes, it picked up moisture and deposited it as snow on the shore, especially in the higher areas a bit inland from the lakes.

Stormy week ahead: It looks like one of those strong autumn storm systems will push eastward across the United States over the next few days. It will plow into some rather mild air, and the result likely will be an outbreak of severe weather Tuesday and Wednesday in the Midwest and Mid-South.

By Thursday, that low will drag a cold front, stretching from the Great Lakes into the South. Strong thunderstorms are likely again, but meteorologists aren't certain if the instability factor will be as high as it is expected to be Tuesday and Wednesday.

Strong wind shear will accompany the front as it moves into the Carolinas on Thursday night. Right now, it's too early to know if there will be enough instability for severe thunderstorms to break out. But it's possible, and we'll have to watch the forecast unfold this week.

Halloween: Those thunderstorms and the cold front will arrive a bit too late to do much damage to trick-or-treating Thursday evening. It's possible a few showers could arrive in the Charlotte region ahead of the main band of precipitation -- possibly as early as the evening hours. But most areas are likely to remain dry.

It will be mild, too. High temperatures are expected to reach the low and mid 70s, and with ample cloud cover, conditions will remain warm Thursday evening, even after the sun sets.