The weather this week is going on a roller coaster ride and, as roller coasters do, the temperatures are going to start out high and make a thrilling plunge to the bottom. For today, a big high pressure system is just to our west, keeping the skies clear and bringing us an afternoon high in the lower 60s, which is just a touch warmer than normal.

The high will move offshore tonight and the resulting southerly breeze will warm the city into the lower 70s under mostly sunny skies tomorrow. A weak cold front is expected to arrive on Tuesday night. Wednesday will still be unseasonably warm with a high in the upper 60s and there will be a slight chance of showers.

We might squeeze out one more warmer than normal day on Thursday, but it will be close. Look for a high in the upper 50s and lots of sun. Friday won’t be quite as warm, the consensus seems to be mid 50s, and clouds will start building in ahead of a strong cold front. The National Weather Service says there is a slight chance of rain on Halloween but the rain shouldn’t arrive until after trick-or-treating hours.

Saturday? Brrr! The cold front comes through and the temperature will plunge into the 40s. The Weather Channel says a high of 43 but other forecasts aren’t that extreme. In any event, gusty northwesterly winds will make it feel much colder than the actual temperature. The wind will die down for Marathon Sunday and the day will start out with temperatures in the mid 30s and top off with a high close to 50.