Bay Area residents, get ready to shed those layers and then promptly retrieve them again. According to the National Weather Service's San Francisco office, you're in for a temperature rollercoaster this week with a sharp climb into above-normal warmth, followed by an expectant drop as rain moves in for the weekend. Soak up the sun until Thursday because by Friday, you might need your umbrella.

Today marks the beginning of a stretch of warm days expected to push afternoon highs to a toasty 5-8 degrees above the norm. The National Weather Service reports that "inland areas will see minor Heat Risk through Thursday." Those most vulnerable, such as the elderly or very young children, are advised to remain cautious and to stay hydrated and cool to avoid heat impacts.

By the weekend, however, the atmospheric seesaw tilts back. A storm system with a "MODERATE to HIGH" confidence of bringing rain and cooler weather is poised to make a grand entrance. At this juncture, though meteorologists have a solid belief in the rainy forecast, they are still pinning down the exact timing and amounts, which remain elusive.

Saturday morning to early afternoon seems to be the target window for the most widespread rainfall. Coastal ranges could see 1-2 inches, with 0.5-1 inch expected elsewhere - a decrease as you move inland. As rain threatens to derail weekend plans, it pays to periodically check the forecast throughout the week for updates, says the National Weather Service.

Maritime conditions will also be choppy, with a Small Craft Advisory in effect for parts of the coast and outer waters through Wednesday afternoon. Stronger winds are expected north of Point Reyes, where smaller vessels must navigate with extra care or stay docked entirely until the weather system eases midweek.