surface ozone mapYou can literally breathe easier this morning. The air stagnation advisory issued yesterday has expired. The stagnant air is around because we are under a shallow pool of relatively dense air. Air circulates within that blob but it doesn't mix with air outside the blob. The result is dirty air. A warm front is slowly moving northward and the gunk, shown in green off the coast, has been largely moved offshore.

When that warm front gets here is uncertain. The Weather Service is predicting late tonight, but they're not very confident:

THIS FORECAST IS HIGHLY DEPENDENT ON THE MOVEMENT OF THE FRONT AND THEREFORE HAS THE POTENTIAL TO BUST.

With the cloud cover and moisture around, there's a slight chance of drizzle, temperatures will hold steady, around 55, until tomorrow morning. Tomorrow will be much warmer, with a high in the mid-60s. It looks like this month will be the seventh warmest November on record.

All the warm weather disappears sometime on Friday. An approaching cold front will kick off a few showers, and perhaps a thundershower, beginning late tomorrow. Winds may be strong enough on Friday to require a high wind advisory. Once the front goes through it will be much cooler, highs only in the 40s, but sunny. Looking far ahead, the Weather Channel's ten-day forecast is calling for snow showers next Friday.

Map of surface ozone concentrations from the National Weather Service.