WeatherWatcher: Weekly Weather, Burn Ban, snow flurries.

• Burn Ban in clear weather?
• The week ahead
• Snow flurries
• Last week's weather data
• Request to our readers for stories on historic weather events

What weather causes the Puget Sound Clean Air Agency issue a Burn Ban? There are several situations that cause a burn ban to be issued, but during the winter months believe it or not, it's when the weather is coldest and driest that these conditions develop. The real issue is stagnant air for a long enough period of time to cause an accumulation of pollution. In the winter this almost always happens whenever we get a high pressure system over us, or in this case, just off shore, blocking any incoming Pacific storms that we normally have during this time of year. Without our Pacific storms moving through the region our winds are blocked as well. So all of this air gets trapped in our region until the blocking pattern is broken by a strong enough storm.

The week ahead: We are going to be in this pattern of cold for the foreseeable future. For the rest of tonight and part of tomorrow it will be cloudy. Models and forecasters are pointing to the high pressure off shore to move inland and clear out the clouds. Clear skies means cold temperatures, so expect lows for the rest of the week to dip below freezing, on clear nights we will probably get near 25-27 for a low. We might crack 40°F for a high temperature by Friday or Saturday, but that is a big if right now.  The first hint of rain or snow, currently is at the earliest for Tuesday January 22nd. That would be our earliest possible date at current model forecasts for a lift on the burn ban as well.  Long range models are still agreeing that we may have snow after this clear weather leaves us.

Snow flurries have been drifting through the area today and there will probably be a couple more tonight and overnight before the ridge of high pressure moves all the way in. Right now storms from the Pacific are moving up and over the ridge of high pressure into Alaska and coming down the east side of the ridge along the Canadian coast and Washington coast bringing the cold air with, but losing most of it's moisture into the coastal mountains of British Columbia. The flurries activity is expected to end by tomorrow morning.

Last week's data:

High temperature: 49.5°F (Monday and Tuesday)

Low temperature: 25.2°F (Friday)

Rainiest day: 1.01 inches (Wednesday)

Total rainfall: 2.04 inches

Warmest day: 45.4°F (Tuesday)

Coldest day: 27.9°F (Friday)

Average temperature: 38.8°F (2.5°F colder than station average)

3-Year average temperature: 41.3°F

Below is a temperature graph of the temperatures so far this month:

New series on historic storms: I am working on a series of reports on historic weather events that have directly impacted the Shoreline and Lake Forest Park areas. We are looking for stories and pictures from our own readers on any past weather event that you can remember.  Please email your stories if you have any, thank you!

Warmest and coldest days are based on average temperature of the entire day, starting at midnight. All other averages are based on the whole week, starting Saturday morning at midnight. All weather data unless otherwise noted is sourced from Carl's Shoreline Weather.

For winter storm updates, check out my weather station web page or follow me on Twitter: @SWeatherWatcher