WeatherWatcher: Weekly Weather - 2 week edition

• The week ahead
• Red Flag Warning - Mainly an East Puget Sound Lowlands concern
• First rainfall of the season
• Previous two weeks of weather data

The week ahead: We have a strong marine on shore flow now that is going to maintain mostly cloudy mornings and days through the majority of the week. We may have a couple of days that break up to sunny skies. Expect high temperatures to be in the upper 50's and low 60's for the weekend and next week. Despite all the new cloud cover, we are not expecting any significant precipitation. Conditions are still very dry resulting in a very high fire danger even here, west of the Cascade Mountains. Longer range models are indicating that we may be switching into a more wet pattern towards the end of September, our warm sunny days may very well be at an end for this year.

Red Flag Warning: The National Weather Service in Seattle, Washington has issued a red flag warning for the East Puget Sound Lowlands from 2am Saturday (September 22nd) morning through 11pm Saturday night. Dry thunderstorms over the Cascade Mountains are expected to develop and move Northwest into the Puget Sound lowlands. Lightning sparked wildfires are a concern, however mainly for eastern Puget Sound Lowland and Cascade Mountain areas.  We may see some lightning and hear some thunder in Lake Forest Park and Shoreline, however most of the activity will remain east of our area.  If you can hear thunder, you are close enough to be struck by lightning.  Remember to seek shelter immediately if you hear thunder, in a fully enclosed building or hard top vehicle.

First rainfall of the season:  On Monday September 10, 2012, we received our first significant rainfall in 48 days.  From about 2:45am to 3:30am we received about 0.5 inches of rain, rest of the morning it was a light sprinkle or drizzle before the cold front left the area. A convergence zone did develop mainly just to the north of Shoreline and Lake Forest Park, affecting Edmonds, Mountlake Terrace and Lynnwood areas.

Last two weeks of data:

Week of September 8th - 14th:

High temperature: 83.6°F (Saturday the 8th)

Low temperature: 45.5°F (Wednesday the 12th)

Rainiest day: 0.51 inches (Monday the 10th)

Total rainfall: 0.51 inches

Warmest day: 67.4°F (Saturday the 8th)

Coldest day: 54.1°F (Tuesday the 11th)

Average temperature: 59.1°F

Average temperature last year: 64.6°F

3-year average temperature:  61.9°F

Week of September 15th - 21st:

High temperature: 82.4°F (Tuesday the 18th)

Low temperature: 48.2°F (Thursday the 20th)

No measurable rainfall

Warmest day: 64.5°F (Tuesday the 18th)

Coldest day: 56.8°F (Friday the 21st)

Average temperature: 59.7°F

Average temperature last year: 59.0°F

3-year average temperature: 60.1°F

We are running pretty close to average the past two weeks for temperatures this time of year.

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 Station.

Twitter: @SWeatherWatcher