WeatherWatcher: Foggy weather ahead

Forecast

December's Highlights

Last Week's Data

Forecast: When it rains it pours, as the old saying goes. After our weekend of heavy rain we are heading back into a short dry spell to last us until about Thursday evening - Friday. Due to the high pressure forming for the mid-week there may be a temperature inversion that could get strong enough to generate locally dense fog, and yes, burn bans. Temperatures will stick to the low 50's and upper 40's for most of the week. A renewed storm track will show up Friday bringing the return of rain and the lift of any burn bans through the end of next weekend. Some cooler air may move in as well at that time, but don't fear, not cold enough for that for the letter S word yet.

December Highlights: December was one of the most active weather months we've had in over 2 years, a month to be remembered as the month of extremes. The month begin with an ending cold snap from November. Then transitioned to a stormy and windy pattern, to rain, then ending with more cold air and record high surface air pressure. We also went from having low temperatures in the lower 20's to having a high temperature of 65°F, which by the way, broke the all time high temperature record for the entire month at Sea-Tac (where official weather data is recorded for the Seattle area).

The temperature on December 10th was very much the same right here in Shoreline with it at 64.6°F (rounding to 65°F).  Just one day later, the strongest winds in two years moved through our area with gusts peaking up to 52 mph causing wide spread power outages throughout Shoreline and Lake Forest Park. We had several other winds that were not quite as strong but noted. 

We then had a series of rain storms followed with our third arctic attack of the season to end the month. During our arctic attack at the end of the month, another record was set on December 30th. This was a more interesting one as it was Seattle's all time high pressure record that was broken. The Shoreline Weather Station recorded a high pressure of 30.327 inHg (Inches of Mercury). Now remember this is not sea level adjusted, the weather station is at an elevation of 373 feet above sea level. At Sea-Tac the official record I was able to dig up was 30.84 inHg at 11am, December 30, 2014.

Rainfall total was close to the middle of the road for Decembers since 2008. December 2010 had 12.06 inches, December 2012 came in at 8.69 inches. Interestingly enough 2010 was a moderate El Nino year, and 2012 was a mild El Nino year, this year we are skirting on the edge of neutral and El Nino (minor if any El Nino is existing right now).

A Darkened Intersection December 11, 2014, caused by wind.
Photo by Carl Dinse

Last Week's Data:

High Temperature: 47.7°F (Saturday)

Low Temperature: 24.8°F (Tuesday)

Rainiest day: 0.08 inches (Tied on Saturday and Sunday)

Total rainfall: 0.16 inches

Warmest day: 42.9°F (Saturday)

Coldest day: 29.0°F (Tuesday)

Average temperature: 35.0°F

Station historic average: 38.3°F

December 2014 High and Low Temperatures compared to station average.
Graphs and data by Carl Dinse

For current weather conditions and weather resources, see http://www.shorelineweather.com