WeatherWatcher: Weekly Report - Thunderstorms - Forecast

Forecast

Last two week's highlights - thunderstorms

Last week's data and graphs

Forecast: It's looking like we will continue our above average temperatures and sunshine for the next 7 days. Highs will range in the 80's with lows in the 60's or upper 50's. Mix in a chance of a thunderstorm here and there as it's possible for upper level disturbances from the southwest to continue to bring some of that monsoon moisture up here once in a while. This was a pattern I was expecting to happen this summer with the weak El Niño going on.

Highlights: Wednesday the 23rd we had a fairly significant Pacific storm move through the region, starting off with some lighting in the area and followed by heavy rain as the storm front moved through. Very out of season, especially because late July and early August are historically the driest time of the year for this area. There was even a large power outage in the North Shoreline area and parts of Lake Forest Park which shutdown the weather station. Backup power normally in place also failed that morning, naturally before the actual power outage. With 4,500 customer affected, Shorecrest High school was the only station I could find that was online during the day and not affected by the power outage, so I pulled the rainfall total for the day from that station. Total rainfall for the day, 0.93 inches, far greater than the normal total rainfall for the entire month of July, records were broken.

The fun continued Saturday morning (August 2nd) and afternoon where moisture from the southwest continued to flow into the Puget Sound area, some of the convection was so rapid you could actually watch these clouds grow out of thin air, and on the visible satellites as they moved north through Seattle. Right around North Seattle and Shoreline is where the clouds got tall enough and heavy enough to produce precipitation and lightning. Some showers started as far south as Seatac as well. Total rainfall for Saturday August 2nd from the storms amounted to about .03 inches, also reported from Shorecrest High School. My rain gauge only measures in 0.04 increments so anything less than that isn't enough to tip it.

Last week's data:

High temperature: 89.0°F (Friday)

Low temperature: 51.6°F (Saturday)

No measurable rainfall.

Warmest day: 69.3°F (Monday)

Coldest day: 63.8°F (Saturday)

Average temperature: 67.7°F

Historic average: 65.5°F

Graphs:

Below I have the daily average dew point for the month of July, as you can see it's been above 50°F most of the month. Things probably felt a bit "muggy" on a lot of days. We dried out quite nicely however right at the end of the month, but that changed at the start of August.

Next is the daily high and low temperatures compared to the average for July, we've been breaking 80°F far more often than normal this year. Low temperatures were also warmer than normal, but not by an alarming amount. Since the El Niño has weakened to an almost neutral state now I think we might have some relief from the heat around the middle of August.

Daily Average dew point for July 2014

Temperatures for July 2014

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