Has Summer Finally Arrived in Western Washington?

After what has seemed like a dreadful start to summer (at least to some), it seems like summer has finally started in the area.

Overall, since meteorological summer began in June, temperatures have been mostly in the 60s and low 70s, as illustrated in the figure below. In fact, at least at Paine Field, the temperature has not yet reached 80 degrees. On average, the first 80-degree day of the year is June 12—so we’re a little behind schedule! The last time it’s been at least this far into summer without an 80-degree day was 2012 (when the first 80 degree day occurred on August 4th)!

Figure 1: Daily temperature data from Paine Field Airport (KPAE) since June 1

In terms of precipitation at KPAE, we are actually slightly below the average accumulation of 2.53 inches since June 1st, with a total of 2.34 inches. However, when you look at the number of days with non-zero amounts of rain, it tells a different story. We are currently at 23 days of rain in the same time span.** And many of those days were on a weekend!

Figure 2: Number of days of rain at KPAE during the above time span

As you can see, this year ranks number 2 for the most amount of days of rain in the available data. So even though the rain didn’t amount to much, we’ve seen more days of rain than usual.

But now it seems like we’ve flipped a switch and summer has finally arrived. And for the most part, it looks like it’s here to stay for awhile.

Figure 3: Euro model of 24-hour rain for KPAE

The above figure shows that besides a small blip of rain expected on Friday, we are supposed to be primarily dry for most of the forecast period, which will no doubt make many people happy. Even some of the most stout rain lovers are ready to have a little bit of real summer-like weather. I’ll admit it’s been a little nice to go outside without worrying about getting rained on.

Thanks to a nice ridge of high pressure setting up shop in the area, temperatures for the rest of the week will be quite comfortable, primarily in the low-to-mid 70s in the Everett area…which is just right, in my opinion. Tomorrow (Wednesday) looks to be the warmest day of the week. Some areas in Western Washington could even reach the low 80s! Friday’s temperature should drop slightly associated with the weak system that looks to bring a bit of rain over the area.

According to most recent models, next week is when more of the heat could make its way back. There’s still time for things to change but it’s definitely something to keep in mind looking ahead.

In the meantime, enjoy the summer weather and get outside…safely of course! It looks like the warm and dry weather is here to stay for awhile.

**Note: one of the precipitation daily values is missing from the 2020 official data, but in combing over other sources of data, I believe it did rain on that day. That would put the number of days with precipitation at 24.

They Say “April Showers Bring May Flowers”… So Where Are The Showers?

The majority of this month has been quite pleasant weather-wise. The sun and dry weather has served as a mood-booster for so many people in the midst of the COVID-19 pandemic. But it still begs the question…where is the rain?

Here is the Paine Field precipitation accumulation graph so far for the month of April.

Figure 1: Accumulated precipitation for KPAE, via NOAA

With the exception of some trace rainfall on April 11, all the rainfall has occurred in the first few days of the month, amounting to just 0.35 inches. The normal amount for this period is 1.48 inches.

When looking at the same graphic for Sea-Tac, we get a similar story.

Figure 2: Accumulated precipitation for KSEA, via NOAA

Except here, there has only been 0.01 inches of accumulated rainfall. You can hardly even see the green line on the graphic.

To put this into perspective, take a look at this tweet.

Much of California has been getting hammered by storms and rainfall and has significantly more than us here in western Washington. Even areas of Arizona have more than Sea-Tac! Wow.

So why has our weather been so nice recently? It has been the result of a ridge of high pressure that has been acting as a block, preventing storms from making it to our region. (You can read more about this in Cliff Mass’ blog, found here.)

And, spoiler alert, this nice weather is likely to continue through the rest of the week.

Highs today should be in the mid-to-upper 60s for most of us.

Overnight tonight, clouds begin to increase as onshore flow (i.e. from west to east) develops. As a result, Wednesday morning has a chance to start cloudy. But as the figure shows below, clouds should burn off by the afternoon. Because of the cloudy start, Wednesday’s highs could be slightly lower than today’s.

Figure 3: Cloud cover percentage (darks = less clouds, lights = more clouds)

Thursday and Friday look to be the warmest and nicest days of the week, with highs in the low 70s possible!

Figure 4: GFS high/low temperatures for KPAE
Figure 5: GFS high/low temperatures for KSEA

It should be perfect to go outside and go on bike rides, walks, and the like… of course maintaining social distancing 🙂

Some models/ensemble members of models show a chance for light showers on Saturday, but if anything falls, it likely won’t amount to much. Models are also suggesting the chance of some rainier weather next week, but it’s too far in advance to know for sure.

In the meantime, enjoy the sunny weather!