Warmup Ahead as Solstice Approaches

 FastCast--Tuesday, June 18 to Sunday, June 23:

After an active couple days with showers and thunderstorms around the region, conditions will calm down, clear out, and warm up as we approach the "official" start of summer and the longest day of the year. Tuesday will begin mostly cloudy, gradually becoming mostly sunny, with highs in the upper 60s to low 70s. Mostly sunny conditions are expected from Wednesday to Friday, with highs in the mid 70s to mid 80s, warming as we get later in the week. Highs will remain in the low 80s on Saturday, with some high clouds moving through the region. A marine push is likely on Sunday, bringing breezy southwesterly winds, an influx of marine stratus clouds, and highs dropping to the mid 60s.

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Continue reading the full blog below!

After an active few days, with lots of showers around, conditions will get sunnier and drier as a ridge builds over the Northwest.

Below is the upper-air forecast for Tuesday, from the European model.

This forecast shows broad troughing across the Western US, including the Northwest, although the trough is starting to move east, giving us sunnier conditions.

Let's fast-forward to Friday, seen again on the European model.

Notice the significant change, with broad ridging across most of the US, including the Northwest. This will bring sunnier and warmer conditions to our area.

Now, let's take a look at what kind of temperatures are in store, especially with a big warmup throughout the week. These forecasts for high temperatures are from the high-resolution NWS NBM (which stands for National Weather Service National Blend of Models, a NWS-run forecast model combining the output of all major models).

First, the forecast for highs on Tuesday, seen below.

On Tuesday, expect lowland highs in the upper 60s to low 70s, coastal highs in the low 60s, Willamette Valley highs in the mid 70s, and Eastern Washington's highs in the upper 60s to upper 70s.

Wednesday will be noticeably warmer across the state, as seen below.

On Wednesday, expect lowland highs in the upper 70s (low 80s Olympia southward), coastal highs in the upper 60s to low 70s, Willamette Valley highs in the mid 80s, and Eastern Washington's highs in the mid 70s to mid 80s.

Thursday will be even warmer, as seen below.

On Thursday, expect lowland highs in the upper 70s to mid 80s, coastal highs in the upper 60s to mid 70s, and Willamette Valley highs in the mid to upper 80s (isolated low 90s possible). Eastern Washington will reach the mid 80s to low 90s, hottest in the Columbia Basin. 

Additionally, Thursday is the "official" start of summer, and the summer solstice. This means that we only have 1 hour and 58 minutes of "night", with partial twilight beginning around 2 AM and remaining until 12 AM the next morning. It will be quite a warm day that will also be the year's longest!

Finally, let's take a look at highs on Friday, seen below.

Notice that the coast has begun to cool ever so slightly as marine air starts to move back in. On Friday, the lowlands will reach the upper 70s (north of Everett) to the mid 80s (Seattle south and east). The coast will reach the upper 60s to low 70s. The Willamette Valley will be quite hot, in the upper 80s to low 90s. Eastern Washington will reach the mid 80s to mid 90s, hottest around the Tri-Cities.

Stay tuned this week as we get more accuracy in the forecast beyond this weekend, and whether we will remain warm and pleasant, or if conditions will turn cooler and potentially wetter.