Thursday, June 20, 2024

Hot Through Saturday, Cooler Sunday with Fire Danger

 FastCast--Friday, June 21 to Tuesday, June 25:

One of the hottest days of the year (so far) is ahead on Friday for the lowlands, with highs likely reaching the mid 80s across the region. Areas north of Everett and closer to the water will likely remain in the upper 70s to low 80s, with areas south of Tacoma and in valleys potentially reaching the upper 80s. Conditions will get cloudier and temperatures will cool somewhat on Saturday, with highs back in the upper 70s to low 80s. Further cooling and a region-wide chance of showers is ahead on Sunday, with highs dropping to the mid to upper 60s. Highs will return to the low to mid 70s on Monday and Tuesday, with partly cloudy to mostly sunny skies and a lingering chance of showers on Monday. Overnight lows through Monday will be in the low to mid 50s. There is significant fire danger in Eastern Washington on Sunday. Keep reading for more information.

-----------------------------------------------------------------------

Continue reading the full blog below!

A hot few days are expected across Washington state, with cooling later in the weekend and potentially significant fire danger in Eastern Washington on Sunday. Let's take a look at the forecast!

We'll start with the high-resolution NWS NBM model forecast for highs on Friday, seen below.


On Friday, expect highs from Seattle northward in the upper 70s to mid 80s (warmest away from the water). From Seattle southward, highs will reach the mid to upper 80s, warmest in river valleys. The coast will be cooling down a bit, with highs in the mid 60s to low 70s. The Willamette Valley will likely reach the upper 80s to low 90s, with Eastern Washington in the mid 80s to mid 90s.

On Saturday, temperatures will cool some west of the Cascades, while remaining hot on the east side. Below is the NWS NBM forecast.


On Saturday, expect lowland highs to reach the upper 70s to low 80s (cooler near the water and in the NW Interior). The coast will cool to the mid 60s, and the Willamette Valley will drop slightly to the mid to upper 80s. Eastern Washington will warm up, with highs in the upper 80s to upper 90s, hottest in the Tri-Cities area.

Sunday will see more dramatic cooling for Western WA, with some cooling in Eastern WA as well.


On Sunday, the lowlands will only reach the mid to upper 60s, with the coast remaining in the low 60s. The Willamette Valley will cool to the mid 70s, and Eastern Washington will cool to the upper 70s to upper 80s (hottest in the Columbia Basin).

However, this cooling will come at a price, especially for Eastern Washington. Below is the forecast for winds on Sunday, from the European model.


This forecast shows a breezy day west of the Cascades (20-25 mph gusts, except 30-35 mph along the Strait). However, Eastern WA is quite windy, especially in the lee of gaps in the Cascades. Gusts of 30-45 mph are expected, strongest east of the Gorge and around the Kittitas Valley.

With these winds will come very dry conditions. Below is the European model forecast for relative humidity on Sunday afternoon.


Notice the extremely low values of 10-20% across Eastern Washington. This will pave the way for rapid fire spread. Any fires that start on Sunday will have the chance of becoming out-of-control very quickly, due to strong winds, very low humidity, and overall dry conditions.

Finally, let's take a look at what will be happening on the western side of the state on Sunday and Monday. The weak weather systems ushering in cooler conditions will have some light showers and a potential Convergence Zone, as seen in the European model rain forecast below, showing rain through Monday night.


This forecast shows light rain across Western Washington, with 0-0.15" in the lowlands, up to 0.25" on the North Coast, and 0.2-0.5" in the Cascades and Olympics.

Stay tuned over the next few days for more information on the Eastern WA fire weather situation and the overall patterns we'll have to wrap up June.

1 comment:

Next Storm System Hits Western Washington

  8-26 Video Briefing: Next Storm System Hits Western Washington