It's about to get hot -- really hot

It's about to get hot -- really hot
SEATTLE -- One 90 degree day in Seattle is not too unheard of. Maybe a nice day trip to Alki Beach and a chance to try on that new swimsuit. Two in a row and maybe it's a change of plans to hide out at the mall or movie theater.

Three in a row starts filling the coffers of hotels along the coast from emergency trips booked by inland residents fleeing the heat, and an outbreak of raspberries from homeowners who had taken a lot of flak from their neighbors for paying to install air conditioning. ("What, are you going to use that for three days a year here?!?" But oh, those three days...)

But four 90s in a row? Perhaps even five -- or, perish the thought -- Six?!?!

I think it means Arizona has a case to start charging us their state income tax.

What is shaping up to be the worst heat wave since 2006, and possibly even longer, is on the near horizon for the entire Pacific Northwest, not only leaving a population where many consider 80 as too hot, but ratcheting up fire danger and air quality concerns.

But first! A change in the forecast for Saturday. An area of low pressure is still stuck over in Eastern Washington, where it has triggered several thunderstorms over the past two days.

Some of those showers and thunderstorms even managed to drift into the North Sound Friday night and early Saturday morning.

And forecasting models now indicate that could be a somewhat frequent occurrence Saturday and possibly Sunday -- bands of storms rotating around that low across the Okanogan areas along the Washington/B.C. border, moving west/southwest into the northern Cascades, and then move west into northern and central Western Washington Saturday afternoon and evening.

One forecast model we use has a brief period of rain moving through the Seattle area in the 6-7 p.m. time frame, with thunderstorms north of that area.

Keep an eye on our weather radar through the day, and if you're going to Torchlight, perhaps carry along some rain defense equipment just to be sure. (An umbrella can double as a sun shield too!)

Outside the storms, we are still expecting sunshine between the towering clouds. Temperature forecasts are really difficult now as any cloud cover would limit the temperature rise, and of course, any shower would cool you off, but we're thinking as general rule it'll be mid-upper 70s north, and upper 70s to mid 80s in the Central Sound area, with mid-upper 80s in south Sound and into Southwestern Washington.

Then, the heat wave really gets going. A very strong and hot ridge of high pressure is building along the West Coast, staking claim to the entire western quarter of North American continent from Baja to the Arctic Circle (save for central and western Alaska) into the frying pan.

For Western Washington, it means several days coming up over 85 degrees, with perhaps a record stretch of days over 90.

The low pressure center moves away on Sunday, and that allows the ridge to really build up. Highs Sunday are expected near 90. There is a chance, but a diminishing chance of a few isolated storms on Sunday, but dry is for the vast majority of the region.

The ridge of high pressure is now anchored on Monday, really turning on the heat. In addition, a raging thermal trough is expected to form, bringing a hot, dry east wind. That wind is an important factor in heat waves because not only its origins over in what will be a scorching Eastern Washington, but as the air comes over the Cascades and sinks down the western slopes into Western Washington, it compresses and heats up further.

Highs around the greater Puget Sound area are expected to be well into the 90s on Monday, Tuesday and Wednesday, with upper 90s to perhaps even a few 100 degree readings in the Cascade foothills closer to that east wind, and in southwestern Washington.

Even the coast will be hot, but it remains to be seen just how hot yet. The thermal trough is expected to settle somewhere near or just off the shoreline, but there is some uncertainty where exactly the thermal trough will set up shop. A few miles in the placement -- whether it's 10 miles offshore or 10 miles inland -- could be the difference between 75 and 94 over there for spots like Hoquiam and Ocean Shores.

So for those attempting to flee the heat, at this point the coast is offering a little better odds of not being in the 90s, but it is not a guarantee, and there still could end up a couple days -- especially Monday and Tuesday - where it could be near 90 or even above. But at least you have a chance. The odds of it not being 90 around Seattle are slim.

The place to go if you can take a longer drive? Try Newport, Oregon, where highs are expected to remain in the 60s to low 70s as the thermal trough is expected to bend to their east.

We're Not The Only Ones Baking

As I said earlier, the entire Pacific shoreline is being affected by the ridge, even in Alaska. (So hopping a cruise next week isn't too much relief). Highs Monday through Thursday are expected in the mid 80s along the panhandle, where Skagway is looking at 84 on Tuesday (relatively like a 95 here in Seattle).

The inland areas of Los Angeles are supposed to near 100, as are parts of the East Bay area. Medford is looking at a high of 106 Monday, while Salem and Portland could reach 100.

In Eastern Washington, 103-106 high temperatures will be widespread through early next week.

Some of the records we're shooting for

The longest stretch of days at 90 or hotter was five in August 7-11 of 1981, when we had a stretch of 91, 93, 99, 98, and 93. We also had a stretch of 5 90s+ in 1941 when records were kept at the Downtown Federal Building.

There have been five times when we've had stretch of four days at 90 or hotter -- the most recent was July 21-24 in 2006, when it was 98, 96, 95 and 92.

But arguably the worst extended heat wave was in 1977 (one of those four-day 90+ stretch years) and this is the one this summer will likely compare to when all is said and done.

During the 17 day stretch between August 1st and August 17th, 13 days were at 85 or hotter, and six days were over 90, including a four day stretch of 90, 93, 93, and 95, followed four days later by another 93 and 95 degree day.

Here are the record highs this week for Sea-Tac Airport:

  • Sat. July 25: 94, 1988
  • Sun. July 26: 92, 1971
  • Mon. July 27: 95, 1988
  • Tue. July 28: 97, 1988
  • Wed. July 29: 95, 1971
  • Thu. July 30: 94, 1960

Fire danger extreme, air quality going down

With the summer already making waves for being hot and dry (this looks like it'll tie for the fourth driest July on record with 0.06" of rain) and even more hot, dry weather on the way, fire danger is extreme across the Northwest. It should be common sense, but be careful with any burning material, be it cigarette butts to campfires. One spark can do a whole lot of damage.

In addition, the Puget Sound Clean Air Agency says that air quality along the Cascade foothills is expected to degrade into the Unhealthy for Sensitive Groups category for Sunday through Wednesday. More information at pscleanair.org

When does it end?!?!? -- Updated Saturday morning

For the first time, forecasting models now show a possible end date for the heat with some sort of cooling marine push Friday night. Until then, they show slight cooling for next Friday, dropping us down to 90. If the cooling holds off until then, this would be historic as we've never had more than five days in a row of 90+, only reaching five twice -- a stretch in August 1981 and in 1941 at the Downtown Federal Building. As of this moment, there's decent odds we could reach six.

Since that is unprecedented, and since wandering low pressure areas tend to gum up forecast models in the long term, there is hope that the heat wave won't turn out as bad or as long as advertised.

Just keep counting the days until October. (68 to be exact.)

Tips for Staying Cool:

We've put together a good web site that has some tips for staying cool. Also, I welcome your tips for beating the heat -- put them in the comments below.

And stay cool out there!