As temps rise, heat records in danger of falling

As temps rise, heat records in danger of falling
SEATTLE -- Ever tried to use a bottle of ketchup on, say, a hot dog, and you mightily whack, shake and jiggle the bottle but no matter what you do, that ketchup won't budge -- until several moments later it finally does let loose and you get a massive blob of ketchup that spills all over everything?

Picture that ketchup as this year's missing warmth -- bottled up in May and June (and early July) to where we've seen just 11 days at 70 or warmer and just one "warm" day at 77 degrees.

But it seems after weeks and weeks of rattling, the warmth is finally going to be unleashed in one big goop of hot air.

The first heat wave of the year is building into the Pacific Northwest, threatening to break record highs as temperatures are expected to soar to near 90 degrees by midweek.

As Western Washington summer heat waves go, this one is looking fairly routine. First, a strong ridge of high pressure is building into the area, pumping in some warmer air from the south. That will be good for highs climbing into the upper 70s and low 80s across the region on Tuesday.

By Wednesday, that ridge is joined by a thermal trough.

The trough draws air from the east, where it's hot and dry as opposed to our usual west wind off the ocean that provides our "natural air conditioning." And as an added bonus for heat fans, as the wind comes over the Cascade Mountains and sinks down the western slopes, the air compresses, causing it to heat up and dry out.

That is why heat waves here are typically a desert-type dry heat as opposed to the muggy heat of the Midwest and South.

So, how hot for midweek? As I mentioned earlier, this heat wave is pretty routine for how hot the air mass is expected to get and how strong the thermal trough will develop. For early July, that's usually good for upper 80s in Seattle -- maybe ekeing into the low 90s.

Getting near water won't help a whole lot as there won't be much of a seabreeze, but getting away from that "blow-dryer-like" east wind in the Cascade foothills will be better as highs in spots like North Bend and Enumclaw could get into the low 90s on Wednesday and Thursday.

The coast will also bake on Wednesday, likely getting well into the 80s if not low 90s near Forks and Hoquiam where you also get that easterly wind warming off the Olympic Mountains. In fact, the coast could be a couple degrees hotter than Seattle on Wednesday.

The thermal trough hangs out over Seattle on Thursday, setting the stage for another day near 90 here, although could see some minor cooling along the coast to the low-mid 80s.

If you are record watching, we are aiming for 88 in Seattle on Wednesday (1953 old record) and 87 on Thursday (1985 most recently). The forecast right now is for upper 80s both days so the Seattle records are in jeopardy. Olympia is 95/94 (likely safe), Bellingham is 88/85 (possible) and Forks is 80/82 (The 80 record should be smashed to bits. Thursday is more marginal.)

When does it end?

Good question. Typically, heat waves last about 2-3 days then stop, one of the many weather advantages of living in the Pacific Northwest. This one? We're not quite sure yet when it'll end. Two main long-range forecasting models differ on what will happen on Friday and into the weekend.

Friday is still looking toasty with highs in the 80s, except 70s now on the coast. But the trick is whether Friday is a transition day to cooler weather over the weekend, or just Day 3 of what could stretch into a nearly week-long heat spell.

One forecast model follows the traditional path of a weak system triggering some sort of push of marine air to roll in Friday afternoon or night that will cool us back to the 70s or low 80s over the weekend. But another model discounts that idea and actually keeps the east wind going through the weekend and into early next week -- shades of the extended heat waves of last summer.

Both models have been consistent in their differences with each other. We'll see if "tastes great" or "less filling" wins out as the week progresses. But for now, we're going to trend back the temperatures for the weekend (but still keep them warmer than usual) siding more with Northwest climate and the idea that we've seemed to have a magnet for attracting low pressure systems for the past two months.

Either way, forecast models don't really show any significant cooling until the middle of next week. In fact, one model has occasionally shown potential for another heat rebound early next week.

So after a stretch where 70 degrees has seemed but a dream, perhaps by the end of next week, we'll be dreaming for 70 degrees for a different reason.

Record High Temperatures This Week

Seattle: 88 on Wednesday; 87 on Thursday; 91 on Friday.
Olympia: 95 on Wednesday; 94 on Thursday; 95 on Friday.
Bellingham: 88 on Wednesday; 85 on Thursday; 85 on Friday
Forks: 80 on Wednesday, 82 on Thursday, 85 on Friday.

Cooling Centers Open In Pierce County

Pierce County has set aside several areas that will be open to the public as cooling centers to avoid the heat. In addition all Lowe’s, Petco, and Petsmart locations and VCA Pacific Avenue Animal Hospital will allow people and their pets to come in and get out of the heat. Pets need to be on a leash or in a crate. Owners must provide water if they plan on staying for long periods of time.