An Extremely Stormy Week On Tap!

Hi everybody! Sorry for the delay in posts. I would have gotten more done if it weren’t for the recent revelations regarding Donald Trump. By the way, Donald Trump would be an absolute disaster for our country for many reasons, but one of them is his refusal to do anything about global warming. Though I doubt he was actually being serious with his famous tweet below, there’s no doubt that he is the “fossil fuel” candidate.

In case you haven’t heard, we have an extremely active week on tap, with several systems promising to bring flooding rains, damaging winds, and massive waves to the coast.

Since there’s so much to talk about, let’s go over each system in order.

Thursday morning – Friday afternoon: Heavy Rain and Wind Along The Coast

On Wednesday night or Thursday morning, an “atmospheric river,” a long, persistent fetch of moisture into the midlatitudes from the subtropics, will reach the area. Although the bulk of moisture will go into Southern Oregon/Northern California, the systems directing the atmospheric river into our area will land further north along the Olympic Peninsula, delivering additional rain to Western Washington. With strong winds aloft, rainfall will be concentrated on the windward slopes of the mountains. Since rivers are currently low, most won’t make it to flood stage, but there is currently a flood watch up for the exceptionally flood-prone Skokomish.

The aforementioned “systems directing the atmospheric river into our area” will give us quite a bit of wind as well, particularly Thursday night along the coast ahead of a strong cold front. The GFS model develops an area of low pressure along the northern edge of the cold front Thursday afternoon and brings a strengthening 975 mb system across the Olympic Peninsula Thursday night, which is nearly as deep and closer to us than the devastating Hanukkah Eve Storm of 2006. However, since pressures over the area will already be quite low, this storm shouldn’t be a major wind producer for the lowlands, though we could certainly see wind advisories throughout the Puget Sound area. There is still a lot of uncertainty with the timing and strength of this feature, so stay posted!

After this surface low comes through, the degrading “parent low” responsible for dragging this atmospheric river into our area in the first place comes ashore around noon Friday, bringing another round of wind and rain to our area.

Generally, that one-two punch would be noteworthy in and of itself. But we have a far more menacing storm slated to impact us on Saturday, and that’s what me and my fellow meteorologists have been ogling over for the past couple days.

Saturday: Historic Windstorm?

What will become Saturday’s storm is currently Super Typhoon Songda over the Western Pacific. All models agree that Songda will get entrained into the westerlies and spin up off our coast Saturday as a terrific extratropical cyclone. However, models disagree on the oh-so-important details, particularly the location of the low.

The European model gives, in the words of the forecasters at the Portland National Weather Service office, a “potentially historic” storm on Saturday. It takes an intense, sub 960mb low and tracks it NE along the Oregon and Washington coasts into south-central Vancouver Island. This brings to mind the “Columbus Day Storm” of 1962, which was also a mid-October storm that originated as a typhoon in the Western Pacific. Thankfully, the European model shows this storm tracking further off the coast than the Columbus Day Storm, which raced north just off the coast and caused devastation throughout Western Washington and Oregon.

Take a look at last night’s European model below, and notice the massive, 958 mb low just off the Washington Coast. This would be the largest regionwide windstorm since December 1995. Though it would likely not affect the Seattle area as strongly as the Hanukkah Eve Storm of 2006, it would have a far more widespread impact.

Now, let’s take a look at the UW WRF-GFS model, which is significantly less threatening.

Taking a look at the chart above, it’s hard to believe that this model is “significantly less threatening.” Look at all those isobars! However, with the storm much further off the coast, winds over Western Washington and Oregon are much lighter. The coast will still receive quite a beating.

Models are showing a weak low resulting from Thursday’s storm hanging off Haida Gwaii Friday and Saturday, and this will play a key role in the path of and strength of Saturday’s storm. If this low sags further south, it could slow down and weaken Saturday’s mega-low, pulling it further northward in the process. If this low remains further north and does not interact with the mega-low as much, the mega-low will likely be stronger, more compact, and further south.

Now would be a great time to make sure you are prepared for major windstorm. My friend Brie Hawkins of Little Bear Creek Weather in Woodinville, WA made a emergency kit to prepare for Saturday’s storm. People on the coast should prepare for a major windstorm with 30+ foot waves and the potential for coastal flooding.

The details with both these storms are still up in the cards, and future model runs will give us a better idea of what we can expect. I’ll keep you posted on the latest developments. Amazingly, some models bring ANOTHER windstorm through our area next week, but let’s just focus on these two storms for now.

Cheers,
Charlie