Monday, December 03, 2007

Down came the rain

Uh, holy Northwest hurricane, Batman:

Updated Monday 8:30 a.m.
Current Headlines: Winds easing a bit along the coast, but still over 60 mph. Peak gusts from 80-120 mph recorded. Almost all major roads along coast are blocked by down trees and power lines. Several local mudslides and urban flooding problems. Amtrak service suspended between Eugene and Vancouver. Flood Warnings continue for several rivers. Freezing rain is falling at Snoqualmie Pass. Heavy rain continues to fall across Puget Sound -- Seattle well over 2.5" of rain since midnight.

SEATTLE - The largest of three consecutive storms was moving through Western Washington Monday, bringing heavy rain, damaging wind, and potential for major flooding along Olympic Mountain-fed rivers.

The Washington and Oregon coast were severely battered by the storm Monday morning. Wind speeds have been clocked at 85 mph in Astoria and 81 mph in Hoquiam. (Hoquiam has since lost power, so we don't know if it's been worse.) Meanwhile, an unofficial report out of Bay Center, Wash. (near Long Beach) had a measured gust of 119 mph. (They stick out on a headland a bit and have a free shot at strong wind.)

But these aren't occasional gusts -- there have been steady gusts in the 65-75 mph range in those areas all morning. Meanwhile, weather instruments at Tatoosh Island and Destruction Island along the coast are reporting sustained winds of 70 mph, gusting to 85 mph.

Power outages and hazardous driving conditions have forced many school districts to delay or cancel classes. (See complete school closure list)

Grays Harbor County Sheriff Mike Whelan says the storm damage on the Washington coast is the worst he's seen in 30 years in law enforcement.

The Washington State Patrol says most major roadways in Grays Harbor and Pacific Counties, including U.S. Highways 12 and 101, are closed or blocked due to high winds and numerous trees and power lines down across the counties. It is not known when roads will reopen.

Two Grays Harbor PUD power line workers trying to restore service were injured, one seriously in a 40-foot fall, when a windblown tree hit a lift truck bucket Sunday night, sheriff's deputy David A. Pimentel said. Both were hospitalized, one with head injuries and the other with back injuries.

Whelan says rescuers had to use chain saws and dodge falling trees to clear the highway to get an ambulance to the scene. One worker has been taken to Harborview Medical Center in Seattle. The other is at Grays Harbor Community Hospital in Aberdeen.

Whelan is a storm victim himself. A falling tree smashed his truck in the driveway at his home. He had to be picked up by a patrol car.

Grays Harbor PUD says they have at least 33,000 people without power, but won't be able to further assess the damage until daylight. In the interim, they have pulled all their crews off the streets until the winds calm down.

Schools in that area closed for the day due to lack of power.

Problems were plenty in the Puget Sound area as well. Sounder service between Everett and Seattle was canceled because of some mud on the tracks. There are extra buses in Everett and Edmonds to help with commuters.

Mudslides halted north-south Amtrak passenger train service between Eugene, Ore., and Vancouver, British Columbia.

In the greater Seattle area, heavy rain -- storm totals of over 2" since late Sunday night -- is creating local flooding problems.

A mudslide blocked part of Westlake Avenue North in the 2400 block. Another mudslide blocked one lane of Highway 99 near 14th Avenue South, and a sinkhole ruptured the road at Golden Gardens Drive NW and NW 85th Street near Ballard.

Standing water was also a big problem on all area roadways.

Several Warnings In Effect

Here are the myriad of warnings and watches in effect for the storm:

A HIGH WIND WARNING remains in effect for the coast, Admiralty Inlet area, northwestern Olympic Peninsula area, the greater Everett/Snohomish County area, the Hood Canal area, the lower Chehalis Valley, and the area around Port Townsend through 4 p.m. Monday.

This storm is expected to bring sustained winds of 40-50 mph, gusting as high as 80-100 mph along the coast and Sekiu/Clallam Bay, Neah Bay area. For the rest of the places listed in that warning, gusts are expected as high as 60 mph.

The largest gusts are expected until around 7 a.m. along the coast, then the winds are expected to abate a bit through the morning (still very windy though), and then perhaps another wave of wind toward late morning/midday, but not quite as strong as before.

As to why the seemingly sporadic locations for the Wind Warning, this storm is poised to bring out a local wind-generating effect, which I'll get to a little later in this discussion.

For the rest of Western Washington, including the greater Seattle-Tacoma (but not Everett since that's in the warning) area, A WIND ADVISORY is in effect for the same time frame. (A Wind Advisory is a notch below a High Wind Warning). Here, winds are expected to gust as high as 40-50 mph. Yes, while the coast is going gang-busters, this does not look like a big wind event for the I-5 corridor, save for perhaps the Snohomish County area, as the Olympics are providing a barrier to strong wind here.

A WINTER STORM WARNING remains in effect in the Cascades through Monday morning. Conditions have warmed considerably, but pockets of cold air near the surface means continuing snow for Stevens Pass, and freezing rain problems in Snoqualmie Pass.

FLOOD WARNINGS are now in effect for all rivers that feed of the Olympic Mountains. That includes the Bogachiel, Skokomish, Elwha, Dungeness, Satsop, Deschutes, and Chehalis Rivers. A FLOOD WARNING has also been issued for the Puyallup River near Orting, the Tolt River and the Issaquah Creek.

The information is fast changing so the best advice is to go to and bookmark this link: ( You might need to scroll down. Some of Portland's flood warnings will be listed there too, and it's listed chronologically by update time.)

That is the direct page to the National Weather Service Flood Warnings. It has specific details on all rivers under Flood Watch and Warning.

As much as 6-10 inches of rain are expected in the Olympic Mountains, and some Olympic-fed rivers could see record flooding with this event. If you live in this flood plain, take immediate precautions and finalize them as soon as possible. Flooding will likely begin Monday and continue through Tuesday and possibly into Wednesday as the water flows downstream.

The Cascades will also see rain approaching 5 inches, so flooding is expected on Cascade rivers as well, but hopefully not to the extent the Olympics will get it.

A FLOOD WATCH remains is in effect for all other mountain-fed rivers in Western Washington in anticipation of Monday's heavy rain, but many Cascade rivers could go on Flood Warning soon.

A HIGH WIND WARNING is also in effect for the mountains, where ridgetop winds could reach 80-100 mph gusts -- especially in the Olympics. This is not a time to be hiking or mountain climbing. Pass travel will also be very difficult.

A HIGH SURF WARNING is in effect for the coast, where seas have been recorded as high as 40-45 feet off the north Oregon coast, and 39 feet off the south and central Washington coast.

And in a related warning, a COASTAL FLOOD WATCH is in effect from Sunday evening through Monday evening for problems associated with high surf and beach erosion.

Finally, an AVALANCHE WARNING is in effect for the Cascades through Monday as conditions are very dangerous in the mountain backcountry.

Storm Stats So Far:

Wind: Peak Gusts So Far

Bay City, Ore.: 129 mph (Unofficial)
Bay Center, Wash: 119 mph (Unofficial)
Tillamook, Ore. (tide station): 100 mph
Florence, Ore: 91 mph
Clallam Bay: 90 mph (estimated)
Hurricane Ridge: 86 mph
Astoria, Ore.: 85 mph
Destruction Island: 84 mph (Sustained 65-73 for several hours)
Tatoosh Island: 82 mph
Hoquiam: 81 mph (Station went dark at 4 a.m.)
Tillamook, Ore (Airport): 74 mph
Aberdeen: 62 mph
Forks: 58 mph
Bellingham: 53 mph
Shelton: 51 mph
Oak Harbor: 49 mph
Kelso: 41 mph
Olympia: 39 mph
Rain: Storm totals since Midnight through 8 a.m.

Shelton: 3.71"
Seattle: 2.58" (About to climb into Top 10 wettest days ever.)
Olympia: 2.17"
Everett: 1.70"
Tacoma: 1.41"
Sequim: 0.18". (The Olympic Rain Shadow is in full force today. Take a peek at the radar and note the big hole over the northeastern Olympic Peninsula.)
The Rain Timeline

Heavy rain will continue through the day and into Monday evening before finally tapering off. As much as 2-4" of rain is expected in the lowlands, while 8-12" of rain are expected in the Olympic Mountains, and 4-6" possible in the Cascades.

Combine that with warm temperatures (highs Monday will be well into the 50s), and that's a classic recipe for major flooding.

And with that much rain in the lowlands, urban flooding is possible as well. You can help by trying to keep drains clear of leaves.

The Wind Timeline

For the areas listed in the High Wind Warning:

Strong winds will pick up along the coast in the wee hours of Monday morning, and continue to blow through the day. This is not a typical windstorm where we have the low center pass through and we get 2-5 hours of wind. This is an extended event where strong winds are expected from 6-10 hours in the areas listed in the wind warning.

So high winds are expected to blow through the day Monday and then taper off Monday afternoon or early evening.

For the areas listed in the Wind Advisory, it shouldn't blow quite as strong or as long, but it will still be a very blustery day.

Why Snohomish County for the Wind Warning?

As we mentioned before, this is not our typical windstorm where the winds don't pick up until we have a big area of low pressure passing through to our north. Those typically last, oh, 4-6 hours on the coast, and 2-3 hours inland.

This one is different, but difficult to explain in layman terms. Suffice to say, even though it's farther offshore, it's a rather large storm, and the way its fronts are aligned, it'll "open the door" to the winds to race out toward the low earlier than usual. That door will open very early Monday morning and won't "close" until late Monday evening, thus making for an extended period of strong winds.

Aside from that, we have something forming called a "lee-side low" or "lee trough". This is a very localized effect caused by large amounts of air rushing around a mountain. On the other side, it'll form an eddy on the back side of the mountains where the air is rushing. (You might see this on the beach, when waves rush past a rock, note how the water swirls in wake of the rock.)

In this situation, the lee trough is forecast to form around the northern Hood Canal area. This creates a localized effect where that low will cause a "mini-windstorm" and enhance the pressure difference over a small area. That area is expected to be that Admiralty Inlet, western Snohomish County, North Hood Canal and the northeastern Olympic Peninsula, like Port Townsend and Port Ludlow.

The other areas in the warning outside this area are just in the warning for "normal" winds to get strong. What a crazy way to start December!