Monday, November 21, 2011
I have to be brief, as I will have classes in 20 minutes, but I thought I’d give you an update on the major storm that will impact us tonight into Wednesday. I looked over the model runs this morning, and it looks as if the storm is now forecast to bring even more rain into the lowlands. Additionally, it will still be very windy on the coast, particularly the Oregon coast, where sustained winds of 40 knots with gusts up to 70 knots in isolated places will pound the area for up to 24 hours.
Today, I was browsing the UW atmospheric sciences website, and I found some early model runs from the beginning of December 2007 showing that massive storm that impacted us at the beginning of the month. For the sake of comparison to today’s storm, I’ll show them below.
Valid 04:00 am PST Mon, 03 Dec 2007 – 12hr Fcst – UW 00z 12km WRF-GFS 10m wind speed
This event was extraordinary. Note the sustained winds over 50 knots on the Oregon coast. Washington was also extremely hard hit by the storm.
The precipitation was also incredible… Seattle saw over 3.5 inches of rain in 24 hours. Bremerton, right across the sound, saw 10.78 inches in 24 hours! And some regions in the Willapa Hills saw over 15 inches of rain in 24 hours.
Now, let’s look at the runs for today’s storm.
Valid 01:00 pm PST Tue, 22 Nov 2011 – 33hr Fcst – UW 12z 4km WRF-GFS 10m wind speed
The winds, while extremely strong, are not as strong as the 2007 event, and will mainly occur on the Oregon Coast.
Just a few minutes left… let’s look at precipitation.
This model is showing up to 5 inches of precipitation for the Seattle area in 24 hours. If this verifies, this could set numerous records for 24-hour rainfall totals across the lowlands. I will be monitoring this situation very, very closely. As far as flooding goes, the Skokomish River off the Olympics is certain to flood. Many other rivers will flood as well… I’ll give you more details as the event unfolds.