Saturday, August 29, 2015

In With The Rains, Out With The Flames

Friday, August 28, 2015
11:36 pm

Most of our wildfires are actually started by lightning, but that doesn't mean you can have a tannerite party during a red flag warning.,

Hey everybody! I’m finally back from summer camp, and while I had an amazing time there, I am very excited to sleep in my own bed, practice lots of saxophone, get a job (hopefully related to meteorology), and, of course, get back to writing weather blogs. I came back in the nick of time, as we’ve got a lot to talk about today.

As I'm sure you have no doubt figured out by now, this summer has been one of the worst fire seasons in Washington's history. Many news stations said that the Okanogan Complex Fire by Omak was the largest in the state's history, but this is not true, as the many fires here have not merged into a single large fire. That title is reserved for the Carlton Complex Fire of 2014 (wow, we really are getting burnt up, aren't we?). I attached a couple amazing shots below of the Wolverine Creek Fire, a fire that has been burning since June 29 and has now burned over 50,000 acres. These pictures are from the USDA (United States Department of Agriculture) Flickr page.

And here is a map of all the fires occurring over Washington and Oregon. It looks like all of Northeast Washington is on fire!

Credit: Northwest Interagency Control Center

Now, let's take a look at our mega-summer-storm. I can't ever remember seeing a storm this strong this early in the season. Even if it were November, this would still be a sizable storm for our region. But August? Good golly.

At 4 am, the storm was off our coast and travelling to the NNE. This is a perfect track for regionwide high winds... and it is the same path that our storm last December. I have a blog on that December storm here and you should all read it because it has an intense video of me in the storm. It's the same general track as the November 13, 1981 windstorm, the December 12, 1995 windstorm, and yes, the infamous Columbus Day windstorm of 1962.

Take a look at the nice, tight bent-back occlusion in the image below. The low center is right in the middle of that spiral.

Image valid 4 am PDT: UW Infrared Satellite

Image valid 4 am PDT: UW Radar

As the morning went on, the low moved further and further north and kept its intensity. One of the great things about our new coastal radar is that you can sometimes see the low centers of these types of storms as they swing on by, and you can clearly see the center with this storm less than 100 miles off the mouth of the Columbia River.

Image valid 6:30 am PDT: NWS NW Water Vapor Loop

Image valid 6:30 am PDT: UW Radar

At 9:30, the storm is moving on inland, and right now (10:56), it is crossing the Olympic Peninsula just to the south of Cape Flattery.

Image valid 9:30 am PDT: NWS NW Water Vapor Loop

Image valid 9:30 am PDT: UW Radar

Winds are reaching their peak now and will remain pretty strong until around 1 or so. After that, they will die down, but things will still remain pretty blustery around here. We have a high wind warning up (when was the last time Seattle had one of those in August?), but given the forecast wind speeds (40-50 mph gusts), a wind advisory would be more appropriate. We just have the warning since we are in the summer and weather like this is practically unheard of. I mean, take a look at all the weather warnings over our area. I've never seen anything like that in the summer.

Rainfall from this particular storm will total around 0.5 to 1.5 inches in the lowlands, with several inches in the mountains, especially the North Cascades, putting an end to any fires there. Though the majority of the rain will not make it over to Eastern Washington, some rain will fall, and this, coupled with high humidity, will be a tremendous help for firefighters fighting the wildfires in NE Washington. They will have to battle with strong winds though.

Valid 05:00 am PDT, Tue 01 Sep 2015 - 72hr Fcst: Retrived from UW mm5rt modeling website

The rest of the week looks showery, but as far as major storms go, I don't see anything in the near future.


Wednesday, August 12, 2015

Heavy Rains Friday

Wednesday, August 12, 2015
10:18 pm

Hello everybody! I have a day off from my counselor duties at Hidden Valley Camp so I thought I'd go ahead and write a blog about the upcoming rains later this week. We could get dumped on Friday, but there's still a lot of uncertainty. 

The weather down here sure was interesting though. I heard some thunder up at camp, and although I missed it, I heard through the grapevine that an intense thunderstorm passed right over Seattle. Today, Sea-Tac got more rain in 24 minutes than the previous 71 days combined. Also, Iwakuma tossed a no-hitter. I gotta say... today was a good day. Too bad it's cloudy for the Perseids meteor shower tonight, but hey, you can't get too greedy. 

Anyway, let's take a look at what we may be dealing with later this week. I get back to camp Thursday afternoon, and everything we do out there is in the great outdoors (including sleeping and eating), so even though I absolutely love the rain, it definitely puts a damper on activities. Me and my tent group of six 12-year-old boys are hiking Mt. Pilchuck on Friday, so I'm definitely interested to see what hiking in the rain with these kids will be like. By the way, the hike is only 5.4 miles roundtrip, but features 2,300 feet of elevation gain. I'm super excited, rain or shine.

Since I'm talking about Friday, I might as well give a brief talk about the weather we can expect Thursday. The newest models from the UW don't show much precipitation at all, but there will be a significant amount of CAPE (Convective Available Potential Energy) over the area in the afternoon, so some thunderstorms may develop. CAPE is defined as the amount of energy a parcel of air would have if it rose until it could no longer rise (i.e. it becomes colder and thus denser than the surrounding air). The more CAPE there is, the more unstable the atmosphere is, and the faster parcels rise. Because of this, high CAPE is an important ingredient for convection, but just because there is high CAPE does not mean there will be convection. There are many other factors that can inhibit convection... strong low-level inversions, high pressure systems, low vertical velocities of air parcels in the lower atmosphere to initialize convection... I could go on. There are plenty others. 

Valid 05:00 pm PDT, Thu 13 Aug 2015 - 24hr Fcst: Retrieved from UW Pacific Northwest Environmental Forecasts and Observations Modeling Page

Anyway, let's move onto Friday. I'm only going to give a brief overview, because the details are pretty murky for reasons I will explain shortly.

The rains are predicted to start heading into the area Friday morning.

Valid 08:00 am PDT, Fri 14 Aug 2015 - 39hr Fcst: Retrieved from UW Pacific Northwest Environmental Forecasts and Observations Modeling Page
A blob of rain will form south of the Olympics (at least in this model run)...

Valid 11:00 am PDT, Fri 14 Aug 2015 - 42hr Fcst: Retrieved from UW Pacific Northwest Environmental Forecasts and Observations Modeling Page

... and this blob will intensify and move eastward as the day progresses.

Valid 05:00 pm PDT, Fri 14 Aug 2015 - 48hr Fcst: Retrieved from UW Pacific Northwest Environmental Forecasts and Observations Modeling Page

This model run gives around an inch of rain to Mt. Pilchuck on Friday. This morning's run gave two. We'll see what tomorrow morning's run gives. All this variance in precipitation is due to a cut-off-low off the Northern California Coast. Since cut-off lows are not connected to the jet stream, they are rather erratic and hard to forecast. This cut-off low is responsible for Friday's uncertain forecast. There is an old weather saying: "cut-off low, weatherman's woe." That saying definitely holds true right now!

Right now, rain seems like a pretty good bet for Friday, but where and how much is up in the air. If the models are correct however, some places could see pretty heavy amounts, especially places north of Everett. But regardless of how much it rains, I'm prepared to have an awesome time climbing Mt. Pilchuck on Friday. 

Thanks for reading!