Marine Pushes, and Their Effect on Summer High Temperatures

Thursday, August 21, 2014
11:03 p.m.

We "only" reached 70 degrees today. At 6 degrees below average for a high temperature, it's fairly cool, but not extraordinarily so. The last time we didn't hit 70 was on July 24th, meaning it's been nearly a month of consecutive 70 degree-or-higher days, with some days much higher (Sea-Tac hit 96 on August 11). That's pretty impressive.

We may have kept our streak going, but setting a new record for consecutive days above 70 is not going to be easy. The record is 61 days (thanks Scott Sistek), so we'd have to keep our streak going into the end of September to set a new one. It'd be pretty amazing if we broke that record, but the chances of doing such a thing are next to nil.

Why did we have such a downward shift in temperatures today? It's not like we had any massive rainstorm come through the area or anything. Besides, even on August 13, our rainiest day of the summer (0.85 inches at Sea-Tac), the temperature got up to 74 degrees. What made this day different.

The answer, my friends, lies in the all-too-familiar phenomenon we call the marine push. Also known as our "natural air conditioning," it occurs when pressure over land is lower than that over the ocean, and cool, moist maritime air flows into Western Washington. Strong marine pushes generally are associated with thick stratiform cloud decks extending into Western Washington all the way to the foothills of the Cascades. As the day goes on, the sun often "burns through" these clouds, but if the push is thick enough, the sun won't be able to disseminate the stratus clouds, and the surface won't heat up as much as a result. Those are the types of pushes that give you particularly cool days, sometimes as much as 10 degrees below average.

Let's take a look at the marine push event that occurred today. All of these images were gotten from the UW weather loops website. It's a great website with satellite, radar, and model loops and time series of general observations throughout our area. They even have lightning strike data available. In addition, they have an archive of tons of previous satellite and radar images, so you can look at all your favorite storms from the past. I've relived many a storm through this awesome feature.

10:00 a.m.

11:00 a.m.

12:00 p.m.

12:45 p.m.

2:00 p.m.

3:00 p.m.

You can see that it took a while for the clouds to clear out. At 10:00 a.m., they were widespread throughout Western Washington and spread far into the Cascade foothills. They gradually declined in extent and depth, and were gone completely by 3:00 p.m. It wasn't the strongest marine push of all time, but it was enough to cause a cloudy morning.

This coming week looks to feature a decrease in the magnitude of these pushes, and by early next week, they may not be happening at all. However, these pushes will return later in the week, and we will cool down again as a result.

Charlie

Lake Washington Beach Temperatures

Wednesday, August 20, 2014
10:27 p.m.

Here fishy fishy

One reason I love warm summers like the one we have been having is because of the excellent fishing they provide. When the water is warmer, the fish are hungrier, and thus grow to larger sizes. This was probably taken in 2004 +- a couple years, but whatever summer it was, I remember that there was a pretty long sunny stretch that was particularly good for fishing.

Let's take a look at the water temperatures at the beach closest to my house - Madrona Beach. All of these temperatures (and fecal coliform levels) for beaches in the lake can be found here.

The temperature has stayed in the low-mid 70s since July. That's absolutely extraordinary. How does this compare to recent years?

2013

2011

2012

2013 was pretty impressive, with a stretch of around for the month of July, climbing into the low 70s for August. Temperatures are measured in Celsius to the nearest degree, so the decimal point is misleading. The temperature wasn't actually 71.6 degrees for five straight weeks. 2012 was a little cooler, and 2011 was much cooler, with temperatures not making it above 21 degrees C.

This data is only for one beach, and is therefore not a good measurement of the lake as a whole. However, it still highlights the relative warmth of the lake from one year to another.

It's easy to see why the lake is so warm this year. We had the second-hottest July on record with an average temperature of 69.2 degrees, 3.5 degrees higher than normal, and August thus far (as of August 20) has an average temperature of 70.7 degrees, 4 degrees higher than normal. The lake temperatures are higher than the average atmospheric temperatures because the water absorbs radiation coming from the sun, heating it further. It's the same concept as an asphalt road on a hot sunny day. It takes a lot of energy to heat water, and Lake Washington is extremely deep - over 200 feet deep in spots - and this prevents the lake from getting too warm as mixing occurs throughout the summer. However, water has a very low albedo (it absorbs almost all the radiation incident on it), so it is very efficient at storing heat. Moreover, because water has such a high heat capacity, it will store this heat well into September and October.

So there you have it. Warm atmospheric temperatures and lots of sunshine = warm water, and warm water = good fishing. And you think Madrona Beach is warm? Check out Lake Sammamish Beach in the shallower Lake Sammamish.

80 degrees? That's starting to get a little gross.

Charlie

Back From Camp!

Tuesday, August 19, 201411:26 a.m.

Hidden Valley Camp - 2003. 

Hidden Valley Camp - 2014.

It's really surreal how time flies. At least I can take solace in the fact that I'm still just as much of a goofball now as I was back then.

This was my 8th summer up at HVC. I was a camper from 2003-2008, then a "camper leader" in 2010. This summer was my first summer on staff. When I was a camper, the only staff job I could ever imagine having was a group counselor, but I'm very happy to have had a job in the kitchen this year. I learned a ton from the man in charge, Steve Stimpson, most notably how to manage my time effectively. I know I will take the lessons I learned from him with me for the rest of my life. I'm also now extremely good at baking for 170+ people. I've got some work to do as far as baking for one person goes though.

Now that I'm back, I've got some serious work to do. I've got a saxophone solo to transcribe, I've got meteorology internships to look into, and of course I've got weather blogs to write. My weather blog productivity will soar in the upcoming days.

Before I sign out for now though and continue to unpack, I'd like to emphasize how amazing this experience was. If you have kids and are interested in sending them to summer camp, definitely check out HVC. And if you are my age +- several years and looking for a summer job that may be the most rewarding experience of your life, talk to me or email the camp director (he's awesome) directly at hiddenvalleycamp@earthlink.net.

It's good to be back!
Charlie

Relief in Sight For Firefighters

Tuesday, July 22, 2014
12:11 a.m.

Apparently, there's been a pretty massive complex of wildfires in Eastern Washington over the past week I've been at camp. I'm finishing another day off and need to be back in the kitchen at 7 a.m., but I have enough time to write a brief blog.

Here are all the fires burning as of Monday:

Carlton Complex Fire - (238,000 Acres Burned; 2 Percent Contained, largest in state history)
Chiwaukum Creek Fire - (11,000 Acres Burned; 10 Percent Contained)
Mills Canyon Fire - (23,000 Acres Burned; 75 Percent Contained)
Buzzard Complex Fire - (396,000 Acres Burned; 75 Percent Contained)
Shaniko Butte Fire - (42,000 Acres Burned; 50 Percent Contained)
Waterman Complex Fire - (12,000 Acres Burned; 60 Percent Contained)
Pine Creek Fire - (30,000 Acres Burned; 35 Percent Contained)

The Carlton Complex Fire near Winthrop, WA on July 18. Soldiers assigned to the 66th Theater Aviation Command, Washington Army National Guard, brought six helicopters to the area to assist firefighters on the ground. 
Washington Army National Guard photo by Sgt. 1st Class Jason Kriess http://www.defense.gov/homepagephotos/leadphotoimage.aspx?id=98018

The Carlton Complex Fire was initiated by a lightning strike in the Methow Valley in Okanogan County in Northeastern Washington on July 14, and at 379 square miles as of Sunday, is the largest wildfire in state history. At only two percent containment, it will likely grow some more. The fire indirectly killed one man as he had a heart attack trying to save his Carlton, Washington home from the flames, and 150 homes have been destroyed so far, with an additional 1100 threatened. 1,400 firefighters are fighting this particular blaze.

The Chiwaukum Creek Fire from Leavenworth: Photo Credit - Dominic Urbano.   http://www.fallenleafimaging.com

The Chiwakum Creek Fire was also initiated by lightning, and was done so last Tuesday the 15th. It is currently encroaching upon the Leavenworth area, and 900 people have been evacuated. 1,580 structures are currently threatened by this blaze.

The Mills Canyon Fire from Entiat Road on the Evening of July 9. http://inciweb.nwcg.gov/incident/photograph/3937/15/

The Mills Canyon Fire stared on July 8, but it is unknown what actually started it. Firefighters are almost done containing it, and hopefully it will be completely contained within the next couple days.

Smoke and a Pyrocumulus Cloud from a Northern Part of the Buzzard Complex Fire.  http://inciweb.nwcg.gov

The Buzzard Complex Fire actually consists of seven different fires in east-central Oregon. It started due to a lightning strike, and this strike occurred on July 14th 45 miles NE of Burns. Even though it, at 396,000 acres, is the largest of the fires, it is also 75% contained, so hopefully it can be extinguished within the week.

The Shaniko Butte fire started after a lightning strike on July 13, approximately 12 miles to the north of Warm Springs Oregon. It spread rapidly at first but has since been contained from the north. However, it is expected to continue to grow to the southeast, with 108 structures still threatened by the blaze.

Bailey Butte Fire on July 15, 2014. Photo Credit: Susan Brock  http://wildfireoregondeptofforestry.blogspot.com

John Day Unit fire   http://wildfireoregondeptofforestry.blogspot.com

The Waterman Complex Fire has four separate fires and was started on July 11 by lightning. At 9,745 acres as of Monday, the Bailey Butte Fire is the largest. These fires are located 20 miles NE of Mitchell, Oregon.

Firefighters spraying water on the Pine Creek Fire - July 20, 2014   http://inciweb.nwcg.gov/incident/photograph/3514/3/

The Pine Creek Fire, another lightning-sparked wildfire, is currently burning in the Deschutes National Forest to the south of Fossil, Oregon and was expected to approach residences in Rowe Creek.

________________________________________________________________

I was surprised to see that most of these fires were caused by lightning. Every single one of them was with the exception of the Mills Canyon fire, which has unknown origins, meaning it very well could have been initiated by lightning. I thought that the majority of these fires would be started by humans, but I was wrong.

Is relief in sight? I'm very thankful to say that rainfall does look to be just around the corner. Depending on where you are, the rainfall might be quite substantial as well. Let's take a look at the models.

Valid 05:00 pm PDT, Thu 24 Jul 2014 - 72hr Fcst    www.atmos.washington.edu/~ovens/wxloop.cgi?mm5d3_wa_pcp72+///3

Over the next 72 hours, Western Washington, especially the Cascades, looks to get hammered, with most of this rain occurring in a single day. Unfortunately, Eastern Washington ends up relatively dry. The same is true for Eastern Oregon. Still, a little bit of rainfall goes a long way when fighting these fires, and even a tenth of an inch of rain is something to be grateful for. 

Also, take a look at this.

Valid 11:00 am PDT, Wed 23 Jul 2014 - 42hr Fcst   www.atmos.washington.edu/~ovens/wxloop.cgi?mm5d3_wa_pcp3+///3

Our best model, the WRF-GFS, is predicting a whole helluva lotta rain over a 3-hour period over the Cascades on Wednesday morning. If this rain moves just a tiny bit to the east, the firefighters will get some serious help from mother nature on fighting these blazes. We will have to worry about thunderstorms, but with the amount of rain associated with this system, I think that the benefits will clearly outweigh the risks associated with lightning. We will also cool down significantly, which will assist fire control.

If you are a person, stay dry. If you are a fire... get ready to get wet.

Charlie

Our "Extremely Warm" Wave

Monday, July 14, 2014
11:13 a.m.

We are in the midst of a period of extremely warm weather. Highs have been in the upper 80s for an extremely long time, and although I can't comment on meteorological figures since I have had very limited access to the interwebs (and outside world altogether) at the summer camp I am working at (hence the very limited blog posts), its been hot and dusty in a place that usually receives copious amounts of summertime rainfall.

But there is one limiting factor. It's not the sunshine we've been receiving, or the time of the year. And it's definitely not because of the Supermoon (however, it would be interesting to see if variations in the distance of the Earth-moon distance would have any sort of impact on temperature, or if they are completely unrelated).

It's the gradients!

Our gradients, for the most part, have been onshore, meaning that there is lower pressure over the land and higher pressure over the ocean. Air flows towards lower pressure, so Washington has been getting a marine push of air, particularly at night, to help cool things down. gets a seaward flux of air, particularly at night. Therefore, even though we've had blazing sunshine with a huge ridge of high pressure giving us warm temperatures, our marine pushes have kept temperatures from getting too extreme. Here are the gradients this morning.

       UIL-  OTH-  PDX-  OLM-  UIL-  HQM-  AST-  BLI-  UKI-  AST-  BLI-  BLI-
DD/HH  BLI   SEA   BLI   BLI   NUW   SEA   UIL   YZT   UIL   SEA   YQQ   YWL 
14/18  +1.0  -1.1  -0.1  +0.8  +0.2  +0.5  +0.2  -2.1 -10.2   0.0  +1.2  +0.7
14/16  +1.8  -1.0  +1.2  +1.5   0.0  +0.2  +0.2  -3.1  -9.4  -0.1  -0.5  -0.5
14/14  +1.0  -0.6  +1.0  +1.0  +0.1  +0.6  +0.7  -2.5  -8.9  +0.3  +0.5  -0.3
14/12  +1.7  +0.1  +1.0  +0.8  +0.5  +0.9  +0.3  -2.7  -9.1  +0.7  +0.4  -0.5
14/10  +2.7  +1.7  +2.1  +1.5  +1.1  +1.5  +0.5  -3.6  -9.3  +1.5   0.0  -0.8
14/08  +2.7  +2.0  +2.4  +1.8  +1.9  +1.1  +0.5  -3.6  -8.8  +1.5  +1.0  -0.9
14/06  +4.0  +2.8  +2.3  +1.8  +2.3  +2.7  +0.1  -4.1  -9.2  +2.3  +1.0  -1.4
14/04  +2.7  +4.2  +2.1  +1.2  +0.8  +3.2  +1.5  -4.3  -7.5  +3.2  +1.0  -1.9
14/02  +2.9  +3.9  +2.0  +1.0  +1.4  +0.9  +1.6  -4.5  -7.2  +2.6  -0.1  -2.7
14/00  +2.7  +3.4  +1.2  +0.4  +1.4  +1.6  -0.7  -4.2  -7.4  +0.4  -0.5  -3.4
13/22  +1.1  +3.4  -0.2  -0.2  +0.4  +1.1  +1.1  -3.9  -6.3  +1.3  -0.6  -2.7
13/20  -0.2  +2.2  +0.4  -0.8  -0.8  +0.7  +0.6  -3.3  -5.5  +0.4  -0.2  -2.7
13/18  -0.4  +1.6  -2.0  -0.8  -0.9  +0.8  +0.8  -2.8  -5.0  +0.8  -0.1  -2.2

       PDX-  UIL-  CLM-  SEA-  SEA-  OLM-  SEA-  YKM-  SHN-  SHN-  SEA-  SMP-
DD/HH  DLS   CLM   NUW   EAT   YKM   YKM   GEG   GEG   SEA   NUW   SMP   EAT 
14/18  +5.2  +0.9  -0.7  +7.5  +7.5  +7.1  +6.4  -1.1  -0.8  -0.4     M     M
14/16  +4.9  +0.9  -0.9  +7.1  +6.7  +6.1  +6.1  -0.6  -1.2  -0.9  +0.9  +6.2
14/14  +4.8  +0.6  -0.5  +6.8  +6.0  +5.6  +6.3  +0.3  -1.2  -0.7     M     M
14/12  +4.4  +0.7  -0.2  +6.5  +5.6  +5.1  +5.6   0.0  -0.9  -0.8     M     M
14/10  +4.6  +1.9  -0.8  +6.4  +5.5  +5.3  +5.5   0.0  -0.9  -0.8  -0.4  +6.8
14/08  +5.0  +1.7  +0.2  +7.0  +5.5  +5.6  +5.1  -0.4  -1.7  -0.8     M     M
14/06  +4.3  +2.6  -0.3  +6.2  +4.8  +4.8  +4.1  -0.7  -0.1   0.0  -0.2  +6.4
14/04  +4.2  +1.8  -1.0  +3.5  +3.4  +3.6  +2.6  -0.8  -0.2  -1.1     M     M
14/02  +2.9  +1.5  -0.1  +4.7  +3.4  +2.5  +3.2  -0.2  -1.3  -0.9  -1.5  +6.2
14/00  +4.9  +1.5  -0.1  +4.4  +4.0  +2.8  +2.5  -1.5  -1.3  -1.0     M     M
13/22  +2.5  +0.5  -0.1  +4.0  +3.1  +2.0  +1.9  -1.2  -1.8  -1.6     M     M
13/20  +4.3  -0.8   0.0  +3.5  +2.9  +2.1  +1.3  -1.6  -1.8  -2.4     M     M
13/18  +1.3  -0.6  -0.3  +2.7  +2.7  +2.3  +1.2  -1.5  -1.6  -2.5     M     M

HQM-SEA is Hoquiam to Seattle, and you can see that the pressure at Hoquiam is always higher than it is at Seattle, leading to onshore flow. This gradient peaked at 4 a.m. UTC July 14 (9 p.m. PDT July 13) per this table, which is pretty typical for these events in Western Washington. The difference is even more stark across the Cascades... take a look at the SEA-YKM (Seattle to Yakima) gradient, which just peaked at +7.5 at 6 p.m UTC July 14 (11 a.m. PDT July 14) and will likely continue to rise.

No picture gives a better example of onshore flow than the one below. I retrieved this from the graphical area forecast discussion (AFD) from Seattle National Weather Service website. Take a look at how the "marine layer" of low stratus clouds and fog has completely engulfed the coast and much of Western Washington.

http://www.wrh.noaa.gov/sew/gafd/latest_webafd.html

Now, take a look at how the clouds look 4 hours later.

http://www.atmos.washington.edu/~ovens/wxloop.cgi?vis1km+1

We had a pretty strong marine push last night, and for that I am grateful. It was very hot in my room, and it was nice to have it cool off. Therefore, it has taken some time for the clouds on the coast to "burn off," and those living on the coast may not even see the sun today. Still, you can see how much it has cleared over the south sound, where the stratus layer was shallower.

So what's in store for the extended? It looks like we'll finally resume to a more normal pattern, but not before another couple warm days. Tuesday will straddle on either side of 90 for much of the lowlands, as the onshore flow that morning will be much weaker than today's. After that, however, we should get into a more typical pattern of highs in the mid-to-upper 70s with clouds in the morning giving way to sunny skies in the afternoon.

However, things look to remain largely dry. Our next shot at rainfall looks to occur next Sunday at the very earliest, and this looks like more of a BB-gun shot than a shot from an UZI.

Valid 02:00 am PDT, Mon 21 Jul 2014 - 165hr Fcst:   http://www.atmos.washington.edu/~ovens/wxloop.cgi?mm5d2_x_pcp3+///3

The CPC (Climate Prediction Center) predicts above normal temperatures and below normal precipitation from now out to two weeks into advance, so long story short, although our warm and sunny pattern may have a few stumbles here and there, we are definitely in the height of summer, and summer isn't going anywhere for a long time.

Charlie