Thursday, December 29, 2011

A very normal situation

A weak disturbance* comes in later today, a stronger system on Friday, and believe it or not, a relatively dry New Year's weekend is ahead.

* in The Force

Monday, December 26, 2011

"There is a lot to discuss"

CliffMassTLDR Rule #1: when someone dies as a result of the weather, we don't make any jokes.

Stay safe out there and have a Happy Holidays!

Friday, December 23, 2011

Rain is coming

This horrible Northwest dry-spell is over, starting...tomorrow.

PS: Not all La Niña years are wet, just most of them.

Saturday, December 10, 2011

Wednesday, December 7, 2011

Still Under Pressure

We'll be stuck in this high pressure, low clouds pattern for several more days, so you better get used to it. The high pressure is causing the sea level to drop, sometimes by almost 2 feet!

Tuesday, December 6, 2011

Saturday, November 5, 2011

Raindrops aren't shaped like raindrops

Here's what raindrops really look like (depending on their size):

The teenaged drop won't take his headphones off so he can't hear you lalalalalalala, whatever "dad" you're not even my real dad so you can't tell me what to do.

Thursday, October 6, 2011

First snow

Snow fell in the mountains.

The forecast for the next two weeks is colder and wetter than normal. Looks like another La Niña year.

Tuesday, October 4, 2011

Why it gets foggy at dawn

The sunlight is bouncing through particles and droplets in the air. It's most intense near sunrise and sunset since most of the scattering is in the forward direction.

Monday, October 3, 2011

I was wrong on Friday

I was wrong about the forecast on Friday. It actually rained.

The solution to this is called "nowcasting", where instead of predicting what the weather will be at some point in the future, you simply describe what it is doing now.

Monday, September 12, 2011

SeaTac temp records are BS

SeaTac said we had the most days in a row with 80+F weather, but since the 3rd runway was built the thermometer there has been off by 2 degrees F, so the record doesn't count. This is a problem around the country (weather stations in crappy locations) so don't ever believe the weather reports.

Lost dog, and Smoke

LOST: black/while cockapoo wearing a pink t-shirt.  Answers to Leah.

Smoke moves up and down.

Lost (the TV show) had a smoke monster that could move in any direction.

La Niña

The U.S. Climate Prediction Center has just upgraded the status from a La Nina Watch to a La Nina Advisory. It was hard to copy/paste that without laughing a little.

Winter forecast: wetter and colder for us, warmer and drier for the SE.

Thursday, September 8, 2011

Hot in the day, cold at night

There's a big difference between the daytime high and the nighttime low temps. This is due to longer nights and clear skys.

This may or may not be good for vineyards, depending on who you ask.

Tuesday, September 6, 2011

Hotest spot in the NW

Is the Hanford reservation, but not due to the reactor. It's because there are no irrigated fields.

(Hottest spot in the world is in Iran)

Saturday, September 3, 2011

More warmth in the NW. More hurricanes in that other part of the country that isn't the NW so who cares?

Also, there are forest fires now.

Wednesday, August 31, 2011

Fog and Fox

There's more fog in autumn because of...

* Longer nights, allowing more time for the air to cool to saturation (the dew point)
* Relatively clear skies, since the storm season has not arrived yet. Clear skies allows infrared radiation to escape, causing more cooling.
* A relatively stable atmosphere, and fog loves stability.

Also, Fox News is dumb.

Also also, my new segment on KPLU starts Friday at 9 AM.

Monday, August 22, 2011

Not-so-dry Seattle (soon)

Big ups to the new coastal radar for the heads up: much of the region should see significant rain in the next 24hrs. Thank you Coastdar!

Saturday, August 20, 2011

Thursday, August 18, 2011

A letter

Dear Global Warming Skeptics,



Tuesday, August 16, 2011

Warmer than usual weather coming up

But what is "usual" anyway?

PS: our lack of hot weather this summer has been due to a lack of "thermal troughs", when warm air rises creating lower pressure near the ground.

Back on the radio

I'll be back on the radio, starting Sept 2. On KPLU, you know that public radio station that didn't screw me over?

Tuesday, August 9, 2011

Good news

I just saved 15% on my car insurance! Oh, and the new coastal radar was turned on and we have received some of the first images.

See one of them here:

Friday, August 5, 2011

Aurora Borealis Tonight!

It's not just the name of some hip band, there will actually be an aurora around here tonight. There's no cover charge at the door, but you just need to find a place without clouds. Try Eastern Washington, or 3000+ ft up.

Friday, July 1, 2011

4th of July Facts

Fact: From mid-July to mid-August, the NW is one of the driest places in the USA. Drier than Arizona!

Fact: Roughly half of the past 63 July 4th's have had precipitation.

Fact: Tomorrow will be the warmest day of the holiday weekend.

Fact: Sunday will be cooler, with showers.

Fact: On Monday (July 4th), there should be clouds in the morning, but a sunny afternoon and evening, with temps in the lower 70s.

Fact: Warm, dry conditions continue into Tuesday and Wednesday.

Fact: The previous 4 facts were actually just predictions.

Thursday, June 30, 2011

July 4cast

Today: clouds and some showers
Friday and Saturday: sunny and warm
Sunday: clouds and perhaps some showers
July 4th: major improvement

And in typical NW fashion, summer weather should officially start on July 5th.

Tuesday, June 28, 2011

Why forecasts are wrong

Tiny differences in the offshore pressure flows can make a huge difference in NW weather.

To mitigate this, forecasters look at a lot of forecasts for one day and average them all together.

Saturday, June 25, 2011

Monday, June 20, 2011

Bottom line

Cooler than normal for the next week or so but then we may well enjoy a normal summer from that point on.

Saturday, June 18, 2011

What the radiation from Fukushima is and is not causing

Radiation from Fukushima is not causing an uptick in infant mortality here in the NW. It IS causing an uptick in reDONK faux-science news articles.

Friday, June 3, 2011

It was cold. It will be warm.

This was the coldest spring ever. Today it will be warm. Tomorrow it will be even warmer, through Monday maybe.

Wednesday, June 1, 2011


A weak-ass tornado touched down for a weak 200 feet, in weak Southwest Washington. Weak sauce.

Monday, May 30, 2011

Lightning in Eastern WA

They get all the great weather.

(They're caused by water condensing, which warms the air and make it lift)

Sunday, May 29, 2011

Cliff is doing video now

Should this blog do TLDR videos?

Forecast: some light showers (especially in the mountains), and cooler than it was today

Thursday, May 26, 2011

A few things

1. There was a tornado in Oklahoma, right over the area's weather station. It survived and recorded some data.

2. The tower for the coastal radar is complete. Next is putting the antenna and radome on top.

3. Check back for Memorial Day Weekend forecast. Don't listen to KUOW expecting a forecast. You'll only get a bunch of "umms" and broken sentences.

Wednesday, May 25, 2011

I say whatever I want on The Stranger

I only talked about non-weather stuff a few times a year, but the folks at KUOW wanted me to stop. I told them I wouldn't do that so they "fired" me (I was working for free). There was a huge outpouring of support for me, which shows how out of touch the folks at KUOW are with their listeners. I'll go back on the radio if I can talk about non-weather topics. (Give me my own show please!)

Monday, May 23, 2011

May and June have low clouds

Clouds are low during May and June, for three reasons:

1. Convection.

2. High pressure (the east Pacific high) builds into our region and the high is associated with sinking motion.

3. The earth is warmer than the ocean, so warm continental air moves over cold water, and gets cooled to its dew point.

And global climate change is going to make this more persistant!

I got dropped from KUOW

For talking about UW admissions. If you want me back, email them and tell them so.

Thursday, May 19, 2011

70F Tomorrow

You read that right. A little preview of it today, then the main event tomorrow. Unfortunately, the weekend will be cooler, with a few light showers. Sorry....

Sunday, May 15, 2011


In parts of the state, it was more rainy yesterday in one day than it usually is in the whole month.

Warm and dry weather expected towards the end of the week and next weekend.

Friday, May 13, 2011

Science proves it

This has been the coldest May EVER. Only 5 days with 60+ degree weather since the beginning of Spring. They had to readjust the graph just to fit a data point that small.

Wednesday, May 11, 2011

Sunday, May 8, 2011

Seattle gets lots of Stratocumulus clouds

Stratocumulus is a low cloud. It's made of large, dark, lumpy elements, with bright sections in between. Most are completely dry, but when they get "blurred together", that's when the precipitation starts!

Tuesday, May 3, 2011

Why we don't get many tornadoes

Thunderstorms like two things: moisture in the air and big change of temperature with height--normally from a warm surface. Our cold water can't put much water vapor into the atmosphere and keeps the surface cold. So we don't get tornadoes.

Wednesday, April 27, 2011

Weatherman Whine

A major car company is making fun of how wrong us weathermen are, in their latest ad campaign. Boo hoo.

Tuesday, April 26, 2011

New computers to predict weather

Thanks to everyone who donated to buy us some new nerdy computers with weird chutes that jut off them to keep them cold.

Also, you can donate to the scholarship fund

Monday, April 25, 2011

Pacific Decadal Oscillation

It ain't about global warming and it ain't about global cooling. It's all about the PDO, baby.

Thursday, April 21, 2011


Saturday is going to be "warm" (by 2011 standards) and sunny. Sunday, it's back to your regularly scheduled program.

Monday, April 18, 2011

Vocab Time!

"Temperature lapse rate" - the difference in temperature between the surface and higher altitudes.

Large lapse rates cause convection (think lava lamps and ... um... cooking oatmeal), which makes for some trippy clouds.

Worst Spring, EVER

Wednesday, April 13, 2011

La Niña Is Dead

Long Live La Niña. Officially the weather phenomenon itself is ending, but we'll still see colder than average temps this spring.

Monday, April 11, 2011

Cliff Explains the UW budget crisis (no TLDR)

I was going to ignore or mock this post, but after reading it, I realized it's actually one of Cliff's best "off topic" posts ever. Please take the time to read UW Admissions and the Budget Cuts. He explains the UW budget crisis, and dispels some myths propagated by last week's Seattle Times cover story.

Upside down rainbow (in which Cliff makes a funny)

If you saw an upside down rainbow, it wasn't just because you were laying on the ground in fetal position crying about the weather. It was real, and caused by the same phenomenon that creates halos (refraction of light in ice crystals).

Also: "Current research has not found any evidence for a pot of gold at the end of this rainbow. Apparently, it is too high for leprechauns to deal with."

Thursday, April 7, 2011

Why it was cold yesterday

Some parts of the region got snow yesterday due to the convergence zone*. Precipitation causes evaporation that cools the air. This only lasts minutes, but then melting snow robs the air of energy which causes even more cooling. Yesterday, that was enough to drop the snow level down to the surface in some places.

* NW wind becomes split by the Olympics, then "converges" over the Sound, creating updrafts. Those updrafts cause convection and then precipitation.

Wednesday, April 6, 2011

Freaky Friday: CA and WA to exchange weather patterns

On Friday, California will get our wet weather and we'll get their dry weather. Just for one day.

Last week I was in Monterey, California attending the Cyclone Workshop. Jeally?

Monday, April 4, 2011


Or the lack thereof. Nothing to report here. Except radioactivity in Boise rainwater was particularly high.


Saturday, April 2, 2011

Wednesday, March 30, 2011

Vocab Time

Atmospheric Rivers: plumes of moisture that generally start in the tropic and subtropics. Usually associated with warm air (since warm air contains more water vapor than cold air). They dump precipitation when they interact with the hilly terrain of our region. e.g Pineapple Express

We're getting one tonight, but it's more westerly than the usual P.E., and thus the rainshadow will move southward making the north Sound virtually rain free. The mountains will get 5-10 inches of rain, increasing avalanche risks.

Monday, March 28, 2011


It's hard to predict weather in Niño/Niña winters. Cascade snowpack is roughly normal this year (which is low for a La Nina year in which we expect it to be above normal)*. But snow in California has been very high.

This pattern will reverse at the end of the week, and we'll go back to more wet weather.

And News Flash, the food on airplanes is bad!

* This sentence was copied verbatim from Cliff Mass Weather Blog, due to its extreme awesomeness.

Thursday, March 24, 2011

Why it was warm

As air descended down the western slopes of the Cascades it compressed and warmed.

Tuesday, March 22, 2011

California Dreamin'

Not. Record-breaking rainfall in CA, while we enjoy this... (look out the window)

Monday, March 21, 2011


Large-scale troughing on the West Coast that is going to send weather disturbances to our south, and at the same time reduce radiation risks. Increased chance of dryness.

The Northwest has been sufficiently wet that even if we don't get a drop for the rest of the month, we will still have normal rainfall for March.

Wednesday, March 16, 2011


March is coming in like TWO lions this year.

More rain tomorrow...but Thursday and early Friday should be dry!

Tuesday, March 15, 2011

Monday, March 14, 2011

Not a great week to be on vacation

Radiation from Japan to reach Seattle in 9 days! But by the time it gets here the radion levels would be minimal, if not infinitesimal.

(Cliff Mass TLDR goes away for a week, and this is what happens?)

(Happy Pi day)

(Please discuss the semantic difference between "minimal" and "infinitesimal")

Thursday, March 3, 2011

The hurricane happened

Or whatever it's called. Winds up to 116mph, and downed trees.

[On a personal note, CliffMassTLDR is taking a vacation next week. While he's gone, please enjoy the tweets of fellow NW Weather abbreviator Weather Girl.]

Tuesday, March 1, 2011

Midlatitude cyclone tomorrow

That's what we call a hurricane in the NW. Huge pressure differences bring VERY strong winds and large waves on the coast.

How come storm-related tourism hasn't caught on? Either it's because The Man is keeping us down, or because it's boring.

Monday, February 28, 2011

Cliff Mass TLDR is tweeting now


In case this blog is too verbose for any of you.

No snow at sea level

Here's why: when it's near freezing and snowing heavily, the snow level can descend to the surface. But it's hard to get snow to the surface unless it's snowing hard.

Friday, February 25, 2011


Forecasting is hard, Jeff. Let's see you run the prediction models in your Double-Doppler Weather Center next time.

(Thank you to reader Mike for the headline idea)

Thursday, February 24, 2011


Hope you enjoyed that snow. It's going to be replaced by cold weather tonight.

Wednesday, February 23, 2011


It's hard to predict what the weather's going to do (forecast), so I'll just tell you what's happening now (NOWCAST!): snow but no ice.

Tuesday, February 22, 2011

Isn't it ironic

There's gonna be a couple inches of snow tomorrow. So Ivar's is canceling my presentation tomorrow night at Mukilteo Landing...due to the predicted snow. Rescheduled for March 9th.

Saturday, February 19, 2011

Forget the snow...

I'll be talking at Ivar's Mukilteo Landing Restaurant at 7 PM on Wednesday Feb 23rd. The destruction of the Mukileto Landing Restaurant will be the theme of this talk.

Reasons you should go:

1. the restaurant was rebuilt with a weather theme

2. the bartender has come up with an exciting new drink: the STRAIT SURGE. This may be the first meteorological phenomenon with its own drink. History will be made.

3. a local bard and songster will sing a specially commissioned ballad on the great 2003 storm on Wednesday evening.

This has been my longest post ever.

Monday, February 14, 2011

Being a weatherman is hot

"The models had a pretty good handle on this event, although they underplayed the extreme winds a bit."

Friday, February 11, 2011

Math bill

Leave a message for Representative Santos (37th district, near Lake Washington between Capitol Hill and Renton) at the legislative hotline--1.800.562.6000 or email her at and tell her to let the math bill have a hearing and a vote in the committee. You don't have to be in her district to let her know about our concerns.

Oh, and the dry period is over starting..... now.

Monday, February 7, 2011

This and that

It was windy yesterday.


When it's warm on the Best Coast it's cold on the Dumb Coast (and vice versa).


The new coastal weather radar will be operational by the end of September!

Tuesday, February 1, 2011

Wednesday, January 19, 2011

Thursday, January 13, 2011

How to summarize this one...

1. Look busy, a bunch of meteorologists coming to town Jan 24.

2. I'm going to put ads on this site. All proceeds will go to my expensive double doppler habit.

3. Lots of people came to the site when I did my nowcast. I'm gonna do more of them (see #2)

Tuesday, January 11, 2011

Seattle <3's Snow

Gonna snow this afternoon, starting in a little bit. It'll be over by midnight, and change to frozen rain and good 'ol rain.

I'll be "nowcasting" each snowflake as it touches the ground.

Sunday, January 9, 2011

Or not

There was some snow today, but the biggie later in the week probably won't materialize. My bad. I just love predicting snow, whether or not it's true.

Saturday, January 8, 2011


Maybe Wed and/or Thursday. Somewhere in the Pacific NW. Where? Stay tuned!