Seattle Turns White From Thunderhail

This afternoon Seattle turned white as thunder and lightning struck the Emerald City.

The thunderstorms were associated with the most pronounced Puget Sound convergence zone in a long time.   You remember the convergence zone, when northerly and southerly flow clash over Puget Sound producing clouds and precipitation?   Here is radar image at 4:46 PM, near the time of the big thunderstorm over Seattle.  The heaviest precipitation was associated with the red colors, which was associated with the pellet size small hail over the city.

Total precipitation from the convergence zone showers was respectable, with the Seattle RainWatch web site suggesting some locations got as much as 1-1.5 inches (see below).  The precipitation extended from the eastern slopes of the Olympics past the Cascade crest.

Snow even fell as low Snoqualmie Pass (see image)....enough to tease the skier but not help them.

But in Seattle the show was thrilling to the weather hungry in the populace. The small hail from the thunderstorm turned the ground white.

But the real thrill was the sound of the innumerable hail pellets striking the windows.   Click on the image below and enjoy.  A second video below that will add to your meteorological pleasure.

Will This Summer Be Warmer Than Normal?

I believe the probability of a warm summer in the Pacific Northwest is quite high.

Let me tell you why.

During the summer, high pressure builds offshore (the East Pacific High) and marine air from off the eastern Pacific Ocean slowly moves into the Pacific Northwest.  The temperature of the ocean surface is an important factor in controlling our surface air temperature (and dew point).

For many months, the sea surface temperature (SST)  of the eastern Pacific has been above normal and that is certainly true today.  Here is the sea surface temperature anomaly (difference from normal) for the past week.  You can see a huge area of warm water off the west coast of North America, with the water temperatures being 3-3.5 C  (5-6F) above normal.  There is no reason to suspect this warm water anomaly won't persist into the summer, and as the air moves over the warm water its temperaturs will be enhanced.

In fact, the latest runs of the NOAA Climate Forecast System (CFS) model suggests a continuation of the warm water off our coast into the summer.

Interestingly, if one plots the departure from normal of the Seattle temperatures for the last year one finds that nearly every day has been above normal (see below), with an average departure from normal of about 2C (3.6F), which is roughly the value of the sea surface temperature warming off our coast.  Really amazing how consistently warmer than normal we have been.

So the existence of the warm water alone suggests a warmer than normal summer.

But what does the NOAA CFS forecast for summer air temperatures look like?  Here is the answer for June-July and August.   Substantially warmer than normal!

But why depend on one seasonal forecasting system?   There is an International Multi-Model Ensemble (IMME) that combines the seasonal forecasts of the U.S. (NCEP), MeteoFrance, the European Center and the UKMET Office.   Here is the surface temperature anomaly forecast for the same period for IMME.  You guessed it....warmer than normal summer in our area.

The official NOAA seasonal  temperature probability forecast?  Warmer than normal over the Northwest, of course.

Seasonal forecasts have an imperfect track record, with some major busts in recent memory.  But making use of all the tools my profession has available, it does appear that the probabilities are strongly weighted towards another warm summer here in the Pacific Northwest.  I haven't discussed precipitation , but similar guidance does not suggest an usually wet or dry warm season.

What are the implications of the upcoming warm summer?  A longer hiking season for sure.  Increased chances of wildfires.  Higher summer humidity. A better beach season than normal. Another great tomato growing season.  Less chance of spring freezes in eastern Washington. And much more.  I enjoy a warmer summer even though it may not be politically correct to say it.

Watering In March

Yesterday, as temperatures surged into the lower 70s, I observed someone in my neighborhood watering their lawn.   So even with all the warm weather, should we be worried that our soil is already drying out?

But first, take a look at the amazingly warm temperatures on Thursday and keep in mind the average high on that date in Seattle is 55F!

 

Lots of 70s in western Washington and Oregon and 60s to the coast.

Although we have been MUCH warmer than normal, the precipitation has been close to normal for much of the winter.  Here is the % of normal for the last 30 days over Washington.  Wetter than normal over Puget Sound and MUCH wetter than normal over the NE Olympics and around Yakima.  A bit drier than normal in some other locations...but not by much.  No drought in Washington State.

So water is reaching the ground.  Warmer temperatures and more sun could mean more evaporation, but that is probably a small effect this time of the year.  But what does the U.S. drought center say?  

For example, they have a Crop Moisture Index (see below)...and that suggests that soils west of the Cascade crest are relatively moist (dark green).

The Palmer Drought Inde, which is more of a measure of long-term drought, is also wet over western Washington, but California is quite dry.

And it looks like we will receive enough moisture to keep the ground wet for a while.  Here is the forecast precipitation total for the next 72 hrs.  The Olympics and north Cascades will get plenty of water and southern BC will get hit fairly hard.

 My own personal experience is that here in Seattle one doesn't have to start watering until late May in dry years and late June in wet years.

So if you want dry, head to Yakima, eastern Oregon, or south.   And don't water your grass now....it doesn't need it.

The Most Unusual Weather This Winter. Normal Weather.

Light rain and a chill in the air.  Some snow accumulation in the mountains.  Towering cumulus clouds and showers.  It seems so strange.  Normal weather.

Here is a plot of the temperatures at Sea-Tac Airport for the past 12 weeks, with the normal high (red) and low (blue) temperatures shown.

During the last few days our average high and lows were near normal. Amazing.

The freezing level dropped below 3000 feet today and the  snow level dipped to around 1500 feet for a short time.   Imagine that.  Paradise, on Mount Rainier, received over half a foot before it warmed a bit.  Here is a shot there near sunset today.

The NW Avalanche Center even has a high avalanche danger out for tomorrow.   First one this year?
The NW Avalanche folks have had plenty of time to repair instruments and complete advanced training this year.

And take a look at the 500 hPa weather map for this morning.  A trough of low pressure over our region.  Haven't seen that in a while.

But don't worry, the ridge from hell (actually from the tropics) is coming back with a vengeance.

A strong WARM front is right offshore and will move in tonight.  To illustrate this, here is the forecast for 11 PM tonight of sea level pressure (solid lines), surface winds, and low-level temperatures.  Look along the coast.  You see the shift from SE to SW winds, a kink in the pressure lines, and a transition from cold (green) to warmer (yellow) temperatures...that is the warm front.

As the warm front passes, our region will be flooded by moisture, warm air and strong SW winds that will dump lots of precipitation tomorrow (Wednesday).  Here is the precipitation total for the 24h period ending 5 PM Wednesday.  Several inches of rain in the mountains on top of the snow today...that is why the NW Avalanche Center folks are worried.

Then...ready for warmth?  A big ridge develops over us on Thursday and we bake, with lowland temperatures near 70F that day.  Remember!  The sun is much stronger now.   As strong as mid-September.  Remember your sunglasses and sunscreen...you will need them.

SDL2 FPS & on Finding New Open Source Games

I took a quick look whether one could find some open source games news (new game projects to be specific) by sorting SourceForge game projects by date but no luck, only established projects seem to show up there.

So I did the same on GitHub, and after making educated guesses whether projects might be worth clicking based on their title and short description, I f ound graphitemaster/neothyne.

The project uses SDL2, is about half a year old, doesn't have shooting functionality but at least movement feels kind of nice and definitely fast. In fact I'm honestly surprised that SDL is usable for 3D.

Neothyne is an attempt at getting back to the roots of good old twitch shooting akin to that of Quake World..

It certainly feels more like Cube 1 or Quake, rather than OpenArena, Sauerbraten or Nexuiz.

What surprised me even more that it compiles in mere seconds.

To come back to the point of finding games: My impression is that development is getting faster, projects are getting more but also less ambitious (read: more realistic to achieve) and less care is being given to licenses but at the same time more legal resources are being used because of OpenGameArt's and Freesound's popularity.

Personally, I have been using old onboard graphics for two years or more (no chance to run anything interesting 3D) because I'd prefer to upgrade from a HTC Wildfire (Buzz) to a OnePlus One, rather than buying a new Power Supply and Graphics card, having a louder computer and the knowledge that it's using more electricity.

This is also the reason why the above video is so tiny. :) No 720p 3D for my GPU.

If you find it interesting to browse through lists of game projects, trying to find a playable one that suits your interest, I recommend the GitHub search. Just don't rely on the "game" search key too much and imagine what the developer might use to describe it (probably genre names...).

For your entertainment, a list of "game" project short descriptions from GitHub.

• Actual game for the Capstrong DePaul capstone team
• recreating cs203-game1 repository because of a corruption in the original repo that I can't figure out how to fix atm
• the tic tac toe game on node.js
• Survival game
• kouluprojekti2
• Hotline Miami inspiered HTML5/JS game for school project
• Island is a programming game designed as a support for Software Engineering classes
• game
• Just a little game I'm working on
• Card game...

What's your favorite? Can you find anything better?