Recommended: Use Adblock to avoid ads.
Hey folks, this is going to be a fairly straight forward article about what to expect, what the probabilities are, and how to prepare for Sunday’s windstorm forecast.
The weather forecast models are in general agreement on the windstorm.
What is very unique about this forecast, is that for the first time I’ve ever seen, the computer generated weather models are in good agreement with each other, and themselves after each run. From the European, to the Canadian, to the US NOAA, to the UW models; every run shows strong winds for the Puget Sound.
The National Weather Service in Seattle has issued a High Wind Warning for most of Western Washington from Sunday afternoon to Sunday night concerning winds of 20 to 40mph with gusts to 70.
The strength of the winds will depend on the track.
One of the most crucial aspects of a northwest windstorm is the track that it takes once it makes landfall on the coast. If the storm wobbles or shifts 50 miles or so, the strength of the winds can change dramatically.
We’ll be watching for a landfall on the northern or central Olympic Peninsula that then cuts towards the northeast, causing strong winds to rush through the Puget Sound.
Even with the model agreement, the forecast is not 100% certain.
As stated above, the slightest changes in the development of the storm can and will alter the strength and impact of the storm, it could be stronger it could be weaker.
UW professor Cliff Mass explains it best
“If this system strengthens more than predicted or moves a bit more inland, things could be worse over Puget Sound. Rapidly developing, small systems such as this one are very difficult forecasting problems…a slight displacement makes ALL the difference in max winds.”
This is definitely something to start preparing for. These kinds of storms are very exciting for weather geeks like me, but also very worrying. People can get hurt or even killed, and the only way to prevent injuries or deaths is knowledge and preparation.
If the strongest possibilities become reality, widespread power outages will be certain. Prepare yourself for long term power outages with water, food, batteries, warm clothes and blankets.
Here is a PDF by the City of Seattle detailing how you should Prepare for Windstorms
I will be running a live stream with the latest updates and discussion about the storm. Link will be posted here soon.
Here is a list of good weather information to check:
If you want to start learning more about weather in our region (and impress your friends with your weather geekiness), there is one resource that you should routinely check. The Area Forecast Discussion(AFD) written by the National Weather Service (NWS).
The NWS is a nation-wide federal service under the National Oceanic and Atmospheric Administration (NOAA, I know, too many acronyms). The NWS has 122 forecast offices across the country that produce forecasts, maintain doppler radars, issue severe weather warnings and work with the local governments to prepare for natural disasters.
Each office provides an area forecast discussion every six hours or so. These pages of text (which are typed in all caps for this reason) are the forecasters’ personal observations, analysis, and general thoughts on their forecasts and their confidence in them. Every once in a while a forecaster will sprinkle in a nerdy joke, reference, or tinge of frustration that makes weather geeks chuckle.
To find the AFD from the forecasters in Seattle go to their home page: http://www.wrh.noaa.gov/sew/
Hidden amidst the menu of white text in the blue banner on the left you’ll find a link to the Forecast Discussion.
This is what the AFD looks like. Try not to be intimidated by the all caps, abbreviations or sciency lingo. If you hover your cursor over a blue word a little box will pop up and explain it. There’s also a lot of information to gather without understanding everything that’s said.
The writers often talk about flows or air masses at different “levels” of the atmosphere. Imagine that the atmosphere like a layer cake above you:
They also talk a lot about “ridges” and “troughs”. I’ve described these before as “hills or domes” and “valleys” in the atmosphere which are like three dimensional gigantic “waves” that undulate across thousands of miles of land and ocean. These weather patterns usually exist in the middle to upper portions of the atmosphere.
Ridges: (Dome of air) These are areas of high pressure, denoted by a blue H on weather maps. They bring fairer weather and warmer temperatures.
Troughs: (Elongated valley of air) Where there is a “dip” in the atmosphere which is typically accompanied by precipitation or cooler temperatures. They are marked as dashed yellow lines on weather maps.
The AFD is broken up into sections so you can focus on certain types of forecasts or summaries.
There’s a lot to learn from these glimpses into the forecasters’ thought processes. This information especially regarding the confidence in the forecasts is more informative and useful than a 7-day forecast graphic in my opinion!
Every once in a while a series of atmospheric systems comes together to make the weather forecasters scratch their head in puzzlement. This is one of those times.
I’ve repeatedly posted articles about the challenges of computer models and have seen forecasts bust pretty dramatically. Here’s a snippit from an article I wrote last March about a storm that the models failed to forecast correctly:
“There are many situations that the weather models handle very well, but we must be wary of the vulnerabilities of the current computer systems, and observation data. The atmosphere is a very delicate and complex system, and the best thing [forecasters] can do in these situations is to learn from our mistakes and improve the art and science of forecasting.”
We’re in another precarious situation of uncertainty with this week’s forecast, and the folks at the NWS expressed their concerns in their forecast discussion this morning:
FORECAST MODELS ARE QUITE INCONSISTENT WITH THE HANDLING OF THE OFFSHORE LOW AND POTENTIAL DEVELOPMENT OF A SECONDARY FEATURE OVER THE NORTHERN OREGON TO CENTRAL WASHINGTON COASTAL ZONES… -FELTON 928AM NWS AFD
Here’s the setup:
Still very much stormy as we inch closer to the spring season!
Hey everyone! I regret to inform those of you who are sick of our winter that we have ANOTHER strong storm moving in.
The typical impacts (albeit a little more windy) are expected from this system Friday night.
Oh what? Is that spring around the corner? I think it is!
Wow, I haven’t seen a forecast that warm and not rainy for months! This sudden arrival of nice weather is the signature of a “high pressure ridge”; imagine it as a big moving dome of air which tamps down on any clouds or rain under it.
Not to say that we’ve moved on to another season (more storms possible by the middle of February, sorry) but this is a great treat for those of us who miss the Vitamin D and not wearing coats.
A warm and soggy batch of moisture is marching across the Pacific Ocean, and within 48 hours it’s going to be pointed right at us.
We’ve had a couple of these “atmospheric rivers” so far this season, but I’m going to call this one the Super Soaker for dramatic effect.
Here’s what you can expect from this week’s Super Soaker:
Forecasts for Friday and into the weekend are a little less sure. An upper level system looks to cool things down and spawn a few showers mixed with sun breaks as well.
A barrage of strong Pacific storms brought nearly relentless bouts of heavy rainfall during the last week, worrying officials who look for signs of landslides and flooding in Western Washington.
Sea-Tac Airport as of Tuesday night, had accumulated over three inches of rainfall during the last three days; more than enough to warrant the National Weather Service and the Department of Natural Resources to warn of extreme landslide danger in the south Puget Sound.
The final straw on Tuesday was the thick swath of moisture fed by tropical air which stalled over the Northwest and dumped inches of rainfall into already saturated and weak hill soils.
The unfortunate consequence was the give-away of a hill on Standring Ln. which destroyed one house and prompted the evacuation of five others.
Here in Burien, we’re all too familiar with the danger of landslides. We’ve lost homes before, and there are many neighborhoods that sit on or near verified slide danger zones.
Luckily, it appears that the majority of the heavy rainfall has passed at least for today (Wednesday). Heavy rain is expected to return on Thursday and Friday, when the threat of high wind will also be in the picture.
Stay vigilant about your nearby hills and cliffs during, and after this active weather spree. Some slides occur after the storms have passed.
Stay safe, and keep updated on the weather by following the Puget Sound Weather Geek Facebook Page
Here is a list of information about landslides in Western Washington:
Nature has decided that it hates the Northwest and that it’s going to use us as it’s punching bag for the next few days. We’re going to take a beating from the weather this week.
All models and forecasts are pointing to a super wet and windy next few days.
Green = Rain | Blue = Snow | Closer the black lines = Stronger the wind
Boom, boom, boom, boom, boom. Right after the other! Some of these storms may have strong winds. After Thursday’s failed windstorm forecast, future windstorm predictions will be released with full disclosure of uncertainty in the forecast.
Stay updated to Puget Sound Wx Geek for the latest weather updates!
A large weather system has explosively intensified off the CA/OR coast and is barreling towards the Northwest as a potent cyclone. This may be a big windstorm folks. Continue reading
The “Washington Drought” was a BIG deal this year. Drought conditions began to emerge last winter when temperatures were much warmer than usual. Strangely, there was not a huge deficit of soggy weather systems, and in fact rainfall amounts were above normal in December. Continue reading
Winds, rain & snow, oh my! This is the time of year for storminess in the Northwest, but rarely do we see this much weather in such a short period of time. Stay tuned to the Puget Sound Weather Geek Facebook page, and blog for the latest updates on this week’s exciting weather! Continue reading