The next time someone makes a weatherperson joke, remember the nearly perfect forecast for yesterday's wind event over Washington.
No longer appropriate
For days, the models correctly predicted the rapid development of the cyclone offshore and the high pressure inland. The combination resulted in strong easterly winds that descended the western slopes of the Washington Cascades.
You want to see how perfect the forecasts were? Here is the wind speed forecasts provided to Seattle City Light from the UW's WindWatch website, which uses the best of the regional weather prediction models.
This graph shows the highest observed wind over Seattle (black line) and the forecasts made starting Monday afternoon.
You don't get much better than that. Earlier predictions were just as good.
A lot of attention was given to the strong cyclone/low-pressure system that developed offshore. It was an impressive low that not only rapidly developed, but deepened to 943-943 hPa, slightly beating or equalling the historical record.
Not impressed? The 72-hour forecast was almost identical.
Something has happened that has not been sufficiently understood by society.
Weather prediction technology has improved immensely in skill and detail.
The above results are not a fluke.... I could show you a dozen more, including the predictions of devasting extreme events, such as the Lahaina wildfires or heavy precipitation from Hurricane Helene.
There is so much talk about extreme events and global warming.
But the truth is that deaths and injuries from extreme events are declining rapidly because weather predictions are so good. Such deaths and injuries could be greatly reduced further if governments and other institutions would better use highly skillful weather prediction.
The Upcoming Storm
Another midlatitude cyclone will be moving up the coast on Friday.
On Friday morning at 10 AM, a 977 hPa low will be directly east of the Columbia River outlet. Much weaker than yesterday's storm, but much closer.
Compared to Wednesday, this storm will produce strong winds on the coast, but weaker winds over the western WA interior.
For example, at 1 PM Friday (below_, fearsome winds on the coast, but "only" gusts to around 25 kt (roughly 30 mph) in the interior.
Here is the latest guidance for our friends at Seattle City Light or Seattle--not so bad.
Very impressive skill with the models and forecast. It played out as if it were scripted, here in North Bend anyway.
ReplyDeleteIf the models were so good, why did the NWS forecast for Seatac only have gusts to 33? Thats what it said all day 11-19 and even in the evening when Seattle was getting hammered with 55+mph winds
ReplyDeleteWondering how many electric and natural gas customers who voted against retaining natural gas as an option are now getting cold.
ReplyDeleteDid y'all notice how modest Cliff is being? Go back to Oct. 5th and check out his blog then. Title: "Improved Chances for a Big Northwest Windstorm This Winter." That prediction sure didn't take long to verify!!
ReplyDeleteI'm also glad he pointed out how well forecast models predicted this complex, unusual event, plus how accurately the data was interpreted.
Thanks for the insight!
ReplyDeleteA big part of what made this forecast impressive to me was looking at the forecast maps Monday afternoon showing the sub-950 mbar low expected to form off the coast...
ReplyDelete...comparing it to the satellite images showing nothing remotely resembling (to my untrained eyes, at least) a major cyclone brewing...
...and then less than 24 hours later, seeing the satellite images showing the storm pretty much right where the models said it would be.
The magicians who run the models said atmosphere was going to pull a rabbit out of its hat. I looked at the hat / satellite images and saw that it was empty. And then the atmosphere actually did pull a rabbit out.
Extremely impressive, and it's awesome how improved weather forecasting is able to save lives.
ReplyDeleteWorldwide, climate change causes hundreds of thousands of extra deaths every year, and the number is rising, not falling. “Extreme events” account for only a tiny fraction of that. Most of it is from drought, crop failures, displacement, and disease.
On Cliff's FB yesterday I expressed concern that Environment Canada's forecast might be gravely underestimating wind gusts for the Saanich Peninsula north of Victoria, with the HRRR and WRF-GFS expecting 45-50 knot gusts around Victoria Int'l Airport (YYJ). But YYJ's highest gust in hourly reports was 37 knots, and the highest for the day was 41 knots. The Saanich Peninsula was much less messed up or blacked out than many surrounding areas. The Canadian GEM, despite allegations of being inferior to some other models, still seems to be earning its keep.
ReplyDeleteSo how come where I live in Brier, there was not really any wind at all? Our power never went out, and there's almost nothing down in our yard. Didn't even blow the lid off of our trash can, much less knock it over. I don't think there are any reporting stations here, but I seriously doubt we had any gusts above 25MPH. Is there something about the track of this low that would account for that?
ReplyDeleteMost people are very simple minded creatures. The way it works is, if you get it right 99 times and wrong 1 time, you will only be known for the 1 wrong time.
ReplyDeleteThe only thing that was off, imo, was that the cyclone was much further off course than predicted, more than 50
ReplyDeleteMiles out — so what would have changed if it was closer but the same power… likely models would have been off. Just thinking.
Thanks Professor. Much appreciated.
ReplyDeleteI love exciting weather but this bomb was a total "dud" here in Tacoma. No real storm was had here, wondering why we missed all the excitement....
ReplyDeleteIm about to travel down the 5 for 2 days worth of driving (starting tomorrow) so this is all very helpful. This blog has been my lifeline to accurate information about the weather.
ReplyDeleteWhat does this mean for power? Will we experience additional outages, damage, etc?
ReplyDelete