As shown by the temperature plot below for SeaTac Airport, the next few weeks are climatologically the warmest of the year (brown indicates average temperature range, red shows record highs). SeaTac's average high temperatures during the next weeks are close to 80°F, and many of our record highs have occurred during late July and early August.
Consider the forecast by the National Weather Service's National Blend of Models--their most highly skillful temperature forecast system (below). High temperatures undulate around 80F, with the highest at 85F next Wednesday and the coldest (74F) today.
Every day, the low temperature drops in the 50s. Very, very average weather. Perfect weather by my book.
Do I have confidence it this forecast?
Yes, because the ensembles of many forecasts....a tool to determine uncertainty in the predictions... shows that virtually all the forecasts are in line with the above forecast.
To show this, the GEFS ensemble of many National Weather Service Model forecasts is shown for the next week below. Most forecasts provide a similar story, and NONE are going for a big heatwave.
You can go to the bank with this forecast 😀.
So what is going on?
Consider the large-scale upper-level weather pattern shown by the heights of the 500-hPa pressure surface (think of this as pressure around 18,000 ft).
Monday morning, there will be a sharp trough of low pressure over our region.....a cold pattern.
Wednesday afternoon, the trough moves out, and an extension of a Pacific ridge/high pressure extends over our region. This is when our temperatures climb into the mid-80s.
The bottom line: no heatwaves and comfortable sleeping at night with AC west of the Cascade crest.
Announcement
I will hold a special online Zoom session at 10 AM next Saturday for Patreon supporters. Will answer questions, take a deeper dive on the late summer forecast, and consider the outlook for next winter.
Clearly the recent Carbon Commitment Act tax increase on gasoline is working to fight climate change and cool Washington!
ReplyDeleteCliff can you discuss the drought conditions over washington state? This is fire season and central washington has seen a very dry spring and summer.
ReplyDeleteNext Saturday's sharp, strong trough looks a little menancing. Judging from the pressure graidents in the image, it looks as though some stronger than normal wind speeds (by summer standards) may accompany it. Is that a fair assessment?
ReplyDeleteFor a long time it has bothered me when the weather is reported warmer/cooler/wetter/drier than "normal." How many seasons are consistently "normal?" A better descriptor would be "average." Weather varies all the time, and metrics higher or lower than average ARE normal. Lets use "average" instead.
ReplyDeleteI hate either descriptor, normal is the average, but what is average? Set of numbers observed picked of any given time frame. This allows people to chose a decade or 5 years or all time. Usually when I read something and I don't get the timeline they pick, I know it's garbage, that is why I like Cliff's assessments he will tell you the time period he chooses. He will also correctly state that the numbers and timelines he chooses don't account correctly for the developement around the stations the people chose. The descriptors are used to just get peoples attention. Just tell people it's hot and dry right now. Like any given summer we have seen. Heck DNR just yesterday July 18th banned campfires in their approved pits in the Upper Basin FDRA which included Spokane.
DeleteUsing averages in weather can be very misleading, particularly over longer periods of time. Let’s imagine a locale where the annual rainfall varies equally between 40 and 20 inches, but never any other amount. This area then has an average rainfall of 30 inches, which it never experiences in any year on record!
DeleteYes, it is normal for the weather not to be average. This is something the climate alarmists aren't able to grasp.
DeleteWhen referring to climatological records, the specific term “normal” generally indicates reference to the current (unless otherwise stated) climatological “normals”, i.e. 30-year moving averages for precipitation and temperature which are re-averaged every 10-years.
DeleteSo far, this is indeed a very "average" Summer...as an old Seattle guy now, my memory of summers goes back over 70 years, and this summer(although light on rainfall!) feels just about right. I will take an 80 degree summer day, as being a classic NW weather day! We always get a few days of 90 degree "extreme" heat...but that just reminds us how lucky we are , to live in this moderate, comfortable climate.
ReplyDeleteDitto, Curbozer! It's a very nice summer in general, and well within range of normal. The east being dry isn't new. As for other comments, I see absolutely no reason to think there's any rational connection between the state's tax on fuel changing the weather (or climate,). Yikes.
ReplyDeleteI'm curious about the flash flood warnings in Leavenworth tomorrow. We won the overnight permit lottery for the Enchantments and our day to enter the Snow Lakes side is Tuesday.
ReplyDelete