7/8/23 Saturday 7 am
I noticed the other day that the European extended model, formerly known as the “Euro Weekly”, is now running daily. I did some research and found out that the entire model has been upgraded and is now running on a new supercomputer in Bologna. It used to be an extension of the 15-day ensemble model with 51 model members. If you missed last Tuesday’s post I explained how ensemble models work, you can read it here–Tuesday Extended Forecasts–Light At The End Of The Tunnel
Now, with the upgrade, the European extended model is no longer an extension of the 15-day ensemble. It is an entirely separate model with 101 ensemble members. In addition to this update, the 15-day ensemble model has been upgraded in its underlying resolution. This is exciting because it will now have the same resolution as its deterministic model (the regular Euro).
For those that I lost a ways back, it just means that the model should be getting more accurate. So what does it tell me now? It reinforces the message I have been shouting for a while. The monsoon is on its way. It will show up fashionably late around July 18th. Before then, we will see the hottest temps of the summer so far. It also shows that deficits in precipitation that have occurred in July will be made up for the last 7 to 10 days of July in the lower and mid-elevation areas. The higher elevations will continue to run slightly behind.
Most of the US will get hot over the next 10 days. Despite what you may have heard, that has not been the case so far. Take a look at the below-normal temperature anomalies over the last 30 days.

The heat that has gotten so much media attention has been a result of the positive anomalies primarily over Antarctica, and a few other mostly uninhabited areas. Despite the heat anomalies there, it is still over 30 below zero at the South Pole, and 97 below zero at Vostok Station.
I got a bit sidetracked there (again) but my point is the heat will build across the US and it will be drier than normal during this period. This will continue to warm the tropics and it should really ramp up tropical development, especially in the Eastern Pacific. The reason this is relevant is that this season is going to be the best in about 5+ years for us to see a recurring tropical storm or remnant bring heavy rains to our area.
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Thanks, Jeff! Your posts are fascinating – thanks for the map in this one, and the explanation of the hysterical heat headlines vs what the map really looks like. I have noticed that the “hottest day ever” headlines seem to have changed in the last few days from “Hottest Day in 125,000 years” to “Apparently hottest day recorded since 1979”, which I heard this morning. Can you expound on that? What is the actual scientific explanation? I have read that weather scientists are becoming frightened by the new daily heat records. Is that a real concern?
Thanks for being here for all of us who have an interest in the SW quarter of the state, which we flatlanders barely see on the Denver stations. I grew up on the far eastern plains of Colorado, and the Denver stations have significantly improved their coverage of the eastern third of the state over the years. But the third of the state west of the ski areas is still barely mentioned. If you blink during the few seconds they are scanning the whole map, you miss it!