This post is dedicated to the servicemen and women who are serving our country, who have served our country, and those who have made the ultimate sacrifice for our country.
It appears that a cooler than normal July is on the way for the nation.
We'll begin by looking over shorter-range indicators; in this case, the Typhoon Rule.
This forecast is valid for July 14th, and we see a system just southeast of Japan, making its way north and east. This system was previously a typhoon, which looks to develop in coming days further to the south. As the typhoon approaches Japan, it will curve and head out to sea. Using the Typhoon Rule, we can expect a cooler bout of weather about 6-10 days after this happens. Recognizing that this forecast is for July 14th, we can extrapolate that to forecast a cool-down around July 20th to 24th, probably spilling over those dates a bit.
However, it's also likely that the entire month will end up cooler than normal for many in the country, due to what is happening in the Central Pacific.
In a nutshell, when the SOI is negative, El Nino conditions are favored in the United States in the following couple of weeks. We see that the SOI has been consistently negative since June 19th, and it's no coincidence that the United States has been predominantly cool since late June.
You can see how El Nino conditions, which are signaled by a negative SOI, make for a cooler than normal summer in the composite chart below:
Typical temperature anomalies during an El Nino summer
- A cooler than normal month of July is expected for much of the United States.