The main purpose of this ongoing blog will be to track planetary extreme, or record temperatures related to climate change. Any reports I see of ETs will be listed below the main topic of the day. I’ll refer to extreme or record temperatures as ETs (not extraterrestrials).😉
Main Topic: U.S. Average Temperature Summer Forecast (It Will Be Anomalously Hot.)
Dear Diary. It is now the start of meteorological summer, so once again as we do on this blog, it is time to make a forecast for this season. Spring 2024 had anomalously warm temperatures overall across the lower 48 states and in fact will be pegged as a top twenty warmest since records have been kept since 1895. I think that we will see this warmth continue into this summer due to climate change, although I doubt that we will see the hottest summer on record. Nevertheless, no matter how far above average this summer will be overall, there will be periods of cooler than average conditions for localized areas of the country.
At the very start of summer, it’s time for me to make another attempt at a forecast for average seasonal temperatures in the U.S. This forecast will be very broad and not specific for any one state comprising the continental United States (or lower 48 states).
So how did the forecast work out for Spring 2024? Here is a link to the post for that forecast:
By June 8th the National Center for Environmental Information will finish their climatological assessment for Spring 2024, so our verification is not complete as of June 5th. Let’s do fill in ranking numbers with 1 being the coldest and 130 warmest for a verification for months during 2024, which have already been assessed (129 would be warmest for 2023.):
Here are my two cents for a broad, rough forecast for the U.S. for Summer 2024, which I guarantee to be hotter than this past spring, of course, as the amount of daylight increases across the Northern Hemisphere. First, I like to look at water temperature anomalies surrounding North America just before the start of a season to get a sense of how much potential anomalous heat can be added to the atmosphere across the continent. Here is what we see:
For a change from the past several seasons, we do have cooler than average waters off of the West Coast. Warmer than average waters remain from the Gulf Coast through the Atlantic coastal region. This leads me to think that cool troughs will be more likely to hug the west coastal area, which would pump up strong heat domes downstream. Indeed, starting in mid-June looking at our latest models this is the dominant solution:
We do note that the first half of the month will see a refreshing cool spell over the East before a big ridge over that area starts to build:
Here is the National Weather Service forecast for Summer 2024:
I do disagree with this outlook, thinking that the Pacific Northwest may be cooler with the Midwest being hotter looking at forecast jet stream configurations.
Next, we can get another clue looking at prior National Center for Environmental Information ranking and temperature record count data. For this I like to drag out my “Record Scoreboard” (updated through 6/01/2024):
For these data sets all monthly ratios of > 10 to 1 DHMX to DLMN or > 10 to 1 DLMN to DHMX are in bold type. The rankings are for the lower 48 states with the warmest ranking since 1895 of average temperatures being 129 and 1 being the coldest as of 2024. Blue colors represent cold months and red warm. Those months and years with counts close to a 1 to 1 ratio of highs to lows are colored black. Boldly red-, blue-, or purple-colored months, such as January 2020 and June 2021, have ratios of >10 to 1 daily record highs to lows or <1 to 10 daily record highs to lows, and are either historically hot or cold, most of which have made news. All-time record hot or cold ranked months are highlighted in purple. I’ve subtracted Alaska records so we can better compare apples to apples with record totals and rankings for the lower 48 states.
Notice that both December 2023 and February 2024 had a better that 10-1 ratio of DHMX to DLMN record reports. All three spring months saw more daily high max records than low min records. Looking at daily record ratio trends by month, anomalous warmth should continue into the summer with a low probability that one month might see more daily min records than daily max records considering what happened in January 2024.
I’m predicting that all three months of Summer 2024 will be above average with August being the most likely month to see temperatures closer to average and July the warmest. Here is the link to avg. rankings per year for the lower 48 states since 1895:
https://www.ncdc.noaa.gov/cag/national/rankings
Not all seasons in the near future will see above average temperatures, but seasonal forecasters are beginning to “chuck it,” discounting colder than average scenarios due to carbon pollution.
Here are all seasons ranked for the last decade:
The last time we had a below average summer season was before 2015. Winter 2023\24 was the warmest in recorded history for the lower 48 state portion of the U.S. An average ranking on the above chart would be 64 as of 2023.
Here is my bottom-line forecast for Summer 2024:
“I think that this summer will be ranked well above average. I’m going to forecast that the Summer 2024 ranking will be around 110 + or – 10, with above average confidence given all of the factors written within this post.“
My forecast for Winter 2023/24 of a ranking of 110 was 19 rankings too cool, but not too bad:
We will see how well my forecast ranking of near 110 for Spring 2024 worked out in a few days.
As of 2024 the top ranking for any month or season would be 129 since climatological rankings for the United States started in the year 1895. Carbon pollution is definitely making below average seasons rarer. As stated, I’m going to guess that Summer 2023 gets ranked around 110 + or – 10, and with above average confidence given all of the factors in this post. Have a fantastic summer but be weather aware for any severe storms and hurricanes from a forecast record active tropical Atlantic season.
Here are more “ETs” recorded from around the planet the last couple of days, their consequences, and some extreme temperature outlooks, as well as any extreme precipitation reports:
Here is some more new May 2024 climatology:
Here is More Climate News from Wednesday:
(As usual, this will be a fluid post in which more information gets added during the day as it crosses my radar, crediting all who have put it on-line. Items will be archived on this site for posterity. In most instances click on the pictures of each tweet to see each article. The most noteworthy items will be listed first.)