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: How Severe Will Heatwave Exxon Get East of the Rockies?
Dear Diary. Meteorological models have been strongly hinting that what I’ve dubbed Heatwave Exxon, which has been with us since it first reared its ugly heat done head across Mexico in early May and is now a major CAT across portions of the West, will expand east of the Rockies for the rest of this month. It will be the “same” heatwave because we can track one heat dome at 500 millibars. But how strong? That will depend upon what I hinted at on X yesterday:
The European model has been the most bullish, building a wickedly strong heat dome, which will be at its zenith on Thursday June 20th:
Such a scenario would produce widespread maxes above 100°F from the Midwest into the Northeast, Southeast and westward into the Plains with some all-time records being threatened. In this case Exxon would be a CAT5 for a few days in my book.
The less bullish American GFS forecasts a scenario that is bad enough for the Midwest and Northeast, but it forecasts a weakness in the ridge across the Plains and South that would allow tropical disturbances to move north from the Gulf, soaking and cooling those areas. The downside to the GFS scenario is that the Gulf Coast would be susceptible for organized tropical activity:
In the above case we would still see a CAT4/5 Heatwave Exxon across the Midwest and Northeast.
The operational Canadian model is much like the GFS:
What has me worried is that model ensembles suggest that the European model might be correct:
Notice how many brown circles located in the interior of the U.S. there are on the above right panel, with the operation white circle representing the 594-decameter line being an outlier, out in the Atlantic. We will see which model is correct in a few days.
Regardless of scenarios, this NWS graphic should verify, so be warned:
Here are more details from the Washington Post:
Serious heat wave to scorch the East next week. Maps show areas at risk. – The Washington Post
Serious heat wave to scorch the East next week. Maps show areas at risk.
The heat wave could produce dangerously high temperatures over a large area for an extended period.
June 12, 2024 at 11:19 a.m. EDT
The heat dome is coming. This forecast is about as high end as it gets for the region in June. (Weatherbell.com)
The eastern half of the United States faces an intense heat wave starting late this week and peaking next week that could produce dangerously high temperatures over a large area for an extended period. It could threaten records and place vulnerable groups of people at risk from heat-related illnesses.
Over the weekend, widespread highs in the mid-90s to around 100 — some 10 to 20 degrees above normal — will spread across the southern Plains, South and Midwest. By Monday, the heat will swell into the Ohio Valley before reaching the Mid-Atlantic and Northeast shortly thereafter.
For much of next week, a punishing combination of heat and humidity will remain lodged over the East — although some relief may arrive in the Upper Midwest during its second half.
The source of the heat is a sprawling heat dome — or strong zone of high pressure — that is centered over northern Mexico and the southwest United States, where record high temperatures are occurring in some areas. It is forecast to shift eastward this weekend and will become centered over the southeast. Next week it will drift northward toward the Mid-Atlantic while strengthening and expanding in all directions.
Some models indicate that the heat dome could reach historic strength for the time of year. The European weather model simulation, shown above, shows its intensity even surpassing the heat dome of June 29, 2012, during which Washington set a June record of 104 degrees. It hit 109 degrees in Nashville and 105 in Raleigh, N.C., that same day.
It’s already been one of the warmest years on record in the East because of a largely absent winter and mild spring. But since the start of June, the nation’s most extreme heat has occupied the West. That’s about to change in a big way.
Brutal heat in the South this weekend
High temperature forecast for Saturday from the Weather Service shows widespread highs deep into the 90s to near 100 across most of the South. (Pivotal Weather)
While the heat dome shifts and reconfigures over the South and southeast, the potential for record highs will arrive as soon as Friday in Atlanta and Raleigh, where temperatures could rise to near 100. Over the weekend, record highs near and above 100 should be common from Arkansas to coastal Georgia.
As the heat dome shifts north and strengthens, record highs are probable across the Ohio Valley on Monday and into the Mid-Atlantic by Tuesday. More record heat is probable in the East after that, too.
Few areas will escape escalating heat risk
The National Weather Service has developed a new HeatRisk product, which evaluates the threat of predicted temperatures on a 0 to 4 scale. Most of the Lower 48 states will experience at least Level 2 or 3 HeatRisk levels over the next week as the heat dome evolves.
Large areas of Missouri, Illinois and Indiana as well as portions of Kansas, Iowa, Michigan, Ohio, West Virginia and Georgia are forecast to experience Level 4 or “extreme” conditions. Des Moines, St. Louis, Chicago, Indianapolis and Atlanta are some of the cities in this zone.
A Level 3 or “major” HeatRisk is forecast for Pittsburgh, New York City, Washington, Nashville, Little Rock and Wichita.
The HeatRisk levels take into account how unusual the heat is, its duration and its potential health effects. At Levels 3 and 4, the Weather Service says the heat will pose a threat to individuals without adequate cooling and hydration. The most vulnerable groups are typically outdoor workers, the homeless, older adults and anyone without access to air conditioning.
Heat indexes to top 100 degrees over sprawling area
Heat index forecast maximum over the next week. Many places will see multiple days near this level. (Capital Weather Gang)
It’s not just the heat but also the humidity that will make this episode potentially hazardous. Heat indexes, a measure of how hot it feels factoring in the humidity, are forecast to reach 100 to 110 degrees across the South by the weekend, according to the Weather Service. Some areas near the Gulf of Mexico could even surpass 110.
The heat dome should produce multiple days of heat indexes of at least 100 from Texas to Washington, and even stretch as far north as Iowa and the lower Great Lakes.
No end in sight
The forecast from mid-next week to the middle of the following week favors more heat over most of the Lower 48 and over the waters of the Gulf of Mexico and Atlantic Ocean. (Climate Prediction Center)
This heat dome may have substantial staying power. It developed in May this year and has already been stubbornly persistent and unseasonably intense — contributing to historic heat in Mexico, the Desert Southwest, Texas and Florida.
The outlook ahead is for more of the same. While the heat dome may relax or move around, it seems likely that most of the Lower 48 will remain under its influence and see warmer to much warmer than normal weather through at least the end of June.
Jason Samenow contributed to this report.
By Ian Livingston. Ian Livingston is a forecaster/photographer and information lead for the Capital Weather Gang. By day, Ian is a defense and national security researcher at a D.C. think tank. Twitter
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 (Other reports are archived on prior daily posts.):
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.)