The Northern Hemisphere saw its first hurricane of the season on Monday in the eastern Pacific Ocean, but overall, the 2025 tropical season is off to a relatively quiet start. In fact, there are reports that this is the latest time since 1993 for the first hurricane to develop in the Northern Hemisphere. In addition, the western Pacific Ocean hasn’t seen a named storm so far this tropical season and there are reports that this may be the latest time ever for that to take place. In the Atlantic Basin, it is still quite early in the season and there has been no activity so far, but there is the possibility of a tropical system in about a week to ten days or so across the southwestern Gulf of America or northwestern Caribbean Sea.
Read More
Mount Etna erupted on Monday, surprising tourists and sending them fleeing to safety as huge plumes of ash and debris shot out of the volcano and into the sky, according to news reports. A pyroclastic flow, or avalanche of burning ash, crashed down the slopes of the volcano’s southeast crater, according to Italy’s National Institute of Geophysics and Volcanology and the Volcanic Ash Advisory Centre in Toulouse reported that the ash cloud had reached an estimated height of 21,000 feet. Despite the many videos of people fleeing down Mt. Etna during the eruption, no injuries or fatalities have resulted or been reported so far.
Read More
While global sea surface temperatures continue to run at above-normal levels, there has been a rather dramatic cooling trend across tropical regions all around the world. During the past year or so, water temperatures in the Indian Ocean have dropped to nearly neutral levels around India and well above-normal levels immediately east of Africa have moderated to only slightly above-normal conditions. In the central part of the tropical Pacific Ocean, relatively neutral water temperatures have replaced the El Nino conditions of a year ago when water temperatures were as much as two degrees higher than normal. Perhaps the most dramatic change in water temperatures has taken place in the tropical Atlantic Ocean where much warmer-than-normal conditions of a year ago are virtually normal as we approach the end of April and there is even a pocket of colder-than-normal water just off Africa’s west coast. The tropics are a critically important part of the world with respect to the total energy budget and cooling trends can certainly have an inhibiting impact on the upcoming tropical season.
Read More
The summer season is fast approaching, and probabilities are high that overall temperatures in the Arctic region will be nearly normal which happens to be right around the 32 degree (F) freezing mark. Chances are indeed high since this temperature pattern of nearly normal conditions during the summer months of June, July, and August has taken place virtually every year since the turn of the century. Meanwhile, the other nine months of the year in the Arctic region have featured above-normal temperatures in a pattern that too has also been very consistent in recent years.
It is the temperatures in the summer months of June, July, and August, however, which are the most important when it comes to Arctic sea ice extent as this is the melting season up in that part of the world. Arctic sea ice extent has been running at below-normal levels since the middle 1990’s; however, if temperatures again remain nearly normal during the summer (melting) season, the chance for any additional significant drop off will be limited. Indeed, given this consistent summertime temperature trend in recent years, Arctic sea ice has shown resiliency both in terms extent and in volume. One possible explanation of this persistent temperature pattern across the Arctic region featuring nearly normal summertime conditions and warmer-than-normal during the coldest nine months of the year is the increased levels of water vapor in the atmosphere.
Read More
The summer is more than half over up in the Arctic region and overall temperatures this season are repeating a pattern that began many years ago in that they are running at nearly normal levels which happens to be quite close to the freezing mark. The cold season in the Arctic has featured above-normal temperatures in the Arctic region in a pattern that has also been very consistent in recent years. It is the temperatures in the summer months of June, July, and August, however, which are the most important when it comes to Arctic sea ice extent as this is the melting season up in that part of the world. As long as temperatures remain nearly normal during the summer (melting) season, the chance for any additional significant drop off in sea ice will be limited. Indeed, given this consistent summertime temperature trend in recent years, Arctic sea ice has shown resiliency both in terms extent and in volume. One possible explanation of this persistent temperature pattern across the Arctic region with nearly normal summertime conditions and warmer-than-normal in the other nine months of the year (i.e., the cold season) is increased levels of water vapor in the atmosphere.
Read More
Numerous signs point to an active tropical season this year in the Atlantic Basin with more tropical storms, hurricanes, and “major” hurricanes compared to the long-term averages. The average number of named tropical storms in an Atlantic Basin tropical season is 14.4 with 7.2 of those reaching (minimal) hurricane status, and 3.2 becoming “major” (1991-2020 baseline period).
Based on my overall analysis of current and forecasted atmospheric and oceanic conditions, I expect around 16 named storms this season with around 9 reaching hurricane status and of those perhaps as many as 4 to achieve “major” classification level. Another metric to use in the assessment of overall tropical activity is known as the accumulated cyclone energy or ACE which utilizes both strength and longevity of tropical storms in its calculation and I expect this to be 150-160% of normal in the Atlantic Basin this tropical season.
The two most important parameters that have been factored into the “2024 Tropical Outlook” include: (1) the development of La Nina in the equatorial part of the Pacific Ocean and (2) warmer-than-normal sea surface temperatures in much of the breeding grounds region of the tropical Atlantic Ocean and Caribbean Sea…both of which are favorable for the development and intensification of tropical activity. I believe the most vulnerable areas to be directly impacted this upcoming tropical season include those in and around the Caribbean Sea, Gulf of Mexico, and Southeast US.
Read More
Temperatures are currently running at warmer-than-normal levels in the Arctic region (not shown) during this late stage of the winter season with actual air temperatures generally well below the freezing mark. This above-normal trend in temperatures during the cold season in the Arctic region has been quite consistent during the past many years. Meanwhile, temperatures during the past several summer months of June, July and August have been nearly normal and this is especially important with respect to Arctic sea ice as this is the melting season in the Arctic region when actual air temperatures can average right near or even slightly above the freezing mark. As long as temperatures in the Arctic region remain nearly normal during the summer (melting) season, the chance for a significant drop off in sea ice will be limited. Indeed, given this consistent temperature trend in recent decades, Arctic sea ice has shown resiliency both in terms extent and in volume. One possible explanation of this persistent temperature pattern across the Arctic region with nearly normal summertime conditions and warmer-than-normal in the other nine months of the year (i.e., the cold season) can be increased levels of water vapor in the atmosphere.
Read More
Above-normal sea surface temperatures continue this month across most of the equatorial part of the Pacific Ocean, but there are signs that this El Nino episode which began about a year ago will flip to La Nina conditions (colder-than-normal) by the early part of the 2024 summer season in the Northern Hemisphere. A flip from El Nino to La Nino across the equatorial Pacific Ocean can have big implications on the upcoming 2024 Atlantic Basin tropical season. In fact, this expected dramatic change in sea surface temperatures across the Pacific Ocean may be a major contributor to a very active tropical season in the Atlantic Basin as atmospheric conditions are typically more favorable (lower wind shear) during La Nina episodes for the development and intensification of tropical storms. A second favorable factor for a very active tropical season in the Atlantic Basin is the likely continuation there of widespread warmer-than-normal sea surface temperatures. Finally, as oceanic cycles play a critical role in global temperatures, a flip from El Nino to La Nina in the world’s largest ocean could mean a return to closer-to-normal levels following a spike during the past year or so.
Read More
The end of the year is closing in rapidly and this blog provides a wrap up of the 2023 US wildfire and tornado seasons and also the 2023 tropical season in the Atlantic Basin.
Read More
The Earth’s upper atmosphere is an interesting place these days and will be impacted in the near-term by a so-called “cannibal” coronal mass ejection (CME). In addition, there is an on-going stratospheric warming event that can have an impact on winter weather conditions across parts of the nation later in the month of December and possibly well into January as well. The incoming CME can result in some communication problems on Friday, December 1st and it certainly can produce northern lights potentially visible all the way down into the middle latitudes. The unfolding stratospheric warming event can increase the chances for cold air outbreaks to make their way this winter season from the higher latitudes to the middle latitudes.
Read More
