Evidence suggests that when surface water temperatures in the northern tropical Atlantic rise sufficiently, moisture is pulled northwards by shifting wind patterns. This brings heavier rains to the north of the rainforest while leaving southern portions drier and, thus, more vulnerable to fires associated with human activity.
At the same time, this process also creates more favorable conditions for hurricanes to form in the Atlantic. These powerful storms require warm, moist air as fuel, which is why the they only form over warm ocean waters near the equator.
“Our seasonal fire forecast provides an early indication of fire risk to guide preparations across the region,” Morton said. “Now, satellite-based estimates of active fires and rainfall will be the best guide to how the 2020 fire season unfolds.”
Morton and Chen say the severity of the fires this year may even be exacerbated by the ongoing COVID-19 pandemic, which could hamper the work of emergency responders.
This human activity is difficult to predict, introducing a significant unknown into long-term forecasts, according to the researchers.
In terms of the Atlantic hurricane season—which officially runs from the beginning of June until the end of November, peaking in August and October—this year has already been particularly active clocking up six named storms already with the formation of Tropical Storm Fay on Thursday.
In fact, two storms formed before the season officially began. And Fay became the earliest forming storm beginning with an “F” since records began, Earther reported. Hurricanes in a season are named in alphabetical order using a predetermined list.
Meteorologists had predicted prior to June that this year’s hurricane season would be particularly active, with the National Oceanic and Atmospheric Administration (NOAA) forecasting up to 19 storms and six major hurricanes. While there is still some time to go, it appears that this prediction could turn out to be relatively accurate.
Forecasts for an active season were based on observations of warmer ocean temperatures in the Atlantic and a trend towards La Niña conditions over the spring and summer. La Niña is the periodic cooling of the equatorial eastern and central Pacific Ocean, which can affect weather patterns all over the world.
On Thursday, the NOAA issued a La Niña Watch, saying the phenomenon could form in fall. This has significant implications for the formation of hurricanes. The effect of La Niña in the tropical Atlantic is to weaken a characteristic known as wind shear, the change in wind speed and/or direction with height into the atmosphere, that typically hampers the formation of hurricanes.
