05/31/2020, 2:19 pm EDT

Explaining Recent Tendency for Stalled U.S. Coastal Tropical Cyclones

Important to seasonal prediction of North Atlantic tropical cyclone activity is the evolution in recent years of the North Atlantic Warm Hole and the attendant upper air pattern. During the tropical cyclone season a persistent upper level trough has formed in the cooler atmosphere across the NAWH compensated for by a persistent upper ridge over Quebec (and vicinity). When the upper ridge is present as tropical cyclones go inland the U.S. coastline storms slow down and produce excessive rainfall similar to Harvey (2017), Florence (2018) and Imelda (2019). A similar dynamic is expected for AUG/SEP 2020.
05/29/2020, 8:31 am EDT

Why La Nina Could Be Stronger

Global SSTA models are forecasting a major contrast between ocean surface temperatures across the eastern equatorial Pacific (cool) versus the far western Pacific and eastern Indian Oceans (warmer). The contrasting ocean temperatures lead to stronger trade winds across the eastern Pacific tropics possibly increasing La Nina strength and duration.
05/21/2020, 12:00 pm EDT

NOAA 2020 North Atlantic Hurricane Outlook

NOAA/NHC issues their 2020 North Atlantic basin tropical cyclone activity forecast. The outlook indicates above normal activity similar to forecasts issued in early April by other leading (market) providers. The seasonal forecast indicates 13-19 tropical storms, 6-10 hurricanes and 3-6 major hurricanes.
05/19/2020, 10:44 am EDT

Warmer Than Normal Ocean Surface Lead To Frequent and More Powerful Tropical Cyclones This Season

Already three tropical cyclones have formed in the northern hemisphere before the official June 1 start to the tropical cyclone season. Warmer-than-normal ocean water played a key role in leading to the formation of Arthur east of Florida, rapid intensification of Vongfong to a category 3 tropical cyclone before striking the Philippines and emergence of a category 5 tropical cyclone (Amphan) in the Bay of Bengal.