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.
05/25/2020, 10:15 am EDT

Indian Ocean Dipole (-IOD) AND La Nina Increases Risk of Stronger La Nina Climate AND La Nina Lingering Into Next Year

Evolution of La Nina during negative phase of the Indian Ocean Dipole suggest that the attendant convection patterns associated with this regime will be stronger and have a more dramatic impact on global La Nina climate. Both strength of La Nina climate anomalies could be stronger and La Nina could linger in 2021.
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.