A semi-permanent high-pressure system off the southeast cost of Brazil shifts eastward to Bolivia this week/weekend allowing wet weather to develop over East Brazil where the pattern of early meteorological summer has been dry. In the medium range, an upper trough forms off the East Coast of Brazil causing more heavy rain in this zone.

Deep layer (10-200 CM) soil moisture anomalies and their trend is an excellent “quick look” assessment of whether ongoing drought and drought potential is increasing or decreasing across the South America drought concern area in Brazil as meteorological summer 2023-24 has arrived.

The upcoming storm for late weekend into early next week on the East Coast is an El Nino storm. Problems: 1.) Develops at a low latitude over very warm water therefore unusually low pressure (980-985 MB off Mid-Atlantic Coast) emerges; 2.) Unusually low pressure running into a high-pressure area southeast of Canada will create hurricane force wind gusts northeast and east of the storm center possibly affecting southern New England and Long Island; 3.) Because the storm was born over warm water, an unusual heavy rain is likely for the Northeast Corridor.

As meteorological summer unfolds, concern regarding Brazilian drought is ongoing. One steady development in recent weeks is the tendency for forecast models to over-forecast rainfall in the medium-range particularly in the 11-15-day period. During the past 7 days, the wet bias has increased.