Tuesday, August 1, 2023
As the sweltering days of summer come to an end, cooler weather and the approach of fall are on the horizon. The formal start of astronomical fall in the United States will be at 2:50 a.m. EDT on Saturday, September 23. However, meteorological autumn begins on September 1.
Summery conditions are predicted to linger in certain areas, delaying the changeover to autumn weather.
Effect of El Nino
AccuWeather’s long-range forecasters, lead by meteorologist Paul Pastelok, have been studying weather patterns throughout the world to create the autumn prediction for the United States. The El Nio climatic phenomenon, which may alter the jet stream, will be an important force determining weather patterns this autumn. El Nio appeared early this year, displacing its colder counterpart, La Nia, which had endured for three years in a row.
Gradual shift from summer to autumn
The Northeast and Midwest will have a slow transition from summer to fall, with moderate weather continuing throughout the new season. During the first week or two of September, temperatures in places such as New York and Philadelphia may approach 90 degrees Fahrenheit. The lovely weather will gradually give way to cooler temperatures as September goes into October. The interplay of cooler air with residual warmth and humidity can lead to thunderstorms, which can lead to severe weather. The Midwest, in particular, may have an early frost towards the end of September or the beginning of October.
Arrival of Cold Air
The Northeast will get its first frost later, perhaps in October, and some coastal locations may not see it until early November. Cooler weather will also bring the prospect of snowflakes falling in higher elevations in late September and October. Flurries are normal in these areas around October, but the timing this year is roughly two weeks ahead of the historical average.
Reduction of Tropical Activity
El Nio, which normally suppresses tropical activity, will also have an impact on the Atlantic hurricane season. Warm water temperatures in the Atlantic basin, on the other hand, might feed severe storms. Temperatures in areas such as the Gulf of Mexico are substantially above average, and El Nio may not completely suppress storm activity in late August and September. Thunderstorms are also possible in the Southeast during the changeover period in late September and October.
Mild Start of autumn in Central U.S. and Rocky Mountain
The central United States and the Rocky Mountains, which had a warm start to October, will see substantial shifts. Meteorologists have identified analogue years, such as 2009, that aid in forecasting weather trends for the future months. A pattern shift is likely to deliver cooler weather to the north-central Plains and northern Rockies. While snow may not be common in October, temperatures in the region are expected to be lower than last year.
Continuation of Hot weather in Southwest. California
The western United States will continue to see scorching weather until the beginning of October, particularly in the Southwest. The central valleys and deserts of California are forecast to continue scorching into October. However, the Pacific Northwest may have rain, and maybe even an atmospheric river, in September, providing much-needed reprieve from wildfires.
Fall Weather for United States
The United States’ autumn weather prediction includes lingering summer heat, gradual shifts to cooler weather in the Northeast and Midwest, and the possibility of early snowfall in higher elevations. Despite the existence of El Nio, the Atlantic hurricane season may see a few storms, and the central United States and Rockies will have cooler temperatures. Meanwhile, the West will see scorching weather in certain areas, as well as the prospect of early precipitation in the Pacific Northwest.