Impact of La Niña
Autumn, a season of metamorphosis, witnesses the brutal heat of summer transitioning into the briskness of fall, as verdant foliage transforms into vibrant hues, and the zest of summer succumbs to the warmth of aromatic spices. Yet, while the nation is engulfed in a pumpkin-spiced fervor, the palpable sensation of autumn might be delayed, with the lingering warmth of a torrid summer threatening to extend into the new season—an omen of a warming planet driven by fossil fuel emissions.
Jennifer Marlon, a climate savant at Yale School of the Environment, posits, “Autumn is increasingly perceived as a mere continuation of summer.” This sentiment is underscored by the persistent and intense heatwaves, likely marking this summer as the hottest on record across nearly 100 cities, spanning the West, South, and East, including Las Vegas, Phoenix, and Washington, DC.
In some areas, a fleeting glimpse of fall has been overshadowed by the relentless return of summer’s swelter. Philadelphia, for instance, recently experienced a brief respite with temperatures in the low to mid-70s, evoking a late-September feel. However, this relief was short-lived as the heat index—a measure of how temperature and humidity combined are perceived by the human body—soared into triple digits.
Wednesday saw tens of millions under heat advisories, with potential record-breaking temperatures across the East and widespread highs reaching into the 90s and low 100s across much of the nation. This erratic temperature fluctuation may characterize the season, as warmth seems determined to persist despite occasional cooler interludes.
Although fall officially begins in September, the more consistent cooler temperatures often associated with the season typically become widespread by the latter half of the month. However, summer-like heat appears reluctant to relinquish its grip, according to recent forecasts.
The most anomalous warmth is predicted to span from the central and southern Rockies southeast through the South and up the entire East Coast. Conversely, the northern swath of the country, stretching from the Pacific Northwest to the Upper Midwest, is anticipated to maintain closer-to-normal conditions, as forecasted by the Climate Prediction Center (CPC).
Above-average temperatures are projected to persist into October and November, per the CPC. Yet, despite the elevated averages, the entirety of fall will not mirror summer. For much of the United States, typical high temperatures drop by approximately 20 to 25 degrees from mid-July to mid-October. Denver, for instance, witnesses a decline from a normal high of around 90 degrees in July to a high in the mid-60s by October.
The East Coast might experience a respite from the abnormal warmth if an active hurricane season influences the weather. Despite some periods of quiet, the Atlantic hurricane season is expected to intensify soon. La Niña, a natural climate pattern characterized by cooler-than-average ocean temperatures in the tropical Pacific, is anticipated to strengthen during the fall, potentially amplifying tropical activity in the Atlantic.
While La Niña’s most significant impact on US weather typically occurs in winter, its effects could be felt later this fall.
Forecasters are closely monitoring potential tropical disturbances as the peak of hurricane season approaches in less than two weeks, with the most active portion of the season continuing through mid-October. Any storms nearing US coasts through the end of hurricane season could also bring rain and “periods of cooler-than-normal temperatures” for these regions, according to the CPC.
The anticipated active hurricane season could also lead to a wetter-than-normal fall for the East Coast. Conversely, vast swathes of the western and central US, where below-average precipitation is forecast, might face exacerbated drought conditions, following a summer of drying out.
Recent Climate – Impact of La Niña on autumn, Impact of La Niña , Update Weather Patterns and the Impact of La Niña, Weather Patterns and the Impact of La Niña