Some portions of the Northeast have a chance at vibrant fall foliage based on forecast weather, while drought-stricken parts of the country may not have much of a display.
Warm and wet weather through the remainder of September and into the first couple of weeks of October would not be good news for leaf-peepers in the Northeast, according to Dr. Marc Abrams, a professor of Forest Ecology and Physiology at Penn State. Abrams began observing how weather conditions affect fall foliage 25 years ago.
A late and muted peak in fall colors would be expected if warmth continues into the second week of October.
Instead, Abrams added, ideal weather for a colorful fall would be drier weather through the remainder of September with colder temperatures, dipping into the 30s at night.
"A frost helps to bring out the color. What happens is that the chlorophyll - which causes the green color of leaves - starts to break down. This basically exposes the other pigments like red and orange," Abrams said. On the other hand, persistent warm and wet weather would extend the growing season, causing leaves to stay green.
A frost and freeze is most likely for upstate New York and north-central portions of New England during late September, according to AccuWeather Lead Long-Range Forecaster Paul Pastelok. This region will have the best chance for a bright and colorful fall.
While nights can get cool farther south, temperatures are not predicted to get cold enough to produce a frost before October, Pastelok added. For the big cities along the I-95, including New York City to Washington, D.C., the central Appalachians and Ohio Valley, the mild weather may mean a late peak of fall foliage with subdued colors.
Typical peaks in fall foliage color across the U.S.
While warm, wet weather limits the bright color display of leaves, the opposite - abnormally dry conditions - can also have a negative impact. Drought conditions can impact the leaf size, vigor and physiology, and exceptional droughts can even kill trees.
Hard-hit drought areas of the Midwest and Plains, especially Iowa, Nebraska and Missouri, are probably not going to have a good display of fall foliage this year, Abrams said.
The red color on the U.S. Drought Monitor map shows extreme drought conditions, while the deep red shows exceptional drought conditions (the highest level of drought).
Extreme to exceptional drought conditions are gripping much of the nation's heartland.
Following a southward push of cool, dry air at midweek, clouds, showers and higher humidity will return to the Northeast.
Even though the tremendous rains have come and gone, flooding will continue on the major rivers in the South Central states for the next couple of weeks.
Severe weather, including isolated tornadoes, will once again target the nation's midsection into Wednesday night.
Summer heat to set the stage for thunderstorms from England to France and Germany on Friday and Saturday.
Major Hurricane Blanca will threaten Baja California with flooding rain and damaging winds this weekend.
While the center of Andres will remain a thousand miles away, its moisture will still get drawn into the Western United States and enhance thunderstorm activity later this week.
Violent thunderstorms and tornadoes; 13 confirmed tornadoes in western PA (most from any outbreak). Widespread wind damage in eastern PA. Wind gusts of 80 mph at ABE and RDG. One person killed in Philadelphia by a falling tree. Largest tornado outbreak in 35 years in western PA.
Harrisburg, PA (1985)
Golf ball-sized hail and 60 mph winds.
Heavy, flooding rains. Milton received 15.57 inches while Crest view was deluged by 11.44 inches.