Astronomical fall begins with the equinox, but meteorologists call the months of September, October, and November ‘fall.’
This year you wouldn’t know it’s fall in the US by the temperatures. The heat wave that has engulfed the central states has spread to the east coast. Europe, too, will begin meteorological fall with well-above-normal temperatures.
The tropics are unusually quiet, both the Atlantic and Pacific Oceans, just a week before the September 10 maximum of activity measured over the long-term. Still, there are a couple of areas of interest.
Hottest Weather Of The Summer In The US Continues: US Open Tennis Tournament
The jet stream, which dipped southward into the midsection of the country earlier this summer, has retreated to the Canadian border. Another warm week is in store for much of the nation, including the east coast, where the US Open Tennis Tournament chugs towards its weekend conclusion in New York.
The warm air is currently fairly stable, and with the angle of the sun lower, thunderstorms that result from daytime heating will be at a minimum. Temperatures through Friday will be in the upper 80s in New York, and the humidity will be high.
The weather for Saturday’s women’s singles finals is problematical: A cold front will be close enough to produce a high probability of rain. The men’s singles final on Sunday will get the benefit of the cold front, with clearing skies and cooler temperatures.
The Start Of Fall In Europe: A Continuation Of The Warmth
Temperatures over the continent have been consistently above normal since last winter. The middle of August saw about a two-week reversal to below normal temperatures, but the warmth is back. A ridge in the jet stream could bring record high temperatures across Europe in September.
Approaching The Seasonal Hurricane Peak: Active Systems In The Gulf Of Mexico And The Pacific South Of Mexico
A tropical wave that moved all the way across the Atlantic Ocean and Caribbean Sea without significant development finally found some more favorable conditions in the southern Gulf of Mexico over the weekend, and has become Tropical Storm Dolly.
The system will bring heavy rain to the east-central Mexican coast and inland mountains, but the storm’s wind will max out at about 50 miles per hour at landfall. Tropical storm warnings are up for the area around landfall, but the major impact will be from flooding and landslides.
The water is now warm enough for tropical storm formation in the eastern Atlantic. These ‘Cape Verde’ storms are often the most damaging to the eastern United States. Right now the area is quiet, but clusters of thunderstorms continue to move across Africa. As they move off the coast as easterly waves, development is possible any time the vertical wind profile is favorable.
In the Pacific, the drumbeat of storms emanating from south of Mexico continues. A disturbance seems very likely to become Tropical Storm Norbert within a couple of days.
Looking Back On Summer (June-July-August) in the US: Records Galore
The summer of 2014 was a summer of extremes: hot, cold, wet, and dry. The west coast was generally hot, the lower midwest was cold, and the upper midwest was wet. Isolated spots in other parts of the country also experienced record-breaking weather.
Santa Ana airport probably set the most notable record: the temperature was above average every single day. In fact the streak goes back to spring, and stands at 117.
Some Summer Records:
- Driest summer ever: Tallahassee, Florida. It’s worth noting that Miami is very close to a record wet summer, which shows how precipitation can vary, even within relatively short distances.
- Wettest summer ever: Fairbanks, Alaska
- Wettest summer ever: Sioux City, Iowa. Sioux City broke the old record by more than 50%, 30.38 inches versus 20.13 inches.
- Wettest summer ever: Chicago, Illinois
- Wettest summer ever: Lake Charles, Louisiana
- Coldest July ever: Little Rock, Arkansas
- Hottest July-August ever: Spokane, Washington
What Do All The Records Mean?
Extremes of hot and cold are consistent with global warming, as are increases in precipitation. The accumulation of data consistent with fossil-fuel-burning-induced climate change is now overwhelming. What changes do you see in your neighborhood?