By Chris Gilberti | August 28, 2023
Flash flooding closes Western Avenue at Stuyvesant Plaza in Albany, NY on July 18, 2023 after extreme rainfall.
Photo Credit: Evan Belkin
Students are being welcomed back to the University at Albany campus not only by friends and faculty, but by a beautiful stretch of late summer weather. Following a June, July, and early August that saw heat, humidity, and record-breaking rainfall in New York State and the Capital Region in particular, the pattern seems to have finally shifted. At least for the near future, we can expect temperatures to remain comfortable, and an end to the flooding rains that soaked the region over the past few months.
It was just around this time last year that upstate New York was feeling the effects of a hot and dry summer, as drought watches were in effect for much of the state. This summer has in many ways written a different story for itself, as flooding rains and a barrage of storms impacted the northeast leading to both widespread river flooding and flash flooding. This flooding caused millions of dollars of damage and endangered many lives, so any relief is welcome. Luckily, just over the last few weeks things have calmed down substantially, and it seems the pattern will remain relatively calm for the near future.
The pattern this summer was impressively stubborn, with a large upper-level trough (elongated region of low pressure) becoming entrenched over the Great Lakes and Northeast for long periods of time. Winds rotating around troughs can cause upward motion and force precipitation. This meant that multiple disturbances could move through this trough and impact the northeast with showers and storms.
This, along with a cutoff low pressure system off the coast of New England that continually circulated in moisture from the Atlantic, meant the ingredients were in place for extreme rainfall. Due to atmospheric moisture (called Precipitable Water or “PWAT”) being anomalously high during this time, by +1 to +2 standard deviations, these disturbances were able to tap into large amounts of moisture leading to major flooding.
With these events occurring one after another, soil moisture also drastically increased. This is dangerous because the ground can only hold so much water. Once it is full, water will stop soaking into the surface and all of the rain will run off, causing flash floods and filling rivers and causing river flooding. This was the case in Vermont on July 11 when the Winooski River completely flooded downtown Montpelier, VT.
While Vermont saw the brunt of the major river flooding, New York and the rest of New England experienced significant flash flooding as well. In fact, July 2023 turned out to not only be the wettest July on record in Albany, but it was also the third wettest of any month since records began in Albany in 1826. By the end of the month, 10.7 inches of rain had fallen in Albany.
Figure shows record breaking rainfall in Albany during July 2023 compared to other similarly wet months.
Photo Credit: National Weather Service Albany, NY
Given all the rainy days this summer, the recent change of pace has been very welcome. Just in time for students’ return to campus; temperatures have settled in near average and besides some passing showers, there haven’t been any major storms. Looking forward, temperatures are expected to be near to even slightly below average, with highs mostly in the 70s to near 80 through the end of the week. Besides some widespread showers Tuesday evening into Wednesday, things also look to remain relatively dry.
Finally, eyes have turned to the tropics recently with Hurricane Hillary impacting southern California. It was the first tropical system to impact the region since 1939 and prompted the first tropical storm watch for the region ever. Since water temperatures in the eastern Pacific are much cooler than in the Atlantic, it is extremely rare for tropical systems to survive as they push north towards California.
Things in the Atlantic have churned up recently as well. Tropical Storm Franklin has moved up towards Bermuda and should remain out to sea, though a disturbance in the Gulf of Mexico could organize into a tropical storm in the coming days that could impact the Gulf Coast of the United States. Eyes will stay on these systems to see if their remnants could bring more rain to the New York area eventually. Any new systems out in the Atlantic will have to be monitored as well to detect the chances of any storms coming up the East Coast and potentially impacting the northeast.
With a record breaking summer mostly behind us now, and the potential always being there for things to turn up again soon, it is definitely a good time to get out and enjoy the calm late summer weather while you still can!