October 2019: Calm Start, Stormy End in the Northeast

The weather in October finally cooled off for the heart of fall and now we are nearing the return of old man winter. Nonetheless, warmth defined much of the month along with wet weather (especially during the second half), as a series of systems pressed across the Northeast. And while severe weather season came to a close for most, the month went out with a bang as a squall line crashed through the region.

The first half of the month was tame outside of the occasional frontal passage which gradually allowed cooler air to settle in. As a result, areas continued to warm well into the 70s and 80s, but then fell off into the 40s and 30s at night following the frontal passages, even into Maryland. Rain was scattered and only amounted to a few tenths worth. There was a failed tropical system (which was briefly named sub-tropical storm Melissa), that swirled off the coast of New England between the 8th and 10th, however it did not bring much weather, outside of some showers across the Mid-Atlantic. This was followed by more high pressure in the middle of the month, briefly cooling things back to near seasonable levels.

The mostly quiet pattern then flipped with a system on the 16th. A low over Michigan pulled up tropical moisture across the Southeastern states and managed to drop 1 to 2 inches of rainfall for quite a few areas, with many topping out at 3 and 4 inches! A “sting jet” also formed behind the rain, which caused wind gusts to exceed 60 mph across Long Island and southeastern Massachusetts (Provincetown managed to reach 90 mph!) This was quickly followed by a smaller system on the 20th that caused heavy rain across the Mid-Atlantic. Following that, two potent systems rounded out the month on the 27th and 31st. The first caused over an inch to fall up the I-95 corridor, followed by brief high pressure that eventually shifted out, allowing southerly flow to return across the Northeast. Onshore winds caused nothing but clouds, drizzle, and mist for two days in a row. This damp weather eventually lifted as a warm front brought unseasonable warmth on Halloween, but stormy weather was close behind.

The day itself ended up mostly dry for trick-or-treating, especially those along the coast and around the major cities. Thankfully, the eventual squall line came in after festivities. Sharply cooler air and a robust south wind caused wind gusts to exceed 40 and even 50 mph, especially across New England. And the front itself brought a plethora of wind damage across Maryland, Pennsylvania, and New Jersey as winds within the line were even higher. In fact, two tornadoes occurred, an EF2 in Glen Mills, PA and an EF1 in Madison, NJ! Unfortunately, the former resulted in two injuries.

Because of the repeated rain events, Washington, D.C. and Baltimore, MD both received over 6” of rainfall, making this the 5th and 8th wettest October for them respectively. Hartford, CT also was just 0.6” off from 7” on the month and also resulted in their 8th wettest October on record. As for temperatures, most areas saw 3 to 6 degree above normal anomalies, making it a rather warm month for October. The I-95 corridor in Maryland saw their 7th warmest October, while Philadelphia came in at their 8th warmest as all saw averages in the low-mid 60s.