Lowell (2020)

A low-pressure trough south of Tropical Storm Beta organized into a tropical depression by 1800 UTC on 20 September 2020 about 500 nautical miles south-southeast of the southern tip of the Baja California peninsula. The system moved west‑northwestward, became Tropical Storm Lowell at 1800 UTC 21 September, slowly strengthened to a peak on 23 September, then encountered increasing wind shear, drier air, and cooler waters and gradually weakened. Lowell became a post‑tropical remnant low by 1800 UTC 25 September about 1,100 n mi west of the southern tip of Baja and opened into a trough by 0000 UTC 28 September about 800 n mi east of the Big Island of Hawaii.

Lowell remained well offshore and did not make any landfalls. No coastal watches or warnings were issued for Mexico or the United States in association with this storm.

The maximum sustained winds reached 45 knots (about 52 mph) with an estimated minimum central pressure of 1001 mb at 0600–1800 UTC 23 September, corresponding to a moderate tropical storm intensity (not a hurricane).

There were no reports of storm surge or rainfall impacts tied to Lowell in coastal stations or populated areas in the official report. No ship or land observations of tropical-storm-force winds were recorded, and the storm remained over open water throughout its life.

No casualties or damage were reported in association with Tropical Storm Lowell.

Noteworthy items: Lowell formed sooner than forecast—the disturbance was given a low chance of formation in the outlooks only 42 hours before genesis—and the official forecasts had some track and intensity biases at longer lead times. Several objective satellite scatterometer (ASCAT) and Dvorak analyses supported the peak intensity estimate.