Arlene — 2023

Arlene formed from non-tropical origins in the eastern Gulf of Mexico after a mid- to upper-level trough induced a surface low on 31 May 2023. It became a tropical depression on 1 June and a tropical storm early on 2 June. The storm moved unusually southward across the eastern Gulf, remained over water, and weakened to a depression by 3 June before dissipating on 4 June. Aircraft reconnaissance provided most of the intensity and position fixes during its brief life. Arlene did not make any landfalls. It remained offshore for its entire lifespan, and no coastal watches or warnings were issued. The storm’s maximum sustained winds reached 35 mph (30 kt) in the official best track, with supporting aircraft and satellite data indicating surface winds in the low-to-mid 30s kt range. The minimum central pressure at peak was 998 mb. Arlene was therefore a minimal tropical storm at its strongest. No storm surge impacts were reported in the NHC report, and there were no reports of direct rainfall totals tied to the cyclone causing damage onshore. A NOAA buoy (42039) in the northeastern Gulf briefly recorded a 1-minute wind of 33 kt with a gust to 45 kt on 1 June, but that was judged to be related to nearby convection and not representative of Arlene’s true intensity. There were no reported deaths or damage associated with Arlene. The storm’s short duration, small size, and remaining offshore meant impacts to land were negligible or nonexistent. Noteworthy items include Arlene’s non-tropical origin and unusually short lead time in forecasts: the medium- and high-probability outlooks were issued at or after genesis in post-analysis, reflecting marginal and inconsistent model signals. NHC track and intensity forecasts had limited verification value because of the few forecasts issued, though official intensity errors were small for the brief forecast record.