Gamma (2005)

A tropical cyclone formed from a vigorous Atlantic wave and became a tropical depression about 85 nautical miles west of St. Vincent at 0000 UTC on 14 November 2005. It first reached tropical storm strength on 15 November but weakened to a depression later that day and degenerated to a tropical wave on 16 November while moving west across the central Caribbean. The system regenerated into Tropical Storm Gamma along the northern coast of Honduras at 1800 UTC on 18 November, drifted northward and then east-southeast, weakened again on 20 November, and degenerated into a remnant low early on 21 November, dissipating by 0600 UTC 22 November just east of the Honduras–Nicaragua border.

Gamma did not make any well-defined high-end tropical cyclone landfalls as a hurricane; its primary coastal impacts occurred near northern Honduras and the Bay Islands region while it was a tropical storm. Watches and warnings were issued for the Bay Islands of Honduras and the entire coast of Belize on 18 November, with warnings later extended along parts of the eastern Yucatán coast. Tropical storm conditions were observed on Roatán Island, Honduras, on 19 November when a 1-minute surface wind of 43 kt (about 50 mph) was reported.

The storm’s maximum sustained winds peaked at 45 kt (about 52 mph) with a minimum central pressure of 1002 mb around 1200 UTC on 19 November, making Gamma a moderate tropical storm at its strongest. Aircraft flight-level winds and a surface observation from Roatán support the peak intensity assessment.

Gamma did not produce significant storm surge reports, and no notable surge heights were recorded. Rainfall was the main hazard: heavy rain produced flash floods and mudslides across Honduras and Belize. An unofficial rainfall report from Roatán Island, Honduras, recorded 4.44 inches. Buoys and ships recorded gusts to mid-30s knots in the northeastern quadrant of the circulation.

The system caused considerable human impact: government and media reports attributed 37 deaths to Gamma’s rains and flooding — 34 in Honduras and 3 in Belize — with an additional 13 people reported missing in Honduras. Flooding damaged homes and infrastructure in Honduras (reports of more than 100,000 people affected), destroyed 10 bridges and damaged seven, and heavily damaged banana crops (private estimates of crop losses of roughly US$13–18 million). Forecast track errors were larger than typical for the period, in part because the cyclone’s speed and then its regeneration and subsequent slow motion were not well anticipated.