[Cyclone monitoring] NHC forecast issued Oct. 24, 2pm (Melissa)

Dear colleagues,

NHC has issued their cyclone forecasts for Oct. 24, 2pm (NY time). There is 1 active storm: Melissa.

This email consolidates exposure estimates from ADAM, GDACS, and OCHA CHD. Full admin-1 figures are in the attached spreadsheet; example alerts with the full charts and the methodology are online.

Best regards,
OCHA Centre for Humanitarian Data

Summary

Storm	Country	Similar storms	Wind	Exposure [% pop.]	Return period
Melissa 2025	Jamaica	Beryl 2024 Ivan 2004 Dean 2007	34 kt	2.9M (100%)	4-year
			50 kt	2.8M (100%)	8-year
			64 kt	954K (34%)	—
	Cuba	Gustav 2008 Irma 2017 Rafael 2024	34 kt	5.5M (50%)	2-year
			50 kt	4.1M (38%)	4-year
			64 kt	836K (8%)	—
	Haiti	Olga 2007 Fred 2021 Irene 2011	34 kt	5.4M (46%)	2-year
	Bahamas	Milton 2024 Ian 2022 Humberto 2019	34 kt	6K (2%)	<1-year
	Bahamas	Milton 2024 Ian 2022 Humberto 2019	50 kt	948 (0%)	2-year
	Turks and Caicos Islands (UK)	Joaquin 2015 Isaac 2012 Cristobal 2014	34 kt	34K (80%)	1-year
	Curaçao (Neth.) (final)	—	—	none observed	—
	Mexico (final)	—	—	none observed	—
	Panama (final)	—	—	none observed	—
	Costa Rica (final)	—	—	none observed	—
	United States of America	Teddy 2020 Arthur 2020 Fiona 2022	34 kt	8K (0%)	—
	Cayman Islands (UK)	Ike 2008 Dennis 2005 Laura 2020	34 kt	2K (3%)	—
	Belize (final)	—	—	none observed	—

Methodology & documentation | Sign up for alerts | Example alerts

Countries already passed (see past emails for final exposure estimate): Melissa 2025: Anguilla (UK) (Oct. 22, 2am), Bonaire (Neth.) (Oct. 23, 8am), British Virgin Islands (UK) (Oct. 22, 2am), El Salvador (Oct. 23, 8am), Guatemala (Oct. 23, 8am), Saint Kitts and Nevis (Oct. 22, 2am), Saint Lucia (Oct. 22, 2am), Saint Martin (Fr.) (Oct. 22, 2am), Sint Maarten (Neth.) (Oct. 22, 2am), United States Virgin Islands (USA) (Oct. 22, 2pm)

Melissa 2025 Atlantic basin

Forecast landfall

Jamaica near Manchester · Oct. 28, 1pm ET (in ~4.0 days) · ~120 kt (Category 4)

Cuba near Santiago de Cuba · Oct. 29, 6am ET (in ~4.7 days) · ~103 kt (Category 3)

Melissa 2025: map of forecast track and population exposed to ≥34 kt winds

Probabilistic forecast

Melissa 2025: 34-knot wind speed probabilities

Reading the charts below: everything sits on one axis, population exposed. Dots are the current estimates by source (labelled beneath the axis) · vertical ticks are past storms since 2002, the most similar ones in bold · the shaded curve, where shown, is the exposure distribution of every storm to affect the country since 2002 — the same storms at every wind speed, so at 50 and 64 kt it concentrates near zero (most storms never bring those winds there) and a storm out in the tail is genuinely rare · the scale never runs past the country's total population · a dashed line marks exposure already observed.

Jamaica 8-year RP

Cuba 4-year RP

Haiti 2-year RP

Bahamas 2-year RP

Turks and Caicos Islands (UK) 1-year RP

Curaçao (Neth.)

This is the last update for Melissa in Curaçao (Neth.). The storm is no longer forecast to expose anyone in Curaçao (Neth.), and no exposure has been reported there — earlier alerts were based on forecast tracks that have since moved away. Figures below and in the attached data are zero and will not change, unless the track of the storm changes significantly and returns towards Curaçao (Neth.) again. In this case another update will be issued for Melissa in Curaçao (Neth.).

Mexico

This is the last update for Melissa in Mexico. The storm is no longer forecast to expose anyone in Mexico, and no exposure has been reported there — earlier alerts were based on forecast tracks that have since moved away. Figures below and in the attached data are zero and will not change, unless the track of the storm changes significantly and returns towards Mexico again. In this case another update will be issued for Melissa in Mexico.

Panama

This is the last update for Melissa in Panama. The storm is no longer forecast to expose anyone in Panama, and no exposure has been reported there — earlier alerts were based on forecast tracks that have since moved away. Figures below and in the attached data are zero and will not change, unless the track of the storm changes significantly and returns towards Panama again. In this case another update will be issued for Melissa in Panama.

Costa Rica

This is the last update for Melissa in Costa Rica. The storm is no longer forecast to expose anyone in Costa Rica, and no exposure has been reported there — earlier alerts were based on forecast tracks that have since moved away. Figures below and in the attached data are zero and will not change, unless the track of the storm changes significantly and returns towards Costa Rica again. In this case another update will be issued for Melissa in Costa Rica.

United States of America

Cayman Islands (UK)

Belize

This is the last update for Melissa in Belize. The storm is no longer forecast to expose anyone in Belize, and no exposure has been reported there — earlier alerts were based on forecast tracks that have since moved away. Figures below and in the attached data are zero and will not change, unless the track of the storm changes significantly and returns towards Belize again. In this case another update will be issued for Melissa in Belize.