Tropical Storm Melissa not but strengthening, however nonetheless anticipated to change into a harmful Caribbean hurricane » Yale Local weather Connections

[ad_1]

A Hurricane Watch is up for the south coast of Haiti and a Tropical Storm Look ahead to Jamaica for Tropical Storm Melissa, which had not but strengthened as of noon Wednesday. The storm was crawling slowly west-northwestward throughout the near-record heat waters of the central Caribbean, which have been untouched by any hurricane or tropical storm up to now this yr.

As of 11 a.m. EDT Wednesday, Melissa was positioned within the central Caribbean about 325 miles (525 kilometers) southeast of Kingston, Jamaica, with high sustained winds of fifty mph (85 km/hr) and a central strain of 1,000 mb, transferring west-northwest at simply 2 mph (4 km/hr). Satellite images confirmed that prime wind shear of 20-25 knots was protecting the western aspect of the circulation largely devoid of heavy thunderstorms, with the storm’s heavy rains occurring over the waters south of Haiti and the Dominican Republic.

The numerous potentialities for Melissa’s future over the following 5 days embrace a number of days of torrential rain over among the Caribbean’s most flood-vulnerable locations. Disastrous flooding and mudslides are a menace to Haiti in addition to the southern Dominican Republic, jap Cuba, and Jamaica. Due to excessive wind shear from the position of the subtropical jet stream from Florida eastward by the Bahamas, Melissa just isn't anticipated to pose any menace to the continental United States for no less than the following week, and ensemble fashions point out solely a distant likelihood that the storm may find yourself far sufficient northwest to have an effect on Florida.

Determine 1. Rainfall forecast by Saturday evening, Oct. 25, issued at 8 a.m. EDT Wednesday, Oct. 22. Rains of eight to 12 inches (200-300 millimeters, orange colours) had been predicted for parts of Haiti, the Dominican Republic, and Jamaica, with widespread quantities of 4 to 6 inches (100-150 mm). (Picture credit score: NOAA/NWS/WPC via NHC )

Close to-record-warm Caribbean waters will gasoline Melissa’s development

This week, Melissa will traverse among the warmest waters ever recorded this late within the season anyplace within the Atlantic basin — close to 30 levels Celsius (86°F), about 1.3 levels Celsius (2.3°F) hotter than common. Human-caused local weather change made the present heat close to Melissa’s location within the central Caribbean about 500-700 instances extra prone to happen, based on Local weather Central’s Local weather Shift Index (Fig. 2).

<img data-recalc-dims="1" decoding="async" width="974" height="974" alt="The amount by which human-caused climate change has raised the odds of unusual warmth in sea surface temperatures near Melissa’s path." class="wp-image-133160 perfmatters-lazy" src="https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=974%2C974&ssl=1" srcset="https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?w=974&ssl=1 974w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=300%2C300&ssl=1 300w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=150%2C150&ssl=1 150w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=768%2C768&ssl=1 768w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=800%2C800&ssl=1 800w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=600%2C600&ssl=1 600w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=400%2C400&ssl=1 400w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=200%2C200&ssl=1 200w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=780%2C780&ssl=1 780w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?w=370&ssl=1 370w" data-sizes="(max-width: 974px) 100vw, 974px"/><img data-recalc-dims="1" decoding="async" width="974" height="974" src="https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=974%2C974&ssl=1" alt="The amount by which human-caused climate change has raised the odds of unusual warmth in sea surface temperatures near Melissa’s path." class="wp-image-133160" srcset="https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?w=974&ssl=1 974w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=300%2C300&ssl=1 300w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=150%2C150&ssl=1 150w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=768%2C768&ssl=1 768w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=800%2C800&ssl=1 800w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=600%2C600&ssl=1 600w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=400%2C400&ssl=1 400w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=200%2C200&ssl=1 200w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?resize=780%2C780&ssl=1 780w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/melissa-csi-oct22.png?w=370&ssl=1 370w" sizes="(max-width: 974px) 100vw, 974px"/> Determine 2. The oceanic model of the Local weather Shift Index, depicted right here for Tuesday, Oct. 21, 2025, exhibits the quantity by which human-caused local weather change has raised the chances of surprising heat in sea floor temperatures close to Melissa’s path (a couple of issue of 500-700). (Picture credit score: Climate Central )

Monitor forecast for Melissa

There's a lot increased uncertainty than standard in Melissa’s monitor, since it's caught in an space of weak steering currents, sandwiched between two high-pressure techniques. If Melissa is ready to strengthen shortly right into a hurricane, its dimension and vertical extent would probably permit it to really feel the steering affect of a trough of low strain over the Bahamas, tugging the storm shortly northward throughout Haiti or jap Cuba and into the Bahamas by this weekend.

Nevertheless, the latest development within the fashions has been to maintain Melissa comparatively weak, which might favor a sluggish northwestward or westward monitor, protecting the system within the Caribbean by no less than subsequent Monday, Oct. 27. On this monitor, Melissa would have extra time over heat water and would possible change into a significant hurricane early subsequent week, as predicted by the Nationwide Hurricane Heart in its 11 a.m. EDT Wednesday forecast. On this monitor, essentially the most important threats posed by Melissa can be to Jamaica, the Cayman Islands, and Cuba.

Determine 3. Chance of Melissa passing inside 92 miles (150 kilometers) of a given location primarily based on mannequin forecasts, together with the most recent AI suite of fashions, issued at 0Z Oct. 22. Most steerage suggests a sluggish drift west-northwest towards Jamaica and the western Caribbean, adopted by a pointy flip towards jap Cuba later subsequent week. (Picture credit score: Tomer Burg, Real Time Tropical Cyclones , through Michael Lowry )

Depth forecast for Melissa

Gradual strengthening seems to be one of the best wager for Melissa over the following three days. The excessive wind shear affecting Melissa on Wednesday afternoon is anticipated to drop to a reasonable 10-20 knots by Thursday and stay reasonable into the weekend. The storm is embedded in an uncommonly moist ambiance: midlevel relative humidity was close to 80% on Wednesday and is anticipated to be 70-80% by Friday. If Melissa makes it to the western Caribbean, it might must take care of some drier air, nevertheless.

In addition to unusually heat floor waters, the Caribbean has ample oceanic warmth extending to a considerable depth proper now (Fig. 4), so even a slow-moving Melissa is unlikely to be vastly hindered by churning up cooler subsurface water. NHC was not predicting Melissa would quickly intensify over the following three days, however the 12Z Wednesday SHIPS model forecast referred to as for a 15% likelihood of fast intensification of 35 mph in 24 hours and a 26% likelihood for fast intensification by 75 mph in 72 hours. That will put Melissa at a Class 3 power on Saturday afternoon, with 125 mph winds.

<img data-recalc-dims="1" decoding="async" width="974" height="798" alt="Tropical Cyclone Heat Potential for the Caribbean." class="wp-image-133161 perfmatters-lazy" src="https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?resize=974%2C798&ssl=1" srcset="https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?w=974&ssl=1 974w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?resize=300%2C246&ssl=1 300w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?resize=768%2C629&ssl=1 768w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?resize=780%2C639&ssl=1 780w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?resize=400%2C328&ssl=1 400w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?w=370&ssl=1 370w" data-sizes="(max-width: 974px) 100vw, 974px"/><img data-recalc-dims="1" decoding="async" width="974" height="798" src="https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?resize=974%2C798&ssl=1" alt="Tropical Cyclone Heat Potential for the Caribbean." class="wp-image-133161" srcset="https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?w=974&ssl=1 974w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?resize=300%2C246&ssl=1 300w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?resize=768%2C629&ssl=1 768w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?resize=780%2C639&ssl=1 780w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?resize=400%2C328&ssl=1 400w, https://i0.wp.com/yaleclimateconnections.org/wp-content/uploads/2025/10/ohc-oct22.png?w=370&ssl=1 370w" sizes="(max-width: 974px) 100vw, 974px"/> Determine 4. Tropical Cyclone Warmth Potential (TCHP) map displaying a reservoir of unusually deep and heat water within the central and western Caribbean. TCHP values in extra of 100 are generally related to fast intensification, if atmospheric circumstances permit. (Picture credit score: cyclonicwx.com)

A number of the newest fashions are outlandishly excessive in depth. Our two greatest hurricane fashions, HAFS A and B are close to 900 mb Cat 5’s BUT this relies on #melissa transferring southwest of the NHC monitor. If the storm will get into the W Caribbean, it's off to the races… 1/

— Jeff Berardelli (@weatherprof.bsky.social) 2025-10-22T12:48:06.018Z

The hazards of late-season hurricanes within the Caribbean

Gradual-moving, late-season techniques that acquire power within the Caribbean could cause immense hassle. In early October 2016, Hurricane Matthew moved north over far western Haiti as a Class 4 hurricane, dumping more than 20 inches (500 mm) of rain over a lot of far jap Cuba and southwestern Haiti and pummeling the Bahamas and several other different islands. Matthew took 731 lives and precipitated greater than $16 billion in harm (2016 USD).

Simply over 20 years in the past, Hurricane Wilma strengthened with astonishing pace right into a Class 5 monster within the northwest Caribbean. On Oct. 18-19, 2005, Wilma set two all-time records for the Atlantic basin for fast intensification, because the storm deepened from 975 to 892 millibars (hPa) in 12 hours and from 979 to 882 mb in 24 hours – the latter making Wilma the strongest hurricane by central strain in Atlantic historical past. Wilma additionally set a report for the most important 24-hour enhance in high sustained winds, going from 75 to 175 mph. Wilma struck Mexico’s Yucatán Peninsula as a robust Cat 4 storm and raced northeast to strike southwest Florida on Oct. 24 at Cat 3 power. Wilma led to 52 deaths and precipitated $26.5 billion in harm (2005 USD).

Close to the tip of October 1998, former Class 5 Hurricane Mitch dumped mammoth quantities of rain over Guatemala, Nicaragua, and Honduras (30 to 40 inches, or 750-1000 millimeters, in lots of areas) even because it decelerated and weakened, coming onshore at Cat 1 power. Flooding and landslides precipitated some $6 billion in harm (1998 USD) and precipitated greater than 11,000 confirmed fatalities, with one other 11,000 lacking folks unaccounted for. Mitch was the deadliest Atlantic hurricane of the satellite-monitoring period (i.e., because the Sixties), and maybe because the Great Hurricane of 1780 .