I'm talking about this boi, of course, which dissipated 24 years ago today. My reading of a paper published about it seems to indicate it as at least subtropical in characteristics, but I'd like answers from more knowledgeable people.

This is to some extent a follow-up to an earlier question I asked, Do you think the term "tropical cyclone" should apply to a storm based solely on its structure or should there be an arbitrary thermal and/or latitudinal cutoff point?, as the answer to this question hinges partially on whether a cyclone, regardless of its structure, forming over 18–19 °C (64.4–66.2 °F) water at ~44° N can be considered tropical or subtropical.

I don't know if this is the right subreddit to ask these questions, but it's worth a try! Studying meteorology became a little hobby of mine, but sometimes it's hard to find articles that answer my questions directly. Sometimes are a bit too hard to understand by someone who doesn't know the scientific terms.

So, some questions I have right now are:

- What are the differences between Tropical, Subtropical and Extratropical cyclones/storms?
- In what cases it is correct to call a storm Hurricane, Typhoon or Cyclone? I know it is in part when its winds reach a certain velocity and it's location on the map, but are hurricanes, typhoons and cyclones usually subtropical or tropical?
- I hear a lot of people calling storms cyclones. Can they be synonyms or should we stick to call them storms and only call them cyclones when they're formed in the Indic ocean?

I hope the way I wrote my questions isn't too confusing. English is not my first language.

Thank you in advance!

I saw that there was a disturbance in the Gulf of Mexico that might develop subtropical or tropical characteristics. I know that December tropical storms are very rare in the Atlantic but what do you guys think about this one? Imo it will at most be subtropical, with barely any chance of being a named storm, but it is already producing some pretty strong wind and waves.

Latest observation

Saturday, 6 November — 11:48 PM Greenwich Mean Time (GMT; 23:48 UTC)

Latest news

Saturday, 6 November — 11:48 PM GMT (23:48 UTC) | Discussion by /u/giantspeck

Wanda weakens once more as it slowly turns eastward

Satellite imagery analysis indicates that Wanda's convective structure has become less defined as it makes its anticipated northeastward turn this evening. Animated infrared imagery depicts the bulk of the storm's convection getting pushed southeastward by strengthening northwesterly shear associated with deep-layered trough which is quickly approaching from the west. Upper-level wind analysis and water vapor imagery reveal that the trough has also begun to cut off Wanda's poleward outflow channel.

Intensity estimates derived from satellite imagery analysis, including recent scatterometer data, indicate that Wanda's maximum sustained winds have decreased to around 75 kilometers per hour (40 knots) over the past six hours. The storm is moving slowly eastward as the steering environment shifts to a more southwesterly component ahead of the approaching trough.

Forecast discussion

Saturday, 6 November — 11:48 PM GMT (23:48 UTC) | Discussion by /u/giantspeck

Wanda may restrengthen as it accelerates northeastward

Wanda is expected to turn toward the northeast overnight and accelerate as mid-level flow begins to accelerate ahead of the trough. While environmental conditions should deteriorate over the remainder of the weekend, with sea-surface temperatures rapidly decreasing and upper-level divergence weakening, the storm could undergo some strengthening due to baroclinic forcing. Wanda is forecast to merge with a frontal boundary by early next week and dissipate altogether by Monday evening.

Official forecast

Saturday, 06 November — 9:00 PM GMT (21:00 UTC) | NHC Advisory #28

Hour | Date | Time

Discuss this potential second south atlantic hurricane here.

Active cyclones

Eastern Pacific

17E - Rick

For more information about this cyclone, please visit our discussion thread.

Satellite imagery analysis indicates that Rick continued to strengthen before making landfall east of Lázaro Cárdenas in Michoacán earlier this morning. The storm reached the coast with maximum one-minute sustained winds around 160 kilometers per hour (90 knots). While storm surge will begin to subside later today and winds will steadily decrease as the storm weakens rapidly over mountainous terrain, heavy rainfall will continue across portions of Michoacán and Guerrero through Tuesday, producing flash flooding and possible mudslides.

Western Pacific

25W - Malou

For more information about this cyclone, please visit our discussion thread.

Satellite imagery analysis indicates that while its convective structure remains broad and asymmetric, Malou continues to gradually strengthen. The storm has turned northward along the western periphery of a subtropical ridge situated to the east, much earlier than originally anticipated. Favorable environmental conditions will allow Malou to undergo steadier development over the next couple of days as it approaches the Ogasawara Islands, reaching typhoon strength on Wednesday morning.

Active invests

Western Pacific

99W - Invest

An area of low pressure situated a few hundred kilometers off the southeastern coast of Vietnam continues to become better organized this evening. While satellite imagery analysis indicates that this system has formed weak convective banding features, its circulation remains fairly broad. Environmental conditions may be favorable enough that the disturbance could develop briefly develop into a tropical depression before making landfall south of Nha Trang on Tuesday.

The Joint Typhoon Warning Center assesses this disturbance's potential to develop within the next twenty-four hours to be high.

Additional areas of potential development

Northern Atlantic

Disturbance 1

A non-tropical area of low pressure is likely to develop off the eastern coast of the United States by Monday. After bringing locally heavy rainfall and gusty winds to the eastern and northeastern United States, the low is expected to drift eastward out to sea, wh

Active cyclones

Last updated: Saturday, 8 January 2022 — 22:00 UTC

05P - Five

Special note:

The Fiji Meteorological Service is issuing advisories for this system as Tropical Depression 03F.

Background:

An area of low pressure developed within the Intertropical Convergence Zone (ITCZ) north west of Fiji earlier this week. While the disturbance initially drifted southward, it began to slow down and meander to the west of Fiji as it became caught between competing steering mechanisms—a near-equatorial ridge to the northeast and a subtropical ridge to the south. Satellite imagery analysis indicates that the disturbance has become more organized over the past several hours, with convective banding wrapping into a well-defined center from the southeast. The Joint Typhoon Warning Center has initiated advisories for this system as the fifth Southern Hemisphere cyclone of the season.

Current situation:

Satellite-based wind data indicates that the newly-formed cyclone is producing maximum one-minute sustained winds near 55 kilometers per hour (30 knots). While the cyclone's center is well-organized, the cyclone is situated along the northern periphery of an upper-level trough. While this trough is helping to produce strong outflow, it is also likely creating moderate vertical wind shear and transporting dry mid-level air into the cyclone's circulation, stunting its development.

Forecast:

Over the next several hours, the cyclone is expected to drift slowly toward the east-southeast. Strong divergence aloft, combined with a warm sea surface, may allow for some modest development, allowing the cyclone to reach tropical storm-equivalent strength later this evening. A subtropical ridge to the south will become the dominant steering mechanism later this evening, forcing the cyclone into a sharp west-southwestward turn. The cyclone is expected to reach a peak intensity with maximum sustained winds around 95 kilometers per hour (50 knots) as it turns away from Fiji on Sunday afternoon. An approaching trough will weaken the ridge by midweek, causing the cyclone to turn back toward the southeast.

Active disturbances

Last updated: Saturday, 8 January 2022 — 22:00 UTC

90P — Invest

The Joint Typhoon Warning Center and the Australia Bureau of Meteorology are monitoring a tropical low which developed off the eastern co

Latest observation

Saturday, 15 January — 5:19 AM New Zealand Daylight Time (NZDT; 16:19 UTC)

Latest news

Saturday, 15 January — 5:19 AM NZDT (16:19 UTC) | Discussion by /u/giantspeck

A subtropical Cody continues southeastward

Satellite imagery analysis indicates that little remains of Cody's convective structure as the subtropical system continues to drift southeastward across the southern Pacific Ocean this morning. The cyclone's low-level circulation remains completely exposed as strong northerly shear has long since stripped it of deeper thunderstorm activity. Satellite-based wind data indicates that Cody is still producing tropical storm-force winds, with maximum one-minute sustained winds gradually decreasing to around 85 kilometers per hour (45 knots) over the past few hours. Cody is moving southeastward along the southwestern periphery of a subtropical ridge situated to the northeast.

Forecast discussion

Saturday, 15 January — 5:19 AM NZDT (16:19 UTC) | Discussion by /u/giantspeck

North Island could see rain, surf, and wind impacts early next week

Over the weekend, the steering ridge is expected to build southwestward, forcing Cody into a southward turn which will bring the cyclone close to New Zealand's North Island early in the upcoming week. While Cody is not expected to have tropical characteristics by the time it passes closely to the island, it may produce strong winds, locally heavy rainfall, and rough seas along the northeastward facing shores on Tuesday and Wednesday. As Cody moves along the southwestern periphery of the ridge, it will begin to pull eastward away from the island on Thursday.

Model forecast

Note: Please note that the following is not an official forecast and is provided for informational purposes only.

Latest observation

Thursday, 13 January – 4:15 PM ACST (17:15 UTC) | Discussion by /u/giantspeck

Latest news

Thursday, 13 January – 4:15 PM ACST (17:15 UTC) | Discussion by /u/giantspeck

Tiffany continues to weaken across the Top End

Satellite imagery analysis indicates that Tiffany's convective structure continues to deteriorate as the cyclone moves westward across the arid and rough terrain of the Top End this evening. Animated infrared imagery depicts a fully exposed low-level center as easterly deep-layer shear continues to displace the bulk of the cyclone's convection westward. Radar imagery indicates that locally heavy rainfall continues across portions of the Northern Territory.

Intensity estimates derived from satellite imagery analysis and surface observations indicate that Tiffany's maximum sustained winds have decreased to around 45 kilometers per hour, or 25 knots, over the past six hours. The cyclone is moving westward along the northern periphery of a deep-layered subtropical ridge situated over central Australia.

Forecast discussion

Thursday, 13 January – 4:15 PM ACST (17:15 UTC) | Discussion by /u/giantspeck

A small chance of re-development exists early next week

Tiffany's low-level circulation could emerge over the Joseph Bonaparte Gulf later this evening or on Friday. Environmental conditions may be favorable enough that re-development is possible; however, Tiffany's low-level center is expected to move back over land on Saturday, ending its chances of further development.

Official advisories

Bureau of Meteorology (Australia)

• Homepage

• Northern Territory outlook

Joint Typhoon Warning Center (United Sta

Latest observation

Saturday, 1 January – 2:16 AM Australia Eastern Standard Time (AEST; 16:16 UTC)

Latest news

Saturday, 1 January – 2:16 AM AEST (16:16 UTC) | Discussion by /u/giantspeck

Seth becomes the fourth named cyclone of the 2021-2022 Australia region season

Satellite imagery analysis indicates that an area of low pressure situated over the central Coral Sea has rapidly transitioned into a well-organized tropical cyclone after exhibiting subtropical characteristics throughout the evening on Saturday. Over the past several hours, a symmetric central dense overcast has become increasingly distinct from a larger curved convective band, suggesting that deep-layer shear has decreased. Australia's Bureau of Meteorology has begun issuing advisories for the cyclone, assigning it the name Seth.

Intensity estimates derived from satellite imagery analysis, including a fortunately-timed scatterometer pass, indicate that Seth is maintaining maximum one-minute sustained winds at 95 kilometers per hour (50 knots). The storm is moving east-southeastward along the southwestern periphery of a near-equatorial ridge situated to the northeast.

Forecast discussion

Saturday, 1 January – 2:16 AM AEST (16:16 UTC) | Discussion by /u/giantspeck

Seth should transition back into a subtropical cyclone within the next couple of days

Seth is currently moving through a generally favorable environment characterized by weak vertical wind shear (10 to 15 knots), a warm sea surface (28 to 29°C), and strong divergence aloft. Seth will gradually turn southward this weekend as a strong subtropical ridge situated to the west becomes the dominant steering mechanism. This southward motion will bring Seth over cooler waters and into an area of stronger shear.

Interaction with a mid-level shortwave trough is

Other discussions

• 18W - Conson

• 19W - Chanthu

Latest observation

Sunday, 12 September — 1:58 AM Central Daylight Time (CDT; 06:58 UTC)

Latest news

Sunday, 12 September — 1:58 AM CDT (06:58 UTC) | Discussion by /u/giantspeck

Convective activity increases across the Bay of Campeche

Satellite imagery analysis indicates that a surface trough has emerged over the Bay of Campeche this evening and is interacting with an upper-level trough to produce disorganized showers and thunderstorms. Over the past several hours, this convective activity has slowly begun to increase, particularly to the east of the surface trough axis, closer to the Yucatan Peninsula. Recent scatterometer data reveals that a closed low-level circulation has yet to form, but winds associated with the strongest convection have increased to 55 kilometers per hour (30 knots) over the past six hours.

Forecast discussion

Sunday, 12 September — 1:58 AM CDT (06:58 UTC) | Discussion by /u/giantspeck

A tropical depression is likely to develop later today

The disturbance is drifting toward the north-northwest along the western periphery of a subtropical ridge situated over the western Atlantic. Moderate southwesterly shear may be offset by very warm waters, abundant mid-level moisture, and strong upper-level divergence, allowing the disturbance to develop into a tropical depression later today or tonight. The disturbance is expected to remain close to the eastern coast of Mexico over the next couple of days and should it remain over water long enough, it could reach tropical storm strength. Regardless, the disturbance is expected to bring heavy rainfall across the coast along the western Gulf of Mexico thr

Active cyclones

Northern Atlantic

21L - Wanda

For more information on this cyclone, please visit our tracking thread.

Wanda is becoming increasingly entangled within an approaching frontal boundary this afternoon. The cyclone is no longer considered to be tropical in nature as the bulk of its deep convection has since diminished. Wanda's low-level circulation will become less distinct as it interacts further with the front and the cyclone will ultimately merge with the front by Monday afternoon.

Eastern Pacific

18E - Eighteen

For more information on this cyclone, please visit our tracking thread.

Eighteen remains highly disorganized as it drifts westward across the open waters of the eastern Pacific this morning. The depression has struggled to maintain its closed low-level circulation as it remains at a low latitude. Over the next couple of days, Eighteen is expected to gradually gain latitude, turning toward the west-northwest. This could allow the depression's convective structure to slowly recover within an otherwise favorable environment. Eighteen could reach tropical storm strength by Monday afternoon.

19E - Nineteen

An area of low pressure situated several hundred kilometers to the southwest of Mexico has become better organized this morning, becoming the nineteenth cyclone of the 2021 Pacific season. While environmental conditions are likely to support further development long enough for the depression to reach tropical storm strength on Monday, the cyclone is drifting toward a drier and more stable environment, meaning that any development will be short-lived.

Active invests

Eastern Pacific

Northern Indian

90A - Invest

The India Meteorological Department has initiated advisories for a tropical depression which formed over the east-central Arabian Sea on Sunday evening. The depression is drifting northwestward into an area with strong shear and is not expected to undergo significant development as it turns west-northwestward over the next couple of days. In fact, the India Meteorological Department surmises that the depression will degenerate as early as Tuesday morning over the central Arabian Sea.

Additional areas of potential development

Northern Atlantic

Disturbance 1

A maturi

Latest observation

Friday, 3 December – 12:15 AM Japan Standard Time (JST; 15:15 UTC)

Latest news

Friday, 3 December – 12:15 AM JST (15:15 UTC) | Discussion by /u/giantspeck

Nyatoh continues to strengthen as it turns northeastward

Satellite imagery analysis indicates that Typhoon Nyatoh continues to strengthen over the central Philippine Sea this morning. Animated infrared imagery depicts a ring of very deep convection surrounding a ragged and partially cloud-filled eye. The storm has turned toward the north-northeast ahead of an approaching mid-latitude trough and has encountered much stronger upper-level divergence which is powering its already robust poleward outflow channel, as evidenced by recent water vapor imagery.

Intensity estimates derived from satellite imagery analysis indicate that Nyatoh has quickly intensified to the equivalent strength of a Category 3 hurricane, with maximum sustained winds increasing to 185 kilometers per hour (100 knots). Nyatoh remains embedded within a favorable environment characterized by a warm ocean surface, abundant moisture, and strong upper-level divergence. However, as the mid-latitude trough approaches from the west, deep-layer shear has increased to over 35 kilometers per hour (20 knots).

Forecast discussion

Friday, 3 December – 12:15 AM JST (15:15 UTC) | Discussion by /u/giantspeck

Further strengthening is possible in the short-term forecast

Environmental conditions remain favorable enough that Nyatoh could undergo some further intensification over the next 12 to 24 hours. The Joint Typhoon Warning Center is projecting a peak intensity near 195 kilometers per hour (105 knots) by Friday afternoon. As Nyatoh rounds the northwestern periphery of a subtropical ridge situated over the Marianas Islands and accelerates ahead of the approaching trough, s

Latest observation

Wednesday, 25 August — 9:59 PM Central Daylight Time (CDT; 02:59 UTC)

Latest news

Wednesday, 25 August — 9:59 PM CDT (02:59 UTC) | Discussion by /u/giantspeck

All eyes turn to the northwestern Caribbean for potential development this week

The National Hurricane Center continues to monitor a tropical wave which emerged over the western Caribbean Sea this afternoon. Satellite imagery analysis suggests that this wave is slowly developing cyclonic rotation and some shallow convective banding. Intensity estimates derived from satellite imagery analysis indicate that the disturbance is producing maximum one-minute sustained winds around 55 kilometers per hour (30 knots). The disturbance is moving generally westward toward Central America along the southern periphery of a subtropical ridge situated to the north.

Forecast discussion

Wednesday, 25 August — 9:59 PM CDT (02:59 UTC) | Discussion by /u/giantspeck

A depression is likely to form, though where exactly it will form is anyone's guess

The disturbance is expected to turn northwestward as it approaches Central America over the next couple of days. The wave is expected to develop into a closed area of low pressure on Friday and continue to steadily develop as it moves through an environment characterized by weak southwesterly shear, abundant mid-level moisture, high ocean content, and strong divergence aloft. Where this system will ultimately develop into a tropical cyclone remains highly uncertain, and could happen anywhere from the northwestern Caribbean to the Gulf of Mexico. In any case, heavy rainfall is likely to affect portions of Central America, the Yucatan Peninsula, and western Cuba over the weekend.

Residents across the region should closely m