BIRDSEYE VIEW POSTS

Since 2012 on the now retired Weather Underground blogs, I have been posting annotated "birdseye view" charts of the Atlantic basin, with a detailed explanation and forecasting that references the chart. From there you may know me as "NCHurricane2009." While I now do these "birdseye view" posts here, I will continue to do comments at Yale Climate Connections via Disqus where the former Weather Underground community has moved to. Feel free to reply to me there, at my Disqus feed at this link, or via e-mail at IOHurricanes@outlook.com 

 
 
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MY 2022 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #110

*******Note that forecast and outlooks in this post are NOT the official forecast from the National Hurricane Center (NHC). They are my own detailed views on the Atlantic tropics based on current observations and latest computer model runs. As such do not make decisions based on my posts...consult news media...watches and warnings from your local weather office...and any evacuation orders issued by local governments to make the most informed and best decisions. Visit the NHC website hurricanes.gov (hurricanes dot gov) for the latest watches/warnings and official forecasts on active tropical cyclones.**********


...SATURDAY SEPTEMBER 24 2022 7:25 AM EDT...

Tropical Storm Ian has formed in the Caribbean Sea. This system is expected to bring impacts from Jamaica to the Florida peninsula in the days ahead while at risk of strengthening into a strong hurricane... see Ian section below for more details.


Fiona has transitioned into a powerful and historic frontal cyclone that has moved into Atlantic Canada with dangerous and widespread impact. See remnants of Fiona section below for more information.


Tropical Storm Gaston is currently over the western and central Azores... and will soon depart the Azores as a remnant low that accelerates westward. See Gaston section below for more information.


Tropical Storm Hermine has formed at an unusual location offshore of northwestern Africa. Its interaction with upper troughing in the region will produce rainfall over parts of northwestern Africa and the Canary Islands... see Hermine section below for more information.


In addition to the above systems... also monitoring multiple areas of interest as follows:

(1) See area of interest #33 section below for a tropical low pressure area expected to meander aimlessly in the eastern and central tropical Atlantic over the next few days. This feature also has potential to become a tropical cyclone.

(2) A tropical wave of low pressure currently over far western Africa will enter the Atlantic tropics over the next 24 hours. However it will be competing for surface inflow with Tropical Storm Hermine to the north and tropical cyclone formation is not anticipated.

(3) Another tropical wave of low pressure is currently over central Africa. There is some potential for this tropical wave to develop in the eastern tropical Atlantic in approximately 3+ days as what is left of Hermine will have exited the region and the tropical upper ridge in the region... featuring low shear and upper outflow... is expected to persist. However I have not added this tropical wave as a new area of interest in this update as models have backed off in developing this wave. Should models return to showing development or if observations warrant... will add this wave as a new area of interest as needed.


New to this site this year... I will be sequentially numbering up areas of interest for possible Atlantic tropical development. In this scheme... will reset back to #1 at the start of next year (January 2023). The current area of interest in this blog post is designated #33 as the other numbers were used in previous birdseye view posts. This scheme is to reduce confusion as Atlantic tropical activity increases during the peak of the hurricane season... when multiple simultaneous areas of interest begin and end which previously required shuffling around the area of interest numbers from update to update.


REMNANTS OF FIONA... From a twelve hour span stretching from 11 AM EDT to 11 PM EDT on Friday... Fiona has undergone an extraordinarily rapid transition from a dangerous category 4 hurricane to a still dangerous enlarging frontal cyclone featuring category 2 hurricane-force maximum sustained winds. While interacting with a major upper trough incoming from eastern Canada... the west side of intense Hurricane Fiona pulled cold air associated with the trough southward and has wrapped in this cold air into the west side of its circulation. This has brought cold air associated with the trough closer to the warm air on the east side of Fiona's circulation... with the sharpening temperature difference leading to a stronger pressure difference aloft and thus increasing the southerly upper wind jet directly over Fiona. In the span of a few short hours... this jet slingshotted the thunderstorm core that was over Fiona's center north-northeastward and away. Under the stress of the upper-level wind jet of course the eye that was in the former thunderstorm core quickly collapsed. The jet has also made Fiona haul northward... with Fiona already moving into Atlantic Canada as of this writing. The southward transport of the upper trough's cold air into the circulation center of Fiona has also made the upper trough more amplified... which has only increased the upper air divergence over Fiona. The arrival of cold air and loss of thunderstorms at Fiona's center means it is no longer tropical... with the remnant non-tropical frontal cyclone of Fiona remaining vicious while supported by the tremendous upper air divergence. The size of the upper divergence region is also making the remnant frontal cyclone grow in size. This is why despite the upper divergence dropping the cyclone's central surface pressure fall further to 933 mb that the maximum sustained winds of the cyclone have dropped from category 4 130 mph to category 2 105 mph as of 11 PM EDT... as the larger cyclone has a more relaxed surface pressure gradient. However the growing size of the cyclone means the field of damaging winds and ocean swells is also growing in size and is expected to cause widespread damage in Atlantic Canada. In other words the drop in maximum sustained winds was already anticipated and does not in any way mitigate the life-threatening damage potential of this cyclone... because the growth in the cyclone's size disperses its severe effects over a wider area. The cyclone is also historic as it will move into Atlantic Canada with one of the lowest surface central pressures ever recorded in the region.


Over the next 24 hours... the west side of the remnant cyclone of Fiona will continue to pull the cold air associated with the trough southward... causing the trough to amplify into a vortex over the Gulf of St. Lawrence. The east side of the cyclone will also pull warm air northward and build an upper ridge over the far north Atlantic. The cyclone will whirl beneath the center of the upper vortex where it will finally begin a post-mature gradual weakening phase due to a lack of upper divergence at the core of the vortex. To the west of the cyclone and upper vortex... the upper troughs currently over North Dakota and western Canada will merge into a potent upper trough... with southerly flow east of the potent upper trough and west of the north Atlantic upper ridge carrying the upper vortex and cyclone northward across eastern Quebec... Labrador... and into the waters between Canada and Greenland after 24 hours. Eventually the remnant cyclone of Fiona will dissipate in these far north waters while decaying below the upper vortex. Fiona will not be featured in my next full update on the Atlantic tropics as it is no longer a tropical feature. However impacts to Atlantic Canada will be mentioned on the home page bulletins of this site and possibly in a special update thread I will setup should the wind observations across Atlantic Canada become more impressive.


Regarding impact to land areas over the next 24 hours:


(1) The remnant cyclone of Fiona will bring coastal swells and rip currents to the United States northeast coastline. The west side of the sprawling cyclone could also bring gusty winds to Maine. The following are recent National Weather Service station observations of wind in mph across Maine:

**Eastport ME... sustained 15... gust 29... now

**Bangor ME... sustained 16... gust 31... 4:53 AM EDT

**Houlton ME... sustained 17... gust 39... 4:53 AM EDT


(2) Damaging hurricane force winds will or are occurring across eastern Nova Scotia... Prince Edward Island... western Newfoundland... and eastern Quebec. Gale force winds with some damage potential are also expected across New Brunswick... western Nova Scotia... eastern Newfoundland... and Labrador. Across all of these areas... expect immense coastal surf with storm surges due to the large size and strength of Fiona's remnant cyclone. Heavy rainfall with flash flooding potential is another hazard to consider. Preparations should have been completed by now as weather conditions are deteriorating with the cyclone's fast arrival. The following are Environment Canada (https://weather.gc.ca/canada_e.html) weather station observations of wind in mph (value in kilometers per hour kept in parentheses):

**Halifax NS... sustained 46 (74)... gust 68 (110)... 3:00 local time

**Sydney NS... sustained 59 (96)... gust 87 (141)...6:00 local time

**Fredericton NB... sustained 20 (33)... gust 40 (65)... 4:00 local time

**Charlottetown PE...sustained 41 (66)... gust 70 (112)... now

**Port Aux Basquess NL... sustained 50 (81)... gust 71 (114)... 6:30 local time

**St Johns NL... sustained 33 (54)... gust 44 (72)... 6:30 local time

**Gaspe QB...sustained 14 (22)... gust 29 (47)... now

**Blanc Sablon QB... sustained 41 (66)... gust 57 (91)... now


Update as of 5 AM EDT... the center of the intense remnant frontal cyclone of Fiona crossed the eastern tip of Nova Scotia while featuring a central surface pressure of 931 mb... incredibly low for a remnant cyclone. Maximum sustained winds in the cyclone were rated by the NHC to be 90 mph.


TROPICAL STORM GASTON...At last and while the moving into the central and western Azores... Gaston has decoupled from the eastern divergence zone of the shortwave upper trough that had been supporting it while it was over water temps below 26 deg C. Evidence of this is Gaston is finally turning more west in its southward track while coming under increasing influence of the building surface ridge to the north instead of continuing eastward with the shortwave. This early decoupling from the shortwave upper trough... perhaps from the growing strength of the surface ridge which has finally gotten a grip on Gaston... means Gaston will not go quiet as far east into the Azores as I previously anticipated and therefore my updated forecast track has a westward adjustment overall. The combination of the below-26 deg C water and decoupling from the shortwave upper trough's eastern divergence zone has caused Gaston to abruptly lose showers and thunderstorms... with whatever remains of this activity now displaced to the east while remaining associated with the shortwave upper trough. Expecting Gaston's cloud swirl to continue lacking thunderstorms such that it will be downgraded to a remnant low in the next 12 hours. The remnant low is then expected to turn westward and away from the Azores under the influnce of the aforementioned building surface ridge.


As discussed in the above Fiona section... a warm upper ridge is building in the north Atlantic. This ridge will push the current north Atlantic upper trough southeastward into the remnant circulation of Gaston just after 24 hours. The upper trough is not expected to be cold enough to help Gaston re-generate thunderstorms while it remains over below-26 deg C water. And although the eastern divergence zone of this upper trough may help Gaston's remnant circulation re-strengthen... this upper trough will then continue moving quickly southeastward and away such that any revival of the circulation will be too short-lived to be meaningful for any kind of re-genesis of Gaston as a tropical feature. This upper trough will then merge with the current western European upper trough to make a sprawling upper trough/vortex feature that may aid Hermine with its eastern divergence zone. Meanwhile the remnant circulation of Gaston looks to be suppressed by convergence on the northwest side of the upper trough/vortex feature in the longer range... even as it moves further west back into warmer 26 deg C water temps. In all... not expecting the remnant circulation of Gaston to make a comeback.


Expect gusty winds across the western and central Azores... as well as sea swells on the shores of all of the Azores... to gradually decrease in the next 24 hours as Gaston's circulation continues southwestward and then westward... eventually taking it away from the Azores.

******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********

0 Hr Position (0000Z Sep 24)...60 mph maximum sustained wind tropical storm centered between the central and western Azores at 38.9N-29.5W

IOH 24 Hr Forecast (0000Z Sep 25)...Remnant low centered southwest of the Azores at 38N-32.5W


TROPICAL DEPRESSION NINE (RECENTLY UPGRADED TO TROPICAL STORM IAN)...The surface swirl of Tropical Depression Nine in the central Caribbean Sea proceeded to bend more north in its westward track while responding to the surface ridge weakness associated with Fiona. Meanwhile upper northeasterly flow on the south side of the current north Caribbean upper ridge has kept the thunderstorm activity of the depression suppressed to the southwest... therefore the more northward walk the surface swirl performed caused it to become more decoupled from its initial batch of thunderstorms. As a result the depression took some time to become a tropical storm as we had to wait for renewed thunderstorm activity to re-fire closer to the center of circulation. The renewed activity is lopsided to the west side of the center by easterly shear... however the activity is making attempts at covering the center as this system's north angle in track is bringing it increasingly closer to the axis of the upper ridge where shear is lower. The delay in this system acquiring tropical storm strength caused it to be named Ian... with the name Hermine instead being assigned to tropical depression ten in the far eastern Atlantic which ramped up faster.


Although the weakness associated with Fiona will close as Fiona lifts northward and away... the upper troughs currently over North Dakota and western Canada will merge into a potent upper trough... with the eastern divergence zone of the potent upper trough creating another surface ridge weakness over the eastern US. In addition the upper trough is expected to displace the current warm air mass upper ridge over Louisiana southward... which in turn will displace the current northwest Caribbean upper vorticity southward into the environment of Ian. The southerly flow on the east side of the upper vorticity... particularly if Ian is strong/tall enough to be influenced by upper flow... and the aforementioned eastern US surface ridge weakness should keep a northward angle in Ian's westward track as Ian moves across the central and western Caribbean Sea. Because Ian is north-northwest of my previous forecast track... my updated forecast track is adjusted accordingly. Ian being further north increases its chances of turning north right into the surface ridge weakness... which is why I prefer a more eastward long-range track similar to this past 1200Z ECMWF for example. As such... the 48 to 96 hour window of my current forecast track has the east side of Ian overspread the Cayman Islands with the center passing just west of Grand Cayman... with the center then crossing western Cuba and moving right into the Florida Keys and southwest coast of the Florida peninsula. Further west solutions such as the GFS model have Ian less influenced by the surface ridge weakness and more influenced by a surface ridge to build underneath the western convergence zone of the eastern US upper trough. Regardless of a further east or west solution... the models show the eastern US upper trough and associated surface ridge weakness lift northeastward and away in 5+ days... potentially trapping Ian south of the building surface ridge. In addition the eastern US upper trough is expected to leave behind a cut-off trough over the southeastern US. This could result in Ian drifting slowly northward in the 5+ day timeframe... a combination of Ian being embedded in steering upper southwesterly flow ahead of the cut-off upper trough while the building surface ridge resists Ian's northward progress.


Regarding the intensity forecast... my updated one is lowered a notch as Ian is behind my previous forecast. Due to the compact consolidated circulation of Ian and its arrival into the low shear environment directly below the north Caribbean upper ridge axis... I anticipate that Ian could begin to rapidly strengthen just after 24 hours. In the prior paragraph it is noted that northwestern Caribbean upper vorticity will near Ian's west side. It is conceivable this vorticity resists the western outflow of Ian in the 24 to 48 hour period... which is why I show only a little strengthening in an otherwise lower shear environment over the next 24 hours. I then show more rapid strengthening commencing just after 24 hours as the cold core upper vorticity begins to fade while cut-off from high-latitude cold air... and as the compact nature of Ian will only require a small area needed for its upper outflow such that its outflow no longer gets affected by what remains of the upper vorticity. And after 48 hours... when the upper vorticity dissipates entirely... nothing in the upper layers of the atmosphere will hold Ian back and the intensity forecast below continues to show brisk strengthening through 72 hours. The strengthening rate is dampened in the 72 to 96 hour range as Ian moves closer to the shearing upper southwesterly flow associated with the upper trough to be over the eastern US. My updated forecast brings Ian to a peak category 3 strength at 96 hours. Weakening is subsequently shown between 96 and 120 hours from land interaction... as my forecast track brings Ian across a large swath of the Florida peninsula. The weakening could be exacerbated as Ian's northward track could slow as discussed in the prior paragraph... causing Ian to fall behind the upper southwesterly wind speed.


Regarding impacts to land areas:

(1) Ian will pass south and then west of Jamaica this weekend. As it strengthens... coastal sea swells are expected to increase. The combination of the current forecast track and small size of Ian could very well cause all of the heavy rainfall and gusty winds to stay just offshore of Jamaica. However Jamaica is under a tropical storm watch in case Ian takes another north jog in track... or if the size of Ian grows... which would bring heavy rains (with flooding potential) and gusty winds onshore.

(2) Interests in the Cayman Islands are under a hurricane watch as of this writing. On the current forecast track... the east side of Ian will overspread the Cayman Islands on Monday... bringing gusty winds with some damage potential... coastal sea swells... and heavy rainfall with flash flooding potential. Grand Cayman has the highest probability of more damaging hurricane-force winds on the current forecast track. I recommend preparations for potential hurricane-force conditions in the Cayman Islands should be completed by Sunday afternoon.

(3) Confidence is increasing that western Cuba will see tropical storm force conditions (heavy rain with flooding potential... gusty winds with some damage potential... and coastal surf) by late Monday and Tuesday... with potential for life-threatening coastal storm surge and wind closer to the center of circulation should Ian in fact strengthen into a strong hurricane. Preparations for Ian may be required here starting Saturday night.

(4) Interests in the Florida Keys and across the Florida peninsula should closely monitor Ian's progress for impacts in the Tuesday to Wednesday timeframe. Life-threatening wind and coastal storm surge is a possible hazard in this region in closer proximity to the center of circulation should Ian in fact strengthen into a major hurricane... however the forecast position of the center of circulation is not set in stone yet. Rainfall flooding across the Florida peninsula... and perhaps over southern Georgia... could be exacerbated should Ian's forward speed slow down as noted in above discussion of Ian's forecast track.


Update as of 5 AM EDT... Ian has strengthened further to 45 mph maximum sustained winds as its area of thunderstorms grows in size. No change to the intensity forecast shown below.

******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********

0 Hr Position (0000Z Sep 24)...40 mph maximum sustained wind tropical storm centered in the central Caribbean Sea at 14.8N-71.5W

IOH 24 Hr Forecast (0000Z Sep 25)...50 mph maximum sustained wind tropical storm centered south-southeast of Jamaica at 15.5N-76.5W

IOH 48 Hr Forecast (0000Z Sep 26)...80 mph maximum sustained wind hurricane centered west-southwest of Jamaica and south of the Cayman Islands at 17.8N-80.5W

IOH 72 Hr Forecast (0000Z Sep 27)...110 mph maximum sustained wind hurricane centered just south-southeast of the Isle of Youth of western Cuba at 20.5N-82.5W

IOH 96 Hr Forecast (0000Z Sep 28)...120 mph maximum sustained wind major hurricane centered between the Florida Keys and southwest Florida peninsula coast at 25N-82.4W

IOH 120 Hr Forecast (0000Z Sep 29)...70 mph maximum sustained wind tropical storm centered over the northeastern Florida peninsula at 29N-82W


TROPICAL STORM HERMINE... Infrared satellite image taken of Tropical Storm Hermine shortly after its naming... at 2250Z Friday evening. The red plus marks the surface center of circulation... just southwest of a circular area of thunderstorm tops:

The tropical wave of low pressure between the Republic of Cabo Verde Islands and west coast of Africa proceeded to become tropical depression ten and then Tropical Storm Hermine in the last 24 hours. It appears that the east side of the tropical wave's low pressure spin overcame the dry Saharan air problem by having its east side lift tropical moisture northward across the western edge of Africa which appeared to moisten out or put a stop to additional dry Saharan air streaming in from Africa. And what remained of the dry Saharan air that the tropical wave previously pulled offshore has ended up as a small patch on the southwestern periphery of the tropical wave's low pressure spin. In addition to defeating the dry Saharan air problem... the strengthening of the tropical wave into Tropical Storm Hermine may have been enhanced by the eastern divergence zone of an upper trough fragment in the region. Hermine's north track since its formation also shows that its circulation is strong/tall enough to be steered northward by the upper southerly flow on the east side of the upper trough fragment. Also noting the upper flow has also been shearing the thunderstorm activity of Hermine north-northeastward from its circulation center.


Between 24 and 48 hours... the current upper trough fragment in Hermine's environment will be replaced by a more substantial upper trough. This trough will be a fusion between the current north Atlantic and western European upper troughs... with the fusion forced by the upper ridge currently building in the north Atlantic (see Fiona section for more information on this ridge). The flow ahead of this upper trough will be more southwesterly instead of southerly... resulting in an east lean in my forecast track during the 24 to 48 hour window. The forward motion of Hermine slows at 72 hours as the upper southerly steering flow will not be able to push Hermine into the Atlantic surface ridge. Regarding forecast intensity... because Hermine already looks disheveled from the wind shear and will soon reach water temps below 26 deg C I forecast a decay to tropical depression status. I do not immediately weaken the depression to a remnant low as the eastern divergence zone of the current upper trough fragment in the region... followed by the eastern divergence zone of the more substantial upper trough to become established... may aid the depression over mild water temps much in the same way Gaston lasted over similarly mild water temps while boosted by a shortwave upper trough. However southwesterly wind shear will become more hostile at 72 hours when Hermine stalls against the Atlantic surface ridge... falling further behind the speed of the upper southwesterly flow. Models agree on weakening Hermine to a remnant low by this time... perhaps from this escalation in the shear... and so my forecast below shows the same thing. After 72 hours... the shallow remnant low is then expected to turn westward while steered around the Atlantic surface ridge.


The upper southerly flow is transporting Hermine's tropical moisture north-northeastward into the Canary Islands as well as Western Sahara and southern Morocco. The divergence on the east side of the upper troughing is also helping to make cloudiness and rainfall from this moisture. Unusual amounts of rain may occur in these areas with this setup over the next day or so... flash flooding cannot be ruled out. Coastal sea swells in these area areas are not expected to be significant as Hermine is forecast to remain a weak tropical cyclone.

******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********

0 Hr Position (0000Z Sep 24)...40 mph maximum sustained wind tropical storm centered in the eastern tropical Atlantic at 19.4N-20.8W

IOH 24 Hr Forecast (0000Z Sep 25)...35 mph maximum sustained wind tropical depression centered in the eastern Atlantic at 22.5N-20.5W

IOH 48 Hr Forecast (0000Z Sep 26)...35 mph maximum sustained wind tropical depression centered in the eastern Atlantic at 25N-19.5W

IOH 72 Hr Forecast (0000Z Sep 27)...Remnant low centered just southwest of the Canary Islands at 26N-19.5W


AREA OF INTEREST #33...The center of the tropical low pressure drifting aimlessly westward in the eastern tropical Atlantic was located in the vicinity of 11N-37W as of 0000Z earlier this past evening. The associated thunderstorm activity has become less organized and is located west of the circulation center. These are signs that upper easterlies on the south side of the tropical upper ridge in the region are pushing the thunderstorms off to the west of the nearly-stationary tropical low. It is also possible this system may be affected by dry Saharan air to the east that has been pushed toward this system by Tropical Storm Hermine. The westward progress of this system around the Atlantic surface ridge has been painfully slow while it gets tugged by the large circulation of Hermine. A further slow down in the west drift... and perhaps a reversal of the drift toward a northeastward tendency cannot be ruled out in the 72 to 96 hour window as a substantial upper trough will interact with Hermine in 2+ days whose eastern divergence zone will help Hermine build an expanding surface ridge weakness to the northeast of this system. Even without the expanding surface ridge weakness... if indeed this system goes on to become a tropical cyclone it could be strong/tall enough to couple with upper westerly steering flow associated with the substantial upper trough. To the north of the cold core upper trough a north Atlantic warm upper ridge is expected to persist in warm southerly flow on the east side of Fiona's remnant cyclone... followed by warm southerly flow to setup on the east side of an eastern US frontal system. The cold core upper trough by day 5 is expected to weaken as the upper ridge keeps it isolated from high-latitude cold air... with the upper ridge also breaking the weakening trough into a pair of upper vortices. The forecast below shows a return to a westward drift by 5+ days as the weakening upper trough and associated surface ridge weakness loses its grip on this system. Some north angle in the long range track is possible... particularly if it is strong/tall enough to couple with upper flow... due to upper southwesterly flow to develop on the southeast side of the western of the two upper vortices.


Due to this system's reduced organization... I have lowered short-term odds of tropical cyclone formation. My peak odds are also lowered to 30% from the 40% shown in my previous update.

******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********

IOH 24 Hr Outlook (0000Z Sep 25)...10% chance of tropical cyclone formation (eastern tropical Atlantic near 11.5N-38W)

IOH 48 Hr Outlook (0000Z Sep 26)...20% chance of tropical cyclone formation (central tropical Atlantic near 12N-40W)

IOH 72 Hr Outlook (0000Z Sep 27)...30% chance of tropical cyclone formation (central tropical Atlantic near 12.5N-41W)

IOH 96 Hr Outlook (0000Z Sep 28)...30% chance of tropical cyclone formation (central tropical Atlantic near 13.5N-40W)

IOH 120 Hr Outlook (0000Z Sep 29)...30% chance of tropical cyclone formation (central tropical Atlantic near 14.5N-41.5W)


...COMPUTER MODEL SUMMARY...

Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/)


1200Z (Sep 23) CMC Model Run...

**For Major Hurricane Fiona... moves into eastern Nova Scotia at 24 hours while transitioning into a large remnant frontal cyclone... continues northward across eastern Quebec... inland Labrador... and into far north waters between Canada and Greenland where it then dissipates by 102 hours.

**For Tropical Storm Gaston... moves south-southwest into the western Azores while weakening through 18 hours... afterwards the weakening remnant low turns west... north... then northeast and reaches 44.5N-37.5W at 120 hours.

**For Tropical Depression Nine... strengthens into a tropical storm and moves northwest into the Cayman Islands at 72 hours... rapidly strengthens into a compact hurricane while turning north into western Cuba through 90 hours... center of hurricane passes just west of the Florida Keys at 108 hours... centered in the eastern Gulf of Mexico at 25.5N-84.5W at 120 hours.

**For Tropical Storm Hermine... weakens to a remnant low southwest of the Canary Islands at 72 hours... remnant low turns west and weakens to a trough near 25.5N-25W at 96 hours.

**For area of interest #33... drifts north and becomes a tropical cyclone near 14N-36W at 48 hours... subsequently drifts northeast and then northward again with tropical cyclone reaching 17.8N-34W at 120 hours.


1200Z (Sep 23) ECMWF Model Run...

**For Major Hurricane Fiona... moves into eastern Nova Scotia at 24 hours while transitioning into a large remnant frontal cyclone... continues northward across eastern Quebec... inland Labrador... and into far north waters between Canada and Greenland where it then dissipates just after 120 hours.

**For Tropical Storm Gaston... moves south-southwest across the western Azores while weakening over the next 24 hours...weakening remnant low accelerates westward and weakens to a trough near 38N-44W at 96 hours.

**For Tropical Depression Nine... strengthens into a tropical storm near 16N-78.8W at 48 hours... moves northwest across the Cayman Islands and into western Cuba as a compact hurricane through 96 hours... moves north-northeast into the Florida Keys and southern Florida peninsula at 120 hours.

**For Tropical Storm Hermine... retains tropical storm strength while reaching waters just southwest of the Canary Islands at 72 hours... subsequently turns northwest while beginning to weaken and reaches 31N-25.5W at 120 hours.

**For area of interest #33... tropical low erratically drifts north and reaches 16N-37W at 120 hours


1800Z (Sep 23) GFS Model Run...

**For Major Hurricane Fiona... moves into eastern Nova Scotia at 18 hours while transitioning into a large remnant frontal cyclone... continues northward across eastern Quebec... inland Labrador... and into far north waters between Canada and Greenland where it then dissipates at 96 hours.

**For Tropical Storm Gaston... moves south-southwest into the western Azores over the next 9 hours... afterwards accelerates west-southwest and weakens to a trough near 34.5N-47.5W at 102 hours.

**For Tropical Depression Nine... becomes a tropical storm near 14.5N-77.5W at 33 hours... subsequently strengthens into a compact hurricane that passes just west of the Canary Islands at 69 hours... compact hurricane moves north-northwest into the west tip of Cuba at 84 hours and then proceeds north-northwest into the eastern Gulf of Mexico... located at 26.5N-85W at 120 hours.

**For Tropical Storm Hermine... weakens to a tropical depression near 23N-20.5W at 30 hours and then a remnant low near 25N-19.5W at 54 hours... remnant low begins to drift west and weakens to a trough near 25N-21W at 87 hours.

**For area of interest #33... tropical low drifts erratically north and then stalls at 78 hours... a slow west-northwest drift then commences with the tropical low reaching 15.5N-39.5W at 120 hours


1800Z (Sep 23) NAVGEM Model Run...

**For Major Hurricane Fiona... moves into eastern Nova Scotia at 12 hours while transitioning into a large remnant frontal cyclone... continues northward across eastern Quebec... inland Labrador... and into far north waters between Canada and Greenland where it then dissipates at 120 hours.

**For Tropical Storm Gaston... over next 24 hours turns southwest with center of circulation just missing the westernmost Azores... remnant low accelerates west-northwest and weakens to a trough near 42.5N-40W at 96 hours.

**For Tropical Depression Nine... becomes a tropical storm near 15N-77W at 30 hours... strengthens into a hurricane while bending northwest in track and crosses the Cayman Islands at 60 hours... center of hurricane moves into western Cuba at 84 hours and passes west of the Florida Keys at 96 hours... turns more northeast in track and makes landfall on the west coast of the Florida peninsula near Tampa Bay at 120 hours.

**For Tropical Storm Hermine... maintains strength while reaching waters just southwest of the Canary Islands through 66 hours... subsequently weakens while continuing on a northward drift and becomes a remnant low just west of the southwestern Canary Islands at 90 hours... remnant low turns west and weakens to a trough near 26N-22.5W at 120 hours

**For area of interest #33... tropical low drifts very slowly west-northwest and reaches 12N-36.5W at 30 hours... subsequently turns on an east-northeast drift and reaches 14N-32W at 96 hours... turns back on a west-northwest heading and reaches 16N-32.5W at 120 hours

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