*******Note that forecasts 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.**********
…SUNDAY JUNE 5 2022 5:40 PM EDT...
See Alex section below for an update on the tropical storm quickly approaching Bermuda. It is quiet elsewhere in the Atlantic tropics.
TROPICAL STORM ALEX…See special update #22A on the home page of this site which documents the transition of potential tropical cyclone one into briskly strengtheningTropical Storm Alex. The brisk strengthening has already brought Alex to high-end tropical storm status with 65 mph maximum sustained winds as of 2 PM EDT… with the strengthening brought on by a zone of upper divergence induced by a batch of weakening upper vorticity to the west and warm core outflow on the east side of the storm induced by thunderstorm latent heat release. The rapid east-northeast motion of the tropical storm is also reducing the effects of upper westerly wind shear as the forward speed is helping Alex keep up with the upper westerlies. The shear however is having some effect as evidenced by all thunderstorm activity being lopsided to the east of the swirl center.
The rapid east-northeast track of Alex is brought on by the combination of the upper westerly flow and surface ridge weakness being kept open by the current northwest Atlantic frontal low. The updated forecast track below is once again adjusted north and east compared to my previous due to Alex’s current position and forward speed. To the west of Alex… the current central Canadian upper vortex will soon spawn a fresh surface frontal cyclone whose warm sector will build an upper ridge over the northwest Atlantic. In turn the amplifying northwest Atlantic upper ridge will cause the current southeast US shortwave upper trough to amplify as it slides into the western Atlantic. However with Alex already located so far east… it is now unlikely for the storm to slow down and move erratically under the influence of those features. Therefore the long range forecast track has Alex continuing east-northeast into the open central Atlantic after it passes Bermuda. And instead of Alex becoming a non-tropical frontal cyclone under the influence of the amplifying shortwave upper trough ejecting from the southeast US… the non-tropical remnant of Alex will instead be influenced by the divergence zone of upper vorticity ejecting from the current central Canadian upper vortex. Other factors that will drive the transition to non-tropical will be central Atlantic water temps below 26 deg C which will reduce the intensity of the thunderstorms and associated warm core upper outflow… and as the northwest Atlantic cold front currently lurking just north of Alex is pushed into Alex by the aforementioned upper vorticity to eject from the current central Canadian upper vortex.
Regarding intensity… Alex in the next 24 hours will find itself in supportive upper divergence between northwesterly flow on the northeast side of the tropical upper ridge to the south and southwesterly upper flow ahead of the upper vorticity ejecting from the central Canada upper vortex. However the tropical storm will reach water temps just below 26 deg C… therefore I agree with the NHC intensity forecast which shows slight weakening as rapid weakening does not make sense with Alex doing fine with the current level of wind shear and with supportive upper divergence continuing. The slight weakening will not be enough to avert potentially strong tropical storm conditions in Bermuda during the early morning hours of Monday. This will be exacerbated by the fact Bermuda will be near the center of the storm and on the south side of the storm where the winds are enhanced by the fast east-northeast forward track of the storm. Preparations in Bermuda for Alex must be finished by tonight.
******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********
0 Hr Position (1800Z Jun 5)... 65 mph maximum sustained wind tropical storm centered in the western Atlantic at 31.5N-71.5W
IOH 24 Hr Forecast (1800Z Jun 6)... 60 mph maximum sustained wind tropical storm centered just northeast of Bermuda at 33N-64.5W
IOH 48 Hr Forecast (1800Z Jun 7)… Remnant frontal cyclone centered in the central Atlantic at 35N-55W
...COMPUTER MODEL SUMMARY...
Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/)
0000Z CMC Model Run...
**For Tropical Storm Alex… center passes just north of Bermuda just after 42 hours… afterwards turns more east in track while becoming an elongated and weakening non-tropical frontal low… remnant low located at 36N-50W at 120 hours
0000Z ECMWF Model Run...
** For Tropical Storm Alex…center passes just north of Bermuda between 24 and 48 hours… afterwards becomes a less tropical and weakening remnant low which reaches 35N-53.5W at 120 hours
1200Z GFS Model Run...
** For Tropical Storm Alex… center passes just north of Bermuda at 33 hours… afterwards shifts east and loses identity along a cold front at 66 hours while located near 34N-52W
0600Z NAVGEM Model Run...
** For Tropical Storm Alex… center passes just north of Bermuda just after 36 hours… as a remnant non-tropical frontal cyclone continues rapidly east-northeast into the northeast Atlantic and reaches 37N-45W at 78 hours… afterwards weakens to a frontal low while turning more east in track and crosses the Azores by 120 hours