******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.**********
...MONDAY SEPTEMBER 5 2022 2:53 PM EDT...
Tropical Storm Earl… located north of Puerto Rico… becoming better organized and stronger since previous update #93. This is a special update to increase the intensity forecast for Earl. Refer to full update #93 on the home page of this site for more information on Hurricane Danielle and the rest of the Atlantic tropics.
TROPICAL STORM EARL... True color visible satellite image of Earl becoming better organized… taken at 1800Z:
The tropical storm that has been tracking west-northwest just north of the northeastern Caribbean islands this morning made a sharp north turn despite the presence of surface ridging over eastern North America. This is due to Earl being strong/tall enough to be influenced steering-wise by the east side of the lingering upper vorticity to the west. The early north turn has kept Earl east of the worst shear induced by the upper vorticity… as a result the tropical storm has become notably better organized and stronger. For the next 3 to 4 days the forecast track has a slow forward speed as the north part of the approaching eastern Canada upper trough is expected to stay too far north of Earl to accelerate the forward speed of the storm. However by 120 hours the next upper trough to approach Earl from Canada will be far south enough to finally accelerate the storm northeastward
For this intensity update... I suggest Earl becoming a hurricane in the next 24 hours but not strengthening much through 48 hours while contending with the current light shear environment. Strengthening is then anticipated at 72+ hours as the shearing upper vorticity finally weakens while continuing to remain cut-off from high-latitude cold air. Some shear may redevelop on day 4 from the second Canadian upper trough to approach Earl late in the forecast period. This shear could relax by day 5 as northerly flow on Earl's northwest quadrant could pull cool air associated with this trough southward... resulting in a more amplified upper trough with less shear and more upper divergence on its east side. This divergence could also aid Earl while the hurricane is still over warm water. This fact in combination with the current higher intensity of Earl now makes me agree with the NHC that Earl will become a category 3. I did not select higher intensity for day 5 due to the possible recurrence of shear on day 4 as noted above.
Regarding impact to land areas... for the next 72 hours the primary impact is expected to be coastal sea swells for the northern Lesser Antilles... Virgin Islands... Puerto Rico... north coast of the Dominican Republic... and also the Bahamas and Bermuda. Earl will be passing just southeast of Bermuda on the latest forecast track later this week... and interests here should monitor the progress of this storm as any shift in the forecast track to the north or west would add heavy rainfall and gusty winds to the list of impacts.
0 Hr Position (1200Z Sep 5)... 65 mph maximum sustained wind tropical storm centered northeast of the Dominican Republic at 21.5N-65.3W
IOH 24 Hr Forecast (1200Z Sep 6)... 75 mph maximum sustained wind hurricane centered in the western Atlantic at 24N-65.3W
IOH 48 Hr Forecast (1200Z Sep 7)... 75 mph maximum sustained wind hurricane centered in the western Atlantic at 27N-65.1W
IOH 72 Hr Forecast (1200Z Sep 8)... 95 mph maximum sustained wind hurricane centered south of Bermuda at 29N-63.5W
IOH 96 Hr Forecast (1200Z Sep 9)... 105 mph maximum sustained wind hurricane centered southeast of Bermuda at 30N-61.2W
IOH 120 Hr Forecast (1200Z Sep 10)... 120 mph maximum sustained wind major hurricane centered in the open central Atlantic at 35.2N-57W