Calvin, the first major hurricane of the season, expected to bring heavy rain and potential flooding to the islands.
Calvin, the first major hurricane of the season, expected to bring heavy rain and potential flooding to the islands.
Soon after Calvin rapidly intensified into the eastern Pacific’s first major hurricane of the 2023 season, it began to weaken Friday night and will continue to unwind into next week as it pushes westward toward Hawaii. “The system will still hold together enough to bring tropical rainstorm conditions to the islands by Wednesday,” said AccuWeather Meteorologists.
Calvin entered a zone that was highly favorable for intensification late this past week with water temperatures in the 80s F and light winds that surrounded the system. The hurricane peaked as a Category 3 system with maximum sustained winds of 125 mph on Friday.
As of Saturday morning, Calvin was a Category 2 hurricane with maximum sustained winds of 105 mph. The system was moving west-northwest at 16 mph and was 1,850 miles to the east-southeast of Hilo, Hawaii.
Steering breezes will continue to push Calvin along to the west, where it will enter a large pool where water temperatures dip progressively lower through the 70s. Temperatures in the upper 70s to near 80 are about the minimum threshold for a tropical system to survive.
“As Calvin moves through progressively cooler waters into next week, winds near the core of the system will steadily drop off,” said AccuWeather Tropical Meteorologist Alex DaSilva. “As a result, Calvin will dip to tropical storm status and then to a tropical depression early next week.”
A tropical storm has maximum sustained winds of 39-74 mph, while a tropical depression has winds of 35-38 mph about a well-defined center.
“At this time, AccuWeather meteorologists believe that Calvin will not be much of a wind producer by the time it reaches the Big Island of Hawaii on Wednesday,” said DaSilva.
A general 1-2 inches of rain is in store for the islands, forecasters say, with 4-8 inches of rain most likely on the eastern slopes of the Big Island. An AccuWeather Local StormMax™ of 17 inches is most likely to occur within the 4- to 8-inch rainfall zone.
Rainfall is typically sparse during the summer months in Honolulu and was close to average during June. The sporadic rainfall has dwindled since. Only 0.12 of an inch of rain has fallen thus far in July, compared to an average of 0.52 of an inch for the whole month.
There may still be locally gusty thunderstorms associated with the system that could trigger sporadic downed trees and power outages. This is most likely on parts of the Big Island.
The majority of tropical systems that were once hurricanes off the west coast of Central America weaken while moving into the cool waters just east of Hawaii. Occasionally, however, one can survive when waters are warmer or when such a more southerly track occurs in the warm water, followed by a northward turn toward the islands.
Despite the cool waters near Hawaii, there is still a chance that Calvin survives the westward track and hits the islands as a tropical storm. There is also the potential the system completely breaks down prior to reaching all the islands.
Should Calvin take a track a few hundred miles farther to the south, impacts on the islands may be significantly less, even though the storm may stay stronger while tracking over warmer waters. Should Calvin veer more to the north, it will encounter cooler waters at a faster pace but may still have some success at bringing downpours and gusty thunderstorms to the islands.
Any non-flooding rainfall may be welcome in parts of the islands. The driest conditions were located in the western and central part of Maui, where moderate drought conditions were ongoing, according to the United States Monitor.
Produced in association with AccuWeather
Edited by Judy J. Rotich and Newsdesk Manager
