Updated: December 1, 2023
Calvin strengthens further with 60 mph sustained winds on approach to Hawaiʻi
2 p.m. update:
Tropical Storm Clavin strengthened further and now has sustained winds of 60 mph with higher gusts, according to a 2 p.m. update issued by the Central Pacific Hurricane Center. Tropical-storm-force winds now extend outward up to 140 miles from the center, forecasters said.
As of 2 p.m., Calvin was 220 miles SE of Hilo; 315 miles SE of Hāna, Maui; 345 miles SE of Kahului, Maui; 380 miles SE of Kaunakakai, Molokaiʻi; 365 miles SE of Lānaʻi City, Lānaʻi; and 440 miles SE of Honolulu, Oʻahu.
Forward movement continues toward the west at a slightly decreased, but still swift speed of 21 mph, according to the CPHC forecast update.
A Tropical Storm Warning remains in effect for Hawaiʻi County.
“On the forecast track, tropical storm conditions will likely begin spreading over Hawaiʻi County starting this evening. Calvin is expected to remain a tropical storm over the next 36 hours, and then will weaken quickly afterward,” according to the CPHC update.
WIND: Tropical storm conditions are expected within the warning area starting this evening. “Individuals in Hawaiʻi County should complete preparations for tropical storm force wind impacts during daylight hours prior to the onset of tropical storm conditions,” the CPHC advises.
RAIN: From later today into Thursday, storm total rainfall amounts of 4-8 inches, with maximum amounts of 10 inches are possible, mainly along the windward and southeast flank of the Big Island of Hawaii. Storm total rainfall amounts of 3-6 inches are expected on the windward areas of Maui, and 2-4 inches elsewhere in the state. This rainfall could lead to localized flash flooding and mudslides.
SURF: Swells generated by Calvin are expected to begin spreading across the main Hawaiian Islands later today and tonight. This will lead to a rapid increase in surf along east facing shores, with high surf continuing into Wednesday.
11 a.m. update:
The Central Pacific Hurricane Center says Tropical Storm Calvin is slightly stronger this morning, and impacts for Hawaiʻi County are expected to start tonight.
As of 11 a.m, the system was about 245 miles ESE of Hilo; 335 miles SE of Hāna, Maui; 365 miles SE of Kahului, Maui; 405 miles SE of Kaunakakai, Molokaiʻi; 390 miles ESE of Lānaʻi City, Lānaʻi; and 465 miles ESE of Honolulu, Oʻahu.
Maximum sustained winds are now 50 mph with stronger gusts, and tropical-storm-force winds extending outward up to 115 miles from the center, according to the CPHC.
Calvin continues on a path west at 22 mph.
A Tropical Storm Warning is in effect for Hawaiʻi County; and a Flood Watch is in effect for the entire state from Tuesday night through Wednesday afternoon. A High Wind Warning was issued for Haleakalā on Maui from 6 p.m. tonight to 6 p.m. on Wednesday.
“On the forecast track, tropical storm conditions will likely begin spreading over Hawaiʻi County starting this evening… Calvin is expected to remain a tropical storm over the next 36 hours, and then will weaken quickly afterward,” according to the latest CPHC Forecast Discussion.
The CPHC forecast calls for the following conditions:
WIND: Tropical storm conditions are expected within the warning area starting this evening. The CPHC urges individuals in Hawaiʻi County to complete preparations for tropical storm force wind impacts during daylight hours prior to the onset of tropical storm conditions. The Maui Emergency Management Agency reports: east winds of 35 to 60 mph with localized gusts over 75 mph are expected at Haleakalā on Maui.
RAINFALL: “From later today into Thursday, storm total rainfall amounts of 4-8 inches, with maximum amounts of 10 inches are possible, mainly along the windward and southeast flank of the Big Island of Hawaiʻi. Storm total rainfall amounts of 3-6 inches are expected on the windward areas of Maui, and 2-4 inches elsewhere in the state. This rainfall could lead to localized flash flooding and mudslides,” according to the CPHC.
SURF: “Swells generated by Calvin are expected to begin spreading across the main Hawaiian Islands later today and tonight. This will lead to a rapid increase in surf along east facing shores, with high surf continuing into Wednesday,” the CPHC advises. ” Surf may reach as high as 15
feet along east facing shores of the Big Island, and up to 10 feet along east facing shores of the other islands. Although peak surf heights on the Big Island will likely occur around low tide Wednesday morning, some minor overwash and erosion is possible for exposed low-lying coastal areas,” according to the National Weather Service.
8 a.m. Update:
A Flood Watch remains in effect for Maui and Hawaiʻi Counties starting this evening. From tonight through Thursday, Maui could see total rainfall amounts of 2-6 inches from the North Shore near Haʻikū to East Maui near Hāna; while the big island (which is currently under a Tropical Storm Warning) is forecast to get 6-10 inches, according to the National Weather Service.
As of 8 a.m, ,Tropical Storm Clavin was located 335 miles ESE of Hilo, Hawaiʻi; and 420 miles ESE of Hāna, Maui. Maximum sustained winds are 45 mph with higher gusts.
Forecasters are urging residents to be prepared now for impacts starting this evening, including high surf, damaging winds and potential flooding.
Satellite imagery of the Central and Eastern Pacific as Tropical Storm Calvin moves to the west. (5 a.m. 7.18.23) PC: NOAA/NWS- Radar imagery of of Hawaiʻi as Tropical Storm Calvin moves to the west. (5 a.m. 7.18.23) PC: NOAA/NWS
- Five day forecast. (5 a.m. 7.18.23) PC: NOAA/NWS/CPHC
- Earliest Reasonable Arrival Time of Tropical-Storm-Force Winds. Calvin (5 a.m. 7.18.23) PC: NOAA/NWS/CPHC
- Calvin wind speed probabilities (2 a.m. 7.18.23) PC: NOAA/NWS/CPHC
5 a.m. Full Forecast
A Flash Flood Watch continues for Maui County and Hawaiʻi Island as excessive rainfall remains a possibility, according to the Maui Emergency Management Agency. A Tropical Storm Warning also remains in effect for Hawaiʻi County with conditions expected within the next 12-24 hours.
The Central Pacific Hurricane Center reports that Tropical Storm Calvin is “taking aim” at Hawaiʻi Island, with impacts starting this evening.
“On this forecast track, tropical storm conditions will likely begin spreading over Hawaiʻi County starting this evening. Deep convection has been developing near Calvin early this morning, which may slow the weakening trend today,” but gradual weakening is forecast from tonight through Thursday, according to the latest update from the Central Pacific Hurricane Center.
As of 5 a.m., the system was about 395 miles ESE of Hilo, Hawaiʻi; 480 miles ESE of Hāna, Maui; 510 miles ESE of Kahului, Maui; 550 miles ESE of Kaunakakai, Molokaʻi; 535 miles ESE of Lānaʻi City, Lānaʻi; and 610 miles ESE of Honolulu, Oʻahu.
The Central Pacific Hurricane Center reports an aircraft from the 53rd Weather Reconnaissance Squadron “Hurricane Hunters” completed sampling wind intensity from Calvin a few hours ago. Calvin has maximum sustained winds of 45 mph with higher gusts, and tropical-storm-force winds that extend outward from the center up to 105 miles.
The system continues on a westward path at swift 22 mph pace.
The National Weather Service say “damaging wind speeds are possible across most of the state as Calvin approaches and passes by each island.” According to the NWS, “Heavy showers and flooding conditions are expected due to deep unstable tropical moisture forced up the windward mountain slopes of islands in Maui and Hawaiʻi Counties.”
The CPHC forecast calls for the following conditions:
WIND: Tropical storm conditions are expected within the warning area starting Tuesday evening. “Individuals in Hawaiʻi County should complete preparations for tropical storm force wind impacts during daylight hours prior to the onset of tropical storm conditions tonight,” according to the CPHC. On Maui, a Wind Advisory is in effect through tonight, and a Wind Watch through Wednesday afternoon.
RAINFALL: From later today into Thursday, storm total rainfall amounts of 4-8 inches, with maximum amounts of 10 inches are possible, mainly along the windward areas of the Big Island of Hawaiʻi, according to the CPHC. Storm total rainfall amounts of 1-4 inches are expected elsewhere in Hawaiʻi, bringing the possibility of localized flash flooding and mudslides.
The National Weather Service reports that “highest potential for heavy rain and flooding” are expected along the windward slopes of the Big Island and windward slopes of the eastern half of Maui. The NWS forecast calls for the possibility of 2-6 inches in parts of Maui of storm total rainfall from the North Shore near Haʻikū to East Maui near Hāna.
SURF: Swells generated by Calvin are expected to begin spreading across the main Hawaiian Islands later today and tonight. This will lead to a rapid increase in surf along east facing shores, with high surf continuing into Wednesday, according to the CPHC. A High Surf Warning is in effect with dangerously large and disorganized waves of 10 to 15 feet in the forecast for Kahoʻolawe, Maui Windward West, Molokaʻi Windward, Molokaʻi Southeast, Windward Haleakalā, Kīpahulu and South Haleakalā.
The National Weather Service expects Calvin to weaken into a Tropical Depression by Wednesday and maintain its westward track, moving away from the island chain by Wednesday night. “Expect improving weather and wind conditions statewide by Thursday as we transition back to breezy trade wind pattern,” the NWS advises.
Original source: https://mauinow.com/2023/07/18/calvin-on-swift-path-west-tropical-storm-warning-for-hawai%ca%bbi-island-flood-watch-for-maui/