HLSHFO HIZ023-026>028-051>054-182315- Tropical Storm Calvin Local Statement Advisory Number 28 National Weather Service Honolulu HI EP032023 507 AM HST Tue Jul 18 2023 This product covers the Hawaiian islands **CALVIN MOVING TOWARD THE BIG ISLAND WITH IMPACTS EXPECTED BY TONIGHT** NEW INFORMATION --------------- * CHANGES TO WATCHES AND WARNINGS: - None * CURRENT WATCHES AND WARNINGS: - A Tropical Storm Warning is in effect for Hawaii County * STORM INFORMATION: - About 610 miles east-southeast of Honolulu or about 390 miles east-southeast of Hilo - 17.5N 149.5W - Storm Intensity 45 mph - Movement West or 275 degrees at 22 mph SITUATION OVERVIEW ------------------ The center of Tropical Storm Calvin is forecast to pass over, or just south of, the Big Island of Hawaii tonight and early Wednesday, then pass well south of the other Hawaiian Islands through Wednesday night. This places the islands in the windier and wetter part of Calvin`s circulation. Impacts are expected to be greatest on the Big Island, but strong and gusty winds, locally heavy rainfall and high surf along east facing shores can be expected statewide. Heavy rainfall will likely begin this evening on the Big Island, with chances for heavy rain increasing elsewhere across through Wednesday as Calvin moves steadily toward the west. Expect storm total rainfall of 4 to 8 inches across mainly windward portions of the Big Island, with around 1 to 4 inches of rainfall elsewhere across the state. Coastal impacts associated with Calvin will include rapidly building surf tonight through Wednesday. 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. Locally strong winds are likely to begin this evening over the Big Island, with north winds shifting to the northeast and east as Calvin moves westward through Wednesday morning. Winds will primarily be northeasterly over the smaller islands, strongest Wednesday and Wednesday night. It is important to note that the mountainous terrain of the islands can produce localized areas of enhanced winds, even well away from the tropical cyclone center. POTENTIAL IMPACTS ----------------- * WIND: Protect against hazardous wind having possible limited impacts across the Hawaiian islands. Potential impacts include: - Damage to porches, awnings, carports, sheds, and unanchored mobile homes. Unsecured lightweight objects blown about. - Many large tree limbs broken off. A few trees snapped or uprooted, but with greater numbers in places where trees are shallow rooted. Some fences and roadway signs blown over. - A few roads impassable from debris, particularly within urban or heavily wooded places. Hazardous driving conditions on bridges and other elevated roadways. - Scattered power and communications outages. * SURGE: Protect against locally hazardous surge having possible limited impacts across portions of windward and southeast Big Island. Potential impacts in this area include: - Localized inundation with storm surge flooding mainly along immediate shorelines and in low-lying spots, or in areas farther inland near where higher surge waters move ashore. - Sections of near-shore roads and parking lots become overspread with surge water. Driving conditions dangerous in places where surge water covers the road. - Moderate beach erosion. Heavy surf also breaching dunes, mainly in usually vulnerable locations. Strong rip currents. - Minor to locally moderate damage to marinas, docks, boardwalks, and piers. A few small craft broken away from moorings. Elsewhere across the Hawaiian islands, little to no impact is anticipated. * FLOODING RAIN: Protect against dangerous rainfall flooding having possible significant impacts across mainly windward and southeastern portions of the Big Island. Potential impacts include: - Moderate rainfall flooding may prompt several evacuations and rescues. - Rivers and tributaries may quickly become swollen with swifter currents and overspill their banks in a few places, especially in usually vulnerable spots. Small streams, creeks, canals, arroyos, and ditches overflow. - Flood waters can enter some structures or weaken foundations. Several places may experience expanded areas of rapid inundation at underpasses, low-lying spots, and poor drainage areas. Some streets and parking lots take on moving water as storm drains and retention ponds overflow. Driving conditions become hazardous. Some road and bridge closures. Prepare for locally hazardous rainfall flooding having possible limited impacts across other Hawaiian Islands from Kauai to Maui. * TORNADOES: Protect against a tornado event having possible limited impacts across the Hawaiian islands. Potential impacts include: - The occurrence of isolated tornadoes can hinder the execution of emergency plans during tropical events. - A few places may experience tornado damage, along with power and communications disruptions. - Locations could realize roofs peeled off buildings, chimneys toppled, mobile homes pushed off foundations or overturned, large tree tops and branches snapped off, shallow-rooted trees knocked over, moving vehicles blown off roads, and small boats pulled from moorings. PRECAUTIONARY/PREPAREDNESS ACTIONS ---------------------------------- Now is the time to complete necessary actions to protect your family and secure your home or business, prior to the onset of tropical storm conditions tonight. When making safety and preparedness decisions, do not focus on the exact forecast track since hazards such as flooding rain, damaging wind gusts, storm surge, and tornadoes can extend well away from the center of the storm. Keep cell phones well charged as localized power outages are possible. NEXT UPDATE ----------- The next local statement will be issued by the National Weather Service in Honolulu HI around 11 AM HST, or sooner if conditions warrant. $$ $$