Tropical Storm Calvin Local Statement Advisory Number 30
National Weather Service Honolulu HI EP032023
458 PM HST Tue Jul 18 2023

This product covers the Hawaiian islands

**CENTER OF TROPICAL STORM CALVIN WILL PASS JUST SOUTH OF BIG ISLAND TONIGHT**

NEW INFORMATION
—————

* CHANGES TO WATCHES AND WARNINGS:
– None

* CURRENT WATCHES AND WARNINGS:
– A Tropical Storm Warning is in effect for Big Island East, Big Island Interior, Big Island North, Big Island South, Big Island
Southeast, Big Island Summits, Kohala, and Kona

* STORM INFORMATION:
– About 390 miles southeast of Honolulu or about 180 miles southeast of Hilo
– 17.8N 153.3W
– Storm Intensity 60 mph
– Movement West or 275 degrees at 21 mph

SITUATION OVERVIEW
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The center of Tropical Storm Calvin is forecast to pass nearby just south of the Big Island of Hawaii tonight and early Wednesday, then pass well south of the other Hawaiian Islands through Wednesday night. Impacts are expected to be greatest on the Big Island, but strong 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, locally up to 10 inches upslope across windward portions of the Big Island. Storm total precipitation on Maui will be 3 to 6 inches and 2 to 4 inches across the rest of the state, highest amounts over windward and mountain areas.

Coastal impacts associated with Calvin will include rapidly building surf tonight through Wednesday. Surf may reach as high as 20 feet along east facing shores of the Big Island, up to 15 feet along east facing shores of Maui, and up to 12 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. Smaller islands will peak later in the day Wednesday.

Locally strong winds will 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 evening. 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
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* 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 across Maui and 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 Molokai.

* 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 all preparations to protect life and property in accordance with your emergency plan. Ensure you are in a
safe location before the onset of strong winds or possible flooding.

If you are relocating to safe shelter, leave as early as possible. Allow extra time to reach your destination. Many roads and bridges will be closed once strong winds arrive. Check the latest weather forecast before departing and drive with caution.

Failure to adequately shelter may result in serious injury or loss of life. Always heed the advice of local officials and comply with any orders that are issued. Remember, during the storm 9 1 1 Emergency Services may not be able to immediately respond if conditions are unsafe. This should be a big factor in your decision making.

Closely monitor weather.gov, NOAA Weather radio or local news outlets for official storm information. Be ready to adapt to possible changes
to the forecast. Ensure you have multiple ways to receive weather warnings.

* ADDITIONAL SOURCES OF INFORMATION:
– For information on appropriate preparations see ready.gov
– For information on creating an emergency plan see getagameplan.org
– For additional disaster preparedness information see redcross.org

NEXT UPDATE
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The next local statement will be issued by the National Weather
Service in Honolulu HI around 1130 PM HST, or sooner if conditions
warrant.