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.
PUNA WEATHER GROUP:
Tuesday 18th July 2023 (5am post)
Warm and humid with little or no rain most of the day today. Winds calm, but with bursts of gusty at times... in general a pretty odd day as it's the "calm before the storm".
Tonight some showers, possibly very heavy at times, but the main event is likely to be from 11pm tonight to 3am Wednesday with intense rain and strong gusts winds. Some thunder is also possible, maybe even an isolated tornado.
Conditions improve by daybreak on Wednesday with much less rain and wind, but very muggy... ick. Power could be out at your home when you wake up... so plan accordingly.
---
Slightly warming sea surface temperatures between Calvin and our island allows Calvin to maintain its strength as it approaches our island tonight. Shear remains around 10mph from the south or southeast, keeping the strongest activity north of the center. The center of Calvin is likely to track over, or just south of Kau, but this should spare them the strongest impacts. Areas from Pahoa north to our Hamakua coast are right in the bullseye.
In the satellite loop Calvin's low level circulation remains symmetrical with a distinct center. Spiral banding to the south of the center is indicative of dry air working its way into the storm. The sustained convection to the north of the center is likely to work its way to the northwest of the center as the storm approaches, and this pushes the time of arrival of the heaviest activity forward an hour or so. It also means the activity is likely to end a little sooner. Calvin is moving a little faster, now 22mph. That also means that activity starts and ends a little sooner. It also means that winds could be a little higher. The winds are calculated by adding the spinning winds around the storm to the forward speed of the storm, so maybe some gusts will approach 60mph around midnight or so.
Calvin Local Watch/Warning Statement/Advisory Number 28
National Weather Service Honolulu HI EP032023
443 AM HST Tue Jul 18 2023
HIZ053-182245-
/O.CON.PHFO.TR.W.2003.000000T0000Z-000000T0000Z/
Big Island East-
443 AM HST Tue Jul 18 2023
...TROPICAL STORM WARNING REMAINS IN EFFECT...
* LOCATIONS AFFECTED
- Hilo
- Pahoa
- Volcano
* WIND
- LATEST LOCAL FORECAST: Equivalent Tropical Storm force wind
- Peak Wind Forecast: 35-45 mph with gusts to 60 mph
- Window for Tropical Storm force winds: early this evening
until Wednesday morning
- THREAT TO LIFE AND PROPERTY THAT INCLUDES TYPICAL FORECAST
UNCERTAINTY IN TRACK, SIZE AND INTENSITY: Potential for wind 39
to 57 mph
- The wind threat has remained nearly steady from the
previous assessment.
- PLAN: Plan for hazardous wind of equivalent tropical storm
force.
- PREPARE: Remaining efforts to protect property should be
completed as soon as possible. Prepare for limited wind
damage.
- ACT: Move to safe shelter before the wind becomes hazardous.
- POTENTIAL IMPACTS: Limited
- 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.
* STORM SURGE
- LATEST LOCAL FORECAST: Localized storm surge possible
- Peak Storm Surge Inundation: The potential for up to 2 feet
above ground somewhere within surge prone areas
- Window of concern: this evening until Wednesday afternoon
- THREAT TO LIFE AND PROPERTY THAT INCLUDES TYPICAL FORECAST
UNCERTAINTY IN TRACK, SIZE AND INTENSITY: Potential for storm
surge flooding greater than 1 foot above ground
- The storm surge threat has remained nearly steady from the
previous assessment.
- PLAN: Plan for storm surge flooding greater than 1 foot
above ground.
- PREPARE: Complete preparations for storm surge flooding,
especially in low-lying vulnerable areas, before conditions
become unsafe.
- ACT: Leave immediately if evacuation orders are given for
your area.
- POTENTIAL IMPACTS: Limited
- 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.
* FLOODING RAIN
- LATEST LOCAL FORECAST: Flood Watch is in effect
- Peak Rainfall Amounts: Additional 4-8 inches, with locally
higher amounts
- THREAT TO LIFE AND PROPERTY THAT INCLUDES TYPICAL FORECAST
UNCERTAINTY IN TRACK, SIZE AND INTENSITY: Potential for
moderate flooding rain
- The flooding rain threat has remained nearly steady from
the previous assessment.
- PLAN: Emergency plans should include the potential for
moderate flooding from heavy rain. Evacuations and rescues
are possible.
- PREPARE: Consider protective actions if you are in an area
vulnerable to flooding.
- ACT: Heed any flood watches and warnings. Failure to take
action may result in serious injury or loss of life.
- POTENTIAL IMPACTS: Significant
- 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.
* TORNADO
- LATEST LOCAL FORECAST:
- Situation is somewhat favorable for tornadoes
- THREAT TO LIFE AND PROPERTY THAT INCLUDES TYPICAL FORECAST
UNCERTAINTY IN TRACK, SIZE AND INTENSITY: Potential for a few
tornadoes
- The tornado threat has remained nearly steady from the
previous assessment.
- PLAN: Emergency plans should include the potential for a
few tornadoes.
- PREPARE: If your shelter is particularly vulnerable to
tornadoes, prepare to relocate to safe shelter before
hazardous weather arrives.
- ACT: If a tornado warning is issued, be ready to shelter
quickly.
- POTENTIAL IMPACTS: Limited
- 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.
* FOR MORE INFORMATION:
- https://www.weather.gov/hfo
$$