ʻO ka huahekili: ʻOi aku ka nui o ka huahekili nui ma mua o 10 knm, Haʻi ʻia ka makani makani i ka wā e kaʻa ana, ke komo ʻana o ka lani, a me ka pale ʻana i ke alanui o loko.¶

Ke hoʻomohala nei ka supercell hekili i ka hoʻonui ʻana ma mua o 130 a 180 kilomita i kēlā me kēia hola (80 a 110 mph), hiki iā ia ke hoʻopaneʻe i ka ulu ʻana o nā pōhaku hau i loko o ka ʻāpana o ke ao hoʻoheheʻe sub-freezing (-10 C to -30 C / 14 F to -22 F) a hiki i ** pilikua (5 to 10 centimeters / 2 to 4 inches, hua moa i ka nui pōpopo)** a i ʻole gargantuan (exceeding 10 to 20 centimeters / 4 to 8 inches, hua waina i ka nui volleyball) ana ma mua o ka hāʻule ʻana i ka honua. Ma lalo o ka World Meteorological Organization (WMO), National Oceanic and Atmospheric Administration (NOAA, United States), a me Insurance Institute for Business & Home Safety (IBHS) ana ballistic, he 10-centimeter (4-inch, softball-sized) ka nui o ka huahekili ma kahi o 350 a 500 grams (0.8 a 1.1 paona i ka honua)135 to 170 kilometers per hour (85 to 105 mph / 38 to 48 meters per second)**, hāʻawi 250 to 500+ joules of kinetic impact energy (more than 3 to 5 times the kinetic energy of a professional 160-km/h / 100-mph MLB fastball, and matching the impact of a solid masonry brick dropped from a 10-story building). When a gargantuan hail core strikes a highway or neighborhood, three acute life-safety emergencies occur simultaneously: (1) Catastrophic Vehicle Glass Blowout, where tempered side windows, rear windshields, and panoramic glass sunroofs explode into thousands of cubes inside the passenger cabin while the laminated front windshield fractures and caves inward, spraying occupants' eyes and faces with high-velocity glass spalls; (2) Residential Skylight, Tile, and Plywood Roof Deck Penetration, where 10-to-15-centimeter hailstones punch straight through acrylic/glass skylights, asphalt shingles, clay tiles, and even aged 11-millimeter (7/16-inch) OSB/plywood uhi hale i loko o ka papahele o luna lumi noho; a me (3) Lethal Blunt-Force Cranial Trauma to Pedestrians and Outdoor Workers, kahi hoʻokahi pā pololei i ka iwi poʻo kanaka pale ʻole e hōʻeha ʻia ai ka ʻeha iwi poʻo, ka hemorrhage intracranial, a i ʻole ka make. Inā hoʻokani kāu kelepona i ke kani kani uila no ka "DESTRUCTIVE" ʻO ka Hekili Koʻikoʻi (hail >= 2.75 inches / 7 cm, baseball size or larger) or Tornado Warning, get off highways into a covered concrete parking garage or move indoors to a lowest-floor windowless interior hallway away from skylights, and call your local helu pilikia (911 ma ʻAmelika Hui Pū ʻIa a me Kanada, 112 ma waena o ka European Union, 999 ma United Kingdom) no ka ʻeha nui o ke poʻo a i ʻole ka maka. No ke alakaʻi pili ʻana i ka ʻino, aniani, a me ka trauma, e nīnau i kā mākou alakaʻi alakaʻi huahekili, nā puahiohio, thunderstorms and lightning, puka makani naha, a ʻeha poʻo.

Ma ka hoʻomaopopo ʻana i ka wikiwiki o ka hopena a me ka hoʻonui ʻana i ka ikehu kinetic o ka huahekili nui, no ke aha ʻaʻole pono ʻoe e kū ma lalo o ke ala nui i ka wā o ka hau nui, pehea e hoʻonohonoho ai i kou kaʻa a me kou kino i ka wā e haki ai nā aniani kaʻa a puni ʻoe, a no ke aha he mau wahi pōʻino kiʻekiʻe nā keʻena o ka papahele ma lalo o ʻAmelika Hui Pū ʻIa a me Midwestal of the Foothills, Colorado. Alley"), ʻĀlia ʻĀkau a me ʻEulopa Waena, ʻĀpana ʻĀkau, ʻApelika Hema, a me Australia hikina.

E hana i kēia i kēia manawa¶

1. E neʻe koke i kahi papahele haʻahaʻa, puka aniani ʻole o loko, lumi ʻauʻau, a i ʻole lalo, a e noho ma waho o nā lumi me nā kukui lewa, nā kaupaku hale pule, a i ʻole nā ​​puka makani makani, ke "CONSIDERABLE" (1.75 in / 4.4 cm golf-ball) or "DESTRUCTIVE" (2.75+ in / 7+ cm baseball/softball) hail warning is issued. Close all interior curtains, blinds, and window shutters before the hail arrives to catch flying glass shards, then retreat to the lowest floor so a 10-centimeter hailstone punching through a skylight or roof deck cannot strike your head.
2. If you are driving when a giant hailstorm approaches, exit the highway immediately and pull under a reinforced concrete parking garage, gas station canopy, or car-wash bay; NEVER stop underneath a highway overpass. Stopping under a highway bridge overpass blocks interstate traffic lanes in blinding rain/hail (causing fatal high-speed rear-end semi-truck collisions) and places you in a wind-tunnel Venturi chute where supercell tornadoes (which develop right next to the giant hail core) frequently track.
3. If caught on an open road with zero overhead cover when giant hail (> 5 cm / 2 in) begins slamming into your vehicle, pull completely off the pavement onto the shoulder, angle the front nose of your car INTO the wind, close the solid interior sunshade under your sunroof, and turn your back to the windows.
4. Why Angle the Front Windshield Into the Wind: Your car's front windshield is made of laminated safety glass (two layers of glass bonded to a tough polyvinyl butyral / PVB plastic interlayer) mounted at an aerodynamic 30-to-45-degree slope that deflects hailstones, whereas your side windows, rear window, and sunroof are made of single-pane tempered glass that shatters instantaneously into thousands of pieces when struck squarely by baseball- or softball-sized hail.
5. Body Position Inside the Car: Recline your seat or lie down across the seats/floorboards below the level of the side window glass, pull a heavy jacket, blanket, coat, or removable rubber floor mat over your head, face, and eyes, and close your eyes so microscopic glass dust ("spall") flaking off the inside of the flexing front windshield does not blind you.
6. If caught outdoors on foot in the open with no building and no vehicle when large hail hits, protect your skull and cervical spine at all costs. A 10-centimeter (4-inch) hailstone hitting at 150 km/h (350+ joules) exceeds the fracture threshold of the bare human cranium. Put on any helmet (bicycle, motorcycle, climbing, construction hard hat) immediately, or hold a hard-shell backpack, briefcase, wooden board, cooler lid, or folded thick jacket/saddle over the crown of your head and neck, duck under dense evergreen tree branches or beside a low masonry wall (only if lightning is not striking the lone tree and winds are not toppling it), and curl into a tight fetal ball on your knees with your face tucked down.
7. If hailstones shatter a window or punch through a skylight in your home, DO NOT try to tape or board up the glass while hail is still falling. A second 150-km/h hailstone striking the pane while your hands and face are at the window will cause severe facial lacerations and arterial wrist bleeding. Abandon the room, close the solid bedroom/hallway door behind you to contain the flying glass and wind-driven rain, and wait until the storm core has completely passed.
8. After the hail stops, inspect your roof-mounted furnace/water-heater exhaust flues, gas meter, and downed power lines before re-occupying damaged rooms, and seek emergency eye or head trauma care if injured. Dial 911 ma ʻAmelika Hui Pū ʻIa a me Kanada, 112 ma ʻEulopa, 999 ma United Kingdom, a i ʻole nānā helu pilikia.

Ballistic Physics and Supercell Meteorology: How Hail Grows Past 10 cm (4 Inches) and Why Kinetic Energy Scales with the 4^th Power of Diameter¶

To understand why a transition from golf-ball hail (4.4 cm) to softball hail (10 cm) or record-class gargantuan hail (15 to 20 cm, such as the 20.3 cm / 8.0-inch, 0.88-kg Vivian, South Dakota hailstone, the 19.0 cm / 7.5-inch Azzano Decimo, Italy hailstone, and the 18+ cm Villa Carlos Paz, Argentina hailstone) turns an expensive property-damage nuisance into a lethal ballistic bombardment, examine the physics of terminal velocity and kinetic energy:

1. Why Kinetic Energy Multiplies 30-Fold When Hail Diameter Doubles¶

For a roughly spherical hailstone of diameter D and ice density rho_ice (approx. 850 to 900 kg/m3) falling through air: 1. Mass (m) scales with the CUBE of diameter (D * D * D): Doubling a hailstone's diameter from 5 cm (2 in) i 10 cm (4 in) multiplies its mass and weight by 8-fold (from 55 grams up to 440 grams / nearly 1 pound). 2. Ka holo wikiwiki (Vt) nā unahi me ka SQUARE ROOT o ke anawaena (sqrt(D)): No ka mea, ʻoi aku ka wikiwiki o ka huki ʻana o ka umekaumaha (e like me ke anawaena cubed) ma mua o ke kauo aerodynamic (kūlike me ka ʻāpana ʻāpana ʻāpana ʻāpana ʻāpana), hāʻule ʻoi aku ka wikiwiki o nā huahekili nui (Vt = sqrt((4 * g * rho_ice * D) / (3 * rho_air * Cd))), e hooikaika ana mai 100 km/h (62 mph) for a 5-cm stone to 150 to 175 km/h (93 to 110 mph) for a 10-to-12-cm stone. 3. Kinetic Energy (KE = 0.5 * m * Vt * Vt) scales with the FOURTH POWER of diameter: - Combining mass scaling with the cube of diameter and velocity squared scaling with diameter means impact kinetic energy increases with the fourth power of hailstone diameter: - Increasing hailstone size from 2.5 cm (1 inch, quarter size: 3.5 Joules) to 10 cm (4 inches, softball size: 380+ Joules), a 4-fold increase in diameter, increases impact energy by more than 100-fold.

Comparison Table: Official Hail Size Scale, Terminal Velocity, Kinetic Energy, and Structural Penetration Thresholds¶

(Compiled from NOAA / National Weather Service NWS, TORRO Hailstorm Intensity Scale, and Insurance Institute for Business & Home Safety IBHS Impact Testing)

Step-by-Step Survival Protocols: Highway Driving, Home Skylights, and Pedestrian Evasion¶

Scenario 1: Caught Driving on a Highway When Gargantuan Hail (7 to 15 cm) Strikes¶

Inā ʻoe e hoʻokele ana a ʻike i kahi ʻōmaʻomaʻo-ʻeleʻele supercell core ma mua, e lohe i ka "BANG" leo nui mua o ka "pōhaku hoʻolaha" kolepa kolepa e pā ana i kou metala o ka hale, a i ʻole e loaʻa i kahi ** DESTRUCTIVE Severe Thunderstorm Warning (baseball+ hail)**: 1. Immediate Exit Search (Before the Main Core Hits): - Look for any sturdy drive-under overhead canopy: a concrete multi-level parking garage, bank drive-thru canopy, car wash bay, or service station fuel canopy (pulling into the downwind bay of the canopy so angled wind-driven hail does not hit your side glass). - Why You Must NEVER Stop Under a Highway Overpass: 1. When 4 or 5 drivers stop side-by-side underneath an interstate bridge to protect their paint from hail, they completely block all travel lanes and the breakdown shoulder. Seconds later, semi-trucks and cars traveling at 110 km/h in blinding whiteout rain slam into the back of the parked queue, causing fatal chain-reaction crashes. 2. If a tornado accompanies the supercell hail core, wind speeds accelerate underneath the bridge girders while channeling flying glass, sheet metal, and hailstones straight under the bridge. 2. If No Shelter Exists and You Must Ride Out Giant Hail Inside Your Vehicle: - Pull Completely Off the Roadway: Pull onto a wide paved shoulder, rest-area lot, or flat firm grass verge well clear of moving traffic lanes and away from large dead trees that could blow down, and turn on your 4-way hazard flashers. - Point the Car's Front Nose Directly Into the Wind (30-to-45-Degree Deflection): Hail almost never falls straight down; supercell outflow winds drive hailstones at a 30-to-60-degree angle. If your car sits broadside or tail-to-the-wind, 150-km/h hailstones slam perpendicularly into your flat tempered side windows or rear window, blowing them out on the first hit. Pointing your hood into the wind forces the hailstones to strike your sloped, laminated PVB front windshield at a glancing angle. - Close the Sunroof Shade & Protect All Occupants from Glass Spall: - Slide the solid interior sunroof cover shut immediately (so when the tempered sunroof glass shatters above it, the fabric/composite board catches the bulk of the falling glass cubes). - Unbuckle only after the car is parked and shifted into Park with the parking brake set in a safe off-road spot, or recline your seat fully backward. - Turn your back to the windows, duck below the metal door sill line, cover your head, neck, and eyes with a thick coat, blanket, pillow, or removable rubber floor mat, and throw a heavy blanket over any infant/toddler car seat. - Keep your eyes closed until the hail stops so microscopic glass spalls shooting off the flexing inner layer of the front windshield do not embed in your corneas.

Scenario 2: Sheltering Inside a Home, Apartment, or Office Building¶

When hail reaches 10 centimeters (4 inches, softball size) or larger, standard top-floor rooms are no longer guaranteed safe from roof penetration: 1. Abandon All Rooms Beneath Skylights, Solariums, and Glass Atriums Immediately: - Standard residential double-pane glass skylights and aged acrylic/polycarbonate dome skylights shatter under 5-to-7-centimeter (2-to-2.75-inch) hail, raining heavy shards of plate glass AND 500-gram hailstones straight down onto kitchen islands, beds, and living room sofas 3 to 5 meters below. 2. Go to the Lowest Floor (Basement or 1st Floor of a 2-Story Home) During Gargantuan Hail (>= 10 cm / 4 in: - Post-storm engineering surveys (such as after the 2010 Vivian, South Dakota 20-cm hailstorm and the 2020 Calgary and Texas 10-to-14-cm hailstorms) document that 10-to-15-centimeter hailstones traveling at 160 km/h punch clean through asphalt shingles, shatter 11-mm (7/16-inch) OSB roof decking between rafters, and crash straight through upstairs drywall ceilings into bedrooms. - Treating a DESTRUCTIVE (2.75+ inch / 7+ cm) Hail Warning like a Tornado Warning, by moving to a basement or a first-floor interior hallway/bathroom beneath an upper story, puts two structural decks between your family and the falling ice stones while also protecting you if the supercell drops an embedded tornado. 3. Never Stand Near Windward Windows: - When 80-to-110-km/h thunderstorm outflow winds drive baseball hail horizontally against the windward wall of a house, windowpanes shatter inward, propelling jagged glass triangles 3 to 5 meters across the room. Close blinds/drapes before the storm arrives, then stay in an interior hallway with the doors to perimeter rooms closed.

Scenario 3: Caught Outdoors on Foot (Hikers, Golfers, Cyclists, Outdoor Workers, and Festival Crowds)¶

In the open, a giant hailstorm is a life-threatening ballistic emergency (in historic open-air events such as the 1986 Gopalganj 1-kg hailstorm, the 1995 Mayfest hailstorm in Fort Worth, Texas, and alpine ridge hailstorms, hundreds of people suffered skull fractures and concussions within 5 minutes): 1. First 60 Seconds (When Isolated Golf-Ball "Announcer Stones" Fall): - Giant hail cores rarely start at peak density; usually, a few isolated large stones fall 30 to 90 seconds ahead of the whiteout core. Do not pause to admire or pick up the first hailstone: sprint immediately for the nearest solid roof, covered porch, culvert tunnel, or parked vehicle. 2. Improvising Ballistic Head Armor If Trapped in the Open: - Skull & Cervical Spine Priority: Your arms and legs can survive severe bruising and even fractures from 10-centimeter hail, but a direct 350-joule hit to the bare skull or C-spine can be fatal. - If you have a backpack: Do not leave it on your back while leaving your bare head exposed; slide the backpack up over the top of your head and neck like a turtle shell (putting the padded frame, hydration bladder, or sleeping pad directly over your cranium). - Other Improvised Head Shields: Use a bicycle/climbing helmet, hard-sided cooler lid, stadium seat cushion, wooden bench plank, trash can lid, spare tire, golf bag held over your head, or thick folded leather/denim jacket. - Body Posture: Never lie flat on your back looking up, and never lie flat in a drainage ditch that is rapidly filling with flash-flood water and 30 centimeters of floating hail slush (which causes rapid conductive hypothermia and drowning in children). Crouch on your knees in a tight tucked ball ("tornado crouch") on high ground beside a low wall or dense shrub hedge, resting your elbows on your knees and holding your pack/helmet shield 5 centimeters above your skull to create a crush-absorption air gap.

Emergency Triage and Sheltering Decision Tree¶

flowchart TD
    A["Giant / Gargantuan Hail Warning:: NWS 'CONSIDERABLE' (4.4 cm / 1.75 in) or 'DESTRUCTIVE' (7+ cm / 2.75+ in) Alert,: greenish-black sky, or roaring sound aloft"] --> B{"Where are you located right now?"}
    B -- "Inside a House, Apartment, or Building" --> C["INDOOR SHELTER PROTOCOL:: 1. Immediately leave all rooms beneath skylights, glass atriums, or patio roofs: 2. Move to the LOWEST floor (basement or 1st-floor interior hallway/bathroom): (10+ cm hail punches through roof plywood & upstairs ceilings; tornado may follow): 3. Close interior doors to windowed rooms; NEVER try to tape breaking glass during hail"]
    B -- "Driving a Vehicle on a Road or Highway" --> D{"Can you reach a concrete garage or gas station canopy in < 1-2 min?"}
    D -- "ʻAe" --> E["Pull completely under concrete garage, car wash bay, or downwind side of canopy: (NEVER stop under a highway bridge overpass)"]
    D -- "NO: Caught on Open Road" --> F["VEHICLE BALLISTIC SURVIVAL PROTOCOL:: 1. Pull completely off travel lanes onto shoulder & turn 4-way hazards ON: 2. Angle front nose of car INTO the wind (sloped laminated windshield deflects hail): 3. Close solid interior sunroof shade immediately: 4. Lie below side-window level, turn back to glass, cover head/eyes & child seats with coats/mats"]
    B -- "Outdoors on Foot with Zero Building Cover" --> G["PEDESTRIAN SKULL-PROTECTION PROTOCOL:: 1. Put on any helmet or pull your backpack/cooler lid/board UP OVER YOUR HEAD & NECK: 2. Crouch in a tight tucked ball on high ground (avoid flooding ditches): 3. Hold shield 5 cm above skull to absorb 300-to-500-joule impacts"]
    C --> H{"Did anyone suffer head trauma, eye glass spall, or hypothermia?"}
    E --> H
    F --> H
    G --> H
    H -- "ʻAe: Loaʻa nā poʻe pōʻino" --> I["Call 911 / 112 / 999 Immediately:: * Eye glass splinters: Do NOT rub eye; tape a rigid cup over eye & go to ER: * Head impact: Monitor for concussion / intracranial bleed; control scalp bleeding: * Post-storm: Check roof furnace/water-heater flues for hail-dented CO blockage"]

Medical First Aid & Post-Hailstorm Home Hazard Inspection¶

1. Ocular Glass-Spall Injuries (Never Rub the Eye)¶

When a vehicle's tempered side window explodes or a laminated front windshield spalls microscopic glass needles into a passenger's face: - Do NOT Rub or Squeeze the Eyelids: Rubbing an eye containing microscopic glass splinters drives the razor-sharp silica shards deep into the corneal stroma or sclera. - Gentle Flush vs. Penetrating Globe Injury: - If fine glass dust is on the eyelids and conjunctiva without globe laceration, flush gently with sterile saline or clean bottled water while tilting the head so water runs outward away from the uninjured eye. - If a larger glass shard is embedded in the eyeball, the pupil is irregular/teardrop-shaped, or vision is lost: Do NOT flush or apply any pressure to the eyeball. Tape a rigid protective shield (the bottom of a paper cup or a metal eye shield) resting on the bony brow and cheek over the injured eye, cover the uninjured eye as well (to prevent sympathetic consensual eye movement), and transport immediately to an emergency department / ophthalmologist (see bungee cord and ratchet strap snapback into eye, hyphema, globe rupture, lens dislocation, and rigid eye shield a eye injuries).

2. Blunt Cranial Trauma and Scalp Lacerations from Hail Impacts¶

• Direct Pressure on Scalp Bleeding: Apply firm, direct pressure with a sterile gauze pad unless you feel a spongy depression or bone step-off (depressed skull fracture), in which case apply gentle ring-pad pressure around the perimeter.
• Red-Flag Intracranial Hemorrhage Signs: Call 911 / 112 / 999 immediately if anyone struck on the head by large hail experiences any loss of consciousness, repeated vomiting, worsening headache, confusion, unequal pupils, slurred speech, or drowsiness over the next 24 hours (see ʻeha poʻo).

3. Conductive Hypothermia in "Hail-Fog" and 30-cm Ice Accumulations¶

Severe hailstorms frequently dump 15 to 45 centimeters (6 to 18 inches) of solid ice accumulation across roads and trails in 20 minutes, dropping local air temperatures from 30 C (86 F) i 2 C (35 F) i ka wā e hoʻopuka ana i ka hukili hauʻoli. ʻO ka poʻe holo kaʻa, kaʻa kaʻa, a me nā mea hoʻokele kaʻa i ʻaʻahu ʻia i nā lole kauwela i pulu i ka ua a paʻa i loko o ka huahekili hohonu e ulu wikiwiki nei ka ** hypothermia **; e neʻe i loko o kahi hale maloʻo, wela a i ʻole kaʻa e holo ana (ma hope o ka hōʻoia ʻana ua maopopo ka huelo o ka huahekili) a hoʻololi i nā lole pulu me nā papa maloʻo.

4. Critical Post-Hail Home Inspection: Crushed Roof Furnace/Water-Heater Exhaust Vents (Carbon Monoxide Trap)¶

Before going to sleep in a house that was just pounded by baseball- or softball-sized hail, inspect the metal B-vent exhaust caps on your roof (which vent your natural-gas or propane water heater and furnace). Large hailstones routinely mash sheet-metal roof flue caps flat shut, blocking combustion exhaust from escaping and backing lethal carbon monoxide (CO) i loko o ka hale i ka wā e hoʻomaka ai kāu mea hoʻomehana wai kinoea. Mai hoʻohana i nā mea hana kinoea inā ʻeha nā pāpale puka makani o ka hale, a ʻaʻole e piʻi i luna o ka hale pulu ma hope koke o ka ʻino (e nānā kalapona kalapona).

Nīnau pinepine¶

Pehea ka wikiwiki o ka hāʻule ʻana o ka huahekili he 10 kenimika (4 ʻīniha, ka nui o ka pōlele, a no ke aha i ʻoi aku ka pōʻino ma mua o ka huahekili kolepa?¶

ʻOiai hāʻule ka huahekili liʻiliʻi he 1 kenimika i ka 30 km/h (20 mph), piʻi nui ka wikiwiki a me ka nui i ka ulu ʻana o ka huahekili i loko o kahi supercell updraft. Ma muli o nā unahi nui me ka cube o ke anawaena a me ka velocity velocity unahi me ke kumu huinahalike o ke anawaena, piʻi ka ikehu kinetic hopena me ka hā o ke anawaena huahekili. He 4.4-centimeter (1.75-inch, golf-ball) ke kaumaha ma kahi o 38 grams a pā i 105 km/h me 18 joules o ka ikehu, aʻo ka 10-centimeter (4-inch, softball) huahekili nui he 350 a 500.1 mau paona i ka honua a hiki i ka 1 paona. 170 km/h (93 a 106 mph) me 350 a 500+ joules o ka ikehu kinetic, ʻoi aku ma mua o ka pākolu o ka ikehu hopena o ka 100-mph Major League Baseball fastball a lawa no ke kuʻi ʻana i nā hale plywood a e hōʻeha i ka iwi poʻo make.

No ke aha e nahaha loa ai nā puka makani ʻaoʻao o ke kaʻa, ka puka makani hope, a me ka hale o ka lā i loko o ka uahehehe ʻoiai e paʻa ana ka pale makani mua ma kahi ʻāpana?¶

By international automotive safety law, your car's front windshield is constructed of laminated safety glass: two sheets of glass fused to a tough central sheet of polyvinyl butyral (PVB) plastic, mounted at a sloped angle that helps deflect hailstones. Even when cracked by baseball-sized hail, the plastic interlayer holds the windshield together (though microscopic glass spalls can flake off the inside). In contrast, almost all vehicle side windows, rear hatchback windows, and panoramic glass sunroofs are made of single-layer tempered glass, which is designed to shatter completely into thousands of small cubes once its surface compression threshold is exceeded by a single 7-to-10-centimeter hailstone impact.

No ke aha he mea pōʻino ke kaʻa ʻana ma lalo o ke ala nui i ka wā o ka ua nui?¶

ʻO ka hoʻokuʻu ʻana i kāu kaʻa ma lalo o ke alahaka o ke alaloa i ka wā o ka hau nui e hana i ʻelua mau pōʻino weliweli. ʻO ka mea mua, hoʻopaʻa ʻia nā kaʻa ma lalo o kahi alaloa i nā ala huakaʻi a me nā poʻohiwi i ka wā e hāʻule ana ka ʻike ʻana i ke kumu o ka huahekili i kahi kokoke i ʻole, e hoʻokau ana nā kaʻa semi-truck a me nā kaʻa ala nui i nā kaʻa kū i ka 100 km/h. ʻO ka lua, ʻo ka huahekili nui (> 7 a 10 kenimika) i hana ʻia ma ke ʻano o ka hoʻohuli ʻana i nā hekili supercell ma ka ʻaoʻao o ka mesocyclone a me ka puahiohio; inā paʻi ka makani ʻino i uhi ʻia i ka ua i ka ʻauwaha, e hana ana nā kāʻei o ke alahaka ma ke ʻano he ala makani e hoʻokē ai i ka makani a hāʻawi ʻole i ka pale mai nā ʻōpala lele. E haʻalele mau i ke alaloa a hoʻohana i kahi kaʻa kaʻa kaʻa a i ʻole ke kumu hoʻoheheʻe kinoea, a i ʻole e huki i kahi poʻohiwi ākea ākea i ʻoki ʻia i ka makani.

Hiki i ka huahekili nui ke kuʻi i ke ala a pau ma ka hale i loko o kahi lumi moe?¶

Yes. Field investigations by the National Weather Service and the Insurance Institute for Business & Home Safety (IBHS) confirm that hailstones begin shattering glass and acrylic skylights at 5 to 7 centimeters (2 to 2.75 inches), and once hailstones reach gargantuan size (10 to 20 centimeters / 4 to 8 inches, softball to volleyball size), their 350-to-1,200-joule impact energy can punch straight through asphalt shingles, shatter 11-millimeter (7/16-inch) OSB or plywood roof sheathing between the rafters, and crash through upstairs ceiling drywall into top-floor bedrooms. During a Destructive Severe Thunderstorm Warning for softball-sized hail, always shelter on the lowest floor of your home (or basement) and stay out of rooms with skylights.

Nā kumu a me ke alakaʻi kūhelu¶

• National Oceanic and Atmospheric Administration (NOAA) & National Severe Storms Laboratory (NSSL, United States): Severe Weather 101: Hail Basics, Supercell Updraft Hail Growth, Terminal Velocity Physics, and the Vivian, South Dakota Record Hailstone Report.
• National Weather Service (NWS, United States): Impact-Based Severe Thunderstorm Warnings ("Considerable" 1.75-inch and "Destructive" 2.75-inch Hail Wireless Emergency Alert Thresholds).
• Insurance Institute for Business & Home Safety (IBHS, United States): Hail Impact Testing on Asphalt Shingles, Roof Decking, Skylights, and Automotive Glass; Class 4 UL 2218 / FM 4473 Impact-Resistant Roofing Standards.
• European Severe Storms Laboratory (ESSL) & TORRO (Tornado and Storm Research Organization, United Kingdom): Ka TORRO Hailstorm Intensity Scale (H0 to H10) and Gargantuan Hail Climatology (Heymsfield et al. / Knight & Knight).
• American Academy of Ophthalmology (AAO) & American College of Emergency Physicians (ACEP): Management of Ocular Glass Spall Injuries, Open-Globe Rigid Eye Shielding, and Blunt Cranial Trauma Triage.

Nā alakaʻi pili¶

• Hail storms
• Tornadoes
• Thunderstorms and lightning
• puka aniani
• Head injuries