Hurricanes

Hurricanes draw their energy from the latent heat released when warm, moist air over the ocean rises, expands, and condenses into clouds and rain. Five conditions must align for a tropical disturbance to organize into a hurricane:

1. Sea-surface temperatures of at least about 26.5°C (80°F) down to roughly 50 meters.
2. A pre-existing disturbance, often a tropical wave moving off the African coast in the Atlantic basin.
3. Low vertical wind shear so the developing circulation is not torn apart aloft.
4. Moisture in the mid-troposphere to sustain convection.
5. A Coriolis effect strong enough to initiate rotation, which is why tropical cyclones do not form within about 5° of the equator.

Once a tropical depression intensifies into a tropical storm and is named, the NHC, the Joint Typhoon Warning Center, and partner agencies track it with reconnaissance aircraft (in the Atlantic and eastern Pacific basins), geostationary satellites, surface observations, and numerical weather models. Forecast skill on track has improved dramatically since the 1990s; forecast skill on intensity has improved more slowly, and rapid intensification — an increase in maximum sustained winds of at least 35 mph in 24 hours — remains a leading challenge.

Climate change is not believed to be increasing the number of named storms globally, but the evidence is consistent with an increase in the proportion of storms reaching the strongest categories, an increase in the highest rainfall rates, and a poleward expansion of the latitudes at which tropical cyclones reach peak intensity. NOAA, the IPCC, and the WMO all caution that natural variability still dominates year-to-year activity.

In the Atlantic and eastern Pacific basins the official hurricane season runs from June 1 through November 30, with peak activity from mid-August through late October. Climatological peak is around September 10. NOAA issues a seasonal outlook each May and updates it in August.

In the western North Pacific the typhoon season is effectively year-round, with peak activity July through October. The Australian/southwest Pacific cyclone season runs November through April. The North Indian Ocean has a bimodal season, peaking in May and October–November because the southwest monsoon disrupts cyclone formation in the intervening months.

US households in hurricane-prone regions should treat May as the planning month: review insurance, refresh supplies, and confirm evacuation routes. Coastal-region directories on this site surface region-specific guidance and links to local emergency management agencies.

Effective hurricane preparedness is a multi-week project, not a 48-hour scramble. The following list combines guidance from FEMA, NOAA, the American Red Cross, and the National Weather Service.

Before the season

• Verify your flood insurance policy. Standard homeowners insurance does not cover flood damage; a National Flood Insurance Program (NFIP) policy or a private flood policy must be purchased separately, and most policies have a 30-day waiting period.
• Take a video walkthrough of every room and outbuilding for claims documentation. Store the file in cloud storage with timestamped uploads.
• Identify your evacuation zone via your county or parish emergency management agency. Confirm at least one out-of-state evacuation destination and one inland evacuation destination.
• Trim trees and remove dead branches that could become projectiles.
• Inspect storm shutters, garage door bracing, and roof flashing.

72 hours before landfall

• Fill prescriptions, refuel vehicles, and refill propane tanks.
• Withdraw modest cash; power outages disable card readers.
• Move outdoor furniture, grills, and potted plants indoors or into the garage.
• Charge phones, battery banks, and any medical devices.

24 hours before landfall

• Fill bathtubs and large containers for non-potable water.
• Place important documents (insurance, deeds, IDs) in a waterproof container.
• Confirm pets are accounted for and accommodations exist at every evacuation destination.
• Move to your safe room or evacuate per your local emergency management agency's guidance.

During the storm, the priority is to stay sheltered and informed. Tune to a NOAA Weather Radio receiver with battery backup; cellular service is often disrupted within the first hour after landfall as towers lose power and backhaul.

Stay on the lowest, most interior level of the building you are in, away from windows and exterior doors. Do not be misled by the calm of a passing eye; the back side of the storm typically arrives with a sudden wind shift from the opposite direction and is frequently as destructive as the front side.

Do not attempt to drive through standing water. Six inches of moving water can knock an adult off their feet, and a foot of water is enough to float most passenger vehicles. The NWS slogan "Turn Around, Don't Drown" exists because every hurricane season produces preventable drownings of drivers and passengers.

If you are in a coastal evacuation zone and have not evacuated, do not call 911 once tropical storm-force winds arrive. First responders will not put their own lives at risk to extract individuals who did not heed evacuation orders, and the call ties up dispatch resources for those who need it.

Recovery begins as soon as the storm weakens enough that crews can re-enter affected areas. The first 72 hours are dominated by life-safety: search-and-rescue, restoring critical infrastructure, and clearing primary evacuation and supply routes.

Households and businesses can take the following sequence:

1. Document damage before any cleanup. Photographs and video, with timestamps, are the single most important piece of evidence for an insurance claim.
2. Make only the temporary repairs needed to prevent further damage (tarping a roof, boarding broken windows). Insurance carriers are generally required to reimburse reasonable temporary-repair costs; keep receipts.
3. File the insurance claim. For flood damage, the claim goes to NFIP or your private flood carrier separately from your homeowners claim.
4. If federally declared, apply for FEMA Individual Assistance at DisasterAssistance.gov. Individual Assistance can cover temporary housing, home repair, and other disaster-related needs that insurance does not.
5. Avoid hiring out-of-area contractors who solicit door-to-door without state licensing. Local roofing, restoration, and public-adjuster directories on this site are filtered by license and verification tier.

Mold remediation typically becomes the dominant cost driver for buildings that took on water. The CDC recommends that any porous material (drywall, carpet, upholstery) saturated for more than 48 hours be removed rather than cleaned. Dehumidification and structural drying within the first 72 hours dramatically reduces total remediation cost.

Mental-health recovery deserves the same intentionality as physical recovery. The SAMHSA Disaster Distress Helpline (1-800-985-5990) is staffed 24/7 and provides immediate counseling for individuals affected by natural disasters.