Severe weather, floods and wildfires

The rain that flooded Kettle Creek on June 22 did not come as a surprise. At 06:00 that morning the National Weather Service had forecast thunderstorms with locally heavy rain for the region. At 14:30 it issued a severe thunderstorm watch, and at 16:00 a flood watch for Port Ardent and the surrounding counties, calling for 2 to 3 inches of rain by morning, with higher amounts in thunderstorms. At 17:15 the county engineer's office warned that Kettle Creek could rise above flood stage for low-lying areas along the creek. The forecast was, if anything, a little low.

Desjardins asks the class how many of them had heard any of those messages at the time. Two of the twenty students had. 'That's typical,' Kowal says. 'Weather information is better than it has ever been, and most people still don't hear it until it's on top of them. Part of our job, and part of yours, is to turn the forecast into action early.' This lesson covers the weather and natural hazards that police deal with most often, the alerts that warn of them, and the police role before, during and after.

Understanding weather alerts

The National Weather Service issues forecasts and alerts in several tiers. An outlook describes hazardous weather that may develop in the coming days. A watch means conditions are favorable for a hazard to develop; people should be prepared. A warning means a hazard is occurring or imminent and is a threat to life or property; people should act. An advisory is issued for less serious conditions that can still cause significant inconvenience or danger, such as heat or dense fog. The most dangerous alerts, such as tornado warnings, flash flood warnings and flash flood emergencies, are also sent as Wireless Emergency Alerts.

River forecasts and flood alerts in the United States come from the National Weather Service, which issues flood watches and warnings, and from river forecast centers that predict levels at gauged locations. Local emergency managers, engineers and floodplain administrators know how forecast levels translate into flooding of particular streets. Port Ardent's flood plan ties each level of the creek gauge to specific actions, such as closing Mill Road, warning Riverside Flats, and moving the seniors' residence.

Floods

Floods kill more people in North America than most other weather hazards, and a large share of flood deaths happen in vehicles. Drivers underestimate the depth and speed of water over a road, and they do not realize how little water it takes to move a car. Moving water exerts force on everything in its path, and a vehicle partly submerged also becomes buoyant. Roads under water may also have been washed out beneath the surface. The public safety message is short: Turn Around, Don't Drown.

Widely used public safety guidance puts it this way: about six inches of moving water can knock an adult off their feet, about a foot can float many cars, and about two feet can sweep away most vehicles, including trucks and SUVs. The exact figures depend on speed, the vehicle and the road, but the point is that no depth of moving water over a road is safe to drive through. That is why closures of flooded roads must be physical and, where the danger is serious, staffed.

# Force of moving water on a standing person or a car (rough illustration)
# drag force = 0.5 * density * speed^2 * drag coefficient * area facing the flow
# (calculated in metric units, then converted to pounds of force)
density = 1000.0
def force_lbf(speed_fts, depth_in, width_in, cd=1.0):
    speed = speed_fts * 0.3048
    area = (depth_in * 0.0254) * (width_in * 0.0254)
    return 0.5 * density * speed ** 2 * cd * area / 4.448
for speed in (3.0, 6.0, 9.0):              # feet per second
    legs = force_lbf(speed, 6, 12)         # two legs, 6 inches deep
    car = force_lbf(speed, 12, 70)         # side of a small car, 12 inches deep
    print(f"{speed} ft/s: legs about {round(legs)} lbf, car about {round(car)} lbf")
print("Doubling the speed multiplies the force by", round(2.0 ** 2))

3.0 ft/s: legs about 4 lbf, car about 51 lbf
6.0 ft/s: legs about 17 lbf, car about 204 lbf
9.0 ft/s: legs about 39 lbf, car about 458 lbf
Doubling the speed multiplies the force by 4

The example is a rough physical model, not a design calculation, but it shows the key point: force grows with the square of the speed, so water that looks only a little faster can push much harder. A car that has been floated even slightly loses its grip on the road and can then be carried by forces that would not have moved it when its tires were firmly on the ground.

Officers face the same dangers. Rescuing people from moving water is a job for trained and equipped swiftwater rescue teams, usually from the fire service. Officers who wade into floodwater to help someone risk becoming victims themselves. The best help an officer can usually give is to call for rescue, keep the person in sight, talk to them, keep others out of the water and, if trained and equipped, throw a line or flotation device from a safe position on land.

Thunderstorms, tornadoes and wind

Severe thunderstorms bring wind, hail, lightning and heavy rain, and sometimes tornadoes. Derechos, long-lived lines of severe thunderstorms with damaging straight-line winds, have crossed Ohio several times in recent years, including in June 2012, when one caused widespread damage and left about a million Ohio customers without power, some for more than a week during a heat wave. After a storm, police deal with downed trees and power lines, dark traffic signals, damaged buildings, and calls from people without power who need help.

Downed power lines are a serious danger to officers and the public. Officers should treat every downed line as energized, keep themselves and others well back, at least 33 feet, and wait for the utility to make it safe. Lines can re-energize without warning, and the ground around a line can carry current. If a line falls on a vehicle, the occupants should usually stay inside until the utility arrives unless the vehicle is on fire.

After storms and during power failures, carbon monoxide poisoning is a hidden danger. People run generators in garages or basements, or use barbecues and heaters indoors. Officers doing welfare checks should be alert to the smell of exhaust, headaches or confusion in a household, and should get people outside and call for help if they suspect carbon monoxide.

Extreme heat

Extreme heat is one of the deadliest weather hazards, although it rarely looks like an emergency. Its victims are often older people living alone, people with chronic illnesses, people who use certain medications, people experiencing homelessness, and outdoor workers. Heat is the leading weather-related cause of death in the United States in most years, and heat waves regularly cause deaths among older people found alone in hot homes. Police support heat response by checking on people when relatives or neighbors are worried, by knowing where cooling centers are, by noticing people in distress during patrol, and by recognizing the signs of heat stroke, which include confusion, hot skin and collapse, and is a medical emergency.

Wildfires and smoke

Wildfire is a growing hazard in many parts of North America. Smoke from record Canadian wildfires in 2023 blanketed much of the eastern United States, including Ohio, causing some of the worst air quality ever recorded in parts of the region. Even communities far from forests feel the effects of smoke, which causes respiratory illness and reduces visibility on roads.

Wildfire evacuations differ from floods in that fire can move faster than expected, change direction with the wind, and close evacuation routes with smoke and flames. Police roles include managing evacuation routes and traffic, keeping people out of fire areas, security of evacuated communities and, as in floods, supporting reception centers. Decisions about evacuation are made with fire officials who understand fire behavior. Officers working near wildfires must never drive into smoke they cannot see through, and must keep an escape route open.

Winter storms and ice

Winter brings its own hazards: heavy snow, blowing snow that reduces visibility to almost nothing, freezing rain that coats roads, trees and power lines with ice, and extreme cold. Ice storms and blizzards in Ohio regularly close highways, strand motorists and cut power to hundreds of thousands of customers, and extreme cold can turn a power failure into a threat to life within hours. For police, winter storms mean collisions, stranded motorists, highway closures and welfare checks on people without heat. Officers should carry winter survival equipment in their vehicles, know where warming centers are, and remember that people in cold, dark homes may be using unsafe heat sources.

Highway closures in severe winter weather are usually decided by the road authority and the police together, and they work only if drivers are kept off the closed road from the start. Officers at closure points may face long lines of frustrated drivers and should know the detour, the expected reopening time if any, and where stranded travelers can wait in safety.

Before the storm

Most of what police can do about weather happens before it arrives. When a watch or warning is issued, supervisors can adjust staffing, make sure vehicles are fueled and equipped, check that officers know the plan for their area, and pass the alert to officers on patrol so they can watch for early signs of trouble. Kowal notes that on June 22 the duty inspector kept two officers on after the evening shift, which put two more cars on the road at 23:15 when the first calls came in. 'That cost the city some overtime,' she says. 'It also meant that the first barricades went up at the creek crossings half an hour earlier than they otherwise would have. I don't know who drove into the water that night who would otherwise have drowned. Neither do you. That's what prevention looks like.'

Officers can also share safety messages with the public during ordinary contacts before severe weather: reminding drivers not to drive through flooded roads, telling residents where cooling or warming centers are, and encouraging people to check on older neighbors. These small actions add up across a whole shift and a whole service.