10 Jun 2019

How Extreme Weather Impacts the Construction Industry

tropical-storm
 

Thunderstorms, blizzards, hurricanes and heatwaves might look and feel like very different problems, but did you know that they’re all created in similar ways? Whether it’s high-pressure or low-pressure systems causing havoc in your area, the result is the same: enormous pressure on your jobsite to cope. Would you know where to start?

What Causes Crazy Weather? 

Dramatic weather events are typically created by shifts and clashes between cold and warm air, water vapor and areas of varying pressure. Let’s take a more detailed look at how this works:

Thunderstorms happen when warm air rises and hits much colder air, condensing in the process. The contrasting temperatures create an unstable atmosphere, and this can quickly drag warm air upwards, forming cumulonimbus clouds. Water droplets increase in size, and can freeze into ice crystals, either falling as hail or rubbing against each other to create either a positive or negative electric charge. These then discharge in a flash of lightning, causing the air around it to heat and expand rapidly - which we hear as thunder. Heavy downpours are common and can last only a few minutes to several hours, depending on the speed of steering winds or associated frontal systems.

Hurricanes form in a similar way, except that the trigger is warm water rising off the ocean, either from storm systems moving off the west coast of Africa, or low pressure systems forming the in Atlantic, Caribbean, or Gulf of Mexico. A hurricane is a large collection of thunderstorms, cycling through buildup and deterioration as it moves along warm waters. When too little wind shear exists to cut the top off the thunderstorm, heat builds up and causes an area of low pressure to form. Wind speeds increase and spin towards the center of the low-pressure area, forming an eye, pulling more and more water vapor, building stronger winds and rains and the barometric pressure continues to drop. As a hurricane makes landfall, storm surges wreak havoc along the coastline, inundating coastal communities with several feet of water, devastating winds, and non-stop rain for several hours. The storm weakens and the eye wall deteriorates as it moves inland, but it will still carry the same effects of wind and flooding.

Snowstorms are similarly created when comparatively warm, damp air rises into a very cold, low-pressure area called an extra-tropical cyclone. If the air near the surface is cold enough, snow falls. If there is a lot of wind circulating, this creates a blizzard. Variations on these are lake effect snowstorms, which form over very large, ice-free lakes, and orographic snowstorms, which occur over mountainous areas, as the wind flows upwards into higher and higher elevations. Orographic storms tend to produce the most snow.

Heatwaves occur through the opposite process. When a high-pressure system moves into an area, air from high in the atmosphere is dragged down towards the ground, where it warms up and compresses. This high pressure stops other weather systems from moving in, keeping out clouds and blocking winds. As a result, it continues to become hotter and hotter. These heat waves can create serious problems for power grids, structures, and transportation systems, as energy use spikes to combat the heat. Droughts can begin or become exacerbated as much needed rain is prevented from falling. The pressure system can become stationary for days and weeks on end, until the system naturally weakens and moves, or until other competing weather forces, like jet streams or frontal systems, move into the same area.

Why Does the U.S. Seem to Get it So Bad? 

North America is a vast continent with varied, unique geography; each region is prone to very different types of extreme weather events. For example, the cold, windy Midwest and Great Plains areas of the U.S. are particularly prone to blizzards, while the hot, damp South and Southwest are ripe for thunderstorms and the coast looping around the Gulf of Mexico creates the perfect conditions for hurricanes.

The 3,000 mile-long Rocky Mountains run from British Columbia to New Mexico, creating a central spine where weather systems of different temperatures and atmospheric pressures converge, with dramatic effects. Because of this orientation, cold air from Canada and warm air from the Gulf of Mexico face no impediments, colliding to create the storms we’ve become so familiar with.

What Does This Mean for Construction? 

No matter where in the U.S. you’re based, you will be vulnerable to some kinds of storms at one end of the scale - and, potentially, heatwaves on the other. For industries like construction, which necessarily involves exposure to the elements and reliance on the weather, this poses enormous challenges.

Deep snowfall can prevent you from physically getting in and out of your jobsite. Heatwaves create intolerable working conditions. Huge storms and hurricanes damage equipment, destroy buildings that are under construction, and frequently put teams at risk. Regional disruptions make it much harder to source, buy and transport the materials you need. 

All of these outcomes lead to downtime, delays and, in many cases, spiraling costs.

Final Thoughts: What Can You Do to Protect Yourself? 

While the weather can be volatile and hard to predict, that doesn’t mean it’s a total mystery. There are no new extreme weather events - no matter how dramatic a particular storm, hurricane or drought might be, it won’t be something that has simply never happened before. 

That means that there are plenty of lessons we can learn from the extreme weather events of the past - and practical steps we can take as a result.

Broadly speaking, shielding yourself from the worst effects of extreme weather events falls into two categories: better strategies for early detection and comprehensive contingency planning for when disaster strikes.

For example, if you take the time to watch your local weather report, analyze available regional data, and observe weather changes and conditions while planning your project, you’ll have a far better idea of what problems might come up and how this will affect your jobsite. 

That means you can make much more realistic projections of how long a project will take, how productive you can expect to be at different times of year, how to adjust your timeline so that you stay on schedule all year round, and what additional utilities, equipment or other support you’ll need to budget for to keep the project on track.

One useful approach that’s gaining popularity is using sine curves to create weather delay maps for construction. This works by cross-referencing day-by-day weather data with actual delays reported on construction sites. Not only does this give you a good idea of how bad the weather will be for business, it also helps you spot potential productivity problems and figure out how to offset these, way ahead of time. 

With or without advance warning that a storm’s brewing on the horizon, proper contingency planning is essential. You need a clear, step-by-step plan that outlines exactly how you’ll deal with any kind of extreme weather event, who will do what in an emergency, and what you need to get back on your feet quickly in the aftermath. 

It’s one thing to understand why wild weather is happening. You also need to know how you’ll handle it. Don’t wait until the wind is whistling outside before you start to figure that out!