Weather Terms RVers Need to Know

All the winter storm advisories, alerts, watches, and warnings that we’ll soon start seeing can be confusing. The National Weather Service does a great job of disseminating weather predictions but sometimes it can be hard to know just what is what.

In the year 350 B.C., the Greek philosopher Aristotle gave one of the earliest descriptions of weather patterns in a text called Meteorologica. It included some of mankind’s first attempts to observe and record natural phenomena like water evaporation and earthquakes. Although it was a far cry from the Weather Channel, Meteorologica was the start of something that had eluded human beings for time immemorial: the ability to understand—and even predict—the weather.

Modern weather forecasting is a $7 billion-a-year industry—and for good reason. Despite all the advanced technology of modern society, humans are still pretty much at the mercy of the elements. America’s GDP can fluctuate by more than $1.34 trillion depending on the weather. In 2020 alone, more than 60,000 weather events killed 585 people in the United States and injured more than 1,700 more with flash floods, tropical storms, heat, tornadoes, ice storms, and thunderstorms doing most of the damage.

Weather forecasters are easy targets because, like football referees, people tend to take notice only when they get it wrong. The reality, however, is that meteorologists are right in astonishing percentages. When weathermen and women issue seven-day forecasts, they’re accurate about 80 percent of the time—90 percent for five-day forecasts.

If someone had told Aristotle that human beings would one day be able to accurately predict the weather nine times out of 10, five days in advance, he likely would have laughed at their overactive imagination.

It’s important to note that climate and weather are not interchangeable terms. Weather describes the short-term—day-to-day and hour-to-hour—state of the atmosphere including temperature, precipitation, wind, and visibility. Climate, on the other hand, measures average weather patterns over several decades.

I used a variety of scientific sources to compile this list of common weather terms that RVers should know and understand.

Coachella Valley, California © Rex Vogel, all rights reserved

Atmospheric pressure

Humans inhabit the very bottom of the Earth’s atmosphere and everything above creates atmospheric pressure. High-pressure systems form when downward pressure creates a clockwise air rotation, unlike low-pressure systems which generate counter-clockwise rotation. Both phenomena which are measured with barometers are critical to predicting weather events.

Black ice

Vehicle accidents are the leading cause of winter-related fatalities so when a meteorologist warns about the potential for black ice drivers should take it seriously. Black ice gets its name because it’s so thin that it’s nearly invisible on the road surface but the ice itself isn’t black. Black ice forms when sudden temperature increases causing snow to melt and drip onto roadways that are still cold enough to make the liquid water freeze on contact.

Blizzard

Not just any big snowstorm qualifies as a blizzard. A storm must meet three criteria to earn the harshest classification in winter weather. Blizzards have frequent wind gusts of at least 35 mph, sustained falling or blowing snow that reduces visibility to less than a quarter-mile, and these conditions are maintained for at least three consecutive hours.

Breezy and windy

The terms windy and breezy are sometimes used interchangeably but they don’t describe the same phenomenon. Breezy conditions involve air moving between 12 and 22 mph during pleasant conditions. Windy days, on the other hand, involve stronger winds up to 50 mph during stormy or inclement weather.

Dew point

The dew point represents the temperature to which air would have to be cooled to reach a level of moisture saturation. When it reaches the dew point, droplets of water or dew begin to form on solid objects like grass and vehicles.

Drought

Most people know droughts result from an extended lack of precipitation and abnormally high temperatures but overpopulation and land overuse are contributing factors, too. Droughts are among the most destructive forces in nature—only hurricanes are more economically damaging to the United States.

Usery Mountain Regional Park, Mesa, Arizona © Rex Vogel, all rights reserved

El Niño

The opposing warm half of ENSO is called El Niño (The Boy) which occurs irregularly every two to seven years and is often followed closely by a La Niña (see below) pattern. It warms the oceans and creates the opposite effect in terms of not just ocean temperatures but atmospheric pressure. It, too, is associated with irregular and sometimes severe weather patterns.

Flash flood

Flash flooding occurs when large amounts of water from sudden torrential rains—or occasionally an incident like the breaking of a dam—gushes through a narrow area that isn’t capable of absorbing high volumes of water. In many cases, flash floods which can roll cars and destroy houses happen in the immediate aftermath of extended droughts where parched land can’t absorb the influx of water quickly enough.

Flood crest

Flooding is one of the deadliest and most destructive weather phenomena in the country and on the planet. Weather professionals use specific terminology to describe rivers as they rise from excess water. A flood crest is the peak—the highest level the water will rise—which is the most significant and dangerous time of a flood but also an indication that the flood will soon recede.

Freezing rain

Freezing rain is formed through the same general process that creates sleet (see below) but they’re not the same thing. Sleet falls to the ground as ice. Freezing rain, on the other hand, remains in liquid form until it hits a cold object and then instantly freezes on contact.

Frost

Gardeners make their plans according to the first and last frost schedules in their respective agricultural zones. The frozen version of dew, frost occurs when cold, moisture-soaked air deposits water that freezes and leaves an icy film on things like plants and car windows.

Hail

Unlike sleet (see below) which is ice formed by rain falling through very cold air, hail is a much more dangerous phenomenon associated with much more dangerous weather. Hail forms when powerful updrafts inside of thunderstorms force water well above the freezing level. That water freezes into large hailstones which eventually become too heavy for the updraft and come crashing down to Earth.

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Haze

The dreaded three H’s are hazy, hot, and humid. Hot is self-explanatory, humidity deals with the level of moisture in the air but what exactly does it mean to be hazy? A haze can look like a thin fog but it isn’t caused by precipitation. Hazy conditions occur when large amounts of fine, dry particulate matter like dirt are suspended in the air which scatters light and gives the lower atmosphere a cloudy appearance.

Heat index

The heat index is essentially the same thing as the wind chill factor (see below) but for the opposite sensation of environmental exposure. It represents how hot the temperature feels when humidity is considered. The more humid the air, the less perspiration can evaporate which cripples the human body’s cooling system and makes it feel hotter when it’s humid outside.

Heat wave

Heat waves are long periods of abnormally warm weather. To qualify as a heat wave, it must last for at least two days and consist of temperatures that are outside the region’s historical average.

Ice storm

Ice storms are extended episodes of freezing rain that occur when precipitation falls in liquid form and freezes on contact. It becomes an ice storm when a quarter-inch or more of ice accumulates creating dangerous conditions. Ice storms which can be deadly and cause a lasting impact can add 500 pounds to the weight of power lines and increase the weight of tree limbs by a multiplier of 30.

Jet stream

Jet streams are thin but intense winds in the highest reaches of the atmosphere. Following the boundaries of cold and warm air, jet streams blow west to east although their flow sometimes shifts to north and south. Not only do these rivers of air affect global weather and help meteorologists identify atmospheric patterns but they’re crucial to air travel as flying into and out of them can dramatically affect fuel consumption and flight time.

La Niña

One half of the El Nino-Southern Oscillation (ENSO) phenomenon, La Niña (The Girl) is a global weather pattern that describes a dramatic cooling of ocean temperatures in the Western Hemisphere. La Niña is known for its disruptive impact on weather specifically heavy rainfall and an increase in low-pressure systems.

Okefenokee, Georgia © Rex Vogel, all rights reserved

Microburst

Microbursts are among the most dangerous and unpredictable weather phenomena on Earth and they form inside of already-dangerous thunderstorms. Updrafts—columns of rapidly rising air—sometimes suspend large amounts of rain and ice and when the updraft weakens, there’s nothing left to hold all that water and ice in place. That leads to a massive downdraft which sends the core of the column crashing to the ground and, upon impact, bursting out in all directions, leading to tornado-like winds, pressure, and destruction.

Nor’easter

Nor’easters are major, dangerous storms that are exclusive to the Northeastern United States. Geography, however, is not where these storms get their name. Nor’easters are named for the direction in which the storm’s most intense winds blow. Those winds are usually severe and they’re known to bring rain and snow and cause flooding and storm surges.

Polar vortex

The menacing phrase polar vortex is a relatively new term for winter weather forecasting but meteorologists have understood it as a concept for decades. A polar vortex occurs when a large section of very cold air, usually the coldest in the entire northern hemisphere, is pushed down the North American continent as far south as the Midwestern and Northeastern United States.

Relative humidity

Relative humidity is closely related to dew point (see above) but the two terms are not interchangeable. This term describes the amount of atmospheric moisture that exists relative to the amount that would exist if the air was saturated.

Severe thunderstorm

There are garden-variety thunderstorms and severe thunderstorms and when meteorologists mention the latter, the public should take it seriously. To be classified as severe, thunderstorms must include two potentially deadly elements: winds of at least 58 mph and hail at least one inch in diameter.

Sleet

One of the more unpleasant precipitation events associated with winter is sleet which stings the skin and turns roads and sidewalks into ice-skating rinks. Sleet graces the world with its presence when rain or melted snow freezes and turns into ice on its way from the sky to the ground.

Bernheim Forest, Kentucky © Rex Vogel, all rights reserved

Storm surge

It’s common to hear meteorologists warn that storm surge is one of the deadliest and most dangerous parts of major weather events like hurricanes. The phenomenon occurs when significant storms cause an abnormal rise in seawater above the limits of the astronomical tide. Storm surges can cause rapid, significant, and deadly flooding in coastal regions.

Tropical depression

Before a weather event graduates into a tropical storm, it’s a tropical depression. The infant stage of a hurricane, a tropical depression is a tropical cyclone with maximum sustained winds up to 38 mph.

Tropical storm

People sometimes use the terms tropical storm and hurricane interchangeably but one is an evolution of the other. Tropical storms form in the same places and under the same conditions as hurricanes but they achieve maximum sustained wind of just 39–73 mph. If a tropical storm’s maximum sustained winds hit 74 mph, it becomes a hurricane.

Watches and warnings

Meteorologists issue precautions to inform residents about the likelihood of serious and fast-moving weather events like tornadoes and severe thunderstorms. Watches are less serious and indicate that conditions are present for the formation of a severe weather event. Warnings, on the other hand, indicate that an event has been identified by a person or radar, a tornado or thunderstorm is imminent and to seek shelter immediately.

Wind chill

Everyone in North America north of a certain latitude knows there are two temperatures they have to consider when getting dressed in the morning in winter—the actual temperature reading and the one that counts: the wind chill factor. Also known as the feels-like temperature, wind chill represents how cold the weather feels on human skin when the chilling effect of the wind is taken into consideration.

Avery Island, Louisiana © Rex Vogel, all rights reserved

Wintry mix

Two words cold-weather commuters never want to hear are a wintry mix. When precipitation travels through an above-freezing warm layer of air followed by a cold, below-freezing layer, snow, sleet, and freezing rain can fall simultaneously.

Since we’re talking weather, here are a few related articles:

Worth Pondering…

In the spring, I have counted 136 different kinds of weather inside of 24 hours.

—Mark Twain (1835-1910)

5 Tips for Avoiding Extreme Weather While RVing

When severe weather strikes, there’s no time to think. That’s why you need to prepare for the worst NOW, before you’re faced with an emergency.

One of the best ways to spend a family vacation is by camping in an RV. After all, combining a vacation home and a vehicle makes for a rather convenient road trip mobile, complete with a full kitchen, a bedroom, and a bathroom. But what does one do in case of inclement weather experienced while traveling?

After all, there seem to be extreme weather possibilities in most of the US states including forest fires in the west, tornadoes across the Midwestern states, extreme snow in the northern states, extreme heat and flash floods in the southwest, hurricanes in the south, and severe thunderstorms almost everywhere during the warmer months. Traveling to an area where you are unfamiliar with the weather may seem risky. However, if you keep these simple considerations in mind, you can successfully plan a fun and safe getaway for the entire family to enjoy.

Be aware of the potential for severe weather © Rex Vogel, all rights reserved

1. Be aware of forecasts prior to and during your trip

This seems fairly self-explanatory but simple considerations can be completely forgotten when excitedly planning for a road trip. Checking the weather before leaving for a trip can help you to have an idea of what you may experience over the next few days. If it all looks sunny and clear, then you are in luck. If you see any potential warnings or thunderstorms coming up, make a mental note to keep an eye on the weather throughout your trip.

Be aware of the potential for severe weather © Rex Vogel, all rights reserved

Hurricanes are typically predicted days in advance and should be easy to avoid. If you know a hurricane is headed to an area where you plan to vacation, alter your plans and return when the weather is less risky.

More on severe weather: Lightning and Thunderstorms: Safety Tips for RVers

In addition, be sure to check the weather on a daily basis in case the forecast changes. NOAA’s NWS, WeatherBug, Weather.com, and other online weather sites can give you a three- to ten-day forecast. In an area where you are not entirely familiar with the weather, it is better to over-prepare than to be surprised by a major weather event.

Be aware of the potential for severe weather © Rex Vogel, all rights reserved

2. Avoid areas with inclement weather in peak season

To avoid dangerous weather altogether, it is best to avoid areas with extreme weather during their bad weather seasons. For instance, spring is tornado season across Texas, Oklahoma, and Kansas. Avoiding traveling to these states in the spring seems like the safest option. Hurricanes are most extreme in Florida, Louisiana, Alabama, Mississippi, and south Texas, so avoiding these states during the late summer and fall may be your safest option. During forest fire season out west, keep an eye on the current fires and their paths/containment when planning trips.

Be aware of the potential for severe weather © Rex Vogel, all rights reserved

3. Have a plan in case of severe weather

Avoiding certain areas altogether may not be entirely possible. If this is the case, have an emergency plan in place before heading out in your RV. Extreme weather is usually more of a possibility than a definite, so your chances of missing a storm are high. Having a plan will serve to set you up for success in case the worst should happen. 

This plan can be as simple as moving into a shelter if a storm strikes. You may also want to plan to evacuate the entire area if conditions are severe enough. Whatever your plan is, make sure all family members know of it. It is best to ensure that everyone is on board before inclement weather even occurs.

Be aware of the potential for severe weather © Rex Vogel, all rights reserved

4. Evacuate or hunker down during a “watch”

During tornado season, knowing the difference between a warning and a watch is important. A watch is when a tornado is possible but none have been sighted yet. These are often issued during the correct conditions for a storm in counties or areas where storms are frequent. A warning means that a tornado has been sighted and could potentially pass through your area.

More on severe weather: Dust Storms and Haboobs: Safety Tips for RVers

When a tornado watch has been issued, you can then choose to either evacuate or stay and wait out the storm. Playing the situation by ear may be your best bet if you don’t want to cancel your trip early. However, the safest option may be to move outside of the danger zone if a tornado watch has been issued. Whatever you choose, keep a close eye on the weather in case it worsens.

Be aware of the potential for severe weather © Rex Vogel, all rights reserved

5. Move to a safer area during a “warning”

If you decide to stay after a watch has occurred and a warning is issued, you must then choose to evacuate or move somewhere safer. Evacuation to an area outside of the tornado range may be the safest option. However, when a warning is issued there may not be enough time to evacuate.

If this is the case, move somewhere safe indoors. Perhaps there are shelters nearby where you and your family could wait. If you are watching the weather and have planned accordingly, this situation is less likely. Still, it is best to have a few different plans and options if you are planning to vacation somewhere where storms are frequent.

Be aware of the potential for severe weather © Rex Vogel, all rights reserved

Being in an RV during dangerous or even deadly weather does not sound fun. Only you know what is best for you and your family and planning can reduce the chances of surprise storms arising. All things considered, having a home on wheels is somewhat convenient in these situations because when a storm is brewing, you can simply gather your things and drive away. Missing out on your vacation would be a bummer, but it may sometimes be the safest decision. Watching the weather and having an emergency plan are very important. Plan accordingly to keep your family vacations safe, fun, and disaster-free.

More on severe weather: Severe Weather: Tornado Safety Tips for RVers

Worth Pondering…

In the spring, I have counted 136 different kinds of weather inside of 24 hours.

—Mark Twain (1835-1910)

Lightning and Thunderstorms: Safety Tips for RVers

If you can hear thunder, lightning is not far away

We don’t usually plan our RV trips around thunderstorms or other severe weather. If we knew we’d be spending our vacations taking cover, most likely we’d reschedule our trips. But storms occur throughout the year in just about every place in the world, so they are a fact we simply have to accept. And accepting the reality of storms should prompt us to prepare for how storms can affect us when we’re traveling in our RVs.

The most basic preparation is an emergency preparedness kit that includes a first aid kit. Make sure you check it regularly to ensure that any used supplies have been replaced and that nothing has passed its expiration date.

Be alert to threatening weather © Rex Vogel, all rights reserved

Heat lightning

The term heat lightning is commonly used to describe lightning from a distant thunderstorm just too far away to see the actual cloud-to-ground flash or to hear the accompanying thunder. While many people incorrectly think that heat lightning is a specific type of lightning, it is simply the light produced by a distant thunderstorm.

An old term to describe summertime storms! After all, all lightning is “hot”—the typical bolt of lightning has a temperature of 50,000 degrees Fahrenheit. Ouch!

Flash flood in the Sonoran Desert © Rex Vogel, all rights reserved

Thunderstorm facts

The definition of a severe thunderstorm is one producing hail one inch in diameter (size of a quarter) or winds of 58 mph or more.

According to the National Weather Service (NWS), “Each year across America there are on average 10,000 thunderstorms, 5,000 floods, 1,000 tornadoes, and six named hurricanes.” The NWS pointed out that weather disasters lead to about 500 deaths annually.

Every thunderstorm produces lightning.

Thunderstorms can produce high winds that can damage property.

More on severe weather: Hurricane Season: Staying Safe in your RV

Park led evacuation following a flash flood © Rex Vogel, all rights reserved

Thunderstorms can cause flash flooding.

Lightning kills more people annually than tornadoes or hurricanes.

A thunderstorm WATCH means that conditions are right for a thunderstorm to develop in the watch area. Be ready to take cover or evacuate.

A thunderstorm WARNING means that a severe thunderstorm has been reported or detected on radar threatening danger to property or life. Take cover or evacuate if there is time and a safe escape route.

Cleanup following a flash flood © Rex Vogel, all rights reserved

If you hear it—clear it

According to the National Weather Service (NWS), if you can hear thunder, the storm is close enough that lightning could strike your location at any moment! NWS strongly urges that “If you hear it—clear it!”

All RVers need to remember the Flash to Bang or 30/30 Lightning Rule. If a thunderstorm develops, count the seconds between the flash of lightning and the bang of the thunder to estimate the distance between you and the lightning strike. Because sound travels at about one mile in five seconds, you can determine how far away the lightning is by using this ‘flash-to-bang’ method.

It’s recommended you seek shelter if the time between the lightning flash and the sound of thunder is 30 seconds or less, or six miles away. Once you’re an inside shelter, you should not resume activities until 30 minutes after the last audible thunder.

Be alert to threatening weather © Rex Vogel, all rights reserved

Stay informed with local weather forecasts

Unless you’ve RVing in the wilderness, there will be a way to monitor the weather and learn about impending thunderstorms. Cell phones, Internet weather reports, NOAA radios, TV news, weather stations, and local warning systems are some of the ways to be aware of weather threats.

If you’re staying at an RV Park the manager may alert park guests when severe weather is approaching. But it’s advisable to enquire about storm or tornado shelters and local warning systems when registering at the campground.

More on severe weather: Tornado Safety Tips for RVers

NOAA’s NWS, WeatherBug, Weather.com, and other online weather sites can give you a three- to ten-day forecast.

Camping under trees can be hazardous in severe weather © Rex Vogel, all rights reserved

Check your RV and site for safety

Most RVers like shady sites on hot summer days. But shade usually comes from trees. Check the trees and shrubs at your site for sturdy branches or ones that might break under high wind conditions. Large branches can cause severe damage to your RV and toad/tow vehicle if not injuries to people. If you notice weak branches ask your park owner to trim them.

>>Check your site for chairs, tables, toys, BBQs, and other objects that can become projectiles in high winds. Bring them inside, tie them down, or secure them in some other way.

Bring your pets inside during inclement weather © Rex Vogel, all rights reserved

>>Bring your animals inside during threatening weather.

>>Get your emergency preparedness kit out.

>>Make sure your outside storage doors are closed and locked.

>>Retract any awnings and ensure they’re securely fastened.

>>Close and latch your windows.

>>If you are going to evacuate, leave early, and make sure you are not heading into the storm.

Rockport-Fulton (Texas) following major hurricane destruction © Rex Vogel, all rights reserved

Take cover before the storm arrives

The safest place to locate during a thunderstorm—if you choose not to evacuate­—is in the basement of a sturdy building. This area will give you the greatest protection from lightning, winds, tornados, and flying objects. The next safest area is an inside room with no windows and plenty of walls between you and the storm.

More on severe weather: Hail Can Be a Killer Especially For Your RV

Like mobile homes, RVs can be blown over in high winds. They’re not the safest place to be. But if you have no alternative, stay in a hallway away from windows and cabinets that can fly open turning their contents into projectiles.

Hurricane damage on the Texas Gulf Coast © Rex Vogel, all rights reserved

If you see lightning or hear thunder, stay inside.

Stay inside for about 30 minutes after you hear the last thunderclap.

Unplug electronics like TVs, DVDs, computers, coffee pots, and so forth. Use cell phones and battery-powered devices. A battery-powered NOAA radio would be very useful at a time like this.

Cleaning up following a flash flood © Rex Vogel, all rights reserved

Other Dangers

Both during and after a severe thunderstorm flooding may be a problem. If you are in a low area, move to higher ground. Some RV parks have a flood gauge showing five or six feet above their entry driveway.

If you are traveling and come across a flooded roadway, don’t try to drive through it. You could get washed away if the water is moving rapidly. Or, if there are downed power lines in that water, you could be electrocuted.

Park directed evacuation following a flash flood © Rex Vogel, all rights reserved

Lightning strikes can split trees, breaking large branches off, and start wildfires.

More on severe weather: Arrival of Summer: On Dehydration, Hurricane Season & RVs

If someone has been struck by lightning, call 911 and start CPR immediately. The American Heart Association has a “learn CPR in one minute eight seconds” course that teaches CPR well enough that anyone can deliver effective CPR in such an emergency.

Worth Pondering…

If I accept the sunshine and warmth, then I must also accept the thunder and lightning.

—Khalil Gibran