Tag Archives: Indiana Severe Weather Preparedness Week

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Know anyone who’s still confused by watch vs. warning?

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Wizard of Oz witch tornado watch warning meme
Meme creator unknown

The U.S. National Weather Service has been issuing tornado and severe thunderstorm watches and warnings since 1965. More than 50 years later, however, people still fail to fully understand the difference between a watch and a warning. You probably know some of them, I certainly do.

As my contribution to the second day of Indiana’s Severe Weather Preparedness Week 2016, I’ve written this blog to share with your friends and family members who remain confused.

A watch is essentially a forecast

Map showing tornado watch for a large part of Indiana and Michigan for 11:20 a.m. to 8 p.m. Nov. 17, 2013.
Map showing tornado watch for a large part of Indiana and Michigan for 11:20 a.m. to 8 p.m. Nov. 17, 2013.

In fact, before 1965, the NWS called what we now know as “tornado watches” “tornado forecasts.” A tornado watch indicates the possibility of tornadoes forming, just as a rain forecast indicates the probability of rain. Similarly, a severe thunderstorm watch indicates the possibility of severe thunderstorms forming. A watch does not mean these things are already happening, it means they could happen.

Like a forecast, a watch covers a period of many hours and usually covers a large area of at least several counties, if not several states. We should watch for possible dangerous weather in the near future.

A warning is an indication of immediate danger

Polygon indicating the area covered by a tornado warning for the Kokomo, Indiana area Nov. 17, 2013.
Polygon indicating the area covered by a tornado warning for the Kokomo, Indiana area from 3:17 p.m. to 3:45 p.m. Nov. 17, 2013. Click the image to see a larger version.

It’s a call to take shelter now, because the tornado or severe thunderstorm is already happening. Depending on where you are, you might only have couple of minutes to protect yourself and your family. Or, you might have 10 or 15 minutes, if you’re at the far edge of the “warning polygon.” If you want to survive a tornado or a severe thunderstorm, don’t waste time seeking more information. When a warning comes out, take shelter immediately.

Because dangerous weather has already formed and is on its way, a warning usually covers a period of less than an hour and a small area that’s sometimes smaller than a county. The time to watch is over. It’s now time to heed the warning and take shelter.

Want even more lead time?

If you’re really interested in weather, or want to know even earlier whether severe weather is possible, there are two other NWS products to check out.

The NWS Storm Prediction Center (SPC) usually issues a “mesoscale discussion” before it issues a watch. This product lets you know that the SPC is thinking about (or planning to) issue a watch, the geographical area of concern and the reasons. Some of the text of a mesoscale discussion can get pretty technical, but anyone can figure out from this product whether a watch is likely to be issued. If any mesoscale discussions are in effect, you can find them on the SPC website.

For even more lead time, the SPC issues “convective outlooks” that indicate the amount of risk of severe weather as much as eight days in advance. You can also find these products on the SPC website.

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A weather safety tip you might not have thought of: Footwear

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Photo of feet wearing flip-flops with red X superimposed. Flip-flops are poor footwear for severe weather days. Indiana Severe Weather Preparedness Week. #INWxReady #WRNSandals, especially flip-flops, which are so popular when the weather is warm, are poor choices for severe weather days.

My feet get warm easily. I have a pair of Chacos brand sandals that I wear almost every day during warm weather. But not on days that I might need to serve as a storm spotter.

If severe weather is coming our way, I usually change into a sturdy pair of ankle-supporting hunting boots I bought on sale at Cabela’s, even if I’ll be staying home during the storm.

Why? On word: debris.

National Weather Service photo

After a storm passes, I might have to walk through storm debris, which can include pieces of trees and pieces of buildings. The walking surface might be uneven. Some of the debris might have sharp edges.

I choose to protect my feet from all that, a practice I learned back in the 90s when I served as an emergency medical technician and communications technician on a Disaster Medical Assistance Team. It’s how I dressed my feet every day, even in tropical weather when assisting the victims of Hurricanes Andrew and Marilyn.

My advice: If you’re a storm spotter or storm chaser, get yourself a good pair of boots to wear anytime you’re in the field, even on hot, humid days. And no matter who you are, if you ever have to take shelter in your house from a coming storm, take the most protective footwear you have with you to the basement, interior room, etc. Put them on after the storm, before you step outside to survey the damage. Your feet will be much safer.

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An even earlier “heads up” on severe weather

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Earlier, in commemoration of Indiana Severe Weather Preparedness Week, I wrote about the important distinctions between watches and warnings. Readers who saw that post will recall that the National Weather Service usually issues weather watches hours before severe weather develops in the watch area.

You can also know about the possibilities of severe weather days in advance, if you know where to look.

In addition to watches, the NWS Storm Prediction Center (SPC) issues convective outlooks. In this case, “convective,” refers to thunderstorm development through atmospheric instability. Convective outlooks include maps that show various risk levels for severe thunderstorms in various parts of the country as far into the future as six days.

For example, on April 27, 2014, a large, violent tornado killed 16 people in Vilonia and Mayflower, Arkansas. Five days earlier, the SPC indicated a risk of severe weather in that area on a convective outlook map (see below).

Day 4-8 convective outlook from April 22, 1014 for Indiana Severe Weather Preparedness Week
“Day 4-8 Convective Outlook” map issued by the Storm Prediction Center on April 22, 2014, five days before a tornado killed 16 people in Arkansas. Note the green area labeled “D6,” which includes the area where the tornado eventually formed and which indicated a 30 percent or higher probability of severe thunderstorms within 25 miles of any point on April 27.

Anyone who wants an advance look at severe weather probabilities can look at SPC convective outlooks on the SPC website. During severe weather season, I review every morning at least the “Day 1 Convective Outlook” (which shows risks for the same day) and the “Day 2 Convective Outlook” (which shows the next day’s risks).

For a more localized outlook, I also view the “Hazardous Weather Outlook” that our local NWS office issues. This text-only product indicates local forecasters’ assessment of the risks of hazardous weather within their coverage area the same day (day one) and for the following week (days two through seven).

So, what can you do with this information? When an outlook indicates a risk of severe weather in a few days, you can:

  • Develop and/or review a plan for what to do if sever weather strikes.
  • Encourage others to develop a plan.
  • Assemble a disaster supply kit and pet kit.
  • Check your NOAA All Hazards radio for fresh batteries and operation.

By knowing about outlooks, watches and warnings when they’re issued, you can keep from being surprised by severe weather.

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Severe weather watches and warnings: Do you really know the difference?

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Tornado graphic for Indiana Severe Weather Preparedness Week 2015Governor Mike Pence has proclaimed March 15 through 21, 2015 as Severe Weather Preparedness Week in Indiana.

Throughout the week, I’ll use my “W9LW’s Ramblings” blog to help build awareness of important severe weather concepts that everyone should know.

If you’re a trained storm spotter, you’ll already know most of the stuff I’ll write about. In that case, I encourage you to use Indiana Severe Weather Preparedness Week to share this information with your family, friends and co-workers. After all, you are probably the closest thing to a weather expert who those folks know personally.

Today, I’ll start with one of the most basic of severe weather concepts, but also one of the most important; knowing the difference between a severe weather watch and a warning.

The National Weather Service (NWS) has used the term, “watch,” since August of 1965 but I still talk to people who don’t really understand what a watch is and others who refer to watches as warnings and warnings as watches.

Here’s a simple table to help you remember the difference. The information below applies to both tornado and severe thunderstorm warnings and watches.

Warning Watch
Your response Take shelter now! Remain alert, determine where you’ll take shelter if necessary
Meaning Severe weather is imminent, has been detected by radar and/or confirmed by trained weather spotters Conditions are favorable for the development of severe weather in and close to the watch area
Timeframe Minutes before danger arrives Usually hours before severe weather occurs
Geography Very local, sometimes less than a county, based on storm location and track Regional, multiple counties, often crossing state lines, based on atmospheric conditions

Bottom line: When the NWS issues a warning, it’s time to take action. Now. When the NWS issues a watch, it’s time to make sure you’ll know about a warning if one comes out later and time to make sure you know what you’ll do if a warning comes out.

Please share this! Do you know someone who doesn’t really understand watches and warnings? Use the buttons below to share a link with your social networks, etc.