Hurricane Warnings, Watches, and More (The Comprehensive Guide)
- Sep 12, 2018
Do you know the difference between a hurricane warning and a hurricane watch? You will when you finish reading this post!
Every hurricane season there is some confusion over the differences between hurricane warnings, watches, and advisories. This post should serve as your comprehensive guide to the different terms meteorologists use during hurricane season.
Once you finish reading this quick guide, you’ll be a professional at understanding the terms we use to describe tropical watches, warnings, advisories and more. Get started below with tropical storms.
Tropical Storm Alerts
First, let’s start with tropical storms. Tropical storms form almost exclusively over tropical seas as tropical depressions. These form when a low pressure area is accompanied by thunderstorms that produce a circular wind flow. Maximum sustained winds for depressions are under 39 mph.
When the maximum sustained winds increase to 39 mph or greater these depressions turn into tropical storms. Besides an increase in wind speeds, tropical storms are also categorized by a more organized storm with a strong cyclonic circulation.
Tropical Storm Watch
When it comes to both hurricanes and tropical storms, a watch is often the first alert.
Tropical Storm Watches are an announcement that tropical storm conditions (sustained winds of 39 to 73 mph) are possible somewhere within the specified coastal area within 48 hours.
If a Tropical Storm Watch is active for your area, you should keep an eye on the forecast. This will help you stay updated with the intensity and direction of the storm as it moves closer to your area.
Tropical Storm Warnings
Tropical Storm Warnings come next. These warnings indicate that tropical storm conditions are expected somewhere within the specified coastal area within 36 hours.
Warnings are more definite than watches as the storm closes in on your area. Mandatory evacuations will often occur during during the warning stage if they haven’t started already.
Next we’ll go over hurricane-related alerting messages.
Hurricane warnings and watches are very similar to their tropical storm counterparts. The only difference is the intensity of the storm. Hurricanes are tropical storms with sustained winds of 74 mph or greater.
There are five categories of hurricanes. Category 1 is the least intense while a Category 5 is the most intense. Category 3, 4, and 5 storms are what we call Major Hurricanes. We use the Saffir-Simpson Hurricane Scale to rate hurricane intensity in the Atlantic Basin.
1: A Category 1 has maximum sustained winds 74 to 95 mph, minimal damage potential
2: A Category 2 has maximum sustained winds 96 to 110 mph, moderate damage potential
3: A Category 3 has maximum sustained winds 111 to 130 mph, extensive damage potential
4: A Category 4 maximum sustained winds 121 to 155 mph, extreme damage potential
5: A Category 5 has maximum sustained winds 156 mph or greater, catastrophic damage potential
A Hurricane Watch is an indication that hurricane conditions (sustained winds of 74 mph or greater) are possible within your area within 48 hours.
If a Hurricane Watch is active for your area you should quickly start preparing. This is because it is often too dangerous to prepare for a hurricane once winds reach tropical storm force. 48 hours should be plenty for you to secure your property, retrieve supplies, and/or evacuate.
Folks under Hurricane Watches should pay attention to the National Hurricane Center’s updates and heed official warnings and evacuation orders.
After Hurricane Watches Hurricane Warnings are likely. When hurricane impact seems more likely the National Weather Service issues Hurricane Warnings. Hurricane Warnings are issued 36 hours in advance and indicated that hurricane conditions (sustained winds of 74 mph or greater) are expected.
During a hurricane warning, you should complete storm preparations and immediately leave the threatened area if directed by local officials.
Other Watches, Warnings, and Advisories
Besides tropical storm and hurricane warnings and watches, there are other advisories to look out for. We’ll list them below:
- Storm Surge Watch: There is a possibility of life-threatening inundation from rising water moving inland from the shoreline somewhere within the specified area, generally within 48 hours
- Tropical Cyclone Public Advisory: Contains a list of all current coastal watches and warnings associated with an ongoing or potential tropical cyclone, a post-tropical cyclone, or a sub-tropical cyclone. This will also include the cyclone position, maximum sustained winds, current motion, and a description of the hazards associated
- Tropical Cyclone Track Forecast Cone: This graphic shows areas under tropical storm and hurricane watches and warnings. It also shows the position of the center of the storm and its predicted track.
- Cone of Uncertainty: This graphic shows where forecasters believe the center of the storm will remain with 60-70% certainty
- Hurricane Local Statement:Local NWS offices in areas affected by a tropical cyclone issue Hurricane Local Statements to keep the public, local decision makers, and the media current on potential storm impacts in their area. The Hurricane Local Statement contains a succinct overview of the event and a generalized summary of potential impacts and preparedness information. Potential impact information is ordered based upon the greatest expected impact from the tropical cyclone within the NWS local office’s area of responsibility
- Tropical Cyclone Threats and Impact Graphics: These graphics provide a threat assessment in terms of potential hazard impacts within an NWS local office’s area of responsibility. The assessment scheme takes into account the forecast magnitude of the hazard, along with the associated uncertainty of the forecast
Earth Networks Alerting Capabilities
We hope this guide helps clear up a lot of questions and confusing regarding tropical alerting. Our weather map infuses NWS watches, warnings, and other alerts alongside 40+ other weather layers to help decision-makers get the real weather story in their area. This helps them make the best weather-related decisions for their businesses, schools, or airports.
We have layers for both NWS Tropical and Coastal alerts as well as layers for both active and historical tropical storms in both the Atlantic and Pacific. After combining these layers you can get one of the most comprehensive weather visualizations out there today.
The image above shows:
- Red tropical alerts
- Teal and blue coastal alerts
- Hurricane Florence’s current position, track, cone of uncertainty, and wind swath
- Temperature contour
- PulseRad radar alternative
Another great feature is that you can toggle these layers to make the map show you exactly what you what to see. First picked all the layers we wanted to show. Then we changed the order and opacity to show you an image that is clean, crisp, and informative.
If you’d like to learn more about Sferic Maps for your severe weather decision-making, please fill out the form. After you fill out the below form one of our weather experts will be in touch shortly!