Hurricane graphics, what they really mean and what you should focus on

June 1- November 30
June 1- November 30(WHSV)
Published: Jul. 31, 2020 at 9:59 PM EDT|Updated: Jul. 31, 2020 at 10:39 PM EDT
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HARRISONBURG, Va. (WHSV) - As we head into August, this is when tropical activity tends to pick up. Peak hurricane season is about mid-August through the end of September.

Peak hurricane season is late August through September.
Peak hurricane season is late August through September.(WHSV)

Over the next few months likely we’ll be talking about tropical storms and hurricanes more. So it’s important to explain some information and graphics you’ll be seeing more often.

THE CONE: We’re all familiar with the cone, and the ‘cone of uncertainty'. So what does the cone mean?

The cone is the projected path of the center of the storm. The cone does not depict where all impacts can potentially be felt. So whether you’re in or out of the cone, that just is an outline of the potential center of the storm.

Cone size is based on official storm track error over the last 5 years.
Cone size is based on official storm track error over the last 5 years.(WHSV)

Hurricane force winds can often extend anywhere from 25-100 miles out from the center of a hurricane.
Tropical Storm force winds can extend much further, sometimes as much as 300 miles from the center of a large hurricane.

Many times you’ll see a line through the center of the cone, but this is just the halfway point of the cone. The path of a storm can track anywhere in that cone.

It’s also important to note that the size of the cone is more narrow closer to where the storm is currently, and then fans out the further away. This is because confidence is best closer to the storm but there is less confidence within 3-5 days.

*Side note: The cone size is based off of the error in the official track of storms over the last 5 years. It’s not based off of the range of current forecast models for a particular storm. The cone has been shrinking in size over the last several years because of better forecasting*

SPAGHETTI PLOTS: Often times you’ll see graphics with all of these lines on it. Meteorologists call these spaghetti plots, so properly names. So what does it mean if the line comes through our area? Does that mean the storm is going to come here?

The closer and more grouped the forecast lines are together, the greater the confidence in a...
The closer and more grouped the forecast lines are together, the greater the confidence in a hurricane path.(WHSV)

Not necessarily. There are many forecast models that put out this information, a projected path. We use this not to guess which path is the correct track of the hurricane, but we use this for confidence in a path or track of a storm.

So the more grouped together the lines are, the more confidence there is in that given track, as shows on the left. The further apart the lines are, or basically no general consensus, then the less confidence in a path.

Spaghetti plots also don’t show where impacts will be felt, it’s simply a projection of the potential path.

HOW STORMS ARE NAMED: The National Hurricane Center does not name tropical storms/hurricanes. The names come from the World Meteorological organization. There are 6 lists of 21 different names. One for each letter of the alphabet (omitting Q, U, V, X, Y, Z)

Each list is used every 6 years. If a particular hurricane is so strong and destructive, that name is retired and another name starting with the same letter is omitted.

For example, the list used in 2020 is the same list used in 2014. Prior to, the same list was used in 2008. That year, hurricane Ike caused so much extensive damage, Ike was retired and replaced with Isaias. In 2014, the last time this list was used, Isaias was on the list but we never made it to I that year. The last named storm in 2014 was Hanna.

So why is Isaias pronounced ‘ees-ah-EE-ahs’ and not Eye-zah-as?

From the World Meteorological Organization:

“Each year, tropical cyclones receive names in alphabetical order. Women and men’s names are alternated. The name list is proposed by the National Meteorological and Hydrological Services (NMHSs) of WMO Members of a specific region, and approved by the respective tropical cyclone regional bodies at their annual/biennual sessions.”

In the Atlantic basin, tropical names are English, Spanish, and French. Per the WMO pronunciation guide, it is the Spanish pronunciation of Isaias.

As we head further into hurricane season, tropical updates are available on your WHSV weather app. Go to radar, and hit the three little dots button. Under overlays, select tropical. If you click on one of the forecast icons on the track that will either give you the current storm information or the forecast information for that particular storm.

Bottom line, don’t focus on the exact path. Pay attention to the impacts from the storm.

For the latest on Hurricane Isaias and our local forecast, click this link:

Tropical updates are available on your WHSV weather app
Tropical updates are available on your WHSV weather app(WHSV)

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