• Bryan Norcross

THE TROPICS GO QUIET AS THE FORECAST FOR THE REST OF THE SEASON GRABS ATTENTION

Government forecasters and researchers at NOAA and the National Weather Service have released their assessment of what the rest of the hurricane season is going look like. It’s eye-catching, for sure. Though not as crazy as it first appears.

The forecast is based strategic measurements of conditions in the atmosphere and the oceans that research has show are indicative of future activity. In many years, some indications point up and some point down, so there is fuzziness factor in the forecast. But this year, everything points to a busy hurricane season. NOAA says there’s an 85% chance the season will be busier than average.

The whole question of what is average is a little murky, however. So we need to apply some perspective to the numbers.

NOAA forecasts the number of named storms to total between 19 and 24. Let’s take the worst case number and work with that. It’s in line with Colorado State University’s team, who put out their updated forecast on Wednesday.

You’ve probably seen graphics showing 12 named storms as the average in a hurricane season. And indeed, the official average number is 12. But that’s based on the time period 1981 to 2010, which has little to do with the modern state of the tropics.


Beginning in 1995, we entered a period of 25 to 35 years of increased hurricane activity. It is well established that the Atlantic oscillates between periods of more and less activity. Whether this increased-activity period is going to end on time due to climate changes is an open question. But whatever the case, we’re in it now.

So the problem with the official average is that half of the time period it covers is not representative of current situation that we’re living with.

Add to that, for just the last few years, National Hurricane Center forecasters have had a new generation of high-resolution satellites surveying the ocean. As a result, some storms are getting named these days that wouldn’t have in the past – not because the rules have changed, but because we now know better when a storm fits the rules.

This further makes the point that the official averaging period, which ended in 2010, is not representative of how tropical system get named and counted these days.

The average number of named storms each year in this current active era has been about 15, and you could make a case for 16 or 17 recently, taking the increased detection abilities of the new GOES-16 satellite into account.

That means that 24 named storms would be 7 or 8 above the modern average – still a significant number. But there’s one more consideration.

Over the 25 years of the active era, on average, we’ve only had 3 or 4 named storms by August 7th. So around 12 or 13 occur after this date.

If the latest forecast of 24 right, and using the high-end estimate, we still have 15 named storms to come, since we’ve had 9 named storms already. So the number of named storms forming the rest of the year would only be 2 or 3 above average.

So even though 24 is an eye-popping number for the number of storms, it’s not crazy big, given where we are.

You can do a similar calculation about hurricanes. We’ve had 2 and NOAA is forecasting 7 to 11 total – so there are 5 to 9 to go. In the modern era, we normally wouldn’t have had the first one yet, so our current average of 7 or 8 over the last 25 years would be still to come. So again, the numbers are quite as abnormal as they seem.

None of this means, of course, that the total this year won’t be higher than 24, and anything higher than average these days is a whole lot of storms.

The bottom line is, we shouldn’t focus on the number, but instead concentrate on what they mean.

Everybody needs a plan, which is even harder in these COVID days. Think it through. Now.


The big questions are: Where will you and your family ride out a storm? How will you protect your property? How will you have enough water to drink and wash and flush the toilet? And who is your family’s point of contact out of town that you can all call and tell you’re okay.

A little effort now will save you a lot of grief after a storm.


Thankfully, Mother Nature is currently taking a break. Dry air dominates the tropics, and there are hostile upper winds to boot. No tropical development is expected into the middle of next week.

© 2019 by Bryan Norcross Corporation

This EXPERIMENTAL and AUTOMATED page displays advisory information compiled from text advisories and graphics issued for public consumption by the National Hurricane Center.  Every effort is made to display the information accurately, however as with any experimental system, errors in the acquisition, storage, analysis, manipulation, or display of the data may occur on occasion.  Refer to www.hurricanes.gov for official information directly from the National Hurricane Center.

 

Terms of Use

Social media posts: Advisory-summary images may be shared with credit to hurricaneintel.com. In blogs, articles, and on websites: Advisory-summary images from this site may be used if hurricaneintel.com is credited. However, you may NOT embed real-time updating content from this page without special permission. For further information contact mail (at) bryannorcross (dot) com.