Measuring hurricanes and tornadoes

Today marks the beginning of the 2017 Atlantic hurricane season, which runs through the end of November. As you may be aware, we measure hurricane intensity by measuring the wind speed. We categorize hurricanes into one of five levels on the Saffir-Simpson scale. In use since 1971, the scale is widely known, but does it serve the public well?

The United States has not seen a landfall from a “major” (category 3 or above) hurricane since Hurricane Wilma in 2005. But that doesn’t tell the whole story. The original Saffir-Simpson scale included effects from storm surge and flooding. However, the Saffir-Simpson Hurricane Wind Scale in use today excludes those; it is solely a measure of wind speed. So even though the U.S. has avoided major hurricanes, it has not avoided major damage. Consider that two of the three costliest hurricanes in U.S. history were not major hurricanes. Sandy wasn’t even technically a hurricane.

More recently, Hurricane Matthew caused a great deal of devastation in the Carolinas and Virginia. Matthew could have caused massive damage along the Florida Atlantic coast, but remained just far enough out to sea. And the damage further north was primarily due to inland flooding, not the near-shore wind and surge. By the time Matthew reached the Carolinas, it was “just” a Category 1 storm. As a result, many in the public did not recognize the serious threat it posed.

The National Hurricane Center in particular, and the weather industry in general, are working to improve hazard communication. The public, after all, doesn’t really care about the wind speed per se, but the effects of that wind (and rain). Last fall, several meterologists on discussed this on Twitter:

The discussion turned to the idea of real-time rating of tornadoes. NOAA researchers found that weather radar velocity data can be used to estimate the ultimate Enhanced Fujita Scale rating of a tornado. While not operational yet, it will be a big benefit to the public if it is further developed.

The ideal situation would combine the impact focus of the EF scale with the real-time rating used for hurricanes. Hurricanes are much easier to evaluate in real time for a variety of reasons, so they have a head start. Now if we can just start measuring hurricanes correctly.

Hurricanes doing laps

As I write this Thursday night, Hurricane Matthew is approaching the east coast of Florida. By the time this post goes live, Matthew will have just made landfall (or made its closet approach to the Florida coast). Hundreds have been killed in Haiti, according to officials there, and I haven’t heard of any updates from Cuba or the Bahamas, both of which were hit fairly hard.

But even as the immediate concerns for Florida, Georgia, and the Carolinas are the primary focus, there’s another though in the mind of meteorologists: a second round.

National Hurricane Center forecast graphic for Hurricane Matthew.

National Hurricane Center forecast graphic for Hurricane Matthew.

If the forecast holds and Matthew loops back around to strike the Bahamas and Florida again, it could exacerbate already devastating damage. It is expected to weaken, so the threat will be more for rain than wind, but with existing widespread damage, it could be significant.

Such an event is not unprecedented, but it is rare. Eduoard and Kyle, both in 2002, did loops over open water, but did not strike the same area twice. Hurricane Esther struck Cape Cod twice in 1961.

From what I’ve been able to find, it looks like 1994’s Hurricane Gordon is the closest analog, but it’s not great. Gordon snaked through the Florida Straights and moved onshore near Fort Myers. The second landfall was near the location of the “seafall” on the Atlantic coast. Gordon’s peak strength was a low-end category 1, not the category 3 or 4 that Matthew will be at landfall (or closest approach).

Matthew is already making its place in history as the strongest storm on record to impact the northeastern Florida coast. Next week, we’ll find out how much gets tacked on.

Hurricane Joaquin forecast contest begins

Hey! The tropics have awoken and there’s a not-unreasonable chance that the newly-upgraded Hurricane Joaquin will make landfall. Here’s your chance to test your forecast skill:

Submit your forecast by 00 UTC on October 2 (8 PM EDT Thursday). If Joaquin does not make landfall, we’ll just pretend like this never happened. For previous forecast game results, see

TS Chantal forecast

It’s that time again. The tropical storm Chantal forecast game has been opened. Be sure to get your forecast submitted by 8 PM EDT on Wednesday. As a new feature this year, I’ll include an approximated version of the National Hurricane Center’s forecast for comparison. You may also note that yet another year has passed without any significant updates to the game code. I swear one of these days I’ll make the improvements I keep promising.

Hurricane Sandy Forecast Game results

We set a record for the number of players with the Hurricane Sandy contest, and the winner is the deceptively-named StormsHitGeorgia. Full results are at The scores were among the lowest I’ve ever seen, although the relatively short forecast period probably helped. It’s interesting to note that the last official forecast from the NHC, roughly converted into a forecast for this game, would have finished in 11th place.

“Frankenstorm”: or how a passing reference can become a popular sensation

It’s not often that career civil service employees get to spark a national craze. Certainly that’s not what forecaster James Cisco of NOAA’s Hydrometeorological Prediction Center (HPC) had in mind when he was writing the HPC’s preliminary extended forecast discussion on Thursday morning. His discussion included the following:


It was, in my view, a harmless way of pointing out the unusual hybrid nature of what is setting up to be a sequel to the “Perfect Storm“. But the media saw the discussion and immediately latched on to the name (seemingly forgetting that it already had a name: Hurricane Sandy). Before long, the name “Frankenstorm” was setting the social media world alight, too.

Not everyone was a fan of this label, though. The Weather Channel’s Eric Fisher complained about it, and apparently so did many others. In a media briefing earlier today, NOAA officials said that “Frankenstorm” would not be used in any further NWS products. Since only the one discussion ever used that term, NOAA is effectively saying “we’re going to stop doing what we already weren’t doing”, but I get the point. They don’t want to create confusion by having two names for the storm.

The Weather Channel, after recently announcing they’d be naming winter storms, has wisely decided to stick with “Sandy” for this storm, even though some of the impacts will be decidedly wintery. Still, the name, much like the monster, won’t die. I’m not sure if that’s good or bad. There’s anecdotal evidence either way. On the one hand, the unusual name might cause people to pay more attention. On the other hand, calling by a non-hurricane name might give a false sense of diminished impact. Only a post-event analysis will tell.

Hurricane Sandy contest

It’s time to take a risk on Hurricane Sandy. I’ve opened the Sandy forecast contest. Forecasts are due at 8 PM EDT on Friday (27 October at 00Z).

Some rule clarifications:

  • If the storm takes on extratropical characteristics, it still counts so long as the National Hurricane Center is tracking it at landfall.
  • Landfall is defined as the first hit of the mainland, regardless of country. Barrier islands, etc, do not count.

What a sysadmin can learn from hurricane corner cases

One thing I’ve been focusing on lately is avoiding “It Works Well Enough” Syndrome. Maybe it’s because of the systems design classes I’m taking, or maybe it’s due to my frustration having to fix something that was done months or years ago because it no longer works well enough. Sysadmins are particularly vulnerable to this trap because we’re often not trying to develop software, we’re just trying to solve an immediate problem. Unfortunately, things change over time and underlying assumptions are no longer valid.

A relevant example from the world of tropical weather came up earlier this month. The National Hurricane Center’s 45th discussion for Hurricane Katia contained some very interesting text:


It makes sense that software focused on the Atlantic basin would only be concerned with western longitudes, right? It’s exceedingly rare for Atlantic tropical systems to exist east of the Prime Meridian, but apparently it’s not impossible. Whether it’s NHC or commercial software that the forecasters are concerned about is irrelevant. Clearly positive longitudes break things. It makes me wonder what broke when Tropical Storm Zeta continued into January 2006.

Sidebar — It’s not our fault/everyone else does it, too

I don’t mean to demonize sysadmins or lionize developers in the first paragraph. There are plenty of sysadmins out there who want to take the time to develop robust tools to solve their problems. Often, they just don’t have the time because too many other demands have been placed up on them. By the same token, developers who methodically design and implement software still end up with a lot of bugs.

Tropical Storm Earl results

Well, the results are in.   Earl weakened pretty significantly as he traveled up the east coast, resulting in fairly minor damage.  The game had a lot of first-timers, and most of them did pretty well.  I’m pleased with my own performance, but I’d rather win.  There might be another chance shortly if the remnants of Gaston get back together.

Also, I finally made a page with a link to all of the scored games and added that link to the tropical weather page.

Hurricane Earl forecast contest

The hurricane season is in full swing, with three active storms.  Danielle is scooting off to oblivion in the North Atlantic, but Earl is gearing up to take a run at the east coast…somewhere.  As of this writing, the forecast track is such that landfall could be anywhere from the Outer Banks to Nova Scotia, or perhaps it may yet turn out to sea.  Of course that means there’s a Funnel Fiasco tropical contest underway. You can enter by clicking the link on the tropical weather page (or go directly to it here).  The deadline for entry is Tuesday at 8 PM EDT (Wednesday 0000 UTC).  Just a reminder to make sure you enter valid numbers, I won’t check them for you.

Stay tuned for more on Hurricane Earl, and also for a potential repeat when Tropical Storm Fiona get closer.