Hurricane season continues to look like it will be an arduous slog

Headlines

  • NOAA has unveiled their prediction for the 2024 Atlantic hurricane season, and to no one’s surprise, it’s active.
  • They predict an 85 percent chance of an above normal season with 17 to 25 named storms and 8 to 13 hurricanes.
  • There’s a Caribbean disturbance that is headed out to sea, unlikely to develop, and we may have another one there in about 10 days or so.

First off, apologies for the gap between posts, though it’s not as if anything has been going on in the tropics of late. The derecho event here in Houston has monopolized most of my time and resources, and while we were thankfully ok at my location, many others in Houston are not. Here’s to yet another recovery for this city. So on that happy note, let’s discuss hurricane season again.

NOAA’s seasonal hurricane forecast is big

NOAA has unveiled their seasonal hurricane outlook today, and it’s a doozy (Editor’s note: I used the same intro for the Colorado State hurricane outlook last month). First, the numbers.

  • An 85 percent chance of an above normal season
  • 17 to 25 named storms
  • 8 to 13 hurricanes
  • 4 to 7 major hurricanes
  • Accumulated cyclone energy (ACE) 150 to 245% of the median

In other words, busy.

There are a number of factors involved in this: We are transitioning into a La Niña event in the Pacific, we are in a background state of above normal tropical activity that likely began in 1995, and sea surface temperatures in much of the tropical Atlantic are at record levels and are running near late August averages. That isn’t a typo. Dr. Kim Wood at the University of Arizona and Michael Lowry in South Florida have been two of many prominent voices sounding the alarm on this for months now.

Sea-surface temperatures in the main development region of the tropical Atlantic are sitting at record levels and are more typical of a later August 1991-2020 average. (Kim Wood, U of Arizona)

Wood has sea-surface temperature maps for various sub-basins of the Atlantic, and while the Gulf of Mexico is only running about 2 to 3 weeks ahead of schedule, the basin overall is running near August levels. The Caribbean? That’s even worse, running *above* peak average sea-surface temperatures for the entire year. Already.

We can hope for a 2010-like outcome, where it was a busy season but most storms avoided land (with a couple notably tragic exceptions). But given these sorts of antecedent conditions coming into the season, this would be a favorable outcome.

The NOAA outlook, combined with virtually every other hurricane season outlook is saying this year will be busy. It may or may not be busy for you, but we are getting to the point where there aren’t a whole lot of ways to describe any of this that in non-hyperbole. The bottom line is that this is the year to be prepared if you live anywhere on the coast. Just in case.

Watching the Caribbean, sort of

And with that, we have a disturbance to keep tabs on in the Caribbean already.

Thankfully, this disturbance only has about a 10 percent chance of developing and is expected to head out to sea anyway. (NOAA)

Looking at satellite, there’s not a whole heck of a lot to this one. There’s definitely a “center” of the disturbance near the eastern tip of Cuba, but it’s on the way east and northeast. So it will be out in the open water before too long.

A tropical disturbance near the eastern tip of Cuba will head out to sea with about a 10 percent chance to develop into a formal tropical system. (Tropical Tidbits)

Ten percent seems like reasonable odds for development at this point, but no impacts of note are expected even if it does form.

Otherwise, things look quiet for another week or so. We may have another disturbance to watch in the Caribbean in about 10 days or so. We’ll keep you posted on that.

Hurricane season kicks off in the Eastern Pacific, as the Atlantic basin looks calm for the foreseeable future

Headlines

  • No high confidence signals for tropical development in the Atlantic over the next 2 weeks.
  • It seems likely that we’ll make it to June 1st without an Atlantic storm.
  • Eastern Pacific may get its first system by next week, but it likely heads out to sea.

A May Atlantic basin storm seems unlikely this year

Over the next seven days, it looks like a relatively quiet stretch in the tropical Atlantic. The area where GFS modeling has been hinting at some kind of potential development, the Caribbean, looks drier than normal through next week.

The next 7 days look rather quiet in the Caribbean and Gulf. Above normal rainfall mainly targets the Gulf Coast and Southeast, while below average precipitation dominates the Caribbean. (Tropical Tidbits)

Any kind of development should be held off through the 25th or so. Heading into weeks 2 and perhaps week 3, it continues to look unlikely that we see development in the Atlantic. The Climate Prediction Center’s global tropical hazards outlook shows above average rainfall developing in the Caribbean and western Atlantic in that timeframe, but as of now, there’s nothing to really latch onto as a development candidate.

The Climate Prediction Center’s tropical hazards outlook shows dryness in the Gulf, but gradually increasing moisture in the eastern Caribbean and western Atlantic. Development is unlikely at this time in the Atlantic. (NOAA)

At this point, I feel relatively comfortable saying that unless something drastically changes soon, we’ll make it to the June 1st start of hurricane season with no preseason storms in the Atlantic.

Hurricane season underway in the Eastern Pacific

Today is the first day of hurricane season in the Eastern Pacific, and the National Hurricane Center has a 30 percent area outlined off the coast of Mexico.

The first system of the season in the Pacific may develop by next week, but it will likely head out to sea. (NHC)

Slow development of this area is possible as it moves west. A building ridge of high pressure in the upper atmosphere, reloading extreme, historic heat over Mexico will keep this one likely moving west out over the Eastern Pacific. If it were to develop, Aletta is the first name on the list this year.

Model silly season may begin soon in the tropics

Welcome back to The Eyewall! We’re going to fire back up some regular updates now as hurricane season approaches. The plan is currently to post an update each Monday, Wednesday, and Saturday until activity necessitates more frequent posts.

Headlines

  • GFS model periodically trying to spin something up around Memorial Day in the SW Atlantic or Caribbean.
  • While that may or may not happen, it’s about this time of year that the GFS model tends to do some wild things that are usually unrealistic so use it carefully.
  • Eastern Pacific may kick up some activity later next week.

Checking in on the tropics: A reminder about the GFS model

Over the last week or so, we’ve started to see some signs in weather models of some very late period mischief in the Caribbean. This is especially true on the GFS operational model. For those of you that track these things, it’s around this time of year that the GFS begins to go a little haywire with tropical activity traditionally. For whatever reason, it likes to latch onto potential tropical disturbances and blow them up into well-organized storms, usually in the Gulf or Caribbean in May and early June. As most of you know, the chances of a very well-organized May or early June storm is extremely low. So we always tell people to generally put little stock in the GFS operational model this time of year in the tropics.

Saturday morning’s GFS operational model was one of the runs that showed a developing organized system in the Bahamas near Memorial Day. (Tropical Tidbits)

Remember, operational models are known as “deterministic” models. They’re one run, one solution. As meteorologists, we have learned to use an ensemble approach to forecasting, particularly when trying to determine if tropical development is realistic in a medium-range to extended range timeframe. Ensembles are where they run these models anywhere from 30 to 50 or so different times. Each time, something is tweaked in the initialization (what the model is seeing at hour 0), and then the model is run out 240 to 384 hours. This allows us to capture a more realistic envelope of outcomes from the modeling that informs our thoughts on development, risks, etc.

Anyway, the thought process right now is that conditions may become slightly favorable in the Caribbean or Southwest Atlantic for something in about 10 to 15 days. But I would encourage a lot of caution about getting worked up regarding some of the GFS model runs. They may begin to show some outcomes that are unrealistic.

In the meantime, keep an eye on the Eastern Pacific. It may be time to fire up that basin in about seven to ten days. We’ll take another look at things on Wednesday.

Hurricane season begins in a month, so what’s new this year?

May the 1st be with you. Today, we just want to briefly acquaint folks with some of the changes to expect in the upcoming hurricane season. Every year, lessons are learned, data is collected, and changes are implemented. Forecasters and those that communicate the risks and impacts are always attempting to improve, even if just a little.

The cone: New graphics available

The biggest and most important change this year from the National Hurricane Center will come via the cone graphic you often see.

Example of the old forecast cone graphic with warnings and watches from Hurricane Idalia last year. (NOAA NHC)

In the older maps, the watches and warnings covered the coastal regions, and that was that. As we’ve learned, impacts extend far from the track of the center and far from the coast very often. Thus, to capture this more, the NHC will now be including a different map, with the inland watches and warnings included.

An example of what the new cone graphics will look like later this season, which includes inland watches and warnings in the U.S. (NOAA NHC)

These watches and warnings have been issued for a number of years, but they’ve never been combined with the forecast cone on the NHC maps. These maps are considered “experimental,” which in NWS parlance means they may not always be available quickly. But they will be there, likely beginning in August. People will be able to provide feedback to the NHC about these images. We plan to include them when available in our posts.

The rainfall forecast: Going global, sort of

One thing I actually made mention of last year either here or on social media was the lack of rainfall forecasts for international locations. That will be partially corrected this season. Experimental rainfall graphics will now be issued by the NHC and Weather Prediction Center for the Caribbean and Central America. This is very good news, as rainfall is sometimes the biggest threat from these storms.

Experimental rainfall forecast maps will be issued for storms that impact the Caribbean and Central America this year, in addition to those that impact the U.S. (NOAA NHC)

This will give us another useful communication tool for individual storms.

U.S. watches and warnings: More frequent updates

In the past, NHC advisories could generally be broken into two groups: Primary advisories issued at 5 & 11 AM/PM EDT, and then intermediate advisories issued every three hours in between the two primary advisories. Very little would change in the intermediate advisories, other than position and intensity. Well, now the NHC will have the option to expand or trim back watches and warnings in these advisories for the U.S. So, if the forecast looks to change or the storm speeds up or something, there will be the option to give an additional 3 hours of lead time on watches or warnings. Every hour counts ahead of these storms, so this is a welcome change.

Other notes: Spanish, size, names

In addition to the big changes noted above, the NHC will implement some other tweaks this year. There will be additional products available this year in Spanish which should allow almost all key information to be accessed from the NHC in both English and Spanish. This is thanks in part to AI, which is really helping improve how much and how quickly information can be translated. I assume additional languages will be on the board in the future too.

Size forecasts for wind radii will extend out to days 4 and 5, previously only available through day three. The size of the cone is adjusted each year based on average track error. As the NHC states, “the size of each circle is set so that two-thirds of historical official forecast errors over the previous five years (2019-2023) fall within the circle.” It’s a little complicated, but it’s built to account for as much potential error as possible. This year’s cone size will actually increase a little in the Atlantic basin, particularly in days 3 through 5, though not by a huge amount.

The storm list for 2024 is above and can also be found here, going out to 2029.

Hurricane season outlooks continue to populate, and according to the Barcelona Supercomputing Center site that tracks these things, the current consensus forecast for the 2024 season is 23 named storms, 11 hurricanes, and 5 major hurricanes, compared to an average of 14, 7, and 3 respectively. So, yes, this season is highly likely to be very active. We’ll have more for you soon, and we’ll start pushing daily outlooks out sometime later this month. Spread the word on our site, and follow us on the socials.

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