30 June 2024

Beryl rapidly intensifies to become unprecedented Category 4 hurricane in June

Since yesterday's post when Beryl just reached Category 1 hurricane intensity, it has exploded and in less than 24 hours it's now a Category 4 hurricane.  It's hard to communicate how unbelievable this is.
The earliest there has ever been a Category 4 hurricane anywhere in the Atlantic was July 8 (Dennis 2005) and that was near Jamaica.  The earliest there has ever been a Category 4+ hurricane east of the Caribbean in the "Main Development Region" was August 7 (Unnamed 1899). And one more incredible stat from Sam Lillo (a good follow on Twitter: @splillo) is that although this intensification rate has happened just a handful of times before, the earliest it ever happened was September 1.  By the way, the earliest Category 5 on record was Emily on July 17, 2005.

24-hour infrared satellite animation spanning early afternoon Saturday through early afternoon Sunday.  Tropical storm to Category 4 hurricane in this time.

With La NiƱa on the way and the ocean temperatures already looking like the second week of September, this is precisely the type of outlier event that people have been talking about for months heading into this season.  When you have an unprecedented favorable environment, you're bound to see unprecedented tropical cyclone activity.

The NHC forecast maintains Beryl at major hurricane intensity through Thursday, then weakening somewhat as it nears the Yucatan Peninsula on Friday, though still a very strong and dangerous hurricane.  The official track forecast follows the model guidance closely, which is tightly clustered with virtually no outliers anymore.

We will have ground-based radar coverage of the hurricane from Barbados, and you can find the latest long animation at https://bmcnoldy.earth.miami.edu/tropics/radar/

Elsewhere, Invest 94L has crossed over the Yucatan Peninsula and is now over the Bay of Campeche where it has a very brief window to develop before its final encounter with land. It's quite close to happening, and NHC is giving it an 80% probability.

And finally, Invest 96L is following in Beryl's footsteps and has a 70% chance of development in the coming week.  It will reach the Lesser Antilles on Wednesday-Thursday, just 2-3 days after Beryl's significant and historical landfall -- a very unwelcome visitor.

The next two names on the list are Chris and Debby.

29 June 2024

Beryl becomes extremely rare June hurricane east of the Caribbean

Invest 95L was upgraded to Tropical Depression 2 on Friday afternoon and then to the second named storm of the season, Beryl, on Friday night.  It is taking full advantage of the September-like conditions in the tropical Atlantic and is now a Category 1 hurricane as of Saturday afternoon...  the furthest east a hurricane has ever formed this early in the year.  It's expected to reach Category 3 intensity by the time it reaches the Lesser Antilles on Monday.

As of Saturday afternoon, NHC is forecasting Beryl to reach the Lesser Antilles midday Monday and then be in the vicinity of Jamaica on Wednesday.  During that trek, it should maintain major hurricane intensity, then perhaps weaken slightly as it nears the Yucatan Peninsula on Friday due to slightly stronger vertical wind shear.  It will still be a dangerous hurricane though... an extrapolated forecast track would be centered near Cozumel by Friday, but as you can see below, the cone of uncertainty would also include areas from Belize up to western Cuba.

This is not normal.  June 30 is early for the first hurricane of the season (technical aside: I say June 30 because as of now, the 18:00 UTC data point in the working best track is 60 kt, a tropical storm... the 00:00 UTC data point on June 30 will be at hurricane intensity).  The last time it happened earlier was in 2012 (Chris on June 21), and the median date over the past fifty years is August 4.  One disclaimer related to this chart: Hurricane Alex occurred in January 2016, but I don't count that as part of the 2016 season; it was meteorologically a late-comer to the 2015 season.

As I pointed out yesterday, there has been just one hurricane formation east of the Caribbean in June, and that was during the all-time record-breaking hurricane season of 1933.  So to say this is extremely rare is an understatement.
Two things could really make Beryl extraordinary if it reaches at least Category 3 ("major hurricane") intensity by Sunday evening: 1) WHERE it's happening and 2) WHEN it's happening.  Since records began in 1851, there have been only two known major hurricanes to occur prior to July 7 and they were both in the Gulf of Mexico:
    - Alma (June 8, 1966)
    - Audrey (June 27, 1957)
And ZERO major hurricanes have crossed the Lesser Antilles earlier than August 4 -- that was the infamous Hurricane Allen in 1980.  This would be a little over a month ahead of that incredible record if it happens (which is the official forecast).

So, back to the storm itself.  Beryl is moving over ocean temperatures that are as warm as they'd be at the peak of the season in the second week of September, so there is endless fuel.  Model guidance for intensity has a bit of a spread, but as of now, it seems likely that Beryl's intensity should peak ~ Category 3 on Monday-Wednesday.

Beyond Wednesday, there's also strong agreement in the models that Beryl will continue the same motion, which will bring it into the Yucatan Peninsula on Friday.

Other than Hurricane Beryl, Invest 94L is over the Yucatan Peninsula now and will enter the Bay of Campeche tomorrow where it has a 50% probability of becoming a tropical cyclone before moving back inland over Mexico.  The primary threat associated with this is heavy rain and the resulting flash flooding.

Then, there is another easterly wave right behind Beryl that has a 70% probability of becoming a tropical cyclone within the coming week.  It should be tagged as Invest 96L already, but for whatever reason, it's not.  Through at least the next five days, it looks like it will take the same path as Beryl... very bad news for the Lesser Antilles. It looks like a bit of a mess in the center of this infrared satellite animation, but as we saw with Beryl, that can change quickly when the ocean says it's already the second week of September.

The next two names on the list are Chris and Debby.

28 June 2024

Second named storm, Beryl, likely to form east of Caribbean

Much like last year, the deep tropical Atlantic isn't waiting until August to wake up.  If you recall, Bret and Cindy both formed east of the Lesser Antilles in June last year... we haven't had the B or C storms yet this year, but that could soon change.  (by the way, the next two names on this year's list are Beryl and Chris.)

There are three features of interest peppered across the deep tropics: Invest 94L is located in the far western Caribbean, Invest 95L is located about 1500 miles east of the Windward Islands, and an untagged disturbance is just east of that and is located about 2400 miles east of the Windward Islands.  As of Friday morning, the National Hurricane Center is giving these a 30%, 90%, and 20% chance of development within the week.  Invest 95L is poised to become Tropical Storm Beryl this weekend, if not sooner.

If you're thinking this seems like a lot of activity to watch in the tropics for June, you'd be right.

Something that is catching a lot of attention is the ocean heat content (OHC) averaged across the Main Development Region (MDR) -- the MDR term was defined about three decades ago to be the slice of the Atlantic from 10-20°N and stretching from Central America to Africa, and it is where the vast majority of major hurricanes develop.  The ocean heat content is a measure of the heat stored through a depth of the ocean, as opposed to the sea surface temperature which as the term implies, is only at the surface.  Alarmingly, as of today, the MDR-averaged ocean heat content is not only a record for the date again, it's where it typically would be during the first week of September.  This means the ocean out there already thinks it's the peak of hurricane season, yet it's more than two months away.


I'll first focus on Invest 95L, or soon-to-be-Beryl.  This is a potent easterly wave that exited the African coast on June 25 and has been cruising westward at 15-20 mph. It will continue to track westward and will reach the Lesser Antilles on Monday, likely as a hurricane.  For reference, the climatological date of first hurricane formation is August 11.

As Michael Lowry recently pointed out on Twitter, the only other time a storm became a hurricane east of the Caribbean during June was in 1933, the all-time blockbuster hurricane season.


Once this enters the Caribbean on Monday, there's high confidence it will continue westward through the Caribbean, reaching Central America or the Yucatan Peninsula next Friday.  In global model ensembles, there are a few outliers that take it further north, but the trend has been whittling away at those outliers.


Invest 94L will pass over the Yucatan Peninsula later today and into Saturday, then emerge into the Bay of Campeche where it will have about one day to develop.  While development into a tropical cyclone is unlikely, it will be a major rain producer in the same areas that got a lot of rain from Alberto a couple weeks ago as it movers ashore near Tampico, Mexico on Sunday evening into Monday. 

The easterly wave that's east of Invest 95L is somewhat favored to develop by the global models, and it's also likely to track west toward the Lesser Antilles, reaching the islands just a couple days after it (Wednesday or so).  Their proximity to each other complicates the forecast, so for now, it would be prudent to see what 95L does before looking too close at what this will do.  Furthermore, there is a large Saharan dust plume immediately north of these two features, so that could also play a big role if any of the dry dusty air gets ingested into their circulations.

Enhanced satellite image of the Atlantic showing clouds in gray and dry/dusty air in shades of yellow to red.

21 June 2024

Two disturbances to watch in the coming days

As a brief follow-up since my previous post on Monday, the season's first named storm, Alberto, did indeed form in the southwest Gulf of Mexico on Wednesday, then drifted westward into Mexico... making landfall near Tampico as a tropical storm.

Today, there are two more systems of interest, one headed for Florida/Georgia and one expected to form in the same area and fashion as Alberto did.  The one headed toward Florida is tagged as Invest 92L.  Fortunately, neither one is expected to intensify much, but another round of heavy rainfall will be a huge concern with the one following in Alberto's footsteps.

A radar animation of Invest 92L from the Jacksonville NWS radar is shown below, spanning the morning hours from 4am-9am.

This disturbance is getting more organized by the hour, but is rapidly running out of time before it's over land.  However, model guidance shows that it will get picked up by an approaching trough and *could* be back over the ocean (including the warm Gulf Stream) early next week where it has an even better chance of becoming a tropical cyclone.  That is, if there's anything left of it after 2-3 days over land.

Shifting our attention 1000 miles to the southwest, another disturbance is brewing over the Yucatan peninsula and the National Hurricane Center is giving it a 60% probability of becoming a tropical cyclone in the next seven days.  As I mentioned in the beginning, the evolution and track of this system will very closely mimic what we just saw with Alberto.

The next couple of names on the list are Beryl and Chris. Tidbit: the first five names on this year's list are all original from the 1982 list when they were first used (there are six lists of names that get reused).  So, Alberto, Beryl, Chris, Debby, and Ernesto were all used in 1982, 1988, 1994, ..., and 2024.  This year, we have two new names on the list: Francine and Milton.  They replace Florence and Michael which were retired after the 2018 season. 

17 June 2024

Season's first named storm could form this week

Atlantic hurricane season officially began on June 1, though it has been fairly quiet so far.  There are a couple of areas of interest now: one headed toward the southeast U.S. coast with a low chance of formation (30%), and one in the southern Gulf of Mexico with a high chance of formation (70%).  If the Gulf of Mexico system reaches tropical storm status, it would take the first name on this year's list: Alberto.

Evident in the infrared satellite animation below is the very disorganized appearance of the eastern one north of Puerto Rico and the huge envelope of moisture and thunderstorms slowly coalescing around a deepening low pressure in the Bay of Campeche.

The models are not in great agreement over what happens, but they do agree on the big picture.  The western system in the Gulf of Mexico will slowly ooze northward, though may track westward enough to run into Mexico before making it as far north as Texas.

There's minimal support for development of the eastern system, and among the ensemble members that do anything with it, it heads northwest toward somewhere between northern Florida and North Carolina.  It remains weak and as of now does not appear to have a big rainfall footprint associated with it.

Regardless of development into a tropical cyclone, heavy rain from the system in the Gulf will find its way to Texas from Tuesday morning through Thursday morning... this map shows the forecast rainfall totals over the coming week:

Over the past five decades, the median date of first named storm formation is June 15, so we're a tad behind that, and this is already the latest a first named storm has formed since 2014 (that was on July 1).