Ernesto getting together while moving through the islands, an eventual threat to Bermuda

Headlines

  • Ernesto is moving through the northeast Caribbean as a moderate tropical storm.
  • It may strengthen into a hurricane as it approaches or passes the Virgin Islands and east of Puerto Rico.
  • Impacts to Puerto Rico will be mainly heavy rain and flooding on the south and east sides of the island.
  • Impacts could be a bit stronger for the USVI, Vieques, and Culebra.
  • Ernesto will then possibly take aim at Bermuda heading toward the weekend.

Ernesto making an effort to intensify

Tropical Storm Ernesto is working through the far northeast Caribbean this afternoon, strengthening in the process. Currently, Ernesto has 50 mph winds and is located just south of St. Kitts and Nevis.

Ernesto wiggling its way toward the Virgin Islands this afternoon (Tropical Tidbits)

Over the next 12 to 24 hours, Ernesto is going to track west northwest toward the Virgin Islands, Culebra, and Vieques. Hurricane Watches have been issued for the US & British Virgin Islands, as well as Culebra and Vieques. Puerto Rico remains under a Tropical Storm Warning, as are a number of other islands in the Leewards. Given the atmospheric conditions surrounding Ernesto, it’s possible that this could become a hurricane in the next 18 to 24 hours as it approaches and passes the islands east of Puerto Rico. By tomorrow afternoon. Ernesto will be north of the islands and conditions will improve.

In terms of impacts, the main threat is probably still rainfall.

Heavy rainfall will impact Puerto Rico and nearby islands to the east, with upwards of 8 inches and flash flooding a good possibility. (NOAA WPC)

Flooding is a good bet on parts of Puerto Rico, mainly on the south and east coasts of the island. Additional heavy rain may impact the US Virgin Islands, Vieques, and Culebra. Lesser heavy rains will impact the British Virgin Islands and other portions of the northeast Caribbean. Obviously, wind will be a bit of an issue, especially north and east of where the center tracks, hence the hurricane watches for the islands just east of Puerto Rico. And rough marine conditions will continue in the northeast Caribbean through tomorrow.

Bermuda bound?

Beyond the Caribbean, Ernesto is likely to turn northwest and then northward, steering clear of the Turks and Caicos Islands, but tracking toward Bermuda. The threat to Bermuda is a potentially serious one. We can examine that closer in the days ahead, but at this point, suffice to say model agreement is good on a track that brings Ernesto very near Bermuda as a hurricane in about 4 or 5 days.

Ernesto is likely to be in the vicinity of Bermuda in about 5 days, with uncertainty in the exact track taking over beyond that point. (Tropical Tidbits)

There are some questions as to how strong Ernesto will get as it tracks toward Bermuda, with the current official forecast keeping it just shy of major hurricane intensity. Modeling has backed off a bit on the high end of intensity as well, but there is always a chance that Ernesto could outpace model forecasts in terms of intensity in the next few days. So for folks in Bermuda, it’s probably a good time to start reviewing your hurricane plans with Ernesto sending a pretty clear message this far in advance.

Beyond Bermuda, there are questions as to exactly how Ernesto is steered which could have implications for Atlantic Canada in time. We’ll review that in more details as we get into tomorrow and Thursday.

The rest of the tropics are quiet with no threats noted.

Impacts in the islands from Ernesto should be mostly manageable as it passes through

Editor’s note: PTC 5 is now Tropical Storm Ernesto, which has little to no impact on the discussion below, as this was expected today or tomorrow.

Headlines

  • Potential Tropical Cyclone 5 will slowly organize itself over the next 2-3 days as it crosses into the northeast Caribbean islands and Puerto Rico.
  • PTC 5 is expected to deliver mostly modest impacts to the islands, with gusty winds, rough marine conditions, and heavy rainfall.
  • As PTC 5 comes north in the Atlantic, it will strengthen and may ultimately threaten Bermuda.
  • Quieter conditions should continue behind PTC 5.

PTC 5 will slowly get itself together

Potential Tropical Cyclone #5 was declared on Sunday, which allows the National Hurricane Center to issue watches and warnings before a storm becomes an actual storm. In other words, we are expecting a tropical depression or tropical storm soon although it’s not there yet, but we need to get warnings out. Thus, the slightly cumbersome PTC language.

PTC #5 forecast track as of Monday morning showing a tropical storm in the islands and a hurricane to the north. (NOAA NHC)

Whatever the case, we are definitely expecting this system to gradually organize as it moves into the islands. If there’s good news today, it’s that models continue to slow walk development initially, despite the fairly warm water across the northeast Caribbean. So a slow transformation into a tropical storm is expected in the next 24 hours. By tomorrow morning, we expect Ernesto and its center to be just west of Guadeloupe. Tropical storm warnings are in effect between Guadeloupe and Puerto Rico.

It would appear on satellite that PTC 5 is battling a good deal of wind shear. It’s not quite consolidating, and while it has a lot of thunderstorm activity overall, it’s generally disorganized.

PTC 5 is loaded with thunderstorms, but at least on satellite it appears to be fairly disorganized, lacking the consolidation needed to be classified as a tropical storm at this point. (Tropical Tidbits)

Modeling suggests that over then next 24 hours or so we won’t see a whole lot of change to this. In that time, we should see PTC’s nascent center move into the northeastern Leeward Islands. While certainly a bit breezy and with some heavy rain, impacts there will probably fall short of anything too terribly serious. Around that time, we should begin to see PTC 5 begin to make a run toward a little organization as it approaches the Virgin Islands and Puerto Rico heading into the 36-48 hour timeframe. This system’s size seems to make it unlikely to become a hurricane now as it moves into that area.

PTC 5 should only slowly organize as it moves past the Leeward Islands and into the Virgin Islands and Puerto Rico. (Weathernerds.org)

So at this point all signs seem to indicate that PTC 5 will only slowly organize as it impacts the northeast Caribbean islands and Puerto Rico, staying under hurricane intensity until it gets comfortably north of Puerto Rico. The islands should again prepare for heavy rain and gusty winds, as well as rough marine conditions, but overall this looks like a mainly modest impact to these locations.

Rain totals from PTC 5 should be around 4 to 6 inches, though higher amounts are likely in portions of Puerto Rico and on Vieques. (NOAA WPC)

Beyond this point, PTC 5 will continue to likely curve northwest and northward, splitting the gap between high pressure over the Deep South and high pressure east of Bermuda. From here, we have two key questions: How strong does this storm get, and how close will it get to Bermuda? We can’t answer either one with a lot of certainty yet, but it’s pretty evident that this will be a very close call near Bermuda. We have a couple days to iron that aspect out.

In terms of intensity, the tropical models are all over the place, but they all show steady strengthening it appears.

Intensity guidance among the various models is very much all over the place, but in general shows steady intensification in the day 2 to 5 timeframe, suggesting PTC 5 will become a hurricane between the Caribbean and possibly Bermuda. (Tropical Tidbits)

The NHC forecast is a fine place to be right now, which shows PTC 5 on the cusp of major hurricane intensity by day 5. So because of all this, it would be important for folks in Bermuda to monitor the progress of PTC 5/Ernesto closely. We’ll keep you posted.

Beyond PTC 5, we continue to see the Atlantic basically shut itself down for the next 7 to 10 days. Don’t get too excited about that quieter period, but let’s just say during a hurricane season like this that has a lot going for it, that is a very welcome thing in August.

Invest 98L may stir up some trouble in the northeast Caribbean before likely turning out to sea

Headlines

  • Invest 98L is likely to develop in the next couple days as it tracks toward the northeast Caribbean.
  • Interests between Puerto Rico and Guadeloupe should be preparing for at least a tropical storm impact.
  • There is a chance that 98L could become a hurricane as well before it likely exits the northeast Caribbean and turns out to sea.

Invest 98L: A concern for the northeast Caribbean

We have been greeted this morning by a 90 percent chance of development in the Atlantic from now-dubbed Invest 98L.

Invest 98L is likely to develop in the next day or so as it tracks toward the northeast Caribbean islands. (NOAA NHC)

Looking at 98L this morning, it’s clearly slowly organizing east of the islands. That said, it’s a relatively large tropical wave, so this process is taking its time.

Invest 98L is spinning east of the Caribbean islands, but it’s only slowly organizing. (Weathernerds.org)

Relative to Friday, the expectations for 98L have not changed a whole heck of a lot: We still expect development as it comes toward the Caribbean, and interests in the Leeward Islands, Virgin Islands, and Puerto Rico should be monitoring the progress of 98L very closely.

Here’s what we know today:

  • Invest 98L is probably going to turn northwest and north and head into the open Atlantic after passing through the northeast Carribean.

Is there a chance it misses the exit ramp? Sure, but that’s not likely at this time. The odds of development are such that 98L is probably going to start to slowly gain latitude as it approaches the Leeward and Virgin Islands, followed by more rapid development after it passes. This should be enough for it to find its way “into” the rather strong trough off the East Coast. The forecast map below is the European model forecast for Tuesday, with a strengthening 98L or Ernesto likely to brush across the northeast Caribbean islands and into the trough off the East Coast.

The upper pattern should allow a strengthening tropical system to be “captured” by the trough off the East Coast around midweek, causing it to turn northward and off the East Coast. (Tropical Tidbits)

In a low likelihood situation, 98L would not develop much and could end up “trapped” in the northeast Caribbean, eventually forced back west or west-southwest by high pressure over the Deep South. That would change the equation entirely, but at this point there is little to no model support for that outcome.

In general, the hope is that once this passes the Caribbean islands, it will (mostly harmlessly) go out to sea

  • Invest 98L is likely to begin wrapping itself up *as* it moves into the northeast Caribbean islands.

Where it really gets tricky is what 98L/Ernesto’s intensity will be as it moves into the northern Leewards, Virgin Islands, and off Puerto Rico. At this point, it seems reasonable to say that a developing tropical storm will be moving through those areas by later Tuesday and Wednesday. Could this quickly intensify into a hurricane? I would not rule it out.

There is moderate to strong oceanic heat content in the area 98L is expected to track in the next couple days. This could help fuel steady strengthening as it moves into the northern Leeward Islands or Virgin Islands. (University of Miami)

The system is going to track through some decent areas of oceanic heat content in the next couple days. This, coupled with low wind shear should provide ample fuel for strengthening as it comes through. The biggest limiting factor in development of this system may be some dry air and lingering Saharan dust in the area of the disturbance as it wraps up.

  • The track into the northeast Caribbean will be tricky in terms of exactly what islands are hardest impacted.

Because of the track and turn of 98L as it comes west, the timing will be everything in determining which islands see the worst impacts from this system. Interests from Guadeloupe into the Virgin Islands should be watching this very closely and currently preparing for at least a stronger tropical storm impact. If 98L really wraps up quickly, then Puerto Rico and the USVI may not see much in the way of direct impacts. If the strengthening is more steady or slower, the odds of impacts there increase. We should hopefully get a little more clarity on this tomorrow, but I’d encourage that whole strip from Puerto Rico into about Guadeloupe to prepare accordingly.

Hopefully once past the islands that’s it for this one, but we’ll keep an eye on things.

More to come? Maybe not.

Behind 98L, there aren’t a whole lot of seedlings for development for now. The Euro says that in about 8 to 10 days we have another opportunity. It would appear that an extremely hostile background state in the atmosphere is going to track across the Atlantic over the next 10 to 14 days, with a lot of suppression and sinking air. This usually works against tropical development, so it’s possible we end up seeing a later August lull this year. I would caution that we’ve seen systems kind of materialize in the day 6 to 12 timeframe this season that didn’t necessarily appear like strong candidates initially. While it should be quiet for a bit, just keep that in mind.

I’ve already seen comments about this season possibly being a bust, which is understandable. But keep in mind that we still have about 90 percent of a typical hurricane season in front of us from an intensity standpoint, and between Beryl, Debby, and probably soon Ernesto, this will end up being one of the most intense starts to a hurricane season on record. Sometimes it’s quality, not quantity.

As Debby departs, we check on the odds of the next Atlantic wave becoming Ernesto

Headlines

  • Debby is causing localized catastrophic flooding in parts of northern Pennsylvania and the Southern Tier of New York.
  • Debby’s remnants will exit into Canada tonight, bringing more flooding risks to Quebec, including Montreal, as well as northern New York and northern Vermont.
  • The next wave has increasing development odds in the Atlantic.
  • While no development is expected before Monday, interests in the Leeward Islands, Puerto Rico, and Virgin Islands should monitor this wave’s progress closely.

Debby on the way out

Debby, no longer a tropical storm, is exiting to the north today, but not before leaving more destruction in its wake. Several flash flood emergencies are ongoing in Pennsylvania and New York this afternoon as Debby’s rains lead to damaging flooding, including reports of rooftop rescues and numerous trapped people in Westfield, PA.

Debby’s remnants lifting through Upstate New York this afternoon. (College of DuPage)

Debby’s remnants will move into Canada and bring more flooding rain, with rainfall warnings hoisted for much of southern Quebec and parts of New Brunswick as well. Portions of northern Vermont, very vulnerable to rainfall are also under a flood watch as Debby’s rains move that way. Isolated tornadoes are possible as well.

Watching the next wave’s development odds increase

As I noted yesterday, I felt that the 30 percent odds of development from the next Atlantic wave were going to increase. A little over 24 hours later, and those odds are now doubled up to 60 percent.

The next tropical wave is up to 60 percent odds of development by next week. (NOAA NHC)

The tropical wave itself is not much to look at today, just an area of clouds, showers, and thunderstorms in an otherwise rather dusty Atlantic. You can see it east of the islands on the satellite image below.

The next wave looks disorganized but holding thunderstorm activity as it rambles west across the Atlantic. (Weathernerds.org)

The first thing I can tell you about this one is that we do not expect any development probably before later Monday. So we have a couple days yet before this gets started. So for folks in the islands, this will probably not be bearing down on you as a big storm; it will probably just be getting organized as it arrives. Whatever the case, by Monday, we have a tropical wave on the cusp of organization, arriving just east of the Lesser Antilles and Virgin Islands.

The tropical wave will be arriving near the islands on Monday afternoon or evening, just likely beginning the process of development. (Pivotal Weather)

From here, the ballet begins. High pressure over the Southern U.S. and Texas, a trough digging into New England, and high pressure in the Atlantic will compete as this wave develops to help steer it. The current majority of modeling suggests this will develop steadily enough that it will probably go north in the islands and eventually into the open Atlantic. However, given that we’re about 6 days or so out from that happening and the inherent uncertainty from an undeveloped system, we can’t say much for sure. Here’s what we can tell you today:

  • The tropical wave is unlikely to develop before Monday.
  • Development may occur steadily, if not rapidly as the system enters the Caribbean or grazes the northeast Caribbean next week.
  • While the model consensus suggests an eventual north turn well off the East Coast, it is far too early to say much about this system’s future track.
  • A Gulf of Mexico track is unlikely at this time but not an impossibility.

I feel like when storms have had an opportunity to come a little farther west than expected this season, they’ve found a way, so I don’t want to write this off for Florida or the East Coast just yet. Right now, folks in the Leeward Islands, Puerto Rico, and the Virgin Islands should be watching this system closely, as once it gets going, it could start organizing fairly quickly. Beyond that, stay tuned this weekend for the latest. We’ll have another update for you on Sunday.