Matt Lanza

Hurricane Erin lashing coastal North Carolina with tropical storm conditions

In brief: Hurricane Erin is passing by the Outer Banks today, and it will begin to accelerate out to sea. Coastal flooding will remain an issue into tomorrow for the East Coast, particularly from North Carolina into New Jersey. Mostly wave impacts for Atlantic Canada, but also perhaps some wildfire concerns there too. The rest of the tropics are noisy, but only one wave bears much watching (Bermuda). Also, the latest on upcoming heavy rains in the Plains.

Hurricane Erin

(NOAA/NHC)

Erin is making its closest approach to the U.S. this morning. The very large storm sits about 210 miles east of Cape Hatteras, and it has begun to turn to the north northeast. The tropical storm-force wind field of Erin extends out over 300 miles from the center. Despite the fact that the storm has weakened to about 105 mph this morning, the hurricane-force winds extend out 105 miles from the center. This is a massive storm.

Erin is large and in charge. (Tropical Tidbits)

A 2 to 4 foot surge on the ocean side of the Outer Banks will be ongoing, coupled with powerful waves. It is expected that this evening’s high tide cycle will be the highest though, with Duck, NC seeing a water level up to about 7 feet, less than a foot below the 2003 Isabel record there and the highest since a nor’easter in 2022.

Tidal forecast at Duck, NC. (NOAA NWS)

Flooding will be minor to moderate on the Pamlico Sound side of the Outer Banks, with downeast Carteret County seeing the worst this evening around 8:30 PM. High water levels are expected to continue into Friday, and it’s likely that some travel will become impossible through today and tonight in the Outer Banks, Ocracoke, and Carteret County.

Even farther up the coast, the tidal flooding will be significant. Cape May, NJ is expecting a peak water level of 8.2 feet this evening, which will be the highest since the “Snowzilla” nor’easter of January 2016. Same goes for Lewes, Delaware.

Tidal forecast at Cape May Harbor (NOAA NWS)

Erin will continue to exit tomorrow, and conditions up and down the East Coast will slowly improve. For Atlantic Canada, the main impact will be rough surf, particularly in Newfoundland and perhaps Nova Scotia, where breaking wave heights could be 3 to 5 meters high. Erin should transition to an extratropical storm by Saturday.

Wildfire concerns?

A minor note, but perhaps a notable one, there will be somewhat enhanced wildfire risk in Atlantic Canada as Erin passes. Note the fire weather danger outlook for today is pretty high to extreme in parts of Newfoundland and even Nova Scotia and New Brunswick.

High to extreme fire weather danger in Atlantic Canada today. (Natural Resources Canada)

Portions of Atlantic Canada remain in severe to extreme drought conditions, so the combination of drier air being wrapped in from the north and gusty winds as the large swath of Erin passes by definitely can enhance fire danger. This is an element of storms that’s now on a lot of people’s minds in the wake of the tragedy in Maui a couple years ago, as a passing hurricane likely contributed some to drier, windier conditions there. Something for folks in Atlantic Canada to be mindful of over the next 2 to 3 days.

Rest of the tropics

The Atlantic is a multi-colored menagerie of disturbances this morning. We have Invest 99L in the central Atlantic, the tropical disturbance approaching the Caribbean islands that we’ve been discussing for a few days now, and a little fella in the open Atlantic.

It’s a party in the Atlantic! (NOAA NHC)

Let’s start from best odds of development to least odds.

The wave approaching the islands with a 70 percent chance of development is looking ragged but stormy today. There’s no sign that this is going to develop quickly, but it’s starting from a pretty decent baseline.

A tropical disturbance approaching the Leeward Islands will bring thunderstorms and locally heavy rain to the northeast islands this weekend. (Weathernerds.org)

This one is expected to pass northeast of the islands, much like Erin did, so the only impacts will probably be some scattered thunderstorms this weekend. It’s hot in Puerto Rico and the Virgin Islands right now, and heat advisories are posted with hot, dry weather and Saharan dust causing hazy conditions. That will change as this passes. From there, it will probably turn straight north toward Bermuda. It seems as though it will turn out to sea before arriving in Bermuda, but interests on that island should continue to monitor this system in the coming days. As you can see below, most European ensemble members miss Bermuda to the east, but it is at least notable that some of the stronger outcomes get a little closer to Bermuda itself. Again, something to monitor at least.

The disturbance near the islands should miss Bermuda to the east, but there are a couple of solutions that are possible that bring it closer to the island. (Weathernerds.org)

We’ll keep tabs on this one.

To the east, Invest 99L continues to percolate west of the Cabo Verde Islands. This wave has looked excellent since emerging off Africa, but it has yet to do anything to get it over the hump yet to become a tropical depression.

Invest 99L looks beefy again this morning, as does the wave behind it, but conditions are expected to degrade for development in the Atlantic in a day or two. (Weathernerds.org)

As 99L comes due west, it’s likely to run into a wall of wind shear. That should kill any chances of organization. The remnant disturbance should continue west toward the southern Caribbean. Typically, it’s a good idea to maintain some degree of vigilance with systems like this, as their ghosts can sometimes be resuscitated once in the western Caribbean. The bulk of what remains of this disturbance may actually end up close to South America, which would essentially wipe out odds of development, even in the western Caribbean. Still, it makes sense to keep tabs on this one in about a week or so, just to ensure it doesn’t pull a fast one on us.

The wave behind 99L is not expected to develop and should remain out at sea.

Meanwhile, the NHC tagged a little one this morning. That one near 30N/50W is kind of comedic looking this morning when viewed next to Erin.

I am reminded of “Aladdin” with this. (Weathernerds.org)

That’s about it. As Eric noted yesterday, after these systems, we don’t exactly have anything noteworthy to home in on. Yesterday’s Euro weeklies suggest below average odds of tropical cyclone development in most of the basin for the week of Aug 24-Sept 1.

Below normal odds of development next week in the tropical Atlantic. (ECMWF)

Notably, these odds turn neutral to perhaps even above normal by mid-September. So the first part of September may be calmer than usual, but we’re clearly not done with hurricane season yet. But this is good news in the nearer-term.

Heavy rain coming to the Plains?

After a somewhat calmer period of weather in the Southern Plains, we may see a return to more active, wetter weather heading toward next week. The WPC has already issued a slight risk (2/4) for excessive rainfall for next Monday.

Flash flooding will return to the forecast potentially by early next week. (NOAA NWS WPC)

Rain totals are currently forecast to be on the order of 2 to 4 inches over the next 7 days, and there could be some locally higher amounts in parts of Kansas, Oklahoma, or Colorado.

Rain forecast for the next week in the southern Plains. (Pivotal Weather)

We’ll keep an eye on this as well.

Erin on track to impact the U.S. East Coast with waves and erosion while we size up the disturbances behind it in the Atlantic

In brief: Hurricane Erin is fighting off some dry air and shear this morning, which has caused it to lose intensity but maintain a large size. Forecast impacts to the U.S. East Coast are virtually unchanged today. Two tropical features in the Atlantic behind Erin are worth keeping tabs on, but none looks to be a serious land threat at this time.

Hurricane Erin

(NOAA/NHC)

Erin has finally hit a bit of a wall since last night in terms of intensity. Maximum sustained winds have dropped to 110 mph. Where Erin has not hit a wall is its size, which remains quite large. For the U.S. East Coast and Outer Banks in particular, this means little has changed since yesterday.

Erin continues to brush the Bahamas and hit the Turks and Caicos with persistent bands of thunderstorms, despite its disheveled appearance this morning. (Tropical Tidbits)

We’ll get the easy part out of the way quickly this morning. Erin’s track forecast remains pretty solid with very little model spread over the next 3 to 4 days as it turns north and eventually northeast. Track forecast confidence is probably a bit higher than usual at 4 days of lead time. There’s a little more spread in the guidance once it gets south of Newfoundland, but all modeling currently keeps it well offshore.

Erin’s intensity forecast is a little trickier. Given the look this morning, with dry air wrapping into the storm and exposing the core, I have to think that Erin is embarking on a long road down. We could see some reintensification once Erin starts to pick up a little more speed. But I think the question is how much weaker it gets in the near term. Erin isn’t in a hurry right now, and it may be churning up relatively cooler water underneath the ocean. Between that and dry air, it’s just flat at this time. Whatever the case, Erin is likely to remain somewhat flat today, with some chance of reintensifying tomorrow and Thursday as it marches north. Erin will then slowly transition into a non-tropical (extratropical) storm by late in the weekend and it begins to accelerate out to sea.

Erin’s impacts remain mostly unchanged. We’ve now got Storm Surge Watches and Tropical Storm Watches on the North Carolina Coast.

(NWS Morehead City)

Wind gusts of 50 mph will be possible on the Outer Banks and in Pamlico Sound. The wave action and higher tides will be what causes extensive damage, likely damaging vulnerable coastal buildings and perhaps even Highway 12. While the surge forecast itself is not eye-popping (2 to 4 feet), in this area, when combined with the waves, that’s more than enough to cause damage. North winds will peak Soundside flooding on Thursday.

(NWS Morehead City)

As we’ve been hammering since the weekend, in addition to the storm impacts on the Outer Banks, waves, tidal flooding, and rip currents are going to impact much of the Eastern Seaboard, causing beach erosion and making swimming challenging, if not dangerous the next several days.

Rip current risk is high the next two days from about West Palm Beach through Block Island. This will continue farther north Thursday and Friday. (NOAA NHC)

Rip currents kill over 100 people each year. These are avoidable deaths. Please heed all flags and warnings this week.

Wave trailing Erin + Invest 99L

Looking at satellite this morning, it’s kind of interesting that the wave we’ve been monitoring for the last few days looks far less impressive than the new one behind it. In fact, that wave near the Cabo Verde Islands is termed Invest 99L. For those curious, now that we’re at Invest 99L, we will recycle the list of Invests. So whenever the next system comes around, it will be tagged 90L. It’s entirely possible that the wave ahead of 99L gets tagged 90L at some point. Whatever the case, here they are.

The wave west of the Cabo Verde Islands is mostly unchanged today and has 60% development odds, while the wave closer to Africa looks very impressive. (Weathernerds.org)

Over the next 2 to 3 days, it is expected that Invest 99L will actually weaken, while the wave in front of it will actually strengthen. As the leading wave strengthens while moving west, it will probably begin to get drawn into the weakness in upper-level ridging left behind by Erin. You can see that by looking at the upper-level weather map on Thursday evening. The leading wave is approaching the islands. Between Erin’s proximity to the north and the weakness in upper ridging left behind, this wave should turn northwest near the islands.

The upper pattern late Thursday shows the next tropical wave (not Invest 99L) in position to turn more northwesterly, following Erin just to the east. (Tropical Tidbits)

Both AI modeling and the Euro ensemble members today favor a sharper turn north, which would draw it on a track east of where Erin is going. I would say this is worth keeping an eye on for the islands and for Bermuda at this point. A long way to go still with this one.

So what about Invest 99L? Well, I’m always leery about waves like this one. As noted above, it should begin to fall apart in a day or two, so any development risk is short-lived in the near-term. But because it falls apart and stays relatively weak or undeveloped, it’s likely to sneak under everything going on to its north and west. This means it will probably ultimately find the Caribbean. From there, it’s anyone’s guess, but interestingly, virtually all modeling (except the GFS operational of course) basically keeps the wave a suppressed, weak feature into Central America. Either way, it’s at least 10 days from probably doing anything, so we have plenty of time to watch and it’s nothing anyone needs to worry about right now.

Hurricane Erin to bring significant coastal impacts to the Outer Banks as it passes offshore this week

In brief: Hurricane Erin will continue to impact the Turks and Caicos and southeast Bahamas today. It remains on course to head out to sea, but it’s likely to cause significant impacts in the Outer Banks and widespread coastal flooding, beach erosion, and rip currents along the East Coast. Meanwhile, the next wave behind Erin is too early on to worry about, though it will be worth watching this week.

Can I just interject for a minute before we get into today’s post? I must be a glutton for punishment, as my “new tabs” in Microsoft Edge show up with completely absurd news headlines. Though this time of year, it becomes more entertainment than anything. For example, according to the Irish Star:

Completely absurd headlines

Let’s simply ignore the fact that the storms that will “batter Florida” are of the typical summertime variety, completely unrelated to Erin. Much to everyone’s relief, I did read the article, and I still don’t know what the “the worst” is that the experts fear. European tabloids are a contact sport, so I’d expect nothing less, but anyway, it’s little things like this that justify The Eyewall’s existence.

Hurricane Erin

Alright, onto the serious matter at hand, which is Hurricane Erin.

(NOAA/NHC)

Erin is back up to category 4 intensity this morning, with maximum sustained winds of 130 mph. It sits just north of the Turks and Caicos Islands. Erin has continued to grow in size since yesterday. The tropical storm-force wind field extends out 230 miles now. Hurricane-force winds have more than doubled in size, now extending out 80 miles from the center. This places Erin in the 80th percentile of major hurricanes in terms of size. In plain language: Bigger than usual.

A buoy about 150 miles northeast of Erin has been reporting wind gusts of 50 mph or better. (NOAA)

Erin remains a very formidable and growing hurricane. Tropical storm conditions will continue today in the southeast Bahamas and Turks and Caicos Islands, where Tropical Storm Warnings remain posted. A Tropical Storm Watch is now posted in the Central Bahamas.

Hurricane Erin emerges from nighttime this morning. (Weathernerds.org)

Erin is likely beginning another period of intensification this morning that may continue into this evening. After that, Erin will likely begin to feel some impacts of wind shear in the area that will slowly erode at its intensity. Erin should remain a category 3 or stronger hurricane through Wednesday, however.

For the southeastern Bahamas, Turks and Caicos, and Hispaniola, squally weather will continue today and tonight. By tomorrow, Erin should finally begin to move away, allowing conditions to improve some.

Beyond the Bahamas, Erin’s track forecast has continued to nudge slightly westward, though not as much as it had this weekend. Erin will remain off the Southeast coast and split the difference between the Outer Banks and Bermuda on its way off to the north and eventually northeast.

Forecast maximum wind gusts on the North Carolina coast and Outer Banks midweek as Erin passes. (NWS Morehead City)

As Erin passes the Outer Banks, tropical storm-force wind gusts will be likely, perhaps approaching 50 mph just offshore. While those wind gusts will be a bit of a nuisance, they aren’t anything too terrible for this area. However, the waves and rip currents will be a big problem. Based on the latest forecasts, this will be a prolonged event for the area with several days of difficult, if not impossible travel along NC-12 for Hatteras and Ocracoke Islands. Heed the advice of local officials in these areas.

Higher than normal tides, beach erosion, and powerful waves will create a very challenging situation on the Outer Banks this week. (NWS Morehead City)

Conditions should be at their worst late tomorrow into early Thursday before slowly easing up. Rip currents and rough surf will be a developing issue up and down the entire East Coast this week. Rip current statements are in place from West Palm Beach northward already. Basically, swimming won’t be advisable, as even the strongest and best swimmers can’t always overcome strong rip currents.

(NWS Mount Holly/Philadelphia)

Tidal flooding will also be an issue up and down the East Coast, with coastal flood advisories or statements posted as far north as Long Island.

Bottom line: Hurricane Erin will directly impact the Turks and Caicos Islands and Southeast Bahamas today. As Erin passes offshore, rip currents, rough surf, beach erosion, and tidal flooding will be a concern from as far south as Florida into the Carolinas into New England.

Eventually, some of these wave issues will make it to Atlantic Canada as well toward the weekend.

Next wave up

The next tropical disturbance is a nascent wave west of the Cabo Verde Islands.

The next tropical wave will make an attempt to organize later this week as it comes west across the Atlantic. (Weathernerds.org)

We have a ways to go here with this one, but I suspect we have an invest area out of this wave by tomorrow. The math on this is pretty simple, but deriving the equation is still very challenging. We know that a weaker tropical wave would probably continue west or west-northwest toward the Caribbean. Basically, if this doesn’t do much in the way of developing, it will probably continue to sneak westward. Alternatively, if it develops quickly as it comes across, or at the speed of Erin’s early organization, it would probably turn northwest and north and follow Erin out to sea. By the time we get to the weekend, we will see if this thing is farther south, closer to the islands, or more out into the open Atlantic, as most AI modeling seems to favor.

By the weekend, the next wave will be somewhere between the Caribbean and the open Atlantic, with a wide possibility of potential outcomes. AI modeling is skewed more to the north and east, while traditional ensembles are all over the map. (Google Weather Lab)

We have a long way to go with this one, but it’s not currently worth worrying about. Just check in daily for updates. We’ll keep you posted.

Hurricane Erin growing in size, likely to cause dangerous rip currents and rough surf on the East Coast

In brief: Erin is weaker but larger today. As the wind field continues to expand and Erin reintensifies, look for significant impacts on the East Coast from rip currents and rough surf. Near term tropical storm impacts will affect the southeast Bahamas and Turks and Caicos Islands. Fringe impacts remain possible later this week for the Outer Banks, Bermuda, and Newfoundland.

(NOAA NHC)

Erin underwent an eyewall replacement cycle (ERC) overnight. An ERC is essentially a way for a storm to press the reset button while it’s at a powerful intensity. A new eyewall forms on the outside of the original eyewall, allowing the storm to expand in size. The trade-off is that when an ERC occurs, the storm loses intensity. Then, typically it will begin to reintensify. In Erin’s case, it weakened from a category 5 to a category 3 storm this morning, and now it should undergo another round of intensification.

24 hour change in satellite presentation of Erin from Friday to Saturday to Sunday. (College of DuPage)

If you look at the satellite imagery above, you’ll see Erin pretty clearly near the Caribbean islands. You can see how ragged it looked on Friday morning, how potent it looked on Saturday morning, with a very, very clear eye. But if you look close enough, you can see how it expanded in size today. Erin’s tropical storm-force wind field has expanded markedly since yesterday. It went from a 125 mile radius yesterday to 205 miles today. Hurricane-force winds remain relatively tightly wound to the center, only extending out 25 miles. The ERC will most often expand the tropical storm wind field, making the storm a bigger surge and wave maker than anything else. Whatever the case, expect Erin to remain a major hurricane the next 2 to 3 days with winds fluctuating between category 3 and 4 intensities. More importantly, Erin could continue to slowly grow in size.

Track is becoming a little more important to potential outcomes for various locations. Starting in the near-term, the Bahamas and Turks and Caicos Islands are likely to experience tropical storm conditions today and tonight. Tropical Storm Warnings are posted for the Turks and Caicos, and a Watch is posted in the southeast Bahamas. That could get upgraded to a warning before too long. Heavy rain and gusty winds in those outer bands, much like we’ve seen in Puerto Rico since yesterday will be possible.

Erin’s track has slowly migrated a bit to the south and west. Coupled with size expansion, this may mean some additional impacts in the Outer Banks or Atlantic Canada, as well as Bermuda. (Brian Tang/UAlbany)

The consensus track from the top performing models has been correcting south and west really since Erin formed, but also over the last day and a half or so too. This adjustment is leading to some slightly increased concerns for the Outer Banks of North Carolina in particular but also perhaps Atlantic Canada, particularly Newfoundland. First off, you can see how the wave forecast will go this week. Large waves begin pounding the East Coast Tuesday, peaking on Wednesday and Thursday, and then diminishing next weekend.

Large waves will propagate outward from Erin, beginning to reach the U.S. East Coast by Tuesday. (Weathernerds.org)

Suffice to say, this will make for very poor conditions at the beach. Anyone planning to visit the beach or go swimming this week from Florida into New England should give second thought to doing much in the ocean through at least Friday. If you do go swimming, please head all flags and posted signs and only swim where lifeguards are present. Between the rough surf and very dangerous rip currents, it will become straight up unsafe at times, even for stronger swimmers.

In terms of whether or not we see any direct impacts, or at least fringe bands make it to the Outer Banks, it’s very much a wait and see situation. If the current forecast holds unchanged, maybe not much more than gusty winds at times. If the trend west continues further, we will begin to say that gusty winds, possibly tropical storm force gusts, and locally squally conditions will become more likely. We’d encourage folks in eastern North Carolina, particularly on the Outer Banks to continue to watch Erin closely. This area is pretty used to hurricane impacts, but as always, keep an eye on things to be safe.

Down the road for Nantucket and Cape Cod, it seems likely that Erin will pass far enough offshore to avoid impacts. Probably still right to keep tabs on any changes. And then heading toward Newfoundland, if Erin impacts that area, it would not be until next weekend. Plenty of time to watch and still most likely just a brush by. For Bermuda, Erin may also cause a brush-by of impacts as it comes north.

Bottom line: The most serious impacts in Erin’s future will likely be rough surf and rip currents on the East Coast, but there is growing consensus that some fringe impacts will affect the Outer Banks, Bermuda, and possibly Newfoundland before all is said and done.

Behind Erin

I’ve already seen the “usual suspects” on social media move on from Erin “fear porn” to the next system. The NHC has assigned this one a 20 percent chance of development over the next week in the eastern Atlantic.

Development odds sit at 20 percent today for the next system that will follow Erin across the Atlantic this week. (NOAA NHC)

Admittedly, I think the odds of development are truthfully higher than this. I would expect we see an attempt at a tropical depression by Wednesday or Thursday. This system is likely to come west across the Atlantic at a slightly farther south latitude than Erin did. So in some ways, this should be a little sneakier. If we look at the upper map that this disturbance will be working around, we can see a couple key things. First, Erin is going to erode high pressure in the subtropical Atlantic. This will keep a pretty stout weakness in place there. If this next wave is quick to develop, it would almost certainly follow Erin to the north in the open Atlantic. However, there is another pretty strong trough of low pressure in the upper atmosphere expected to dive southeast into the Eastern U.S. after next weekend. If and when this occurs, it would also be likely to “capture” this next wave.

The next wave has a couple opportunities to be picked up and pulled northward. Questions remain as to what shape it will be in if that happens, or if it will even develop at all. (Tropical Tidbits)

Of course, this all matters. But it’s too soon to speculate on how it matters. Generally speaking, the quicker this is to form, the quicker it would be to exit. The slower it is to develop, the higher chance it may become a disturbance of land impact eventually. But there remain questions on if this will be able to develop a whole lot at all. AI modeling strongly supports the “follow Erin out to sea” outcome. European modeling is less sure but also less bullish on development. The GFS is literally all over the map, ranging from the Gulf to east of Bermuda. So, we have a couple thoughts here, but we’ll need to watch things over the next few days before we can begin to say anything with any degree of confidence. Stay tuned.