WxWatcher007

Erin is rocketing along in the tropical Atlantic tonight, and despite a day of convective challenges the system is generating some deeper convection. As of now, Erin continues to tick south of forecast, and models think this south of due west motion will continue for a little longer. This is reflected in the subtle changes in the NHC track, which has ticked south over time. This shift that increased the odds that the Windward Islands, USVI, and PR receive indirect impacts, and depending on the extent and amplitude of the Atlantic ridge, it may have longer term consequences. Currently, the odds overwhelmingly favor Erin recurves before reaching the U.S. east coast. Using the Euro, I want to illustrate why. (sorry about the gif size lol) The models have been trending toward more of an Atlantic Canada risk, but of course we're far from knowing too much that far out.

New England weenies talk crazy in the tropical thread every year

Heat wave achieved here. High of 91.8° so far.

Let him go…you can’t save him

Euro recurves well east of the U.S. coast, but with the trough to the north it pulls Erin into Newfoundland. Again, long way out, but highlights the risk to Atlantic Canada.

I’m not sure it makes a difference at the end of the day with the Atlantic ridge being weakened.

Never to be found in winter

Forgetting Atlantic Canada lol. There’s a 948mb over St. John’s. Is Nick still up there?

Same. Maybe impacts in the Antilles. Perhaps a more direct impact for Bermuda and Atlantic Canada. This does not look like a steering pattern for a direct US impact.

Headlong into it

That’s exactly what a TC would look like in a stable airmass lol.

That HCCA trend is interesting

Continuing to move south of forecast

For our friends in the Antilles, this is increasingly becoming a little close for comfort. Could be some indirect impacts there that become more direct if the south shift continues. To @40/70 Benchmark’s point earlier, that can muck things up if the ridge also ends up trending stronger or the big ULL in Canada is weaker in the long range. Still a lot to sort out here.

Tropical Storm Erin Discussion Number 5 NWS National Hurricane Center Miami FL AL052025 1100 AM AST Tue Aug 12 2025 Erin still has a well-defined low-level circulation, but the convective pattern has degraded since overnight, with only a band of moderate convection located within the southern part of the circulation. A 1226 UTC ASCAT-C pass showed a maximum wind barb of 36 kt north of the center, and the intensity is held at a possibly generous 40 kt. Most likely, this is a result of Erin's fast motion, which has been south of due west (265 deg) at about 20 kt. The guidance suite indicates that Erin may continue to lose some latitude during the next 24 to 36 hours due to strong low- to mid-level ridging over the eastern and central Atlantic, but overall the general motion should be westward through early Thursday. After that time, indications are that the ridge may weaken over the western and central Atlantic, causing Erin to turn west-northwestward, but there are model discrepancies on when that might happen and where the break in the ridge actually forms. The trend has been for a weaker Erin in the short term and possibly a stronger ridge, and a number of track models, including HAFS-A and -B, HWRF, the European, HCCA, and the Google Deep Mind, have shifted south and west for much of the 5-day forecast. The NHC forecast has shifted in that direction accordingly, and it should be noted that a significant number of deterministic models and ensemble members still lie even farther south. The environment of marginal water temperatures (26-27 deg Celsius) and low atmospheric instability and moisture appear to remain nearly constant for the next 24 hours or so. Therefore, little to no intensification is expected through early Wednesday. The environment and water temperatures become much more suitable for strengthening by 48 hours, and since the cyclone already has a well-defined structure, it could become a hurricane by late Thursday. Continued strengthening is forecast after that time, and the NHC forecast continues to show Erin becoming a major hurricane by day 5 (early Sunday). There is quite a lot of spread in the intensity models, and the NHC prediction is in the upper regime of the envelope, close to the SHIPS model, Florida State Superensemble, and ICON intensity consensus. KEY MESSAGES: 1. Although it is still too early to know exactly what impacts Erin might bring to the northern Leeward Islands, the Virgin Islands, and Puerto Rico, the risk has increased for Erin to move closer to these islands over the weekend. Interests there should monitor the progress of this storm. 2. There is even greater uncertainty in what impacts, if any, might occur in portions of the Greater Antilles, the Bahamas, the east coast of the United States, and Bermuda next week. As we approach the climatological peak of the hurricane season, this is an opportune time to ensure your preparedness plans are in place. FORECAST POSITIONS AND MAX WINDS INIT 12/1500Z 17.2N 36.3W 40 KT 45 MPH 12H 13/0000Z 16.8N 39.1W 40 KT 45 MPH 24H 13/1200Z 16.5N 42.3W 40 KT 45 MPH 36H 14/0000Z 16.6N 45.2W 45 KT 50 MPH 48H 14/1200Z 17.1N 48.3W 55 KT 65 MPH 60H 15/0000Z 17.8N 51.3W 65 KT 75 MPH 72H 15/1200Z 18.5N 54.4W 75 KT 85 MPH 96H 16/1200Z 19.8N 60.3W 90 KT 105 MPH 120H 17/1200Z 21.4N 65.0W 100 KT 115 MPH $$ Forecaster Berg

That's a lot ot get rid of lol

You don't need to look far to see why Erin is struggling convectively this morning. First, it's still in a marginally favorable SST environment Second and more important, it is plowing into an area of drier, more stable atmospheric conditions--something that was anticipated days ago. The microwave image I posted last night was illustrative of its organization, which still exists this morning. Note the well defined center and its symmetrical nature. Note also the more stable conditions to its northwest. This should keep Erin in check for a bit, but given the internal organization, if that doesn't fade once this finds a more favorable environment it should still be primed to ramp up. As for track, I still think it's highly unlikely to directly impact the US coast, but Atlantic Canada should be monitoring more closely.

The maritimes have been on a generational run. Seriously.

And once the system becomes convectively active again (as it did last night in the southern part of the system) we’ll have to see if that tugs the LLC in one direction or another temporarily.

It’s underdispursive but you get the picture.

I know tropical is an imby sport to most here, but some do forget that we have Atlantic Canada posters too. While the pattern isn’t conducive for the EC, the maritimes have more wiggle room and NS and especially Newfoundland are still squarely in watch territory right now. The exact parabolic curve matters to them.

I mean…this says it all.

Pretty well organized despite the marginal SSTs

The Atlantic ridging may actually be doable. Erin has been south of modeled so far and the trend toward a stronger ridge seems to have some legs (though the GFS was always underdoing it imo). The issue is later--that UL steering pattern over the EC in the long range is anything but a NE landfall look--as folks have said. If that massive trough in Canada can be blunted and the ridging in the Atlantic continues to look stronger...then maybe we're talking.

The trend today has been a further south track and that seems more plausible given the convective trend tonight with Erin but generally agree. Still a long way to go.