These were the individual European Ensemble solutions from the last 0z solution.

1. Day 7

2. Day 10

3. Day 12

4. Day 15

Thanks, Mike!

 At this point, it is a higher threat to Bermuda than to the US. But it’s still early. Regardless, this is projected to become a large ACE producer.

Thanks, Larry!

Pretty strong system when it matures, even though the track, as of now is unlikely to hit the US mainland.

Here's the latest.  Low threat to US East Coast but possible. Top winds 115 mph in 5 days.

https://www.nhc.noaa.gov/graphics_at5.shtml?start#contents

Up to 125 mph in 5 days.

https://www.nhc.noaa.gov/graphics_at5.shtml?start#contents

 Thanks, Mike. I’m currently at 90% chance of no U.S. center landfall/10% chance of center landfall with a higher chance when considering significant effects from non-landfall that isn’t too far offshore.

Much appreciated, Larry!

This was the SLP map with individual solutions for day 6 of the last run of the European Model ensemble model.  It lines up well with your assessment!

Erin has become the first hurricane of the Atlantic season. It’s forecasted to become a MH but with no hit or even close miss of the US. The E Bahamas, Bermuda and Canada are at more risk.

Thanks very much, Larry!!

Peaks winds at 145 mph in 72 hours but as you know, a brief period of rapid intensification, not forecast well by models could cause it to spike higher than that. 

https://www.nhc.noaa.gov/text/refresh/MIATCDAT5+shtml/152043.shtml?

++++++++++++

1. 500 mb map(midpoint of the atmosphere-around 18,000 feet up) at 120 hours from the EE mean.

2. SLP from the individual European Ensemble solutions at 120 hours.

3. Same thing at 144 hours

Now cat 5!

WOW! That was fast but with rapid intensification not forecast well by the models, especially over warm water it's always a distinct possibility!

At 155 mph from rapid intensification which should end or is ending now. Peak forecast of 165 mph. 

Not much threat to the US East Coast, other than what huge waves cause. Erin, though weakening in speed will grow enormously in size to double or even triple the current size. One reason that it strengthened so fast the last 24 hours is its current smaller size. 

It's interesting that the ACE index does not use size for the calculation(which would have been almost impossible to calculate in hurricanes before the Hurricane Hunters and satellite era).

We were having a great discussion on ACE earlier this month before Erin interrupted by becoming a reality which always trumps forecasts and theories or speculation. 

                2025 NATL Tropical Season                        

                18 responses |           

                Started by WxFollower - Aug. 3, 2025, 12:08 p.m.            

Accumulated cyclone energy

https://en.wikipedia.org/wiki/Accumulated_cyclone_energy

I have found the fact that 7 out of the top 10 ACE seasons occurring BEFORE the year 2000 to be very intriguing as the last 25 years have the warmest water in the tropical Atlantic basin.

I have always felt that its because hurricanes act as a natural mechanism to re-balance the heat distribution on the planet. 

Because of the higher sun angle and  solar heating, the tropics are much warmer than the higher latitudes. This results in a steep temperature/heat gradient from warm to cold going south to north. Increasing CO2 impacts the coldest(driest) places MUCH more than warmer places. This is because the radiation absorption bands for CO2 and H2O overlap and where there is already alot of water vapor(warm/humid places) those bands are near saturation from existing H2O, so adding CO2 can't cause more absorption to something that's already saturated. This part is rock solid, well tested science to explain why the Arctic and high latitudes are warming so fast( not me speculating).

So climate change, warming the coldest places by a much greater magnitude is doing some of the work of hurricanes by shrinking the difference in heat between low latitudes and high latitudes. As a result, hurricanes in this era of warmer oceans in the tropics don't need to redistribute as much heat by transporting it north, pushing it into the deep oceans or exhausting it into the stratosphere. 

I wanted this to stand alone in a post as its the best discussion on this topic that I know of. I love the illustrations/graphs!

I believe that CO2 warming of the highest latitudes by a much greater magnitude(coldest places) is doing some of the work that hurricanes do with their redistributing/balancing of planetary heat by taking it away from the warmest places. This is reducing the need for nature to use hurricanes for this purpose and is at least one explanation for why hurricanes have not increased in a way that one would expect from just the increase in ocean temperatures alone. 

The biggest flaw in comparing data in 2025 (or recent decades) with historical data is that before the satellite era and especially before Hurricane Hunters we don't have comprehensive data on hurricanes away from land which was most of them, most of the time.

One thing for certain. The warmer water is causing more rapid intensification with solid evidence of that the past few decades. However, past rapid intensification events were all in a part of the ocean that we couldn't observe a century ago. 

Hurricanes and the Global Energy Balance 

Beyond the dramatic images and the damage, hurricanes help balance energy inequalities across the planet

https://lessheatmorelight.substack.com/p/hurricanes-and-the-global-energy

An earlier essay was something of an ode to the power and beauty of hurricanes.  This one asks some more analytical questions:  What role do these powerful heat engines play in redistributing energy within the climate system, and is that role changing as the planet warms?

This is a good track to minimize damage/negative impacts!

The eyewall replacement weakened it a bit but that's over and now it will bump back up to 145 mph the next 12 hours, then slowly weaken the rest of the week as it gradually turns farther and farther to the right.

https://www.nhc.noaa.gov/text/refresh/MIATCDAT5+shtml/180255.shtml?

https://www.nhc.noaa.gov/refresh/graphics_at5+shtml/180534.shtml?cone#contents

https://www.nhc.noaa.gov/text/refresh/MIATCDAT5+shtml/180255.shtml?

Erin is increasing in size now. This has been expected. 

Tracking a hurricane,  trying to contemplate the enormity and appreciating the physical laws/process can be a very profound experience when put into perspective. 

The NHC says that Erin's storm size is in the 80th percentile of major hurricanes which means 80% of major hurricanes were this size or smaller. 

https://www.dummies.com/article/academics-the-arts/math/statistics/what-percentile-tells-you-about-a-statistical-value-169667/

Based on an evaluation of storm sizes of major hurricanes over the past couple of decades in the subtropics, Erin is around the 80th percentile. Erin's wind field is expected to keep growing over the next few days. The expanding wind field will result in rough ocean conditions over much of the western Atlantic. It should be noted that the 34- and 50-kt wind speed probabilities beyond 36 hours in the text and graphical products are likely underestimating the risk of those winds occurring.  This is because the forecast wind field of Erin is considerably larger than average compared to the wind field used to derive the wind speed probability product.