Hurricane LEE

[Casuarina Head]

^ Based on steering, climatology, and modelling, if this develops, it could threaten the northeastern Caribbean, but at this time seems likely to curve away from the CONUS later on. The notorious “shield” that has been protecting metropolitan Southeast Florida from major-hurricane impacts is almost certainly going to continue, but the Leeward Islands need to keep a close eye on the potential for a tropical storm, though dry air may limit the likelihood of a hurricane by then. We shall certainly wait and see.

 

[Timhsv]

If 95L become the forecasted intensity down the road, it MAY create its own steering environment. We shall see. Looks like a potential BIG one.

 

[JPWX]

There is a very surprising amount of agreement at this range from the 18z GFS, 12z Euro, 12z HWRF, 12z HMON, 12z HAFS-A, and 12z HAFS-B that Invest 95L intensifies into a strong category 4 hurricane. Granted, the hurricane models are sooner (by the 8th) than the Global models (12th or 13th). The only model that doesn't take it to major intensity is the 12z Canadian. Too early to speculate on potential impacts for the U.S., but if anything did pose a threat in the longer term, it would be Invest 95L.

 

[Taylor Campbell]

12z EURO

 

[Taylor Campbell]

The intensity forecast from the models is remarkable.

18z GFS

 

[Casuarina Head]

There is virtually 100% agreement among the guidance that 95L will miss the Lesser Antilles and the U.S. altogether. An OTS track at this stage is virtually assured, regardless of intensity. Interestingly, WESH 2, whose forecast for 2022 turned out fairly accurately, is once again using the Lezak recurrence cycle to highlight a possible TC threat to Southeastern Florida between 8–14 September.

One thing that I must note: certain parts of the CONUS seem to have developed an “immunity” to powerful hurricane strikes. Take Tampa Bay and metropolitan Southeast Florida. So many storms that were forecast to strike these areas as strong hurricanes within a few days of impact unexpectedly turned away, defying models and/or official forecasts. Examples: Charley, Frances, Matthew, Irma, Dorian, Ian, and others.

(Of course, this could be just a coincidence, but outside these cases two-day forecasts have tended to be quite accurate.)

I have also mentioned how several recent storms that hit the CONUS seem to have been overestimated in terms of maximum sustained wind (*cough* Ian and Idalia *cough*), while the strongest landfalls have seemingly occurred outside the CONUS: in Central America (Eta, Iota), the Bahamas (Joaquin, Irma, Matthew, Dorian), the Antilles (Matthew, Irma, Maria), and so on. The latter produced unambiguous evidence of extremely powerful winds on land.

So I think that this system is either going to a) make landfall outside the U.S. as a potentially strong hurricane, most likely on Bermuda, or b) miss land altogether. Southeast Florida is probably the safest place to be.

 

[Casuarina Head]

There is virtually 100% agreement among the guidance that 95L will miss the Lesser Antilles and the U.S. altogether. An OTS track at this stage is virtually assured, regardless of intensity. Interestingly, WESH 2, whose forecast for 2022 turned out fairly accurately, is once again using the Lezak recurrence cycle to highlight a possible TC threat to Southeastern Florida between 8–14 September.

Regarding this agency, I must note that its unconventional method has often proven accurate, albeit within a limited timeframe.

Above: WESH 2’s forecast for the 2020 hurricane season. Hurricanes Isaias, Laura, Sally, Delta, and Zeta made landfall within the highlighted areas.

Above: WESH 2’s forecast for the 2021 hurricane season (see previous link). Hurricanes Ida and Nicholas affected the Gulf Coast.

Above: WESH 2’s forecast for the 2022 hurricane season. Hurricane Ian affected both of the highlighted regions.

Above: verification for the preceding forecast.

Above: WESH 2 (see previous link) highlights the potential for a TC impact on Southeastern Florida between 8–14 September 2023.

Above: 500-mb pattern on the 00Z EPS as of 186 hours.

Above (two images): 500-mb pattern during the five days preceding Hurricane Irma’s landfall on the Florida Keys.

Above: data from the latest EPS as of 06Z. For the first time many members show a slight bend westward around 60°W. The mean just clips Hebert Box #1.

Hmm...nevertheless, I’m quite confident that this will still find a way to miss Southeastern Florida, unless trends are sustained up until the very day of impact or so. The “shield” is almost certain to hold.

 

[Casuarina Head]

Interestingly, while the 06Z EPS mean crosses 60°W around 19.9°N, the 12Z GFS does so nearly two degrees farther north. This is significant because the 06Z EPS suite, compared to 00Z’s, as a whole has shifted considerably farther south and west during the same timeframe, while generally being stronger as well. Moreover, consensus among the individual members has tightened considerably from run to run, suggesting increased confidence. Furthermore, even though the 12Z GFS is much farther northeast and slower than its predecessor at 06Z, it, like the past few EPS runs, has trended toward a more retrogressive pattern by day five and beyond, with more of a cutoff low over or near the Great Lakes during this timeframe, along with a ridge-bridge across Canada, from Newfoundland to British Columbia. Furthermore, the 12Z GEFS, which is just arriving, indicates a much slower path and more southerly location by D10, at least among individual members. In any event, at this point the chance of a landfall on the CONUS, and particularly Southeast Florida, remains extremely low.

^ Regardless, all indications are that this is likely to be a powerful hurricane, given short-term trends and projected conditions.

 

[JBishopwx]

 

[Taylor Campbell]

913mb from the EURO.

 

[Taylor Campbell]

The HFAI intensity model very near 175knts (200mph). 18z HFASA at 927mb and HFASB at 920mb at 126hrs.

I can’t wait to see the beauty of this beast. Should be a breath taking view. The Hurricane Hunters are in for a heck of an airplane ride.

 

[Casuarina Head]

@JBishopwx I’m not sure as to why he implies that 95L may have an opportunity affect the U.S. Most of the models suggest that 95L will miss Hebert Box #1, which he highlights, so there is a 99.9% chance that 95L will not hit the U.S. So there is virtually a near-zero probability. The element of suspense in this case is exaggerated and unhelpful (except maybe for ratings?). Bermuda, on the other hand, may well receive one of its strongest hurricanes on record. Given Franklin, I think that a high-end Category-4+ landfall on the island is possible, though the island is well prepared for extremely intense storms, fortunately.

 

[Casuarina Head]

If 95L does not pass through Hebert Box #1, under the given pattern, then it will not impact the CONUS. Mid-level ridging over the Canadian Maritimes will be too weak and the flow too progressive to permit otherwise. Also, by day five a mid-level trough over the central subtropical Atlantic will allow 95L to assume a more northward component, allowing it to avoid Hebert Box #1. At this time the EPS and GEFS concur that 95L will track outside Hebert Box #1, thereby practically guaranteeing a path east of the CONUS, toward Bermuda. Yet on social media the system is already being touted as a second Sandy (2012). This is extremely irresponsible and illustrates the hazards of social media in general.

 

[Jacob]

Maybe I’m old school, but it seems to me like saying that a hurricane (that is expected to be in the cat 3-5 range) 5-7 days out north of Puerto Rico has no chance of impacting the US is quite irresponsible in itself.

Yes, the pattern certainly favors a fish type storm. But again that’s a week or more out.

 

[JBishopwx]

Here. We. Go.

 

[Clancy]

Here's the first forecast.

 

[Casuarina Head]

Maybe I’m old school, but it seems to me like saying that a hurricane (that is expected to be in the cat 3-5 range) 5-7 days out north of Puerto Rico has no chance of impacting the US is quite irresponsible in itself.

Yes, the pattern certainly favors a fish type storm. But again that’s a week or more out.

@Jacob A threat to Bermuda certainly isn’t a “fish-type storm.” Also, I am speaking of current trends: on this basis I base my 99.9% probability. Hebert Box #1 is only about four and a half days out. Unless the models were to a) dramatically shift toward a different pattern and b) show a track through Hebert Box #1, I am still quite confident in calling for a threat to Bermuda instead of the U.S. If this alternative trend—of which there is absolutely no sign thus far—were to transpire, then I would obviously be thinking differently. I would be much more confident in a threat to the U.S. if the EPS and/or GEFS were to shift southward by days four and five, showing a track through Hebert Box #1 instead of just to the north. At this time, the odds overwhelmingly favour no U.S. impact: of this I am 99.9% sure. This is close enough to certainty, though not absolutely there.

In other words, the possibility that the opening discussion mentions is necessary but not sufficient for a threat to the U.S.:

The spread in the model guidance is remarkably low for a first advisory, and the official forecast is near or west of the model consensus. However, it should be noted that the NOAA corrected-consensus aids and some ensemble members are still to the left of the official forecast, so it is too early to determine exactly how close this system will get to the Leeward Islands given the average track forecast error at those time ranges.

However, the same discussion notes that the forecast is west of the guidance, so further shifts westward seem unlikely.

The low degree of spread among the guidance certainly implies that westward adjustments are implausible at this stage.

As an aside, this is likely to become an extremely intense hurricane. I’ve never seen an initial advisory-package that calls for 120 knots five days out!

 

[JBishopwx]

 

[Taylor Campbell]

I see on the model predictions that there is a very good possibility that Lee becomes an upper echelon category 5, and could find its place on the list of most intense Atlantic hurricanes on record.

06z HAFS-A



06z HAFS-B

 

[Casuarina Head]

^ In my view, the above is essentially certain to transpire—my level of confidence in this solution is 99.9%. But we shall see.