Leslie and Michael both at fairly high latitudes as seen on this recent satellite image
September 10 is regarded as the peak of the Atlantic hurricane season and today is no exception. We have Leslie, Michael and a new tropical depression forming in the east Atlantic which should go on to become tropical storm Nadine.
The only system that will affect land is Leslie. Top winds are still below hurricane strength but Leslie is such a large storm that its effects will reach Newfoundland well ahead of the center. In fact, the center is of little consequence due to the general lack of an inner core. The wind field is spread out over a very large area and this means tropical storm force winds or higher will spread in to the region and last for several hours. Leslie will also bring heavy rains to the area but at least it will be moving quite quickly.
It is interesting to note that the 5-day NHC forecast map shows the remnants of Leslie passing very close to Iceland, of all places, by day 5. By then, the storm will be transitioned from a warm-core cyclone to one that has its energy spread over a wide area with a more or less level temperature throughout. Tropical cyclones are warmer the closer to their centers you get. I think this is a great example of how tropical cyclones remove heat from the tropics and disperse it towards the poles.
Elsewhere, hurricane Michael continues to churn along at a high latitude with winds near 80 mph this morning. It is forecast to eventually turn north and northeast and should not pose any problems to land areas. However, its energy will also translate north in to the far reaches of the North Atlantic, perhaps reaching portions of Europe before all is said and done.
Then we have invest 91L which is likely to become tropical storm Nadine later this week. No worries about this system as the pattern currently in place does not favor significant westward tracks of eastern Atlantic tropical cyclones. I think that we will not see any threats to the U.S. or Caribbean until after the 20th of the month when the pattern begins to change some. This is a natural evolution in the season as development areas shift from the deep tropical Atlantic towards the western Atlantic and the Caribbean Sea. If we factor in the non-event that the growing El Nino has turned out to be, then I believe we can expect a fairly active late September and early October. For now, with the exception of Leslie, none of the existing tropical systems will impact land areas.
Atlantic Hurricane Season Climatology
We are almost to the half-way point of the hurricane season, at least from a climatological perspective. Over the past 100 years of all tropical cyclones, it seems that September 10 is the tip of iceberg and this year, it will be no different. We have two named storms out there with Leslie and Michael as well as a new area of interest, 91L, just off the coast of Africa. The peak of the season will indeed be a busy one this year.
However, the impacts from all of this activity will likely be minimal. Leslie is still struggling and should pass Bermuda well to the east, bringing only passing showers and a few squalls at most. Of course, the surf will be up, but that’s the extent of it and certainly great news for Bermuda. It also looks like Newfoundland will escape any major impacts from Leslie as the forecast for track and intensity are much more favorable than what it looked like a few days ago.
The rest of the tropics are busy but I do not see any threats to land from anything over the next five days at least. In fact, the MJO is quite unfavorable right now which means sinking, converging air over much of the western Atlantic Basin. We should see a nice quiet period before things ramp up again towards the last half of the month.
I’ll have more here tomorrow. Be sure to check the HurricaneTrack app for today’s video blog which covers all of the above-mentioned info. Don’t have our app? Get it now from the app store.
The latest from the NHC is more of the same for Leslie. It is a large storm, expected to get larger and get stronger at the same time. It is also forecast to pass very close to Bermuda this weekend but the effects will be there much sooner. Waves, generated by the enormous wind field of Leslie, will pound the island, one set at a time. These waves will just get bigger in time as the storm grows in size and intensity over the warm Atlantic waters. Bermuda could be in for a very rough weekend.
As such, I am going to fly to Bermuda and be on site for what ever Leslie brings. I will have a full update as to my plans and how I intend to cover the effects from Bermuda in tomorrow morning’s update.
Elsewhere in the tropics, Michael is of no concern to land as we also watch some left-over energy from Isaac that is trying to work its way back in to the northern Gulf of Mexico. There is a chance that this piece of energy will in fact develop some but conditions do not seem very favorable there right now. Anything that does pop up over the Gulf will be fairly weak and should move back over land quickly. We’ll watch it in case something bizarre happens but honestly, it looks like more of a rain maker with some squalls than anything serious.
As I said, I’ll have more here in the morning regarding Leslie and my plans to cover its impact on Bermuda.
Kirk and Leslie both headed out to sea
It’s back. The seemingly permanent weakness or hole in the Atlantic ridge that has turned numerous hurricanes away from the United States since 2008. Obviously Isaac was able to sneak in underneath; as did Irene last year. But Leslie? It will not. The pattern is such that there will be a trough too far east over North America for Leslie to make it much past 60 W longitude.
With the forecast calling for Leslie to become a hurricane, it should still produce a few days of nice long period swells for surfers to enjoy. Any increase would be nice I suppose. But that should be the extent of it as the global models are firm now in showing a turn away from the U.S. with the track.
Kirk is also heading out farther in to the North Atlantic and will lose its tropical characteristics within a day or two as waters underneath its circulation gradually cool.
The rest of the tropics are quiet and even in the east Pacific there are no areas of concern this weekend.
I am back at home in North Carolina and will resume the daily video blog for our app. On Monday, I will have a longer write-up about Isaac as well as announce plans for our first DVD since 2008. Have a great weekend!