X marks the spot as tropics stay busy

NHC's Graphical Tropical Weather Outlook map showing several areas worth monitoring over the coming days

NHC’s Graphical Tropical Weather Outlook map showing several areas worth monitoring over the coming days

We are in prime time of the hurricane season and with the Atlantic Basin as warm as it is, it comes as no surprise really that there is plenty to talk about.

The NHC has several areas outlined this morning, including the remnants of TS Grace, that bear watching over the coming days.

First up, TS Henri is weak and is moving quickly now to the north. The forecast calls for a turn to the northeast as it transitions from a tropical storm in to a more spread out extra-tropical system over the far reaches of the North Atlantic. Seas will begin to subside in and around Bermuda where some beach erosion took place over the past couple of days due to the constant easterly swell that Henri was generating.

Henri could bring a period of heavy rain to parts of extreme southeast Newfoundland but the fast movement will limit the impact and its duration.

Next we have the remnants of tropical storm Grace moving towards the northern Leeward Islands. There has been a significant increase in deep convection with the system which could lead to periods of heavy rain and gusty winds as the low pressure area moves through. While there is little chance for it to become a tropical storm again, we know by now that rain alone is enough to cause major issues if too much falls at once. The forecast indicates that the remnants will track westward towards Puerto Rico over the weekend. We’ll have to watch and see what happens once the energy gets in to the southwest Atlantic or possibly the southeast Gulf of Mexico some time next week.

Off the coast of Africa is where the next large tropical wave is making its debut. The NHC is giving it a medium chance of development over the next five days and if it does in fact do so, it would be the 5th such development in the MDR or Main Development Region since late August. This is almost unheard of during strong El Nino seasons yet here we are, Danny, Erika, Fred and Grace all developed between Africa and the Lesser Antilles. This next system shows promise to become a hurricane over the open waters of the Atlantic in the coming days. As long as it remains away from land, so be it.

Finally, a small low pressure area has developed well to the southwest of the Azores Islands in the northeast Atlantic. It has only a small opportunity for development and of course wouldn’t be an issue for any land areas; something to watch but nothing to be concerned with.

To sum things up, there is plenty to keep track of but no major issues brewing in the tropics as of now. Enjoy the weekend, nice fall-like weather will be in store for much of the eastern part of the nation but then we return to the summer look and feel to things shortly, so take advantage of the cooler temps while you can! I’ll have a video discussion posted later this afternoon.

M. Sudduth 9:40 AM ET Sept 11



Tropics very busy on this peak day of the season

Leslie and Michael both at fairly high latitudes as seen on this recent satellite image

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.

Bermuda gets brushed by Leslie; Newfoundland to get full landfall it appears

Leslie could remain a poweful storm or hurricane as it makes landfall in Newfoundland

Leslie could remain a poweful storm or hurricane as it makes landfall in Newfoundland

As expected, the effects of Leslie on Bermuda were not much more than a few power outages and some minor vegetative damage from the large circulation of the tropical storm. The weather will improve significantly by tomorrow as Leslie finally picks up some forward speed and moves out of the area.

However, now it’s time for Newfoundland to be ready and this could mean getting ready for quite an impact. The NHC mentions on their most recent update that Leslie could be transitioning from a tropical cyclone to an extratropical cyclone at about the time it makes landfall in Newfoundland. This means it is possible for hurricane conditions to be felt in the region as Leslie moves through. One key here is that the wind field will likely expand with this transition even though it looks as if Leslie already has an enormous wind field. Folks in Newfoundland will feel the effects from Leslie well before any center it has left arrives.

Elsewhere, 91L in the east Atlantic is taking its time to develop and when/if it does, I highly doubt it will get past 60 W longitude as this is the pattern we seem to be in right now. Obviously, we’ll watch it closely but I do not see any indication from the long range models that we’ll see any threats from the east Atlantic anytime soon.

I’ll have more here on Leslie and its expected effects for Newfoundland on tomorrow morning’s blog post. Be sure to check the HurricaneTrack app this evening for today’s video blog that was recently posted.

As peak of season nears, no major impacts expected

Atlantic Hurricane Season Climatology

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.