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 busy but nothing set to impact land

Atlantic looking fairly busy considering the strong El Nino season

Atlantic looking fairly busy considering the strong El Nino season

We are closing in on the mid-point of the hurricane season in terms of climatology- September 10th marks the traditional peak of the season. Despite a fairly strong El Nino currently dominating the Pacific, the Atlantic Basin has managed to eek out enough activity to keep the maps active. Today is no exception with several areas to monitor in the coming days.

First, we have TS Grace which is likely to weaken and eventually dissipate somewhere in the Caribbean, if not before. It may bring additional rain to the region but it shouldn’t be too much and hopefully nothing like what Erika brought to Dominica recently.

Grace has little chance of making it to the United States as a tropical cyclone due to the persistent band of strong upper level winds and dry mid-level air situated over the deep tropics.

Next up is invest area 92L which is situated to the east-southeast of Bermuda this morning. The NHC says that it consists of a broad area of low pressure that is supposed to be nearly stationary over the next day or two. Water temps in the region are quite warm and most computer guidance suggests that this will become a tropical depression and perhaps a tropical storm before heading on out in to the far north Atlantic. No worries in Bermuda except for a possible increase in surf as the system organizes.

Elsewhere, a rather innocent looking tropical wave is moving through the southeast Caribbean Sea that could end up in a position where it could fester and try to develop down the road. The global models have been hinting at development somewhere in the western Gulf of Mexico within about a week. In fact, for what it’s worth, the often reliable ECMWF has been rather consistent with this scenario over the past few days. Right now, it’s just something to take note of but nothing more. I think that within 72 hours we’ll have a much clearer idea of what may or may not take shape in the Gulf of Mexico as we get in to next week.

Hurricane Linda satellite photo

Hurricane Linda satellite photo

In the east Pacific, hurricane Linda remains well offshore of Mexico and is expected to weaken as it moves to the northwest with time. However, this morning, it sure seems like it’s on a strengthening trend with a clearer eye showing up in satellite imagery. There is likely to be an increase in the wave action along portions of the Baja as the hurricane moves past but the heavy weather should remain far enough to the west to limit any additional impact. Some high-level moisture may get pulled northeast in to the Desert Southwest later in the week as the hurricane has a large circulation associated with it.

I’ll have a thorough video discussion posted later this afternoon that will take a closer look at all of the happenings in the tropics.

M. Sudduth 8:50 AM ET Sept 8


It won’t be Grace…

Satellite image of TS Grace - notice the lack of any significant deep convection or thunderstorm acticity

Satellite image of TS Grace – notice the lack of any significant deep convection or thunderstorm activity

If the United States is going to hit by a hurricane this season, it won’t be Grace. How can I be so confident? The pattern is simply not favorable and Grace will likely never become a hurricane at all, much less impact U.S. shores.

The reason that conditions are so hostile is a little tough to explain. There is just too much dry mid-level air in the deep tropics and this is literally putting a cap on the development of deep convection or thunderstorm activity. If the air cannot rise then tropical cyclones cannot form. Add to the mix the fact that upper level winds are also blowing too fast against the direction of movement and it all equals a “no-go” for Grace from here on out. I fully expect to see the storm weaken to nothing more than an open wave of low pressure by the end of the week if not sooner.

Elsewhere, the Atlantic Basin is quiet this Labor Day 2015. There is some chatter about a possible low pressure area developing in the western Gulf of Mexico in about a week but nothing more, just chatter. We’ll wait and see if the computer guidance begins to latch on more consistently before worrying too much about that.

NHC track map showing the forecast for hurricane Linda in the east Pacific

NHC track map showing the forecast for hurricane Linda in the east Pacific

In the east Pacific, hurricane Linda is gaining strength quickly in the warm water off of Mexico. Fortunately, it is forecast to remain far enough off the coast to keep the impacts to a minimum.

Another area of disturbed weather is now taking shape farther to the south and east of where Linda is located. This should go on to develop steadily over the coming days as it moves roughly parallel to the Mexican coastline but several hundred miles offshore.

M. Sudduth 12:55 PM ET Sept 7

New tropical storm forms in east Atlantic – has tough path ahead

Newly formed tropical storm Grace just to the southwest of the Cape Verde Islands

Newly formed tropical storm Grace just to the southwest of the Cape Verde Islands

The NHC has begun issuing advisories on tropical storm Grace in the far eastern Atlantic. Top winds are 40 mph and it is moving westward over open water.

The forecast calls for modest strengthening despite the fact that the track takes Grace over fairly warm sea surface temperatures. It seems the once again, strong upper level winds coming in the opposite direction could inhibit development if not halt it completely. For the time being, Grace has a chance to strengthen some and it should be noted that some intensity models do make it a hurricane.

Fortunately, the storm is far out in the open Atlantic and there is plenty of time to monitor its progress over the coming days. It will have to battle increasingly stronger upper level winds and, as I mentioned above, those winds may end up causing the storm to dissipate, we will just have to wait and see.

I find it interesting that Grace makes it four storms in a row to develop in the MDR or Main Development Region over past few weeks. This part of the Atlantic, also known as “the deep tropics”, was supposed to be very hostile this hurricane season. Granted, Danny was the only hurricane to really take off, so to speak, but even Fred a few days ago, reaching hurricane intensity just off of Africa, was quite interesting considering the El Nino season we are in. If Grace becomes a hurricane, it will add to the seasonal ACE count which is currently at ~22 and slowly climbing. The ACE index measures the energy output by tropical cyclones each season and is a better indication of the quality of each storm, not the total amount that formed. Most predictions for this season are around 40 ACE points, we are more than half way there.

Elsewhere, Fred is hanging on as a tropical depression, fighting off periodic bouts of strong upper level winds. Once in a while, those winds relax just enough to deep convection to fire up, making Fred a tropical storm once again. Right now, it’s currently on the losing end of the shear duel. I suspect that within a the next 12 hours, Fred will make another comeback and be designated as a tropical storm yet again. Eventually, Fred will be kicked out in to the westerly wind flow of the Atlantic and whisked away.

The east Pacific has an area of interest, 98-E, well to the south of Mexico, that bears watching. It will slowly consolidate and become a tropical storm over the coming days but should remain well to the west of the Baja and vicinity.

I’ll have more on Grace and the rest of the goings on in the tropics tomorrow.