Over the last 24 hours, Harvey degenerated into an open wave thanks to an area of strong wind shear that tore the system apart. That being said, Harvey’s remnants still have a good shot of redeveloping in a few days, especially as they move over the Bay of Campeche. Regardless, this system won’t have an impact on the United States.
Of more interest perhaps, is Invest 92L, which was located about 100 miles NNE of the Turks and Caicos Islands on Sunday evening. Odds of development are still on the low side, but it will be moving into a more favorable environment by mid-week as it near the Bahamas and Florida. Most models are still keeping this system an open wave ultimately, but it does bear watching. One thing’s for sure, central and south Florida can count on increased rain chances and perhaps locally heavy rainfall mid to late week.
As of Saturday evening, we’re still watching three separate disturbances in the Atlantic basin. Harvey has been battling with dry air today and has weakened to a tropical depression for the time being. Over the next 24 hours, it should be able to regain tropical storm status as it moves west-northwest toward Central America. Harvey will bring heavy rains to portions of Nicaragua and Honduras on Monday before moving into Belize and the Yucatan Peninsula on Tuesday. As of now, no tropical storm watches or warnings have been issued for those areas yet.
There are still two tropical waves riding in the wake of Harvey. Of most interest is Invest 92L; although, odds of development with this wave continue to drop. It will have to contend with quite a bit of wind shear in addition to pockets of dry air over the next few days as it moves towards the Bahamas. Even though development is not likely, it will likely bring periods of heavy rain to the islands; as well as increased rain chances for parts of Florida by mid-late week.
On Sunday afternoon, Tropical Storm Gert formed about 350 miles NE of the Bahamas. At 5pm Sunday, max sustained winds were at 40 mph and Gert was moving NNW at 10 mph. Gert is expected to strengthen further as it moves north and eventually northeast, shooting the gap between the U.S. mainland and Bermuda. It is not a threat to land at this point.
As we head toward the peak of hurricane season the Atlantic basin is heating up. A new wave (Invest 91L) has emerged off the coast off Africa; and while it is a long way away, it bears watching as it moves westward over the next week and a half. This wave should have a pretty favorable environment for development at times as it makes its way across the Atlantic. It is far too early to speculate what may become of Invest 91L, but we’ll be watching it closely.
Tropical Depression 8 has formed east of the Bahamas late this evening. At 11pm Saturday, sustained winds were at 35 mph and TD 8 was moving NNW at 13 mph. The system is expected to become our 7th named storm of the season, Gert by early Sunday morning. The good news is that Gert should stay well east of the U.S. mainland, moving just west of Bermuda before moving into the north Atlantic by the middle of next week.
The rest of the Atlantic basin remains quiet for now.
We’ve had Invest 99L on the map for a while now as it has made its way across the Atlantic over the last week and a half or so. It’s a disturbance that refuses to give up, but has never been able to gain any ground due to an on & off battle with wind shear and dry air.
On Friday afternoon, it was a couple hundred miles north of Puerto Rico. There have been flare-ups of convection at times, but still no indication of a closed circulation. Upper level winds are becoming a little more favorable for development as we head into the weekend, but it will still have to contend with some pockets of dry air. The National Hurricane Center currently has development odds at 50% over the next 5 days. However, our latest model runs still aren’t too excited about any development with system… keeping it an open wave through the rest of its journey.
Whether or not a tropical depression, or even Gert, forms; steering flow should keep this well offshore as it moves north and northeast up the eastern seaboard.
On Wednesday afternoon, Hurricane Franklin formed over the Bay of Campeche before making landfall late Wednesday night and rapidly weakening this morning. The formation date of August 9th was just one day shy of the average formation date of the Atlantic season’s first hurricane. The season’s first hurricane brought several inches of rainfall and sustained winds as high as 85 mph to portions of eastern Mexico. Looking forward, there is a slight chance that Franklin’s remains regenerate over the eastern Pacific.
Back in the Atlantic, Invest 99L continues to fight despite slim development chances. On Thursday afternoon, the disturbance was located a few hundred miles northeast of the Lesser Antilles. It will have a window this weekend as wind shear in its path begins to decrease. Recent runs of both the GFS & ECMWF have low expectations for Invest 99L, keeping it an open wave as it moves NNE of the Bahamas by Sunday evening.
At 5pm Wednesday afternoon, Franklin became the first hurricane of the 2017 Atlantic Hurricane Season. Sustained winds were at 75 mph and it was moving W at 12 mph. The system continues to thrive in a very favorable environment over the Bay of Campeche with very warm sea-surface temperatures, plenty of moisture, and only moderate wind shear. As a result, a little more strengthening is possible before landfall late tonight. This system doesn’t pose any threat to the United States, but it will bring very heavy rainfall, as much as 15″, to the mountainous terrain of eastern Mexico over the next 48 hours.
Meanwhile, about 350 miles east of the northern Lesser Antilles, Invest 99L continues to struggle to get organized thanks to strong mid-upper level winds and an abundance of dry air. That being said, conditions should become a little more favorable by this weekend as this system moves WNW.
Even if 99L develops into Gert, steering flow over the western Atlantic and eastern U.S. should steer it north/northeast and keep it offshore. We’ll continue to watch it closely.
In other news, today NOAA released their final update for the 2017 Atlantic Hurricane Season Outlook – further increasing the amount of activity expected over the next few months. The 2017 season could end up being the most active since 2010, now with a 60% chance of an above-normal season.
Late Sunday evening, the National Hurricane Center began issuing advisories on Tropical Storm Franklin in the western Caribbean. Moving into an increasingly favorable environment for further development, Franklin is likely to strengthen as it moves toward the Yucatan over the next 24 hours. Tropical Storm warnings are now in effect for the Yucatan Peninsula, as impacts in that area may be felt as early as Monday afternoon. From there, this system should move across the Bay of Campeche and into eastern Mexico late Wednesday into early Thursday. Heavy rain and gusty winds are likely in the aforementioned areas, but at this time, no U.S. impacts are expected.
On Sunday evening, the National Hurricane Center began issuing advisories on Potential Tropical Cyclone Seven in the western Caribbean. Moving into an increasingly favorable environment for further development, this is likely to become Tropical Storm Franklin within the next 24 hours. Tropical Storm warnings are now in effect for the Yucatan Peninsula, as impacts in that area may be felt as early as Monday afternoon. From there, this system should move across the Bay of Campeche and into eastern Mexico late Wednesday into early Thursday. Heavy rain and gusty winds are likely in the aforementioned areas, but at this time, no U.S. impacts are expected.
We also continue to monitor the progress of Invest 99L in the central Atlantic. As of Sunday night, convection was almost non-existent around the disturbance, and the National Hurricane Center continues to lower its expectations for development in the short-term. It has a very tough road ahead of it thanks to strong upper level winds, but it still bears watching as it moves WNW over the next week or so.
By next week, it’s possible that we’ll be tracking two named storms in Atlantic. On Friday afternoon, Invest 90L was located in southern Caribbean Sea, while Invest 99L was out in the open Atlantic, several hundred miles southwest of the Cabo Verde Islands.
Invest 90L is battling quite a bit of wind shear in the short term and is currently nothing more than a disorganized area of showers & storms. However, environmental conditions should become more favorable for development as it emerges near the Yucatan Peninsula early next week. There is growing model support that we may have a tropical storm or hurricane in the Bay of Campeche by the middle of next week, which could then make a run at eastern Mexico or southern Texas.
Invest 99L certainly bears watching as well. It is in a pretty good environment for further development, but is taking its sweet time getting organized. If it can get its act together, it should take advantage of an increasingly favorable environment over the next few days as it moves west-northwest toward the northeastern Caribbean. Beyond that, it is still too early to speculate whether or not it will have any U.S. impacts.
Below is the 12Z GFS Ensemble MSLP and the 0Z Euro Ensemble MSLP valid for next Wednesday evening. Images courtesy of Tropical Tidbits.
Time is certainly on our side, as we’ll have several days to keep an eye on both of these systems.