The Atlantic Basin remains rather active as what's left of Helene continues to deteriorate over the center of the country. A total of five areas are currently being watched by the National Hurricane Center, including two named storms. These named storms are Hurricane Isaac and Tropical Storm Joyce. Neither of these storms pose a threat to land. The three other areas of interest aren't an immediate concern, but will need to be watched eventually.
Isaac and Joyce represent numbers nine and ten for named storms as we continue to inch toward the average for named storms in a season, which is 14 (based on the 30 year average from 1991-2020). In addition to these storms, three other areas are being watched for potential development in the coming days.
ISAAC
Hurricane Isaac formed from a coastal storm that brought heavy rain and wind to Cape Cod last weekend. As the storm drifted away, it began to take on tropical characteristics. A few days ago, the storm officially became tropical and was given the name Isaac. This storm gained strength and is currently a category 2 hurricane as of Sunday evening.
The storm will continue to drift in the northern Atlantic Ocean where very unfavorable conditions exist for hurricanes (as one would expect this far north). Isaac has begun to weaken and will continue to do so, likely becoming post-tropical by early Monday morning. The storm will not affect any landmass as it gets gradually torn apart.
JOYCE
Tropical Storm Joyce formed in the eastern Atlantic yesterday. The storm formed from a tropical wave off the African coast. This storm is a Cape Verde system, which can become powerhouse hurricanes as they drift across the open, warm Atlantic, however, the storm is being hit by a double whammy preventing any strengthening.
Joyce is being heavily affected by wind shear along with moving into relatively dry air. These elements will gradually weaken Joyce, which is expected to revert back to a Tropical Depression by Monday. Additional weakening is expected thereafter. The storm will not come close to any landmass (even if it was able to strengthen into a powerhouse system).
AREAS OF INTEREST
As stated above, there are three areas of interest in addition to these two named storms. Two of them are Cape Verde systems, which are systems that emerge as tropical waves off the African coast near the Cape Verde Islands. The fact that three Cape Verde systems are currently in the pipeline (Joyce along with the two waves) is not unusual as the late summer/early fall is when this type of storm is most likely to form. In addition to these systems, another is being watched closer to home.
Disturbance 1
This group of showers and thunderstorms have become more organized over the past 24 hours. The storm will follow in the footsteps of Joyce at least initially. Environmental conditions currently look more favorable for this storm than they do for Joyce. Continued organization and gradual strengthening is likely and a tropical depression is now expected to form by the middle of next week.
The National Hurricane Center gives this storm an 80% chance of development as of Sunday morning. Many models point to this system gradually strengthening into a hurricane. They also show the system curving north well away from the United States, similar to Tropical Storm Joyce.
Disturbance 2
An area of low pressure has formed and is producing disorganized thunderstorms in the Caribbean Sea. Conditions will likely be favorable for gradual development of a tropical system by the middle of this week. The system is expected to meander northwest into the Gulf of Mexico by the end of this week. The National Hurricane Center currently gives this system a 50% chance of developing within the next week.
With the expected timing, this system will not be an immediate threat or concern, but this system will need to be closely watched as next week progresses. The Gulf Coast will need to pay attention to this storm's progress. It's much too soon to try to speculate on a track or intensity (remember, a tropical system hasn't formed yet and currently has a 50% chance to do so).
Disturbance 3
Overnight, a new tropical wave emerged off the African coast producing limited shower activity. Some gradual development is possible with this system over the next several days. The National Hurricane Center gives this system a 20% chance of developing within the next week.
Next for Helene
The remnants of Helene continue to sit over the central United States as the storm dissolves. The storm was blocked from taking a standard path out of the country through the northeast by an expansive area of high pressure. A frontal system will move across the United States next week, which will push what's left of the storm out to sea.
Continued showers are likely through the weekend, but the flooding threat has dropped significantly. Scattered flash floods may be possible across the Virginias, but nothing like what occurred on Thursday and Friday.
Excessive rainfall outlook for Sunday:
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