This year, the Atlantic tropics are reminding the United States and Caribbean Islands how brutal September can be when it comes to hurricanes. Perhaps coastal residents have forgotten, as the Atlantic tropics have slumbered in recent Septembers, according to a widely used metric that calculates the total energy of storms during their lifetimes—Accumulated Cyclone Energy.

The Atlantic basin's combined Accumulated Cyclone Energy for the last four Septembers, from 2013 to 2016, was lower than it had been over a four-year period since 1911 to 1914, according to Phil Klotzbach, a hurricane scientist at Colorado State University. This year it has been among the ten most potent. This is also just the ninth year on record with seven or more hurricanes by September 17 in the last century and a half.

So it's busy out there. And for some people, more pain lies ahead. Here's a look at the threats posed by hurricanes Jose and Maria.

Hurricane Jose

Jose has been a persistent storm, having now existed as a tropical storm or stronger for 13.25 days. This eclipses Irma's duration of 12.75 days and is the longest-lived Atlantic named storm since Nadine in the 2012 season. (Nadine meandered much farther out at sea and never threatened land).

We can now have pretty high confidence that Jose will move north, offshore of the US East Coast, before making a pretty sharp turn to the east by Wednesday or so. This should keep the center of the storm away from land, but that does not mean there will be no effects from Jose—which is likely to be a tropical storm or transitioning to an extratropical system by Wednesday.

Minor coastal flooding is possible from Delaware to Southern New England as a result of the storm, and Jose could produce as much as 5 inches of rain over eastern Long Island and up the coast through the southeastern area of Massachusetts. The eventual movement of Jose to the east should limit the flood potential of the storm this week, however.

Many models (including the European ensemble forecast) show Jose meandering over the Atlantic between Bermuda and Maine for days. Because the waters are colder there, it likely will eventually fizzle out. But this storm has survived for nearly two weeks now, so it may have a bit of life left in it. Either way, it very likely does not present a significant long-term threat to land.

Hurricane Maria

Maria, however, does present such a threat. A reconnaissance aircraft on Monday morning found sustained winds of 110mph, and with low wind shear and warm seas, the storm was expected to become a major hurricane later on Monday. (Note: As of 11am ET, it had become a major hurricane at 120mph). Unfortunately it is also nearing the Leeward Islands and will threaten Puerto Rico later this week.

Along such a forecast track, Maria could bring 140- or 150-mph sustained winds to Puerto Rico by late Tuesday night or Wednesday morning. Although the island was battered by Irma, Puerto Rico remained on the weaker, left side of that storm's passage through the Caribbean.

A fair amount of uncertainty remains in the track forecast beyond about three or four days. Most of the forecast models (and their ensembles) show the storm recurving near or before reaching the Bahamas, and this is because high pressure to the north of Maria is expected to weaken and allow a more northward track.

However, it remains possible that there is a bias in the model forecasts toward this earlier recurve solution. Therefore, while it is probable that the United States will not see significant, direct effects from Maria—I'm not ready to rule that out for the East Coast of the United States just yet. We will keep an eye on it.