Seasons (Waiting on You): The Hurricane Watch for September 9th

Watching and waiting continues in a calm Tropical Atlantic.

Florida tropical threat synopsis: No landfall threats to Florida or the continental U.S. over the next 8-10 days.

Almanac: It’s Tuesday, September 9th… day 101 of the 2025 hurricane season, 82 days to go. By total storm energy, the season is 43.3%, 54.3%, and 43.1% complete for the Atlantic, continental U.S., and Florida, respectively. With no sign of tropical activity in sight, the 2025 hurricane season now has the exact median amount of Accumulated Cyclone Energy through September 9th for the seasons since 1950. That’s quite a climbdown after reaching as high as 85th percentile to date following Hurricane Erin.

Active Storms: None.

Other Disturbances in NHC outlook, with 2-/7-day NHC development odds: None. And this is very, very weird— there have been a few other years without named storms in the second week of September, but none since 2003 for which the NHC was not even highlighting a potential area of development on this date.

Elsewhere: There’s no more indication of when the inactivity across the Atlantic Basin will end than there was yesterday. The Atlantic’s (purported) Main Development Region between West Africa and Central America is mostly convection-free due to sinking, dry air originating in the mid-latitudes being forced south into the Tropics. The Gulf and western subtropical Atlantic do have quite a bit of storminess associated with a persistent dip in the jet stream and cool fronts. That’s a nice pattern for brisk dewpoints across the eastern U.S., but not conducive for any kind of tropical activity.

GFS analyses of mid-level humidity and winds (with surface pressure) since September 6, with 06z GFS forecast into early Sunday. (TropicalTidbits.com)

The dry air intrusion into the Deep Tropics is likely to slowly diminish heading into early next week as shown above. That may open the door beyond the 15th for tropical waves to at least have some shot of development, as the upper-level divergence forecasts I showed yesterday would indicate. The GFS, European, European-AI, and Google Deepmind ensembles all have a decent signal for some eastern Atlantic development in the 6-10 days out range, but given recent busts a skeptical stance is justified until an actual wave is out there generating actual convection. There is also no indication that this wave would pose any threat to the U.S., even if it does develop.

06z Google Deepmind and European ensemble low centers for Monday morning (9/15), showing some support for a tropical wave slowly organizing next week.

Finally, it’s worth noting that the operational GFS is intermittently trying to develop a sloppy tropical storm in the western Caribbean in about 7-10 days, then send it north into the Gulf. The GFS has a well-known bias for doing just that, and no other models support development in that region. I’ll be watching carefully for this type of threat later in the season, but it’s likely still too early for Central American Gyre threats.

Next report/time-passing mood music: Weekly column out tomorrow afternoon, and some waiting music for the meantime.