Talking the Tropics With Mike: Last day of the Atlantic hurricane season!

Jacksonville, Fl. — THE TROPICS:

***** ALWAYS CHECK & RE-CHECK THE LATEST FORECAST & UPDATES! ****

Tropics threats/impacts for Jacksonville/NE Florida/SE Georgia: None

The Atlantic Basin Overview:

The Atlantic hurricane season is June 1st through Nov. 30th.

The 2nd named storm of the Atlantic season is *on average* July 17th.

Early Wed. the NHC outlined a yellow area (“low chance”) over the NE Gulf extending across Fl. & the SE U.S. coast which has since been shifted west & colored in red (“high chance”). Surface low pressure has finally emerged beneath an upper low that’s over the NE Gulf for several days with multiple but disorganized bands of thunderstorms rotating counterclockwise some which are scraping west Fl. & northward to the Gulf coast. The favorable MJO phase + warm water temps + a decent amount of moisture may very well be enough to overcome persistent moderate shear to allow for gradual organization & development into “Bertha”.

AI models have led the charge on this development & have been the strongest while the tradional European & GFS models have been slowly coming around to development albeit weaker.

So it’s heads-up time along the Gulf coast from the Fl. Panhandle to Texas. A strengthening upper level high to the north should solidly steer the system northwest then more west. To what degree to the west will become important for Texas because if the low stays out over the water while moving west then it could become a stronger tropical system. A hurricane is not out of the question is such a scenario. A move inland sooner - Louisiana/Mississippi/Alabama - would likely result in a weaker storm.

In any case... there will at least be a heavy rain threat along the west coast of Florida & from the Panhandle to Louisiana through midweek. Exact track (north vs west or northwest) will dictate threats - possibly an increasing wind & storm surge threat - by late week along some parts of the Central & Western Gulf coast.

5-day rainfall forecast:

‘Velocity potential anomalies’ below. “Rising” air (green lines) equates with an uptick in overall convection. With rising air, conditions are generally more favorable for tropical development. Where there are brown lines, the air is generally sinking & is often less conducive to tropical cyclones (though not impossible to have development).

The “Buresh Bottom Line”: Always be prepared!.....First Alert Hurricane Preparation Guide... City of Jacksonville Preparedness Guide... Georgia Hurricane Guide.

STAY INFORMED: Get the * FREE * First Alert Weather app

FREE NEWS UPDATES, ALERTS: Action News Jax app for Apple | For Android

WATCH “Preparing for the Storm”

READ the First Alert Hurricane Center “Preparation Guide”

LISTEN “First Alert Weather: Preparing for the Storm”

Federal Alliance for Safe Homes (FLASH) * here *.

REMEMBER WHEN A TROPICAL STORM OR HURRICANE IS APPROACHING: Taping windows is *not* recommended & will not keep glass from breaking. Instead close curtains & blinds.

Realize the forecast cone (”cone of uncertainty”) is the average forecast error over a given time - out to 6 days - & *does not* indicate the width of the storm &/or where damage might occur.

The map below shows the *average* time for a tropical wave coming off Africa to travel west & northwest. Only about 1 in 5 tropical waves - on average - become a tropical cyclone of some sort (depression/storm/hurricane):

Water vapor loop (dark blue/yellow is dry mid & upper level air):

July Atlantic tropical cyclone origins:

Averages below based on climatology for the Atlantic Basin for July:

Wind shear (red - strong shear; green - low shear). Shear is typically strong to start the hurricane season:

Saharan dust spreads west each year from Africa driven by the prevailing winds (from east to west over the Atlantic). Dry air = yellow/orange/red/pink. Widespread dust is indicative of dry air that *can* interfere with the development of tropical cyclones. However, sometimes “wanna’ be” waves will just wait until they get to the other side of - or away from - the dust plume then try to develop if other conditions are favorable (we saw this with Beryl & Debby last year). It’s my personal opinion that there is way too much “hoopla” about the presence of Saharan dust & how it relates to tropical cyclones. In any case, the peak of Saharan dust typically is in June & July, & we are indeed seeing a large “blobs” of Saharan dust over the Central & Eastern Atlantic that’s thinning with westward extent but enough of it to make for hazy skies across the Caribbean & - at times - across parts of Florida.

2026 names..... “Bertha” is the next name on the Atlantic list (names are picked at random by the World Meteorological Organization... repeat every 6 years). Historic storms are retired [Florence & Michael in ’18... Dorian in ’19 (the last time this year’s list was used) ... Laura, Eta & Iota in ‘20 ... Ida in ‘21 ... Fiona & Ian in ‘22... no names were retired in ‘23 for the first time since 2014... Beryl, Helene & Milton in 2024 & Melissa in 2025). The WMO decided - beginning in 2021 - that the Greek alphabet will be no longer used & instead there will be a supplemental list of names if the first list is exhausted (has only happened three times - 2005, 2020 & 2021). The naming of tropical cyclones began on a consistent basis in 1953. More on the history of naming tropical cyclones * here *.

Hurricane season climatology:

East Atlantic:

Mid & upper level wind shear (enemy of tropical cyclones) analysis (CIMMS). The red lines indicate strong shear - typically the “enemy” of tropical systems: