Jacksonville, Fl. — THE TROPICS:
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Tropics threats/impacts for Jacksonville/NE Florida/SE Georgia: None.
The Atlantic Basin Overview:
The Atlantic hurricane season is June 1st through Nov. 30th.
A Tropical Storm WARNING: Bay/Gulf County Line in Florida to the Terrebonne/Lafourche Parish Line in Louisiana...
A Tropical Storm WATCH: West of the Terrebonne/Lafourche Parish Line to the Vermilion/Cameron Parish Line* Metropolitan New Orleans, Lake Pontchartrain, and Lake Maurepas
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 & was colored in red (“high chance”) by early Sunday & upgraded to tropical depression #2 late Sunday morning. Then hurricane hunter aircraft determined t.d. #2 had strengthened into tropical storm Bertha Mon. evening.
The development was a pretty classic “top/down” formation of a tropical cyclone as a surface low pressure finally emerged beneath a persistent upper low that’s been was over the NE Gulf for several days with multiple bands of thunderstorms rotating counterclockwise some which are scraping west Fl. & northward to the Gulf coast. The poorly defined center may jump around some as thunderstorm clusters wax & wane. The favorable MJO phase + warm water temps + a decent amount of moisture (though is some dry air being absorbed from the NE over the continental U.S.) may very well be enough to overcome persistent moderate shear to allow for continued gradual organization prior to approach to land. In addition Bertha is moving with the shear instead of against it which will probably not be as detrimental to the storm’s intensity. Occasional dry air intrusions & proximity to land may end up being the most significant modulators of the storm’s intensity.
AI models have led the charge on this development & have been the strongest while the traditional European & GFS models have been slowly coming around to development albeit weaker. Both the Euro & GFS consistently bring the system inland by Wednesday east of New Orleans then dissipate it. The AI models are generally more west & at least a little stronger though some of the AI model runs also bring the system in early enough to dissipate it.
The greatest threat looks to be heavy rain along the Gulf coast. A strengthening upper level high to the north/northeast should solidly steer the system northwest then more west. To what degree to the west will become important for Texas because if the depression stays out over the water while moving west then it could become a stronger tropical system. A move inland sooner - Louisiana/Mississippi/Alabama - would result in less time over a water & therefore, a weaker storm.
In any case... there will continue to be a heavy rain threat along the west coast of Florida & from the Panhandle to Louisiana this week. Exact track (north vs west or northwest) will dictate threats - an increasing wind & storm surge threat - through the next few days along some parts of the Central & Western Gulf coast. The persistent shear out of the northeast will maintain the core of heaviest squalls & strongest winds over the southern portion of the circulation. But daytime heating will help enhance loosely organized bands to the east & north of the center each afternoon before weakening during the overnight hours.
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.
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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..... “Cristobal” 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:
Water vapor imagery (dark blue indicates dry air):
Deep oceanic heat content over the Gulf, Caribbean & tropical Atlantic. Brighter colors = warmer temps.:
Sea surface temps.:
Sea surface temp. anomalies:
SE U.S. surface map:
Surface analysis centered on the tropical Atlantic:
Surface analysis of the Gulf:
Caribbean:
Atlantic Basin wave period forecast for 24, 48, 72 & 96 hours respectively:
East & Central Pacific:
This basin will most likely be the generally more active area in ‘26 due to the anticipated El Nino.
“Fausto”:
Central Pacific:
Hawaii satellite imagery:
Global tropical activity:
West Pacific:
Cox Media Group
