South Florida’s weather is punctuated by three primary seasons – wet (or rainy) season, dry season and hurricane season. We put up with the lesser of these for the splendor of dry season, which usually hits around mid-October.
Right on cue, the first big cold front of the season is pushing through South Florida today, officially kicking off dry season and ending the most oppressive summer and early fall on record for the area.
Today will bring the coolest temperatures to South Florida since April, with overnight lows expected to drop into the low 60s and even upper 50s for the first time in 210 days.
As late as last Thursday, Miami’s low temperature never dipped below 84°F, tying the all-time warmest low temperature on record (typically reserved for July or August, not October) and several degrees higher than the forecast high temperatures for today.
The humidity added to the misery this wet season, with heat indices topping 105°F for an astounding 180 hours in Miami, shattering the old record of 49 hours in 2020.
According to heat index records maintained by Brian McNoldy, Senior Research Associate at University of Miami’s Rosenstiel School, Miami recorded 46 consecutive days of heat indices above 100°F earlier this summer, surpassing the previous record by two weeks.
Needless to say, the cooler temperatures and much drier air over the next few days will feel glorious after such a long, brutal extended summer.
Dry season is also an important right of passage for hurricane season in South Florida. While the start of dry season doesn’t give us a pass for the remaining 6 weeks of hurricane season (the Atlantic hurricane season officially ends November 30th), the odds of a hurricane impact on South Florida do drop significantly after the passage of our first big cold front.
Once cold fronts begin to make it routinely through South Florida and into the southern Gulf of Mexico, strong wind shear in the wake of these fronts usually deters tropical development. The exception to this rule are cold fronts that stall and linger for too long over the still-warm Gulf or southeast coast, giving time for low-pressure systems to organize.
For now, we don’t see any signs of this or other tropical mischief in our part of the tropics for the week ahead.
Models hot and cold on Invest 94L
Invest 94L – the area of low pressure we’ve been tracking since it rolled off Africa last week – remains a mess today as it moves through the central Atlantic between Africa and the Caribbean. Models have been waffling on its development potential for the last several days, with solutions ranging from an open wave to a potential hurricane.
Although models have generally softened on development odds in recent runs, given the overall conducive environment ahead and trajectory toward the islands of the northeastern Caribbean, those with interests in the Leeward Islands will want to follow the forecasts this week.
For now, the majority of forecast models bend 94L or what forms from it northward as it approaches the islands by late Friday into the weekend.
It’s too soon to say what, if any, impacts the system will have on the islands of the eastern Caribbean, but a stronger storm would tend to favor a more northern track away from the islands. The trend over the weekend has been for a weaker system, but we’ll need to give the models a little more time to shake this one out.