Rainy season showers bring needed relief
National Weather Service predicts ‘wetter and warmer’ summer months
With Lee County reporting June rainfall totals thus far ranging from just shy of 3 inches at Gateway to more than 11 measured at the North Reservoir, rainy season is in full swing across Southwest Florida, bringing with it afternoon downpours and humid climates.
Consistent showers and flash storms during the afternoon commute are a sure sign that “rainy” or “thunderstorm season” has arrived. In Southwest Florida, the rainy season runs from May 15 to Oct. 15, according to the National Weather Service.
“During the late spring and summer months of June through September the tropical climate shifts north into our area and this combined with the oceans surrounding the Florida peninsula and daily sea breezes leads to our Thunderstorm Season,” said NWS in Tampa Bay officials.
The NWS said rainy season can begin abruptly some years, while others can see a period of waiting. There are certain circumstances that need to be in place for thunderstorm season to become active.
A combination of the presence of Bermuda high (a high-pressure system over the Atlantic Ocean with the ability to influence the movement of tropical systems in the Atlantic Basin), sea surface temperatures greater than 82 degrees offshore, the increase of moisture and surface dew points in the 70s.
NWS officials said these conditions begin to form in late May or early June before declining in late September, early October. Roughly 55 to 70% of the state’s rainfall comes between June and September.
According to NWS, the rainy season usually has three phases:
• Late May through early July is the “stormiest” part of the season. Severe weather impacts include damaging winds, waterspouts, tornadoes, excessive lightning, hail, and flooding rain.
• Early July through early September remains hot, humid, and wet
• Mid-September through early October tends to have higher rainfall variability due to potential tropical systems and early-fall cold fronts.
NWS’s Rainy Season 2021 Outlook calls for a higher likelihood of wetter and warmer than normal. NWS predicts that temps will likely range about .5 to 1 degree F higher-per-month above the 30-year normal, resulting in warmer-than-normal night and morning temperatures.
When it comes to precipitation outlook, NWS has a “low to medium” level of confidence due to weak, as well as mixed signals from competing factors.
NWS officials said current LaNina conditions, which contributed to drier-than-normal conditions for much of the dry season, is forecast to transition to ENSO-neutral conditions. A consensus of long-range models points to an increased chance of above-normal rainfall, while trends point slightly towards more rainfall than normal.
NWS said the flood risk for South Florida is average.
“Despite the increased likelihood of above normal rainfall this rainy season, the flood risk for South Florida is average (8-10 significant events per rainy season) as water levels to begin the rainy season are at near to slightly below normal levels,” officials said.
Weather hazards associated with the rainy season include lightning, damaging thunderstorm winds, flooding, hail, and even tornadoes. NWS defines May to August as being the period when most of South Florida’s severe weather (flooding, large hail, tornadoes and strong winds) takes place.
“Also, rip currents are common due to the persistent onshore winds,” NWS officials said. “These hazards do not include impacts from any tropical systems that can affect South Florida, particularly during the peak months of August, September and October.”
Fertilizer ban now in effect
June 1 marked the first day of Lee County’s fertilizer ban as per an ordinance adopted in 2008. The ban runs until Sept. 30. Throughout the period, the use of fertilizers containing nitrogen or phosphorus is prohibited.
This regulation was enacted to keep potentially harmful nutrients found in fertilizer from washing off from lawns into storm drains during the rainy months. The fertilizer restrictions apply to citizens and professional landscapers in unincorporated Lee County..
Key points the remember:
• Fertilizers containing nitrogen and/or phosphorus is not permitted between June 1 and Sept. 30
• No fertilizer use is allowed of any kind if a storm watch or warning is in effect
• No fertilizers can be used within 10 feet of any water body, seawall or wetland.
• No grass clippings or vegetative debris may be swept or blown into ditches, drains, waterbodies, sidewalks or roadways.
• Any fertilizer ending up on an impervious surface must be immediately contained and removed to be stored or applied appropriately. Fertilizer may not be swept, washed or blown off impervious surfaces into any water body.
• Deflector shields must be used on spreaders and positioned so granules are deflected away from fertilizer buffer zones, impervious surfaces and water bodies.
Water restrictions and how to be smart
The Southwest Florida Water Management District is encouraging residents who irrigate their lawns to take advantage of the upcoming summer rainy season and “watch the weather, wait to water.”
During the summer months of June, July, August and September, yards need no more thana half to three-quarters of an inch of water every two to three days.
“If your lawn has received enough water from rainfall, turn off the irrigation system and turn it back on when needed,” SWFMD officials said.
The simplest way to determine if your yard needs water is to look for these visual clues:
• Grass blades are folded in half lengthwise on at least one-third of your yard.
• Grass blades appear blue-gray.
• Grass blades do not spring back, leaving footprints on the lawn for several minutes after walking on it.
Follow these tips when you “watch the weather, wait to water”:
• If your yard is showing signs that it needs water, check your local forecast to see if rain is on the way.
• Use a rain gauge to determine how much rain your yard has received.
• If you have a rain sensor, make sure that it is working properly.
• Take full advantage of the rain. Make sure gutter downspouts are directed into landscaped areas or lawn.
• Install a rain barrel to capture excess rainwater.
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