It comes just days after Nicholas made landfall southwest of Galveston, Tex., as a Category 1 hurricane, bringing winds gusting to 95 mph and up to 14 inches of rainfall, spurring pockets of flash flooding and a damaging coastal storm surge. Flash flood watches remain in effect from Acadiana and the Florida Parishes of Louisiana through coastal Mississippi and Alabama and as far east as the Florida Panhandle.
Nicholas marked the 19th named storm to make landfall in the Lower 48 in the past 17 months, representing a period of hyperactive tropical activity that appears virtually unmatched in the historical record.
Tropical weather specialists continue to highlight the likelihood of a continued above-average season, with a number of additional storms likely to develop. Last year’s record-busy season produced named storms all the way to December.
Nicholas dissipates after drenching Gulf Coast
Nicholas is mostly gone, but certainly not forgotten — and its lingering remnants, mostly decayed, are still juicing up the atmosphere to invigorate daily thunderstorms rumbling along the Gulf Coast. On Wednesday, the heaviest rainfall targeted areas along Interstate 10 from Biloxi, Miss., to near Panama City, Fla., including the greater Mobile area. Roughly 4.45 inches fell in Pensacola, Fla., with more than a foot in northwest Escambia County, while a 7.48 inch total was reported at the immediate coastline.
Gulf Shores, Ala., had a 4.58-inch total, and 5.85 inches were measured just west of Mobile Bay. Rain totals of 4 to 8 inches were observed in coastal Louisiana, and a jackpot of 13.98 inches was tallied in Galveston.
On weather maps, Nicholas still appeared as a remnant swirl dejectedly fading in southern Louisiana, but, for all intents and purposes, it is gone — all that is left is some cloud cover and a more robust ribbon of tropical moisture that is energizing isolated to widely scattered downpours and thunderstorms. The most intense band stretched from the northeast Gulf of Mexico to Interstate 59-20 in western Alabama, northwest of Montgomery, shortly after sunrise, but the overall haphazard spattering of downpours was virtually indistinguishable from a typical late summer array of daily Deep South storm chances.
Areas that see any additional showers or thunderstorms could pick up another inch or two. Some locations could see up to four inches if storms train, or repeatedly move, over the same areas. Otherwise, the main act of Nicholas is mostly over, allowing beleaguered residents hit by the back-to-back storms, including Ida, to begin a return to some semblance of normalcy.
System to spin up by Eastern Seaboard
For days, a lobe of spin has been daintily whirling around and minding its own business north of the Bahamas. Water vapor data from satellites shows the system is marked by a concentrated pocket of moisture, illustrating a saturated atmosphere. Visible satellite imagery shows a healthy arc of convection, or shower and thunderstorm activity, tracing around the center of nascent low pressure.
It also appeared the system had healthy upper-level outflow, meaning air exiting thunderstorms at high altitudes as “exhaust” is easily evacuated from the center. This outflow allows more air to be drawn in at the low levels, permitting the system to intensify.
Dry air on the western side was preventing any flare-ups of thunderstorms closer to the Carolina coastline, and it appeared the fledgling disturbance may have been ingesting more stable, cool continental air. That should keep the system rather lopsided, with the bulk of rain east of its center.
It’s probable that the system will develop into a tropical depression or, perhaps, tropical storm by Saturday. The National Hurricane Center estimates a 70 percent chance of development. The name “Odette” is next up on the list.
An Air Force Reserve hurricane hunter aircraft will investigate the system later today. As it stands now, however, the system looks to remain fully offshore, steered out to sea by a cold front. The only direct impacts to U.S. soil will be high surf and rip currents. The National Weather Service in Morehead City, N.C., issued a high rip current risk for parts of the Carolina coastline, cautioning of “life-threatening rip currents” on Thursday.
The system will probably intensify over the Gulf Stream before ejecting into the north central Atlantic and transitioning into a powerful extratropical cyclone early next week.
Area to watch off African coastline
A suspicious area of disturbed weather called Invest 95L ejected offshore of Senegal in western Africa earlier this week. Invest 95L is located about 800 miles west-southwest of the Cabo Verde Islands and is drifting nearly due west.
Shower and thunderstorm activity has struggled to materialize and remain sustained, though the system possesses healthy spin and is decently consolidated. Despite the obstacles that have plagued it thus far, it is likely to become a tropical depression or storm by the start of the workweek.
There are signs it will gradually develop and could approach or skirt the northern Leeward Islands by Tuesday. Then it becomes a question of how quickly it “recurves” north-northeast and out to sea. While it probably will avoid most land masses, one should never let their guard down in September.