Boats along the U.S. East Coast have mere weeks to safely make their way south to Florida in time for the Fort Lauderdale International Boat Show – and as one might expect, weather systems in the area have already become significantly stronger than they were just a month ago. Let’s take a look at what the weather pattern is like now, how it is expected to evolve over the next two to three weeks and how that is likely to affect general routing for yachts transiting the U.S. East Coast.
The movement of low pressure systems is controlled by the position and strength of the jet stream. We are seeing more of a “zonal,” or west to east, jet stream at this time, resulting in systems that move rapidly from west to east across the Mid Atlantic or New England States. We are not expecting any significant changes to this pattern through the next week, with relatively strong lows moving through the northeastern U.S. about every three days.
There are indications of a sharp upper-level trough developing across the eastern U.S. by the weekend of October 17 and 18. This has the potential to lead to a larger low pressure system developing in the Appalachians or over the East Coast. With the sharper trough aloft, any system that develops would likely be stronger and more of a slow-mover than the systems we will see for the next week.
Beyond next weekend and through the remainder of the month, available data indicates that the trough at the jet stream level may tend to persist in the eastern U.S., perhaps even strengthen and move farther south into the southeastern states. Were that to be the case, the active weather pattern along the East Coast would continue with the systems shifting southward into Virginia through the Carolinas, with associated cold fronts having a much improved chance of moving into and through Florida.
Choosing a route south along the East Coast – the “Ditch,” coastal or offshore route – will be different for each vessel, depending on what the vessel can handle. Over the next week, areas north of Cape Hatteras will have windows for transit southward, though these will often be short-lived due to fast-moving weather systems. Enhanced southerlies ahead of the systems will make for very rough conditions at times, though more offshore northwest-westerly winds following the systems may allow for more coastal routing.
Areas south of Cape Hatteras will feel the systems passing north with periods of enhanced southerlies developing, which will then ease as the system exits to the north. Weather windows here will be longer in nature than those farther north. A stronger high following the system in the middle of next week will likely result in at least a couple of days of enhanced northeast-easterlies along the southeastern U.S., and delays for vessels unable/unwilling to route via the ICW.
A slower moving/stronger system potentially arriving by next weekend could have more impacts for the entire East Coast, with enhanced southerlies followed by northerlies along the length of the coast. Those vessels needing to make headway southward during this time may be restricted to the ICW.
With a potential trough developing in the eastern U.S. toward the end of the month, those vessels looking to make a last-moment dash southward may be in for rough weather. Systems passing thru the Carolinas would result in enhanced easterlies near/north of Cape Hatteras, strong squalls through the Southeast, and enhanced northerlies for much of the coast following the systems. Vessels with weather constraints and those that cannot or will not transit the ICW may potentially find themselves in port for extended periods (perhaps as long as three to five days) while they await an adequate window to head southward.
Stay tuned to the weather forecasts, stay alert and stay safe as we forge ahead through October. Safe travels to all!
Weather Routing Inc. (WRI) has provided meteorological consultation, including route planning and weather forecasts, to private yachts since 1961. For more information, visit www.wriwx.com.
All Quiet on the Atlantic Tropics Front