New: Lightning Detection Warnings
Jeremy Davis, Director of Operations

Weather Routing is pleased to announce that we have launched a brand new product - Lightning Detection Warnings. These are alerts that will keep you informed when lightning is likely within the next 30-60 minutes, so that you can be informed of potentially dangerous strikes, anywhere in the world. These alerts are included when you are onboard receiving services from us, if you already requesting heavy weather alerts. If you are not already receiving heavy weather alerts when using our services and would like to, just let us know. Alerts will also be available to all SeaWeather.net subscribers who opt to receive heavy weather alerts at no extra charge. Alerts will be sent via a notification on our SeaWeather.net app, or via email. 

Below - an example of a Lightning Detection Warning notification on the SeaWeather app, with similar information sent via email.

On SeaWeather, you can also view our lightning alert maps, available in the choices under forecast parameters. You can see recent lightning strikes, and a cone showing the potential area of concern in the short term. If you click on the area of concern, you can view more details about the alert. 

If you have any feedback or suggestions on this new products, or if you have any questions, please email them to wri@wriwx.com, thank you. 

Trans-Atlantic Crossing and Routing Strategies
Alex Glasser, Meteorologist

As spring begins, many vessels begin to plan for their trans-Atlantic voyages to the Mediterranean. As gales/fronts shift northward and a strong semi-permanent ridge of high pressure develops across much of the Central Atlantic, these passages do not come without numerous challenges. Strong ridging can expose vessels to sustained head conditions. Large swell fronts become common across large swaths of the Atlantic due to interactions with gales and fronts.

Another notable concern for a passage is the presence of cut-off lows. These systems typically track further south relative to their parent systems and are often found between 23N and 30N and east of 50W. Cut off lows will often meander in place for several days before accelerating northward as they merge with a passing front. Due to the more unpredictable nature of cut-off lows, more creative routing often becomes necessary to avoid hazardous conditions. For example, routing south of a cut-off can aid in minimizing head conditions which would otherwise be encountered north of the low. 

There are several routing strategies which can be implemented to aid in mitigating the various weather driven risks. Given the climatological position of the semi-permanent ridge of high pressure, a great circle route is often more effective than rhumbline as it better aligns the vessel within the axis of a high-pressure ridge. Conditions along the ridge axis are more favorable because of the weaker pressure gradients, reducing both breezes and the sea state. 

For vessel departing from Florida or the Bahamas, a way to more effectively position your vessel within a ridge of high pressure is to initially route further north toward northern Florida (often using the Gulf Stream) and then commence either a rhumbline or great circle route. This approach not only improves positioning relative to the ridge axis but also provides more accessible bailout options, in Bermuda and/or the Azores, should conditions deteriorate. For vessels departing from the Caribbean, a rhumbline or great circle may be valuable, pending the position/location of the broad ridge axis and strength of the trades. However, a dogleg route north toward/between 35N-30N and 50W-60W and then a turn toward Gibraltar will often be more effective. This altered route will allow initial trades to be more on the beam, allowing the vessel to reach the broader ridge axis and lighter conditions farther to the north sooner.

Finally, when planning a stop either to fuel or to avoid heavy weather, locations such as Madeira, Bermuda, or the Azores are generally more favorable than the Canary Islands. Routing toward Madeira, Bermuda or the Azores will better position vessels within the ridge of high pressure, thereby minimizing head conditions in the process. In contrast routing toward the Canary Island will require vessels to cross through the subtropical ridge axis, leading to stronger head conditions not only while on route to the Canary Islands, but also later to Gibraltar.

 

Potential Routes for Trans-Atlantic Crossing via SeaWeather (www.seaweather.net), including options from N'rn Bahamas/Florida and from the Northeastern Caribbean. 

We at WRI look forward to working with you and finding the route that best meets your needs for your upcoming Trans-Atlantic Voyage. For more information on how we can assist call us at +1 518-798-1110 or email us at wri@wriwx.com.