Hurricane season is about to arrive in a very physical way on the East Coast of the US, as current tracking shows that Hurricane Florence, recently upgraded to a Category 4, could make landfall Thursday evening at Wilmington, North Carolina.
However, with the worst effects of the storm not expected until Thursday or Friday, there’s still a great deal of uncertainty about the storm’s path. Weather forecasting is notoriously tricky to get right, even with supercomputers and some of the world’s best scientists on the case. Different approaches to forecasting have led to a mess of different predicted storm paths, with the options including a full-on hurricane hit for North Carolina, or a stall offshore that could bring torrential rain.
With all that said, you can still stay informed about the storm and understand the different probabilities involved in its future.
Know your models
There’s a few different ways that meteorologists use to try and predict the path of a storm. Historically, the most accurate model for predicting the track of a storm is that produced by the European Center for Medium-Range Weather Forecasts, known as the “European model.” It uses an array of supercomputers to model weather for the entire planet. By knowing what the weather will be like all round the world, the theory goes, it’s easier to predict the path of any one particular storm. The downside to the European model is that it only runs twice a day, thanks to the amount of computational power required.
The American equivalent is called the Global Forecasting System (GFS), run by the National Weather Service. It’s run four times per day at a lower resolution, and although it’s not held in as high regard as the ECMWF, the timely data is still useful to forecasters.
J Emory Parker, a journalist in Charleston, SC, has collected some useful information on the publishing times and sources of different forecasts:
The National Hurricane Center in Miami uses data from both models, as well as other inputs, when producing its reports. The US also has the Hurricane Weather Research and Forecasting (HWRF), which uses real-time data from aircraft and satellites to monitor changing weather conditions faster than the scientific models. The HWRF was recently key in monitoring the intensity of Hurricane Harvey.
Check the National Hurricane Center
Luckily, you don’t have to weigh the pros and cons of different weather forecasts and monitoring services. The National Hurricane Center produces a number of constantly-updated maps and advisories for tracking a hurricane, and should be your first port of call for information.
It has a central page of information on Florence that provides an overview of the hurricane’s current status, predicted track, and areas that should be taking action. The page also shows the most recent public advisory, forecast advisory, and forecast discussion. The public advisory is a one-page statement that tells you about the likely outcome of the storm, and what action you should take; the forecast advisory and discussion give more information and are more technical.
The best visual aide is the interactive warnings/cone map, which shows the current best-guess prediction for the hurricane’s path. The “cone” shown on the map is where the eye of the storm is probably going to pass; anywhere within that cone is possible, with the line down the middle showing the storm’s most likely path — but it’s far from a guarantee.
Understand the dangers
The dangers from Hurricane Florence likely won’t be limited to waves and high winds. Storm surges, which cause extreme flooding, are also possible, as well as freshwater flooding from rainfall. Wind speed probabilities are published here, while the wind arrival times are here. Storm surge warnings will be published closer to the date if necessary.
If you want one single easily-digestible piece of information, the key messages bulletin is regularly updated and can give you a simple-to-understand overview of what’s going on.