Tropical Storm Marie was upgraded to a hurricane Wednesday, and the National Weather Service said it could affect Southern California over Labor Day weekend. The forecast points to rain, gusty winds and high surf if Marie gets close enough to the coast.
The National Weather Service said Tuesday there is a high chance of large waves and strong rip currents for Labor Day beachgoers. It also put the chance of impactful coastal flooding on south-facing shores at moderate, along with a moderate chance of light rain affecting holiday events.
Spaghetti plots and Marie
Some computer models showed Marie getting close to the Southern California coast on Wednesday, but most of the spaghetti plots kept it away. Those plots matter because the clustered lines show where a tropical system may go and how much confidence the forecast carries. The simple lines come from some of the fastest computers in the world making billions of computations.
The forecast spread reflects different ways the models estimate Marie’s path. Dynamical models run for hours on a supercomputer and solve physical equations of motion. Statistical models use historical relationships between storm behavior and details such as location and date. Ensemble models combine forecasts from a collection of other models.
United States Navy model
The Navy Global Environmental Model, run by the United States Navy's Fleet Numerical Meteorology and Oceanography Center, is one of the models feeding those track plots. Its output helped show why one run could point toward the coast while the wider set still leaned away.
For people heading to the beach or planning holiday events, the immediate read is simple: Wednesday’s upgrade did not settle the forecast. Marie still has to make a closer run at Southern California before the region sees anything beyond surf and rip current concerns.
