Over the last few weeks, we have been working to expand the current CNAPS forecast from 3 to 7 days. With the appearance of Hurricanes Harvey and Irma, and the peak of the hurricane season on September 10, we were graciously allocated additional computing power from the High Performance Computing (HPC) Center at North Carolina State University to perform some experimental simulations of a 7-day forecast. We now have a framework to run our CNAPS nowcast/forecast for 168 hours quasi-operationally.
This forecast, initialized at 00Z on September 5, shows Irma entering the CNAPS domain near the Leeward Islands in the Caribbean, moving along the northern coast of Cuba, abruptly making a turn to the north to bisect the state of Florida, then weakening over the southeast U.S. This is in line with several of the national forecast models run at the same time.
Our usual 72-hour CNAPS forecast will run as normal, and we will provide additional experimental analysis and products about Irma as it threatens the U.S. Stay tuned for more updates.