According to the latest National Hurricane Center (NHC) advisory, Otto should regain hurricane strength prior to landfall, although this depends upon a number of varying factors. Hurricane Watch Net Manager (HWN) Bobby Graves, KB5HAV, reports that southeasterly shear has increased, allowing drier air to enter the storm. Global models are suggesting the shear will decrease before landfall, and later today Otto, with sustained winds of 70 MPH, should be moving over warmer waters that have not be subjected to any storm-forced upwelling. These factors suggest Otto could regain strength overnight or into Thursday.
“Whether or not Otto makes landfall as a hurricane, rainfall remains a huge concern,” Graves said. According to the 1500 UTC NHC advisory: Outer rain bands from Otto are expected to produce rainfall accumulations of 4 to 8 inches over San Andres and Providencia islands, and the higher terrain of central and western Panama and southern Costa Rica through today. Total rainfall of 6 to 12 inches, with isolated amounts of 15 to 20 inches, can be expected across northern Costa Rica and southern Nicaragua through Thursday. These rains will likely result in life-threatening flash floods and mudslides.
Graves said that given the uncertainty in the forecast, he will wait until after the 2100 UTC NHC advisory to decide on the Net’s activation status. For now, the Net remains in Monitoring Mode.