Forecast Process

In this section, we will follow the forecast process from observations, through numerical weather prediction (NWP) models, into the hands of a weather forecaster, and then out to the emergency managers and the public.

The path through the forecast process from observations through NWP, then NHC divisions, followed by the local weather forecast office then to the emergency manager.

Observations are taken by a variety of monitoring systems, including satellites in the upper atmosphere and instruments closer to the surface. Aerial reconnaissance has become an important part of those observations, and these flights are coordinated by a group called CARCAH (Chief, Aerial Reconnaissance Coordination, All Hurricanes), which is based at the NHC.

The observations go into the Numerical Weather Prediction (NWP) system, which uses hurricane models to produce the forecasts that are then analyzed and refined by several groups at NHC, including:

  • TAFB (Tropical Analysis and Forecast Branch), which mainly produces tropical ocean forecasts, but provides additional services during hurricane season
  • HSU (Hurricane Specialists Unit), whose primary task is preparing the forecasts for dissemination
  • HLT ( Hurricane Liaison Team), which serves a communication function between NHC and public officials

Once the NHC forecast products are sent out, the affected WFOs use the information to tailor their local forecasts by including details specific to their warning areas so that emergency managers and the public can use the forecasts to prepare for the expected impacts.

We will begin our look at the forecast process by discussing the observations.