With this knowledge, forecasters can determine their forecast biases and subsequently adjust their TAF forecasts. The end result will be more accurate TAFs and better service to everyone in the aviation community. In the last newsletter, I discussed Santa Ana winds. Now, I would like to discuss another type of offshore wind, the Sundowner. Sundowner winds are gusty downslope winds that affect the coastal plain of Santa Barbara county, south of the Santa Ynez Mountains.
Sundowners get their name due to the fact that they develop in the late afternoon or early evening.
The atmospheric pattern which produces Sundowners is quite simple. The major ingredient is a strong pressure gradient between Santa Maria and Santa Barbara with higher pressure over Santa Maria. In addition, low level north winds are necessary. Given the topography across southern Santa Barbara county, the pressure gradients and low level winds combine to generate strong winds through the passes and canyons of the Santa Ynez Mountains. Sundowners, based on their strength, can have a wide variety of impacts.