Understanding Local Diurnal Winds Sea Breezes and Land Breezes dependent on the differences in heating and cooling between land and water. Upslope and downslope winds forced by the differences in heating and cooling between terrain and lowlands.

Diurnal Local Winds

Diurnal Winds 101

Why?

Sea and Land Breezes Influence Clouds!

Converging Sea Breezes Can Force Convection in the Middle of Peninsulas and Islands

Fig. 7-6, p. 175 Stepped Art

Fig. 7-7, p. 176

Summer Diurnal Winds Over Western Wa

The Sound Breeze Viewed Using Ferry Data

Picture take in Sequim looking N Strong Regional Sea Breeze Winds During the Summer

Sea Breeze Winds Along the Southern Oregon Coast Gusts frequently reach knots during the summer during the afternoon. Very painful to stay on the beach! Strong pressure gradient normal to the coast between the warm land areas and the cold upwelling water.

Southern Oregon Coast Near Brookings

2-minute average July-August winds along the Northwest coast.

Land Breezes Tend to Be Weak in the Northwest Why? Because the land rarely cools down more than the water. Local minimum temperatures generally in the low to mid-50s…similar to the temperature of the Sound and the Pacific Ocean. But it can happen in winter during unusually cold periods.

Land Breeze example during a cold period.

Slope Winds Upslope Flow on Heated Slopes Downslope Flow on Cooled Slopes

Fig. 7-11, p. 178 Upslope Winds Can Produce Clouds Over the Mountain Crests During the Day

Fig. 7-12, p. 179

You can feel upslope winds on warms days and hang gliders often take advantage of them!

A Local Example of Upslope and Downslope Flow: Eastern WA

Low temperatures are generally cooler in low spots on cold, cloud-free nights due to downslope flows.

The Columbia River Gorge: A Regional Local Diurnal Circulation

Diurnal Local Winds in the Columbia Gorge Hot Low Pressure High Pressure

Stateline Wind Farm