We've been in the midst of a glorious weather pattern for most of the last three weeks. These days begin with fog in the mornings in Paso Robles where I live (though usually not at the vineyard) and nighttime temperatures in the mid-40s. The fog burns off by around 8am and the temperature jumps rapidly, getting up into the mid-90s by 1pm. Then, right as you feel it might get stifling, a sea breeze kicks up, and by 4pm it's already noticeably cooler. By 5pm it's cool enough to want to open up the house, and it's chilly by the time we put the kids to bed around 8.
I was struck this morning by the dramatic changes outside, almost by the minute, and did some browsing on my favorite weather sites. I stumbled across an experimental part of the NOAA (National Oceanic and Atmospheric Administration) Web site that offers lots of options for long and short loops of satellite data. I turned one of these loops into an animated GIF which is reproduced below. It shows a great example of fog retreating north up the Salinas Valley, while other fog that has penetrated through some of the gaps in the Santa Lucia valleys retreats west. Tablas Creek is in an area that looks clear, even in the first frame from 6am. The location of the vineyard is located in the satellite map below.
This is another example of what makes our location at Tablas Creek so unique. We're close to the coast (and so get enough rain to farm largely unirrigated) but are east of the coastal range and so we heat up during the day. We get an afternoon sea breeze, which combined with radiational cooling allowed by our dry climate, creates nighttime temperatures routinely 45 degrees cooler than the daytime high. Even better, we get cool nights usually without fog and so avoid the accompanying struggle against mildew and rot that comes with regular moisture. Finally, we're far enough south that we don't typically get our first winter rains until two weeks after Napa and a month after Sonoma and Mendocino. This is an enormous luxury and allows us to safely wait until mid-November to pick our latest-ripening grapes.
This is just one selection of the many weather resources at the National Weather Service. It's well worth checking out for anyone who (like me) loves to look at weather information graphically.