For grape growers and winemakers like Jennifer Lamb of HL Vineyards, spring in the Napa Valley is all about emerging buds not much bigger than the tips of pencils.
"What we worry about is the moment these little tiny buds come out, how to protect this vine and this crop for the rest of the growing season," says Lamb.
In that sense, a person could view all of the Napa Valley as an intensive care nursery, right now. A place with so much potential and yet, so much danger.
At this early point in the season, the small buds are very sensitive to temperature change. Three degrees can make all the difference.
"It could mean a healthy crop versus a completely damaged green tissue which you would get relatively no crop off of," says Paul Goldberg of Bettinelli Vineyards.
As Goldberg knows, full well, temperatures can fluctuate even within a few yards, and he has vineyards spread across the valley. But at least he can monitor them all at once, thanks to a series of weather stations to the Internet.
"We have air temperature at different heights, soil temperature, soil moisture, dew point, leaf wetness, solar radiation, wind speed, humidity..." says Goldberg.
Yes, such variables do matter. And now growers like Matt Lamborn use satellites and Google Earth to track progress on smartphones.
"It's a snapshot -- an aerial photo of your property and it measures the reflectance of light off grapevines, and by doing that it says these are the vigorous areas and these are the non-vigorous areas."
Or to put it another way -- so much for the little old winemaker with bare feet, dust between his toes, and a hunch.