DGShots

Mt. Helix with an East County Thunderhead in the background.

Towering Thunderstorms have visited parts of the back country, and prompted flash flood warnings, but gentle showers fell along the coast. Mt. Laguna and Pine Valley both received well over an inch of rain, but most rainfall totals were low, with just 0.05 inches in Santee, 0.04 in Poway, 0.03 in Del Mar and 0.1 at Montgomery Field. The seasonal arrival of moisture from the east and south, more or less typical for late summer, contributes to the greening of certain kinds of vegetation.

Ocotillo plants dancing in the wind, Anza Borrego Desert

On the desert floor, for example, the spidery ocotillo can grow an instant crop of green leaves after a storm, only to drop them two to three weeks later if no further rain arrives. The distribution of green-leaved ocotillos tells not only where rain has recently fallen; it also indicates where the runoff has collected and remained for enough time to be absorbed by the ocotillo’s root system.

A male Costa's Hummingbird sits on a barb.

Three hummingbird species are San Diego residents and can be spotted regularly: Anna’s, Black-chinned, and Costa’s hummingbird. Costa’s Hummingbirds arrive at the Anza–Borrego Desert in December and are abundant in spring. Feeding on nectar from many desert plants and small flying insects, they nest in the desert from February into April then leave in early summer. They are also widespread along the coast, on the foothills of the mountains, and in chaparral forests and remain along the coast until mid-August. During the non-breeding season they are found in similar dry habitats as well as parks, gardens, and higher elevation mountains. Adult male Costa’s Hummingbirds have an iridescent purple crown and gorget, a green back, and a green vest. Females and immatures are greenish above with a white eyebrow stripe and whitish underparts.