Summer has arrived

California’s summer weather regime has already taken hold across the state. The weather has been warm inland…and breezy and cool along the coast where a pronounced marine layer has resulted from upwelling in the near-shore Pacific. A summer-like offshore flow event is expected to develop over the weekend ecross the northern half of the state, bringing a moderate heat wave and serving to dry out fuel moistures across the state. Snowmelt in the Sierras is already occuring at a rapid rate, and has likely already peaked. What little snow is left will probably be gone completely, even from the highest peaks, by the middle of June. Fire danger has been steadily increasing across the northern half of the state as the breezy and dry weather has taken hold, and NorCal may see its first fires of the season this weekend once strong offshore flow develops. Aside from the outside chance of an isolated early evening thunderstorm near the Sierra crest, all of CA and the entire West for that matter will remain high and dry for the next 2 weeks and likely longer. SoCal’s fire season has been in full swing since December–in other words, the 2006 season never really ended. This year’s fire season in CA is shaping up to be exceptionally severe. In SoCal, extreme and in some cases record-breaking drought has left brush and trees tinder dry, and even with a relative sparseness of fine perennial grasses in some areas, major fires are unfortunately a near-certainty this year. NorCal, which has largely escaped extreme or damaging fires during the past few seasons, will probably not be so lucky this year. The rains were much lighter than usual this year…but some light showers did fall frequently enough to keep the ground somewhat moist for nearly the entire winter and much of the spring…allowing grasses and brush to grow to their full potential but causing trees and other heavier multi-seasonal fuels to dry out much earlier that normal. This is especially true in the upper elevations, where conifer stands will be at serious risk later this summer. La Nina still has yet to develop officially, though the Australian BoM and NOAA CPC models still indicate a high likelihood of development at some point during the next 2 months. We’ll see…as it’s going to be an interesting summer in any case…