Critical fire weather likely

The last 48 hours have seen quite a bit of thunderstorm activity over the state of CA. Hundreds of lightning strikes occurred as far north as the Monterey Bay Area yesterday, especially over inland areas. Many of these storms actually dropped some rain, but a number of wildfire starts did occur in remote locations. More numerous thunderstorm activity will continue over the mountains of SoCal and over the Sierras for several more days, possibly approaching the coast in more southern areas. The main focus is currently on the medium range, however, when two interesting events have the potential to occur. Firstly and most likely, a moderate to strong offshore wind event will occur by midweek in NorCal and CentCal, possibly affecting SoCal as well. A fairly strong trough will pass well north of CA and turn winds offshore, bringing extremely dry and breezy to windy but still hot (in some places, quite hot as a result of downsloping and compressional heating) temperatures to nearly the entire state, including the coastline. Fire weather will be critical, especially considering the fire starts already smoldering from this week’s continuing lightning. Stay tuned…could be a major fire outbreak next week.

The other item of interest is soon-to-be-Hurricane Henrietta in the Eastern Pacific. Models had waffled quite a bit as to the storm’s eventual track, but now seem to be converging on a rather interesting one. Latest NHC forecast brings the storm about 50-100 miles west of Baja and indicates a continued N/NW motion after day 5 as a strong tropical storm (60 kt). After this week’s offshore event passes through, flow will once again develop at least some southerly component, which would encourage remnant moisture (at least) to advect over CA. Areas from the Central Coast south would be most liekly to recieve moisture from Henrietta, but areas further north should stay tuned in case flow does become more favorable or the remnants maintain a circulation more robust than is currently indicated. After a very boring summer weatherwise in CA, the activity has begun to pick up…