Synopsis…
Severe to extreme drought across South Ops will continue to worsen through the spring time as dry conditions persist. Fuel moisture levels are running below average across most of the operational area. Grass and brush fires will continue to ramp up with large fire activity occurring 3-4 weeks ahead of normal. A smaller grass crop due to lack of precipitation could lead to a shorter window for grass fire season as the small grass crop decays earlier in the season. Modoki La Nina over the eastern pacific should promote a higher chance of monsoonal moisture influxes from the south this year, with the possibility of an early monsoon. However, extreme drought across the desert SW will limit the amount of low level moisture available. The Southern Sierra Nevada is reporting 11% snowpack or 14% of normal for this time of year. South ops major reservoirs apart of the aqueduct system are running an average of 72% of normal for this time of year, however with virtually no snow pack available there is a major threat for this number to drop to critical levels.
Short term…
High pressure continues to build across South Ops with weak offshore flow at the surface. The winds are gradient and subsidence driven as upper level support has dropped off from yesterday. The anomalous upper level high pressure is causing near record heat across Southern CA along with RH in the 8-15% range. This is causing further drying of fuels through Saturday. Cooling begins this weekend as an inside slider deepens the marine layer and promotes strong NW flow across South Ops. The widespread deeper marine layer is short lived as the inside slider moves away and ridging builds back over the area into the middle of next week.
The highly amplified, see-saw pattern that has been occurring since last spring that brings cooler weather followed by much above average temperatures is continuing. This pattern promoted strong NW flow followed by drying offshore flow, which reduced the amount of marine layer coverage and days it was present plus dried fuels out. This is continuing through at least the middle part of May.
Long term…
Sea surface temperatures off of the Southern CA coast continue to be below average, whereas the Western and Northern Pacific continues to be above average. The increased SST in the West and North Pacific could promote stronger tropical cyclone activity and a robust jet stream in the N pacific this summer as a result. This could lead to an extremely chaotic weather pattern across the US, with increased tropical cyclone activity across the southern US, high pressure across the central plains, and severe weather across the northern US. The modoki La Nina could lead to stronger high pressure across the 4 corners region, allowing for increased chances for monsoonal moisture. We are overdue for an active season. Due to extreme drought across the SW, the beginning of the monsoon season could start off very dry.
It is too early to predict past 3 months regarding offshore wind season.