DISCUSSION
The passage of a weak disturbance across Northern California allowed for an increase in the onshore flow which resulted in cooler and drier conditions. So far this morning, temperatures have been running some 5 to 10 degrees cooler as overnight lows across the San Joaquin Valley will fall in the 60s (instead of the 70s). The onshore flow also helped the marine layer (as seen on the Fort Ord Profiler) to rise above 2000 feet MSL and provided for additional meso-scale cooling.
Along with the cooling temperatures, surface pressure gradients from KSFO to KLAS were running at around 12.5 mb which correspond to the strong winds observed over Tulare and Kern Counties. Furthermore, Precip-water which had been observed at over one inch is now cut in half and sitting at around half an inch. This rapid drop in moisture in contributing to the lowering in temperatures and the lack of significant convection across the region. While heat and moisture will return to the region, the current weather pattern will delay its return until closer to the end of the week.

Hi-Res short-range Ensemble analysis in very good agreement with the solution of introducing an onshore as the region will see a significant cool-down. Probability of Exceedance (PoE) of reaching 100 degrees has dropped to 20 percent or less this afternoon. Confidence is therefore high that today highs will remain in the 90s. PoE of reaching 100 degrees does not go above 50 percent until Thursday and begins to show 80 percent on Friday.

The cooler air that is pushing into the region is helping maintain a tight surface pressure gradient across the region.
Therefore, with windy conditions expected today, will maintain the Red Flag Warning as dry air and wind contribute toward rapid fire spread. PoE of 30 mph is around 30 percent today and drops to near zero by Sunday. Therefore, will expect the gusty conditions to persist for one more day.

Ensemble moisture analysis is showing a significant push of dry air as the convective potential across the regions shows a sharp drop in value. By this afternoon, ensemble mean precip- water values below 0.4 inches will overspread much of the Sierra Nevada and keep higher values more in Arizona. Therefore, expect plenty of sunshine for most of the week and a slow rise in temperatures. Ensemble Cluster Analysis hints toward the return of the ridge pattern by late in the week as heat and moisture makes it’s return closer to Friday. In the meanwhile, will have to deal with area fires as dry conditions add to the fire danger.

AVIATION
Areas of MVFR and local IFR visibility will continue in and around wildfires. Otherwise, VFR conditions will prevail across the central CA interior over the next 24 hours.

AIR QUALITY ISSUES
None.

CERTAINTY

The level of certainty for days 1 and 2 is high.
The level of certainty for days 3 through 7 is medium.

Certainty levels include low
medium
and high. Please visit www.weather.gov/hnx/certainty.html for additional information and/or to provide feedback.

HNX WATCHES/WARNINGS/ADVISORIES
Wind Advisory until 6 AM PDT early this morning for CAZ338.
Red Flag Warning until 11 PM PDT this evening for CAZ595.