textproduct: San Joaquin Valley

KEY MESSAGES

1. Below Seasonal Average Temperatures will exist across the region through the weekend. A slow rise in temperatures begins near the middle of next week.

2. Precipitation chances increase by this weekend with the best chances of precipitation early next week.

DISCUSSION

Upper Level Disturbance pushing through the West Coast over the next 24 hours will usher in much cooler conditions. While cooler conditions were felt this Monday, even cooler conditions will be observed on Tuesday as Max temperatures drop by as much as 10 to 15 degrees below seasonal normal values. Along with a significant drop in temperatures, the passage of the disturbance will also introduce stronger winds over the wind favored locations of Central California. Latest ensemble surface wind analysis has a good chance (40-70 percent) of observing wind gusts up to 25 mph across some of the higher terrain locations of the area. Furthermore, due to the lack of moisture being introduced over Central California, will expect the passage of the disturbance to remain dry. While Fire Weather concerns due exist, joint probabilities of humidity less than 15 percent and wind gusts at or greater than 25 mph range from 10 to 25 percent across the Mojave Desert. Will monitor.

Probability of Exceedance (PoE) of reaching 90 degrees will start out low during the early part of the forecast period and slowly rise to over 20 percent by next Monday. Therefore, will expect afternoon highs to remain below normal through the week and into the weekend.

Across the Eastern Pacific, satellite imagery and surface marine analysis is still shows an active pattern across the ocean. Tropical Storm Lowell is nearing the Hawaiian Islands with a southerly trajectory as Hurricane Karina is also moving northwest and approaching the Hawaiian Islands to the north. Invest 95E (which is southwest of Acapulco) with greater than a 60 percent chance of forming into a named storm. While high uncertainty exist with the development of Invest 95E, Integrated Water Vapor Transport still show some subtropical moisture is progged to push into the Desert Southwest as the Probability of Measurable Precipitation of receiving a tenth (0.10) of an inch rises to near 25 percent on Sunday with a peak percentage near 30 percent on Monday. The best chances of receiving measurable precipitation will exist over Southern California.

AVIATION

VFR conditions prevailing for 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

None.