textproduct: San Joaquin Valley

KEY MESSAGES

1. Below average temperatures and dry conditions are expected for the next several days.

2. A disturbance moving south from near Alaska and a low pressure system tracking south of us and coming off the Pacific Ocean could potentially bring the next chance for precipitation in our area by this coming weekend (low confidence).

DISCUSSION

Central California experienced mostly sunny skies and near- seasonal temperatures today. A disturbance moving through the Pacific Northwest brought cooler conditions and stronger winds over the higher terrain of the Sierra Nevada and the Coastal Range, though it remained too far north to bring precipitation. Temperature-wise, the Probability of Exceedance (PoE) of reaching 70 degrees remains above 70 percent through Friday, dropping below 20 percent over the weekend. The PoE of reaching 75 degrees outside the Mojave Desert remains below 10 percent into early next week. Lingering moisture may produce mist and haze across the San Joaquin Valley-primarily between Visalia and Hanford-ahead of the next storm system. Fog remains unlikely, with the PoE of visibility dropping below 3 miles sitting at less than 10 percent.

Long Term Ensemble models continue to show strong consensus for a robust storm developing off the Pacific Northwest coast on Saturday, bringing another round of precipitation to Central California starting late Saturday into early Sunday morning. The heaviest precipitation is expected later in the day on Sunday. While confidence in precipitation is high, model variability remains regarding exact accumulation totals due to a split flow weather pattern. Current guidance indicates:

* 48-Hour Probability of Precipitation (Late Saturday Early Monday): 25-45% chance of receiving 0.50 of an inch across the Sierra Nevada. * 48-Hour Snow Probabilities (Late Saturday Early Monday): 20-40% chance of receiving 4 inches across the Sierra Nevada above 7,000 feet. * 50th Percentile: Precipitation is very likely across the region this weekend. * 90th Percentile: (Worst-Cast Scenario): Up to 2 inches of liquid equivalent (rain/snow) across Central California.

We will continue to monitor and evaluate the potential for heavy (excessive rainfall) rainfall as new guidance become available.

AVIATION

There is a potential for visibility to be slightly reduced over KBFL early tomorrow morning resulting in MVFR conditions. Otherwise, VFR conditions will prevail 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.