textproduct: San Joaquin Valley

UPDATE

AQ Section Updated

KEY MESSAGES

1. Warming trend into next week.

2. A warmer system slides into Northern California with precipitation in the northern portions of the Sierra Nevada through Wednesday morning. Snow levels will rise to 10,000 to 11,000 feet by Wednesday morning.

DISCUSSION

A warm system is expected to move through Northern California today and is likely to enter Central California by tonight. Snow levels with this system are expected to rise to around 10,000 to 11,000 feet by Tuesday and maintain that level into Wednesday. This would then cause any precipitation that falls to be mainly rain that would fall onto the freshly fallen snow from the previous winter system. Current rain totals for this system are likely to be 1 to 1.5 inches north of Fresno County, with the highest amounts around Yosemite NP. There is also a 10% chance for 2 to 3 inches in that location. This rain falling onto the snow may then lead to additional runoff that would raise rivers and may cause some flooding, though much of the rainfall is expected further north. As for additional snowfall above 10,000 feet, amounts range from a trace to a few inches of new snow, mainly around Yosemite NP.

After this system moves out of the region by Wednesday afternoon, the warming trend is expected to continue as the ridge currently aloft remains in place, keeping the region in above normal temperatures and leading to below average precipitation. This ridge would also allow for the development of dense fog in the San Joaquin Valley from Thursday into Saturday. This pattern is expected to continue through next week, with the Climate Prediction Center keeping with a similar pattern through Day 14.

AVIATION

VFR conditions across central California for the next 24 hours.

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.