Area Forecast Discussion
National Weather Service - San Joaquin Valley / Hanford, CA
Issued: Wednesday, April 2 2025 - 4:45 PM PDT
UPDATE... Updated AVIATION section.
KEY MESSAGES...
1. 30 to 40 percent chance of mountain showers today and Thursday.
2. Warm and dry through the weekend into next week.
DISCUSSION... The trough that brought us rain yesterday as well as thunderstorms to the San Joaquin Valley has moved slowly southward. However, it is still influencing a cold air flow into our air with drier conditions. This morning we had some low clouds persisting in some areas before burning off along with areas of fog close to the ground. This trough will continue to slowly move south and then east through Friday as a strong ridge starts to move in. However, mountain showers in the afternoon remain a possibility at 30 to 40 percent due to the cold air still being brought in by the trough.
Once the ridge slides in Friday through the weekend, we will see a major warmup in temperatures. Sunday has most of the Valley at a 60 to 85 percent chance of highs of at least 80 although Merced has a 30 percent chance of getting into the 80s. Temperatures drop a bit on Monday and Tuesday as the ridge weakens a bit as a shortwave trough tries to make its way into the Pacific Northwest before the ridge restrengthens next Wednesday. The long term outlook for the 6-10 and 8-14 day outlooks favor a 60 to 80 percent chance of above average temperatures for the San Joaquin Valley and a 40 to 60 percent chance of below average precipitation which favors a very warm and dry pattern as we leave our wet season.
AVIATION... Across the San Joaquin Valley, VFR conditions will prevail.
Over the West Side Hills, the Sierra Nevada and Tehachapi mountains, areas of mountain obscuring IFR in clouds and precipitation thru 06Z Thursday. A slight chance (10%-20%) of thunderstorms thru 03Z Thursday.
For the desert in eastern Kern County, VFR conditions will prevail although westerly winds will remain strong.
AIR QUALITY ISSUES... None.
CERTAINTY...
The level of certainty for days 1 and 2 is medium. 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.