Projected rainfall totals for Mariposa: 0.25" to 0.50"
Projected rainfall totals for Oakhurst: 0.50" to 1.00"
Projected rainfall totals for Yosemite Valley: 0.50" to 1.00"
April 25, 2021 - The National Weather Service Hanford Office reports a storm system will continue to impact Central California through Monday morning.The majority of precipitation associated with this storm system will fall today.
Snow levels will start at around 6,000, before falling to about 4,000 feet Monday morning.
Area Forecast Discussion National Weather Service Hanford CA 345 AM PDT Sun Apr 25 2021 .SYNOPSIS... A storm system will move into the region this morning, and will continue through Monday morning. This system will bring some very beneficial precipitation for the entire district, as well as below average temperatures on Sunday and Monday. Dry weather will return by Tuesday as temperatures trend up. Temperatures will then increase to well above average by mid- week into the weekend. && .DISCUSSION... Change in the weather is occurring across Central California as precipitation is once again being observed. Currently, very light precipitation is starting to reach the Yosemite NP area along with portions of Merced, Mariposa and Madera Counties. Regional Radar estimated precipitation rates are showing mainly trace amounts. Upper-air analysis, along with satellite IR imagery is showing the upper low still off the West Coast and expected to make landfall this morning. Until the upper low makes landfall the district will be under the influence of the warm sector ahead of the advancing cold front. This has allowed surface temperatures across the area to remain in the 50s along with a lull in winds. Once the upper low makes landfall and begins pushing ashore, the cold front near the Northern California coast will begin sweeping through the state and is expected to move pass Kern County before sunset. Unsettled weather conditions are expected this Sunday, mainly, during the passage of the cold front across the region. The light precipitation currently being observed will become heavy at times during cold frontal passage along with stronger winds. Precip- water satellite imagery is showing a good plume of higher moisture values pushing in from the west. Therefore, support will exist on having the heavier precipitate rates today as a surge of cold air invades the Central California Interior. This combination will allow for Winter-like conditions to exist across the Sierra Nevada as significant snowfall is expected today. Weak Atmospheric River conditions along with a +100 knot jet max will provide good orographic (mechanical) lift of the higher moisture values entering the district. Therefore, even with the movement of the upper low remaining north of the district and keeping the bulk of its dynamic energy over Northern California, enough energy could sweep through the area as a very high potential of receiving widespread measurable precipitation will exist. Furthermore, instability will increase during cold frontal passage this afternoon. A threat of thunderstorms will exist and could reach as far south as the San Joaquin Valley portion of Kern County. Along with the other unsettled weather conditions, temperatures this afternoon with is poor recovery and may not rise much higher then where they will be at sunrise. This surge of cold air will also allow for snow level to reach the 5000 foot level for late April. Yet, being late April, the cold air conditions will be short-lived as the area will quickly rebound by mid-week. Tuesday may still see lingering effects of the storm as ensembles are still leaning in the direction of another ridge pattern by mid-week. Having to deal with a closed low, uncertainty is still to high to call the next ridge a blocking pattern, yet, the ensemble mean is attempting to develop and then break down the ridge toward next Friday. At the moment, will lean in the direction of keeping the ridge pattern in existence over the West Coast for the remainder of next week. Therefore, will see precipitation in the short term and then return to a dry pattern for the remainder of the forecast period.Source: NWS
