Projected rainfall totals for Mariposa: 2.00" to 3.00"
Projected rainfall totals for Oakhurst: 2.00" to 3.00"
Projected rainfall totals for Yosemite Valley: 2.00" to 3.00"
March 4, 2019 - The National Weather Service Hanford Office reports an atmospheric river is expected to bring significant rain and high elevation snow to much of the Central California interior during Tuesday through Thursday.
Area Forecast Discussion National Weather Service San Joaquin Valley - Hanford CA 258 AM PST Mon Mar 4 2019 .SYNOPSIS...High pressure will move over the region on today for a brief period of dry weather. However, a moisture laden weather system will arrive on Tuesday and persist until Thursday. Another system will bring unsettled conditions Thursday night into at least Friday. && .DISCUSSION...Mostly cloudy skies persist during the overnight hours, although cloud cover is expected to partially clear for today, as a weak upper-level ridge of high pressure moves over Central California. At this time, a few showers remain in the Sierra Nevada foothills towards Mariposa and Oakhurst, but are expected to weaken by daybreak. The remainder of today into tonight will likely be the only dry period for the next several days, as the weak ridge quickly exits our forecast area. Clouds will once again increase by late tonight and Tuesday morning as subtropical moisture begins to stream in the mid and upper levels. Additional moisture, or the atmospheric river plume, will into our area from the southwest by Tuesday afternoon to begin producing rain over much of the region, and the heavier precipitation will begin in earnest by Tuesday night. As the subtropical airmass will be fairly warm, snow levels will rise above 8,000 feet during Tuesday and Tuesday night before falling back to around 7,000 feet by Wednesday with the arrival of the cold front that will push the moisture plume over Southern California. Rain amounts from Tuesday afternoon into Wednesday will be quite impressive. Around one to two inches of rain is expected in the San Joaquin Valley, with 2 to 3 inches in the Sierra Nevada foothills and Kern County Mountains. In addition, rain amounts could reach as high as 3 to 5 inches in the Sierra Nevada below the snow line. Flooding, mudslides, and debris flows remain a concern, with the greatest threat near the recent burn scars. It appears the greatest amounts of precipitation will occur over the Sierra from around Kings Canyon and into much of Tulare County, as models have been consistently advertising for the last few days. Snow amounts in the Sierra Nevada, though at very high elevations, will range from 1 to 2 feet in most locations, but quite a few locations could receive around 3 feet. During Tuesday night into Wednesday, the bulk of the precipitation is expected, although a secondary concern during this time could be gusty winds along the west side of the San Joaquin Valley and through the Kern County mountain areas towards the Grapevine, as south- southwesterly flow moves over our region. Also, expect isolated thunderstorms for Wednesday afternoon and evening, as the atmosphere becomes unstable behind the cold front. During Wednesday evening and into Thursday, snow levels will continue to lower a little, and at least showery precipitation will likely continue until Thursday, as upper-level impulses will pass over our region. Another low pressure trough will arrive by Thursday night and is expected to be relatively cold. Snow levels could lower to around 3,000-3,500 feet in the Sierra Nevada foothills and around 4,000 feet by Friday morning in Kern County. Snow is a possibility at the pass levels in the Tehachapi Mountains. Forecast precipitation amounts will be relatively light with this next system, due to limited moisture. Showers will linger into Friday behind the trough. A brief break in the precipitation is in store for Saturday with another weak ridge of high pressure, but another weather system is forecast to arrive by Sunday. Models are in agreement that another decent subtropical moisture plume will set up, but placement of this feature varies greatly. It appears this system will pass mainly to our south, but could at least bring some showers to our southern forecast area, such as south of Fresno County. So, unsettled conditions are possible once again for early next week.
Source: NWS