November 28, 2018 - The National Weather Service Hanford office has updated storm totals for rainfall and snowfall for the area, including Mariposa County and Madera County.
Area Forecast Discussion National Weather Service San Joaquin Valley - Hanford CA 420 AM PST Wed Nov 28 2018 .SYNOPSIS... Wet weather will spread southward this afternoon. Heavy snow is expected in the higher elevations of the Sierra Nevada this evening into Thursday night, while moderate to heavy rain at times will fall elsewhere. Mud/rock slides or debris flow is possible in the Sierra Nevada Foothills this afternoon through Thursday night. Isolated thunderstorms are possible Thursday afternoon and Thursday evening. && .DISCUSSION... KHNX detects patchy, light rain from Fresno County northward. This light rainfall is oriented just ahead of an approaching cold front. This cold front will become stationary over Central California this morning, before moving northward as a warm front this afternoon. It looks as if some subtropical moisture may move across this frontal boundary this afternoon, thereby increasing the possibility of heavy rainfall. As a result, a Flash Flood Watch is in effect starting late this morning for the Mariposa, Madera, Fresno, and Tulare County Foothills. A much stronger storm system will approach the coast of Northern California tonight. The low pressure system will move eastward through the northern half of California Thursday, before passing through the Great Basin Thursday night. This storm system will be responsible for copious amounts of rain and mountain snow from this evening through most of Thursday night. A Winter Storm Warning is in effect starting this evening for the Tulare County mountains and the Sierra Nevada from Yosemite to Kings Canyon for total snow accumulation of around two feet, with locally heavier amounts up to three feet, above elevations of 7000 feet. As the aforementioned low pressure system moves through the northern half of California Thursday, mid-level lapse rates should steepen and cooling should take place aloft. Atmospheric instability may be sufficient for isolated thunderstorms to develop in the San Joaquin Valley and in the Sierra Nevada Foothills Thursday afternoon and Thursday evening. In addition, as this storm system exits the region, we expect strong and gusty west to northwest winds in the Kern County mountains and desert Thursday afternoon and Thursday night. A Wind Advisory may be required for this area Thursday afternoon and Thursday night. In summary, impacts include severe winter weather in the higher elevations of the Sierra Nevada, possible mud/rock slides or debris flow in the Sierra Nevada Foothills, minor urban/street flooding, isolated thunderstorms, and strong, gusty west to northwest winds in the Kern County mountains and desert at various times this afternoon through most of Thursday night. What a mess. An upper-level area of low pressure will approach the Pacific Northwest Friday, before moving onshore Friday night. This area of low pressure aloft will progress southeastward into northwestern Nevada Saturday. A more due eastward trajectory is expected through the Great Basin Saturday night. A ridge of high pressure between longitude 140 West and 130 West will approach California late in the upcoming weekend into early next week. Another Eastern Pacific storm system may begin to impact California Tuesday.
Source: NWS
