Projected Precipitation for Mariposa 0.25" - 0.50"
Projected Precipitation for Oakhurst 0.25" - 0.50"
Projected Precipitation for Yosemite Valley 0.50" - 1.00"
December 21, 2021 - The National Weather Service Hanford Office reports a the first in a series of atmospheric disturbances will impact Central California after midnight Tuesday night and Wednesday.
Most of this precipitation will fall Wednesday afternoon.
Much larger amounts of rain and snow are likely Wednesday night into the holiday weekend.
Area Forecast Discussion National Weather Service Hanford CA 311 AM PST Tue Dec 21 2021 .SYNOPSIS... Cool and mainly dry conditions continue through most of the day Tuesday. Periods of occasionally moderate to heavy rain and mountain snow will begin by Tuesday night and continue into early next week. && .DISCUSSION... A cool raw day in the San Joaquin valley yesterday due to a stubborn low stratus cloud cover. Most locales reported less than a 5 degree difference between the low and high temperature. The low clouds have been lowering to less than 1kft and will likely result in some patchy fog forming this morning. Some subtropical moisture has been streaming in from the southwest, making it difficult to see the lower level cloud cover on the differencing fog channel. Think the low stratus deck should mix out this afternoon due to an increasing low level south flow. Otherwise the remaining of the forecast area should see sunshine with some mid and high level clouds. Ensemble model solutions in fair agreement that dry pattern will turn wet by midweek and turn cooler and wet during the Christmas weekend. A storm off the pacific Northwest Coast will shift towards west coast as several short waves move through the north flow out of Alaska. 500MB cluster analysis show lots of variance in the timing of individual short waves. Models show subtropical moisture moving from the southwest with well above normal precipitable water across Central CA on Wednesday. The high moisture with atmospheric river values could last until Christmas morning. Precipitation associated with the incoming low pressure system is progged to begin impacting our area as late Tuesday night, spreading southward across the area through the day Wednesday. Snow levels will rise above 7000 feet in the warm southwesterly flow ahead of the approaching system. Rainfall amounts ranging from around 1/10 of an inch in the south San Joaquin Valley to 1/4 inch farther north can be expected initially, with a bit higher amounts in the foothills. Where snow does accumulate in the higher elevations, around 8 to 16 inches is likely. A winter Weather Advisory is in effect for the Sierra Nevada from Sequoia National Park northward Tuesday night and Wednesday. Additional waves of energy will bring further precipitation across central California Wednesday night through the Christmas holiday weekend. Larger accumulations of rain and snow will occur, and snow levels will lower as colder air moves into the region. By Thursday snow levels begin lowering and will be down to around 4000 ft by Friday, then as low as 3500 ft over the weekend. With additional widespread snow accumulations of 1 to 5 feet expected, A Winter Storm Warning has been issued for the Sierra north of Lake Isabella from Wednesday afternoon through Sunday afternoon. In addition to the snow, San Joaquin Valley locations will receive around 1 to 1.5 inches of rainfall, with around 2-3 inches in the foothills and 1/2 to 3/4 of an inch in the desert areas. Temperatures will run close to seasonal averages but turn cooler during the weekend due to a strong ridge over the NPac providing a cold north flow out of Alaska. && .AVIATION... Widespread IFR and and local LIFR visibilities and ceilings in mist/fog and stratus across the San Joaquin Valley through 18z Tuesday. Otherwise, VFR conditions will prevail across the central CA interior for the next 24 hours. && .AIR QUALITY ISSUES... On Tuesday December 21 2021... Fireplace/Wood Stove Burning Status is: No Burning Unless Registered in Fresno... Kern... Kings... Madera... Merced and Tulare Counties. Further information is available at Valleyair.orgSource: NWS
