Includes Mariposa, Oakhurst and Yosemite National Park
March 9, 2021 - The National Weather Service Hanford Office reports a few strong thunderstorms are possible in most of Central California Wednesday.
In addition to dangerous lightning strikes, small hail, and wind gusts near 45 mph, any thunderstorm can produce intense rainfall rates, leading to localized flooding.
Area Forecast Discussion National Weather Service Hanford CA 1025 AM PST Tue Mar 9 2021 .Updated to add Wind Advisory for the Kern County mountains and desert... && .SYNOPSIS...A slow moving storm system will bring cooler conditions and precipitation this afternoon through Thursday. There is a slight chance of thunderstorms Wednesday afternoon and evening, mainly across the San Joaquin Valley. Dry weather along with a warming trend are likely Friday into the weekend. && .DISCUSSION...Strong upper level jet to the south of a cold core low currently situated off the Pacific Northwest coast will support strong southwest to west winds through and below the Kern County mountain passes through 10 pm this evening. As the cold core low and the associated upper level jet migrate southward, winds will diminish in the advisory area tonight. Otherwise, we expect an increase in convection over much of our CWA, especially the mountains, as the cold core low drifts southeastward during the next 24 to 36 hours. && .PREV DISCUSSION... /issued 435 AM PST Tue Mar 9 2021/ Satellite images show a southwest flow bringing mid and upper moisture into central CA this morning. Radar picking up on a few showers off the Monterrey coast as a short wave approaches the coast. This feature is well south of the main core low which is still off the CA/OR coast. The initial disturbance will bring an increasing threat of precipitation this afternoon. Models indicate some instability for possible thunder towards the Merced area. The cold core low moves south along the CA coast through Thursday. The heavier precipitation may occur early Wednesday morning with the low situated off the North CA coast placing central CA in a favorable dynamic area of the upper trough along with a SSW flow providing additional forcing due to orographic lift over the sierra mountains. Models show more widespread instability across central CA Wednesday afternoon with pretty unstable conditions with lapse rates of 8.5C/KM at mid level. Isolated thunder will be more probable Wednesday afternoon across the San Joaquin Valley and towards the coast. Winds finally turn North as the low approaches Point Conception Thursday morning and over S CA Thursday afternoon. Latest guidance for precipitation amountgs is slightly less but still prog up to one inch and half over the parts of the sierra high country. Snow levels will be relatively low around 4kft this afternoon and lower to road pass level around 3-3.5kft tonight. Thus Kern county mountain road passes could see impacts Wednesday morning. A stronger offshore flow develop over the sierra Thursday night as the trough moves onshore over SCal. Weak to moderate Mono wind may be possible into Friday morning. Models are in poor agreement for the latter part of the forecast. But general consensus is for an upper ridge along the EPac shifting inland over the area during the weekend bringing a drier and warming trend.Source: NWS
