August 14, 2021 - The National Weather Service Hanford Office reports there is a low chance that thunderstorms will develop over the Sierra Nevada each afternoon through Monday.
The storms are expected to be dry or produce little rainfall.
In addition to dangerous cloud to ground lightning, there will be an increase threat of fire starts due to gusty erratic winds, dry vegetation and little rainfall.
Area Forecast Discussion National Weather Service Hanford CA 243 AM PDT Sat Aug 14 2021 .SYNOPSIS... Hot temperatures will continue this weekend and early next week due to high pressure aloft over the area. Afternoon convection remains a possibility through Monday in the Sierra Nevada. Cooler by the middle of next week, but seasonably warm temperatures remain across the forecast area. && .DISCUSSION... Another warm day is forecast for the San Joaquin Valley and the Mojave Desert as the ridge pattern continues to strengthen. Afternoon high temperatures ranging from 102 to 106 degrees are forecast for the valley, which is prompting the Heat Advisory today. Hot temperatures will occur in the Mojave Desert this afternoon, with highs of 105-110 expected there, so an Excessive Heat Warning will be in effect there today. The ridge of high pressure continues to strengthen tomorrow, so highs may top out a degree or two higher than today for the entire forecast area with similarly hot conditions Monday. An Excessive Heat Watch is valid in the valley on Sunday and Monday, where temperatures may reach the 105 to 110 degree depending on where you are in the valley. The Mojave Desert will get quite hot Sunday and Monday, with highs of 107-112 degrees forecast. The Excessive Heat Warning in the desert is in effect through 8 PM Monday. Along with these hot afternoon highs will be daily chances of afternoon thunderstorms in the Sierra Nevada. Modest easterly/southeasterly flow aloft will provide the mountains with enough moisture and instability for afternoon convection, however, not enough for any heavy rainfall. Low QPF is continued to be forecast for these thunderstorms. Dry weather is forecast after Monday as the ridge providing southeasterly flow gets eroded by an incoming trough. Cooler temperatures are forecast to begin starting on Tuesday (but still warm) as ensemble guidance shows the ridge of high pressure overhead getting squashed by a trough passing through the Pacific Northwest. We still are likely to see triple digit heat through much of the area on Tuesday. NBM guidance shows Wednesday to drop into the mid to upper 90s for the SJ Valley, with a rebound in high temps afterwards. && .AVIATION... In the Sierra Nevada, areas of MVFR and local mountain obscuring IFR in showers and isolated thunderstorms until 03Z Sunday. Elsewhere, VFR conditions will prevail over the Central CA Interior for at least the next 24 hours. && .AIR QUALITY ISSUES... On Saturday August 14 2021... Unhealthy for sensitive groups in Sequoia National Park and Forest. Further information is available at Valleyair.org
Source: NWS
