September 9, 2021 - The National Weather Service Hanford Office reports isolated, dry thunderstorms are possible in the Sierra Nevada and Kern County mountains this afternoon and this evening.
Dry thunderstorms are thunderstorms that produce little or no precipitation at the surface.
Cloud to ground lightning strikes could ignite new wildfires in the Sierra Nevada and Kern County mountains this afternoon and this evening.
Any wildfires that develop will likely spread quickly.
Area Forecast Discussion National Weather Service Hanford CA 137 AM PDT Thu Sep 9 2021 .SYNOPSIS... Widespread triple digit heat is expected in the San Joaqin Valley, Coastal Hills, and Kern River Valley this afternoon. Isolated, dry thunderstorms are possible in the Sierra Nevada and Kern County mountains this afternoon into this evening. A downward temperature trend is anticipated Friday and Saturday. High temperatures will be two to four degrees above normal Sunday through Wednesday. && .DISCUSSION... An upper-level area of high pressure will be centered near the Four Corners of the United States today. Some subtropical moisture from the Baja Peninsula will progress northward along the western periphery of this anticyclone this afternoon. This bit of moisture influx coupled with orographic forcing will be responsible for the possibility of isolated, dry thunderstorms in the Sierra Nevada and Kern County mountains this afternoon into this evening. Dry thunderstorms can ignite new wildfires with lightning, but will not produce much rain to put the wildfires out. Widespread, triple digit heat is anticipated in the San Joaquin Valley, Coastal Hills, and Kern River Valley this afternoon. Triple digit heat probabilities in Bakersfield are 91%, Fresno 86%, Hanford 81%, Merced 69%, and Visalia 66% this afternoon. An Eastern Pacific trough of low pressure will approach the northwest coast of the United States tonight. This trough of low pressure will move eastward across the Pacific Northwest Friday. A few dry thunderstorms cannot be ruled out Friday afternoon in the Sierra Nevada from Fresno County northward. A ridge of high pressure will extend westward across Southern California Friday night through Saturday night. A downward temperature trend is expected Friday and Saturday. An Eastern Pacific trough of low pressure will approach the northern coast of California Sunday. This trough of low pressure will move eastward through Northern California Sunday night. Cyclonic flow aloft is expected early next week. High temperatures Sunday afternoon through Wednesday afternoon will be two to four degrees above their typical values for the first half of September. && .AVIATION... In the Sierra Nevada and Kern County mountains, areas of MVFR visibilities, with local mountain obscured IFR visibilities, are expected due to smoke and haze near active wildfires through at least the next 24 hours. In the San Joaquin Valley, intermittent MVFR visibilities are likely due to haze. && .AIR QUALITY ISSUES... On Thursday, September 9th, 2021, unhealthy for sensitive groups in Fresno, Kern, and Tulare Counties, as well as in Sequoia National Park and Forest. Further information is available at Valleyair.org.Source: NWS
