Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
261 FXUS66 KHNX 172036 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 136 PM PDT Fri May 17 2024 .KEY MESSAGES... 1. Temperatures will remain above normal through the weekend. 2. A few strong thunderstorms are possible in the Sierra Nevada this afternoon and evening then a better chance on Saturday afternoon and evening. 3. Gusty westerly winds will develop across the Kern County mountains and desert each afternoon and evening with the strongest gusts expected on Sunday and Monday. 4. Temperatures will lower to near climatological normals early next week. && .DISCUSSION...Winds have diminished across the Kern County mountains and deserts as the shortwave the passed to the south of our area overnight is now moving east across the desert southwest region. Meanwhile, the upper ridge off the CA coast will continue to retrograde through the weekend. The will result in lowering heights and thicknesses across our area which will in turn bring about a diurnal cooling trend each day through Monday. The high resolution WRF is showing enough CAPE and instability for another round of isolated afternoon and evening showers and thunderstorms over the higher elevations of the Sierra Nevada today. Saturday looks to be more favorable for afternoon convection as the WRF is indicating CAPES of 1200 to 2000 J/KG and LI`s of -3 to -6 DEG C over the Sierra Nevada tomorrow afternoon while RH progs are showing a slight increase in mid level moisture. SPC guidance is indicating that most of the Sierra Nevada is in the general thunderstorm risk area on Saturday. Much of the Sierra Nevada has a 25 to 50 percent chance of measurable precipitation on Saturday afternoon while a slight chance exists in the higher Sierra foothills. Latest NBM is indicating the following probabilities of measurable precipitation at selected locations. Yosemite Valley 25% Tuolumne Meadows 32% Shaver Lake 27% Grant Grove 28% Oakhurst 16% Three Rivers 17% SREF is showing an upper trough deepening over the PAC NW on Sunday and dropping further southward into the Great Basin area on Monday. This will help amplify the ongoing cooling trend with maximum temperatures expected to be near seasonal normals on Monday. Here are probabilities for a high temperature of 85 degrees or lower for selected locations in the San Joaquin Valley on Monday afternoon. Merced 49% Madera 59% Fresno 44% Reedley 69% Lemoore 49% Hanford 49% Visalia 39% Porterville 59% Bakersfield 49% The upper trough will also bring about an increase in onshore p-grads across the area which will bring about a potential period of strong wind gusts over the ridge tops of the Kern County Mountains as well as and along the Mojave Desert Slopes between Sunday afternoon and Monday night. Ensemble means are showing the trough moving east of the Great Basin by Tuesday which will result in some temperature recovery on Tuesday and Wednesday before another upper low pushes through the PAC NW on Thursday and Friday which will bring another cooling trend to our area with daytime temperatures expected to be close to seasonal normals once again by next Friday. && .AVIATION...Local MVFR in isolated showers and thunderstorms until 06Z Sat and areas of MVFR with local IFR in showers and thunderstorms after 18Z Sat over the Sierra Nevada. Otherwise, VFR conditions will prevail across the central CA interior over the next 24 hours. && .AIR QUALITY ISSUES...None. && .CERTAINTY... The level of certainty for days 1 and 2 is high. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit www.weather.gov/hnx/certainty.html for additional information and/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES...None. && $$ public/aviation/fire wx...DAS idss...SM weather.gov/hanford