Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
222 FXUS66 KHNX 230832 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 132 AM PDT Sun Jun 23 2024 && .KEY MESSAGES... 1. Heat Advisory is in effect until 11 AM Monday as temperatures will be about 9 to 12 degrees above average today. 2. There is a 40 to 70 percent probability of high temperatures of at least 105 degrees for most of the San Joaquin Valley but northern locations including Merced and Madera having a 25 to 35 percent probability of a high temperature of at least 105 degrees for today. 3. Above average heat will continue into the middle of next week, with 100 degree heat persisting for many locations. 4. There is a 10 to 25 percent probability for thunderstorms Tuesday afternoon along the Sierra Nevada crest from Yosemite National Park to Kings Canyon and Sequoia National Park. && .DISCUSSION... We currently have an upper level ridge of high pressure that has established itself over the western half of the United States leading to temperatures to be well above average. Latest model ensembles are showing this ridge will remain. However, the models are showing the moisture from the former Tropical Storm Alberto will be carried by the ridge`s anticyclonic flow and pumped into the Sierra Nevada. This moisture brings a 10 to 25 percent chance of thunderstorms over the Sierra Nevada on Tuesday. The ensembles show a strong agreement that the ridge will weaken midweek and flatten as a trough moves across the Pacific Northwest. This trough will help lower temperatures back to average on Thursday and Friday. The ensembles also are hinting at a shortwave on Saturday into next Saturday but with less certainty. Today, we are looking at the following probabilities for high temperatures of at least 105 degrees according to the NBM. Delano 61% Hanford 51% Madera 31% Visalia 51% Lemoore 41% Merced 26% Porterville 71% Bakersfield 61% Fresno 61% Reedley 31% The probabilities remain high for triple digits on Monday with a 60 to 90 percent probability for the entire Valley. The probabilities decrease on Tuesday as the northern portions of the Valley have a 40 to 50 percent probability of triple digits while Fresno and points south have a 60 to 90 percent probability of high temperatures of at least 100 degrees. Most of the Valley will see a decrease to a 50 to 75 percent probability of at least 100 degrees for most locations. However, Merced and Madera will have a 25 to 40 percent probability on Wednesday. Probabilities really cool down to 30 percent or less on Thursday and 10 percent or less on Friday of high temperatures of at least 100. However, this is due to the trough sliding across the Pacific Northwest bringing cooler air. This trough also raises a concern with the wind speeds especially on Thursday for the Kern County Desert Slopes and the West Hills. Right now, we have a 5 to 30 percent chance of 45 mph wind gusts on the Kern County Desert Slopes for Thursday evening. && .AVIATION... VFR conditions will prevail across the Central CA interior for 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... Heat Advisory until 11 AM PDT Monday for CAZ300>317-319-321- 332. && $$ JPK weather.gov/hanford