Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
993 FXUS66 KHNX 091958 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 1258 PM PDT Thu May 9 2024 .KEY MESSAGES... 1. A warming trend will continue through Sunday. 2. By Sunday afternoon, high temperatures will be around twelve degrees above normal for this time of year. 3. High temperatures will remain well above seasonal values Monday through Thursday. 4. A few strong thunderstorms are possible in the Sierra Nevada and a portion of the Kern County mountains and desert Friday afternoon into early Friday evening, and then each afternoon over the Sierra Nevada through Tuesday of next week. && .DISCUSSION... An upper level area of low pressure is wandering westward and will be centered near the Great Basin region on Friday. Meanwhile under sunny skies in the resultant dry northeasterly flow, much of our area is seeing a notable warmup. Current 24 hour temperature trends are running up around 5-10 degrees in the San Joaquin Valley and adjacent terrain, while Kern County desert areas and adjacent slopes are seeing just a couple of degrees of warming. Higher Sierra elevations are near yesterday`s temperatures or even a couple of degrees lower. These trends are expected to continue through the afternoon, and highs in the Valley should top out around 4 to 8 degrees above climatology this afternoon. Tomorrow will bring another few degrees of warming, and high temperatures in the San Joaquin Valley will reach around 90 degrees. The nearby upper level low pressure area will also increase instability, leading to 15 to 20 percent probabilities for thunderstorms Friday afternoon over the Sierra Nevada and portions of the Kern County mountain and desert areas. The upper low will lift out over the weekend as a high pressure ridge edges ashore. Thunderstorm chances will be reduced to around 10 to 15 percent and limited to the Sierra zones. Further warming will occur through Sunday under the ridge, and by Sunday afternoon, highs will be as much as 10 to 15 degrees above normal. Here are probabilities of maximum temperatures of 93 degrees or higher for select locations in the San Joaquin Valley on Sunday, May 12th, 2024: Fresno - 76% Lemoore - 71% Hanford - 66% Delano - 66% Bakersfield - 61% Madera - 61% Merced - 56% Visalia - 51% Porterville - 41% Reedley - 31% A weak low pressure center will cut across Southern California and into the southwest states Monday and Tuesday, during which time we will see little change in temperatures. Thunderstorm probabilities each afternoon during this time will be 15 to 20 percent in the Sierra Nevada. Temperatures will tick slightly upward for the middle of next week under the influence of a Pacific high pressure ridge behind the exiting weak low. Probabilities are around 30 to 50 percent for high temperatures of at least 94 degrees in the San Joaquin Valley. Thunderstorm probabilities over the Sierra Nevada Wednesday and Thursday are generally reduced to 15 percent or less. && .AVIATION... A few thunderstorms are expected over the Sierra Nevada after 18Z Friday, otherwise VFR conditions will prevail throughout Central California for at least 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 high. 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 Weather...JEB PIO/DSS........................DS weather.gov/hanford