Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
676 FXUS66 KHNX 202116 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 216 PM PDT Thu Jun 20 2024 && .KEY MESSAGES... 1. Temperatures will rise 10 to 15 degrees above average this weekend with widespread triple digit afternoon highs across the lower elevations. A Heat Advisory is in effect from Saturday through Monday morning. 2. There is a 30 to 70 percent probability of 105 degrees across most of the San Joaquin Valley on Saturday and Sunday afternoons. 3. There is a 70 to 90 percent probability for morning low temperatures to exceed 65 degrees across most of the San Joaquin Valley Sunday morning. && .DISCUSSION... An upper level trough is currently centered along the western Pacific coast, driving upper level flow across central California from the southwest. These winds aloft will continue a warming trend over the region as we move into the weekend. Probabilistic guidance from the National Blend of Models expresses only a 10 to 30 percent probability of exceeding 95 degrees this afternoon in the San Joaquin Valley, however these probabilities jump to 85 to 95 percent for Friday afternoon. An upper level area of high pressure, currently located over the eastern United States is expected to gradually shift westward into the weekend. The ridging pattern will raise afternoon temperatures ten to fifteen degrees above season normals Saturday and Sunday across central California. Most locations in the San Joaquin Valley have an 85 to 95 percent probability to exceed 100 degrees each day, however the following are probabilities to exceed 105 degrees. Saturday ----------- Bakersfield 76% Delano 76% Fresno 76% Hanford 61% Lemoore 41% Madera 26% Merced 26% Porterville 66% Reedley 26% Visalia 61% Sunday ----------- Bakersfield 61% Delano 46% Fresno 61% Hanford 41% Lemoore 36% Madera 36% Merced 26% Porterville 46% Reedley 26% Visalia 46% The aforementioned ridge will also affect the morning low temperatures across the region with poor recoveries overnight from the daytime heat. Minimum temperatures have a 70 to 90 percent chance of reaching 65 degrees or above Sunday morning for much of the San Joaquin Valley. However, in Bakersfield and Fresno, urban heating is expected to hinder overnight recoveries even further with NBM ensemble guidance suggesting a 60 to 80 percent probability to exceed morning lows of 73 degrees on Sunday. Because of the lasting heat through the weekend, a Heat Advisory has been issued for the San Joaquin Valley and the area surrounding Lake Isabella from 11 AM PDT Saturday through 11 AM PDT Monday. Cluster analysis suggests the upper level ridge will remain mostly dormant over the desert southwest through midweek. Ensemble guidance from the NBM expresses a 70 to 90 percent probability triple digit heat Monday, however these probabilities only fall to 50 to 70 percent for Wednesday. The ridge is expected to weaken into Thursday, bringing a slight cooling trend to the region in the latter portions of the work week. However, probability of exceedance (PoE) for 100 degrees remains at 20 to 40 percent for both Thursday and Friday. && .AVIATION...VFR conditions will prevail across the Central CA interior for the next 24 hours. && .AIR QUALITY ISSUES... ISSUED: 06/19/2024 14:24 EXPIRES: 06/20/2024 23:59 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 from 11 AM Saturday to 11 AM PDT Monday for CAZ300>317-319-321-332. && $$ public/aviation...SM weather.gov/hanford