Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
410 FXUS66 KHNX 052025 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 125 PM PDT Fri Jul 5 2024 && .KEY MESSAGES... 1. Temperatures will climb to around 15 degrees above normal this afternoon. This is a dangerous, prolonged heat wave that will last several days with an Extreme Heat Risk. 2. An Excessive Heat Warning remains in effect through Thursday, July 11th at 11 PM, and may need to be extended further as the week progresses. 3. A Red Flag Warning has been issued for the Kern County Mountains and the Mojave Desert Slopes until 6 AM Monday. 4. The risk of grass fires will continue to increase with herbaceous fuel loading at or near 120% of normal. A long period of excessive heat, minimum relative humidities near or below 15%, and poor overnight relative humidity recoveries will add to the grass fire risk. && .DISCUSSION... An upper level ridge of high pressure continues to propagate over the western United States today with the center of the ridge located off the northern coast of California. The subsiding air aloft from the system will continue to keep temperatures above season averages for this time of year. Maximum temperatures across the San Joaquin Valley are expected around 12 to 15 degrees above normal, hovering close to 110 this afternoon. The National Blend of Models expresses a 30 to 60 percent probability for temperatures to exceed 110 degrees this afternoon in the valley areas, with probabilities 70 to 90 percent for the Kern County Desert. The aforementioned ridge is projected to move further inland, with the center tracking over central California Saturday and Sunday; temperatures will continue to warm across the region as a result. The following are probabilities for maximum temperatures to reach or exceed 110 degrees this weekend across the region. SATURDAY --------------- Bakersfield 65% Coalinga 55% Fresno 65% Hanford 55% Madera 50% Merced 50% Oakhurst 15% Ridgecrest 75% Visalia 65% SUNDAY --------------- Bakersfield 65% Coalinga 50% Fresno 65% Hanford 55% Madera 50% Merced 40% Oakhurst 15% Ridgecrest 85% Visalia 70% In addition, there is a 10 to 30 percent probability for temperatures to reach or exceed 115 degrees in the San Joaquin Valley both Saturday and Sunday. This weekend is expected to have the warmest temperatures of this heat wave, with around a 40 to 60 percent chance for new record highs in Merced, Madera, Fresno, and Hanford. A relative cooling trend will begin Monday, lasting through Friday, July 12th as the upper level ridge slides eastward into the desert Southwest. However, the ridge is expected to keep its strength from this weekend through next week, resulting in temperatures across central California remaining above season normals. NBM ensemble guidance expresses at least an 80 percent probability for 100 degree temperatures in the San Joaquin Valley, with a 40 to 70 percent chance for afternoon temperature 105 degrees or more each day. && .AVIATION... MVFR and local IFR visibility due wildfire smoke will continue. These areas of smoke may increase. Otherwise, VFR conditions will prevail across the central California interior for the next 24 hours. && .FIRE WEATHER... A Red Flag Warning is in effect for the Kern County Mountains and Mojave Desert SLopes through 6 AM PDT Monday. This is due to very low minimum relative humidities near or below 15%, breezy winds with gusts up to 40 mph, above normal temperatures and very dry fuels, increasing the risk for fast-moving grass fires. && .AIR QUALITY ISSUES... ISSUED: 07/01/2024 14:37 EXPIRES: 07/02/2024 23:59 None. && .CERTAINTY... The level of certainty for days 1 and 2 is medium. 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... Excessive Heat Warning until 11 PM PDT Thursday for CAZ300>322- 324-332-334>339. Red Flag Warning until 6 AM PDT Monday for CAZ596-597. && $$ public/aviation...SM IDSS..............AS weather.gov/hanford