Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
613 FXUS66 KHNX 292115 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 215 PM PDT Sat Jun 29 2024 .KEY MESSAGES... 1. Warming continues this weekend, before a dangerous, long- duration heat wave hits the central valley of California through the holiday week and into next weekend. 2. An Excessive Heat Warning has been issued for Tuesday July 2nd through Saturday July 6th, and may need to be extended through next weekend as the event nears. 3. 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 15% and poor overnight relative humidity recoveries may require a Fire Weather Watch as the event nears. 4. During the middle and late next week, there is up to a 10% chance for thunderstorms across the Sierra Nevada. && .DISCUSSION... Satellite loops show sunny skies prevailing across the interior of central California this afternoon with a dry southwest flow aloft. Temperatures across the San Joaquin Valley are forecast to top out right around the century mark this afternoon. Highs will be around 5 degrees above climatological averages for this time of the year. Little changes are expected during the next couple of days. Strong high pressure over the Eastern Pacific will build over the west coast beginning on Tuesday and looks to persist across the region through the week and into next weekend. Widespread triple digit heat will dominate the lower elevations with some areas potentially reaching 110 degrees. Here are probabilities for a high temperature of 105 degrees or above for some of the larger population areas in the San Joaquin Valley. Tue Wed Thu Fri Sat Merced 31% 86% 61% 46% 51% Madera 21% 81% 61% 46% 51% Fresno 46% 91% 81% 61% 66% Reedley 16% 66% 46% 41% 46% Lemoore 31% 86% 76% 61% 61% Hanford 31% 86% 66% 56% 61% Visalia 46% 86% 71% 61% 61% Porterville 31% 86% 66% 56% 61% Delano 46% 86% 71% 61% 66% Bakersfield 46% 86% 66% 56% 61% Here are probabilities for a high temperature of 110 degrees or above for the same areas in the San Joaquin Valley. Tue Wed Thu Fri Sat Merced 0% 26% 11% 11% 21% Madera 0% 21% 11% 6% 21% Fresno 0% 41% 26% 21% 26% Reedley 0% 16% 6% 6% 11% Lemoore 0% 36% 21% 16% 26% Hanford 0% 36% 16% 16% 26% Visalia 0% 36% 16% 16% 26% Porterville 0% 36% 21% 16% 26% Delano 0% 41% 21% 16% 26% Bakersfield 0% 41% 11% 16% 26% Overnight temperatures will remain warm, especially in urban areas. Lows are forecast to remain in the 70s across the San Joaquin Valley beginning Tuesday night. Larger cities such as Fresno and Bakersfield will only cool into the upper 70s due to the urban heat island effect. The combination of the well above normal daytime temperatures and warm overnight temps will result in a major to excessive heat risk across much of the lower elevations. An Excessive Heat Warning is in effect for the SJ Valley and adjacent foothills, Yosemite Valley, the Kern River Valley, Tehachapi Mountains and Kern County Desert from 11 AM Tuesday through 8 PM Saturday. An Excessive Heat Risk means there is an extreme risk of heat-related illnesses for the entire population. && .AVIATION... Continued areas of MVFR and local IFR visibility due to smoke nearby the Fresno County fires will continue in the Sierra Nevada and adjacent foothills. Otherwise, VFR conditions will prevail across the central California interior for the next 24 hours. && .FIRE WEATHER... Fuel moistures are typically their lowest and Energy Release Component typically the highest from late June through July. Near record low 100 hour and 1000 hour fuel moistures are forecast to occur during the heat wave next week. Additionally, ERC is forecast to near a record high. This will create an increased risk for grass fires, especially on the 4th of July. && .AIR QUALITY ISSUES... Air Quality Alert due to smoke impacts from wildfires. && .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... Excessive Heat Warning from 11 AM Tuesday to 8 PM PDT Saturday for CAZ300>322-324-332-334-336>339. && $$ DCH weather.gov/hanford