FXUS66 KHNX 042122 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 222 PM PDT Sun Aug 4 2024 && .KEY MESSAGES... 1. Afternoon temperatures will trend warmer this weekend with major Heat Risk returning to the San Joaquin Valley. Most of the San Joaquin Valley has a 95 to 100 percent chance of triple digit heat today. 2. Hotter temperatures are in store for the first half of this week. Chances of highs at or above 105 degrees are around 50 to 80 percent in much of the San Joaquin Valley for Tuesday and Wednesday. An Excessive Heat Warning has been issued for this time. 3. The Excessive Heat Watch for the Kern County Desert has been upgraded to an Excessive Heat Warning. It will be valid beginning tomorrow at 10 AM through 9 PM Tuesday. && .DISCUSSION... A warming trend has begun and will continue through late next week. A ridge currently just to the east of the Golden State has strengthened, bringing heat to most of the state. As this ridge starts to retrograde back West, temperatures will increase. The two hottest days of this warm up will be Tuesday and Wednesday. Temperatures during these days will be 10-12 degrees above normal for this time of year. During these two days, the San Joaquin Valley will see chances of over 50% for high temperatures above 105 degrees. Here are the probabilities that certain cities in the valley will see temperatures higher than 105 this Tuesday: Bakersfield: 85% Coalinga: 90% Visalia: 85% Fresno: 75% Hanford: 65% Madera: 55% Merced: 45% Due to widespread moderate to major Heat Risk throughout the San Joaquin Valley for Tuesday and Wednesday, an Excessive Heat Warning has been issued for those two days. Southwesterly flow will also bring drier conditions to the forecast area alongside elevated afternoon breezes. This will lower relative humidities and overnight relative humidity recovery, particularly around areas currently being impacted by wildfires. Chances of thunderstorms have lowered considerably, and do not look to be a threat to our forecast area for the next few days. Ensemble guidance shows a trough deepening just north of us in Canada, which could weaken the ridge and bring temperatures down near the end of the week, with some medium range guidance showing a chance at dropping below triple digits. && .AVIATION... Areas of MVFR and local IFR visibility will continue in and around wildfires. Otherwise, VFR conditions will prevail across the central CA interior over the next 24 hours. && .AIR QUALITY ISSUES... 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 from 10 AM Monday to 9 PM PDT Tuesday for CAZ337>339. Excessive Heat Warning from 10 AM Tuesday to 9 PM PDT Wednesday for CAZ300>317-319-321. && $$ public/aviation...AS IDSS..............AB weather.gov/hanford