Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
587 FXUS66 KHNX 061931 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 1231 PM PDT Sat Jul 6 2024 && .KEY MESSAGES... 1. A long-duration, rare, heat wave with an Extreme HeatRisk through next week will have many impacts on all of our citizens and all sectors of the community. 2. An Excessive Heat Warning remains in effect until Saturday. A Heat Advisory remains in effect for the Sierra Nevada through Monday at 10 AM, and Yosemite NP through Wednesday at 10 AM. 3. A Red Flag Warning has been issued for the Kern County Mountains and the Mojave Desert Slopes until 6 AM Monday. 4. The high risk of grass fires will continue with herbaceous fuel loading at or near 120% of normal exhibiting behavior typically not experienced with such low wind speeds. && .DISCUSSION... Many eyes are on Tropical Storm Beryl in the Gulf of Mexico, including us in Central California. Not because we will see direct impacts from the tropical storm, other than it will influence the broad trough across the Central US and allow the ridge parked overhead to slide east. However, for the next 36 hours that ridge will remain in place resulting in record or near record heat today and tomorrow. Again, the aforementioned ridge will slide east Monday settling over Nevada allow heights to fall some over the state resulting in a few degrees drop in temps. Probabilities of extreme heat remains to be high, 50 to 75% for greater than 105 degrees on Monday. Tuesday probabilities will decrease by 20% across much of the northern half of the CWA, though that trend won`t continue as the broad trough pushes to the eastern states the ridge will broaden over the western states pushing temps back up. However, the ridge axis will remain to our east. Ensemble guidance is hinting at some troughing late week into next weekend, though the depth and resulting influence remains uncertain. The excessive heat warning for much of the area continues through Saturday as heat impacts due to this prolonged heat wave. && .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... Extreme heat continues with very low afternoon humidity levels around 10-15% in the Valley. Under 10% for the desert. Then even the High Sierra is witnessing mainly teens with some valleys dipping into the single digits. Overnight recoveries are poor for the elevated areas of the Western Hills, Sierra, and Kern County Mountains. The desert recovers only to 15 to 20 percent. In the San Joaquin Valley 40 to 60% fair recovery has the highest probability. The RH trend for the weekend and next week is flat with poor recoveries and sub 20 percent afternoon minimum RH. The wind will remain fairly light for the weekend and week ahead with the exception being the Mojave Slopes with periods of elevated wind that may require more fire weather highlights. && .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... Excessive Heat Warning until 3 AM PDT Saturday for CAZ300>322- 324-325-332-334>339. Red Flag Warning until 6 AM PDT Monday for CAZ596-597. Heat Advisory until 10 AM PDT Wednesday for CAZ323. Heat Advisory until 10 AM PDT Monday for CAZ326>331-333. && $$ Meadows