Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
972 FXUS66 KHNX 200926 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 226 AM PDT Thu Jun 20 2024 && .KEY MESSAGES... 1. Temperatures rising to 10 to 15 degrees above average this weekend with widespread triple digit maximum temperatures across the lower elevations. A Heat Advisory is in effect from Saturday through Monday morning. 2. About a 30 to 70 percent probability of 105 degrees across most locations below 2,500 feet on Saturday and Sunday afternoons. && .DISCUSSION... A trough continues across the west coast this morning with very weak waves moving through the flow. Enough that some cirrus is noted in the light of the Strawberry moon. The trough weakens on Friday as the Central Pacific ridge and the ridge over the eastern CONUS put the squeeze on the trough pushing the main upper flow to near the 49th parallel. On Saturday the ridge from the eastern US retrogrades over the Lone Star State for its center and the trough once over the Golden State lifts to off the Pacific Northwest shore. Sunday the Southern Plains ridge center relocates over the Land of Enchantment and the Grand Canyon State. Heights over the Central Valley of California head upward to 590 dm at 500 MB. Sunday`s aforementioned ridge will continue to hold position over the Four Corners general vicinity for next week and the stronger upper flow remains relegated to the Pacific Northwest and across the Northern Plains and Southern Prairie Provinces. This Thursday the impacts across the region are minimal as a few cirrus clouds in the morning and maybe a lone puffy cumulus cloud might appear over the Sierra. Otherwise, climatological hazy sunshine will prevail for the region. The probability to exceed (PoE) of seasonal average, on this official first day of summer starting at 1:50 PM this afternoon with the solstice, ranging from 56 to 81 percent for the lower elevations of the San Joaquin Valley. On Friday, the first full day of summer, temperatures push past normal and nudge to near 100 degrees in the Central Valley. The PoE of 100 degrees remains low with less than 20 percent probability for most locations, the best chance, remains with Fresno and Delano coming in at 31 percent. Saturday brings the heat, with an heat advisory in order, as temperatures make a run at 10 to 15 degrees above normal. The PoE of 105 degrees, about 12 to 13 degrees above normal, ranges from 31 to 41 percent for Merced, Madera, and Reedley to 61 to 71 percent for Bakersfield, Fresno, Porterville, Visalia, Delano, and Hanford regions. Sunday has a high probability of being a rerun of Saturday. The main difference will be morning low temperatures across the region. The urban areas of Fresno and Bakersfield have a near 100 percent PoE of staying above 70 degrees. The PoE of 75 degrees is 36 percent at Fresno and 56 percent at Bakersfield. The record high minimum at Bakersfield is 81 and Fresno 80 both set back during a heat wave in 2017. The PoE of setting a new record is less than 10 percent. However, remains fairly warm to continue the heat advisory. Then a slim chance for a rumble of thunder and flash of lightning, 5 to 10 percent, is possible over the highest elevations of the Sierra south of Fresno County. Monday through the end of next week temperatures stay fairly steady from 100 to 105 degrees each afternoon. As average temperatures climb into the mid 90s as we approach July 1st the body acclamation to heat improves and the heat risk levels start to moving up the benchmarks. On Monday again a slim possibility, this time north to the highest peaks of Yosemite Park, of 5 to 10 percent of a brief thunderstorm. Otherwise, just a few evenings of elevated wind along the Mojave Slopes with some blowing dust, below impact levels, during the week ahead. && .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 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... Heat Advisory from 11 AM Saturday to 11 AM PDT Monday for CAZ300>317-319-321-332. && $$ public/aviation/fire weather...Proton IDSS....DCH weather.gov/hanford