Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
600 FXUS66 KHNX 262018 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 118 PM PDT Wed Jun 26 2024 && .KEY MESSAGES... 1. Above average temperatures will continue today, with 100 degree heat persistent at many locations. Temperatures will cool slightly on Thursday, but remain above normal. 2. There is a 5 to 20 percent probability for thunderstorms this afternoon along the Sierra Nevada crest. 3. Winds pick up on this evening through Friday morning with a 80 to near 100 percent chance of wind gusts of 45 mph or higher along the Mojave Desert Slopes. A Wind Advisory is in effect from this evening through Friday morning. 4. Maximum temperatures are expected to rise back up to well into the triple digits over the lower elevations by next Tuesday. && .DISCUSSION... The ridge that has provided the triple digit heat the past few days has nudged over to the four corners region this afternoon. A series of upper level waves move through the Pacific Northwest keeping a trough pattern over most of California. This provides a break from the triple digits for a short period. As the calendar flips the page to July the eastern Pacific ridge builds into the Golden State. The ridge centers over the Bay area and the rest of the state by the holiday cranking up the heat again. The impacts this afternoon and tonight are the Mojave Slope wind. The wind will continue to build through the afternoon and ramp up during the overnight hours. The probability of exceeding 45 mph for the region continues 80 to near 100 percent for the Highway 58/14 junction near the town site of Mojave and along the Highway 14 corridor. Otherwise, concerns focus on fire weather issues discussed below. Thursday the focus remains on the Mojave Slope wind with a lull during the day picking back up in the afternoon and especially during the night time hours. The probabilities again for 45 mph continue 80 to near 100 percent for the aforementioned regions. In the San Joaquin Valley, it will be a bit cooler in relative terms, the probabilities of exceeding (PoE) 100 degrees is less than 20 percent. The focus moves down to the 95 degree mark and the PoE ranges from 20 to 30 percent north of Fresno and Fresno south 60 to 80 percent. Friday through Sunday is a relaxed period of weather with PoE of 100 continuing below 20 percent for the north end of the San Joaquin Valley and 30 to 55 percent for the central and southern valley. Monday through Thursday the fourth of July. The PoE of 100 degrees increases each day through the period. Monday the range is 60 to 80 percent and by Thursday it is 65 to 85 percent. Now moving the bar up to 105 degrees for the PoE on Thursday the range is 25 to 50 percent. The heat risk for Wednesday and next Thursday moves into the category of 3 (major) with some 4 or (extreme) showing for the urban areas. This will have to be monitored for a trend over the next day or two for any excessive heat products for the extended holiday weekend. && .AVIATION...Isolated thunderstorms are possible along the Sierra Nevada crest between 20Z and 24Z today. Wind gusts above 35 KT possible along the Mojave Desert Slopes after 03Z Thu. Otherwise, VFR conditions will prevail across the central CA interior for the next 24 hours. && .FIRE WEATHER... Several fires burning from the dry thunderstorms earlier this week. The cooler flow is also a drier flow. This is maintaining relative humidities in the teens for the San Joaquin valley during the afternoon and overnight recoveries only in the 35 to 50 percent range. The wind is not settling down until the very early morning hours. This combined with the low RH recovery is creating the ability of any fires to take advantage of the terrain driven winds to continue to move during the nighttime hours. The daily trend looks to continue through the weekend. Then looking into next week the heat comes back up along with continued low to poor relative humidity. The best news is that the wind is expected to be lighter heading into the holiday. && .AIR QUALITY ISSUES... ISSUED: 06/25/2024 15:50 EXPIRES: 06/26/2024 23:59 None. && .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... Wind Advisory from 8 PM this evening to 8 AM PDT Friday for CAZ338. && $$ public/aviation/fire weather...Proton IDSS....EW weather.gov/hanford