Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
890 FXUS66 KHNX 300957 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 257 AM PDT Thu May 30 2024 && .KEY MESSAGES... 1. A warming trend begins Thursday and Friday which will result in afternoon highs of 5 to 10 degrees above normal. 2. There is a 66 to 86 percent probability for temperatures to reach or exceed 95 degrees on Friday in the San Joaquin Valley and a 11 to 31 percent probability of triple digits on Friday. 3. Gusty west winds are possible Saturday night and Sunday morning for the Mojave Desert Slopes and Kern County Desert. 4. A more significant warming trend starts next week with probabilities of exceeding 105 degrees at 25 to 55 percent Wednesday through next Friday. This increases the heat risk for sensitive populations in the San Joaquin Valley. && .DISCUSSION... A weak northwest to west flow aloft continues for California and on the surface a thermal trough set up to the east and the northeast Pacific high is set firmly in place. The slight northwest component of the upper levels will help keep the temperatures from the century mark this afternoon. The probability of exceeding 95*F ranges from 15 to 45 percent for the San Joaquin Valley. The threat of Sierra convection is near zero this afternoon. Tonight, as in most late spring early summer evenings, the focus moves to Mojave Slope winds. The surface gradient is only 5 MB for the evening and overnight. Short range high res ensembles show of the PoE of 45 mph to be near zero. For the PoE to exceed the mark of 50 percent the wind speed has to be reduced to 35 mph for the windy spots. Highly unlikely a wind advisory will needed tonight. Friday brings about a slight uptick in upper height and thickness allowing for little extra to help nudge temperatures up. The PoE of 95 on Friday increases to 66 to 86 percent, and the PoE of 100 increases to 11 to 31 percent. Friday night the gradient remains relaxed and the Mojave Slope winds are again expected to remain below advisory levels. Saturday and Sunday an upper trough zips across the west coast not allowing heights to build any and keeping the threat of the triple digits down below a 5 percent probability, outside of the Kern County Desert where the threat is higher. Saturday night into Sunday morning the pressure gradient between Bakersfield and Vegas increases to near 8 MB and PoE of 45 mph increases to near 100 percent. It is highly probable that a wind advisory will be needed for the Slopes. Monday into Tuesday heights start to slowly build over central California. the PoE of 100 remains less than 10 percent for the San Joaquin Valley. Monday night the pressure gradient flirts with the 6 MB mark for another possible wind advisory evening for the Mojave Slopes, however Tuesday night the gradient is relaxed enough that the threat is reduced. Wednesday through next Friday brings the threat of heat stress issues to the forefront of impacts to the San Joaquin Valley. Upper heights increase to near 590 DM over the region. This increases the PoE of 100 to 50 to 80 percent, and the PoE of 105 peaks at 35 to 55 percent on Thursday. This raises the issue of Heat advisories and warnings. Overnight lows in the Urban areas of Bakersfield and Fresno have a 60 to 70 percent chance of staying above 70*F increasing the heat stress probability. Will continue the messaging of the heat risk with the upcoming heat wave as preparations for the first significant heat wave draws near for the Central California. How long is the heat wave expected to continue for the region... well CPC long range 6 to 10 day and 8 to 14 day indicate a high probability of above normal temperatures for the western US. && .AVIATION... VFR conditions will prevail across the central CA interior over the next 24 hours. && .AIR QUALITY ISSUES... ISSUED: 05/29/2024 15:09 EXPIRES: 05/30/2024 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... None. && $$ public/aviation/fire weather...Proton IDSS....BSO weather.gov/hanford