FXUS66 KHNX 171027 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 327 AM PDT Mon Jun 17 2024 && .KEY MESSAGES... 1. A Red Flag Warning has been issued for strong gusty winds coupled with low relative humidity that will bring Elevated Fire Weather concerns to the Kern County mountains, West Hills, Kern Desert and the San Joaquin Valley through Tuesday morning at 8am. 2. A cooling trend will bring temperatures closer to seasonal averages for today. Monday temperatures will be around 3 to 5 degrees below normal. 3. Strong to damaging wind gusts will develop along the Mojave Desert Slopes each afternoon and overnight through Monday night. Afternoon and evening breezes will develop across the San Joaquin Valley with locally gusty conditions near the passes of the West Side Mountains through Tuesday morning at 5am. 4. Snowmelt from the higher elevations of the Sierra Nevada, will continue to result in dangerously cold and fast flows along rivers and waterways. 5. Starting Tuesday a warming trend will begin with triple digits anticipated starting Friday lasting through next weekend. && .DISCUSSION... The second of two low pressure systems moving through the Pacific Northwest and lowering heights will have the cooldown continuing through today with lower than normal temperatures before a gradual warming trend begins tomorrow. High temperatures throughout the San Joaquin Valley today have very low probabilities (15 to 25 percent) of reaching even 90 degrees. These temperatures are roughly 4-7 degrees below normal for this time of year. These low pressure systems have brought cool, dry air into the region alongside gusty winds. The gustiest winds will occur in the usual windy places, the Mojave Desert Slopes. NBM probabilities show a 70 to 100 percent chance of winds in the desert slopes gusting to at least 60 mph through the early morning today. As of 1:40 AM this morning, the Mojave weather station has recorded a gust of 75 mph. The West Side Hills will also experience gusty winds, with localized areas having a 65 to 85 percent chance of gusting to at least 40 mph. Winds in the San Joaquin Valley will be breezy this afternoon and evening and there is a 65 to 75 percent chance of winds gusting to at least 25 mph. These winds will all peak early this morning and then pick back up again this afternoon and evening. These winds combined with low relative humidity results in an elevated risk for grass fires. Please see the Fire Weather section below for more detailed information. As the low pressure system begins tracking eastward and out of the area of influence, a ridge will slowly begin to set up and raise heights. Temperatures will start increasing tomorrow and increase gradually as the ridge strengthens. By next weekend, probabilities that we will see triple digits again are rising. On Friday, there is a 30 to 40 percent chance of temperatures in the San Joaquin Valley hitting 100 degrees. By Saturday, these chances increase steeply to a 85 to 95 percent chance of the San Joaquin Valley seeing 100 degrees. Stay tuned for more information on this as we get closer to the weekend. Snowmelt in the Sierra Nevada continues due to these increasing temperatures, resulting in dangerously cold and swift waters along rivers and waterways. Precautions when getting in these bodies of water should be taken to ensure safety. && .AVIATION... VFR conditions will prevail across the Central CA interior for the next 24 hours. Gusty winds will result in chances for blowing dust in the Kern County Desert and West Side Hills through late morning today and this afternoon and evening. Additionally, reduced visibility will result around and near any fires. && .FIRE WEATHER... Minimum relative humidity values in the Kern County Mountains and Desert and West Side Hills will hover around 10 to 15 percent. In the San Joaquin Valley, minimum relative humidity will hover around 15 to 20 percent. These very low relative humidities combined with the gusty conditions occurring through early this morning, and this afternoon and evening have resulted in an enhanced risk for grass fires, per the Storm Prediction Center. This evening, there are local 60 to 80 percent chances of wind gusts above 25 mph combined with relative humidity values less than 15 percent for the warning area. As such, a Red Flag Warning has been issued for the Kern County Desert, West Side Hills, and San Joaquin Valley through Tuesday morning at 8am. && .AIR QUALITY ISSUES... ISSUED: 06/16/2024 12:51 EXPIRES: 06/17/2024 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... High Wind Warning until 5 AM PDT Tuesday for CAZ338. Red Flag Warning until 8 AM PDT Tuesday for CAZ579-580-596-597. && $$ public/aviation/fire weather...AS PIO/IDSS.......................VJP weather.gov/hanford