205 FXUS66 KHNX 272228 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 328 PM PDT Sun Apr 27 2025 .UPDATE...Updated 00Z Aviation. && .KEY MESSAGES... 1. Temperatures will be much cooler than climatological average today and Monday, but will overall be trending warmer this week. 2. Winter-like weather, or valley rain and mountain snow, will be ending by this afternoon. 3. Another system arrives midweek which will provide a chance of showers and thunderstorms to mainly the mountain areas. Otherwise, warmer than average temperatures continue until the end of the week. 4. A cooldown and stronger system will bring a chance of more widespread precipitation and locally gusty winds by next weekend. && .DISCUSSION... Latest satellite imagery shows our region underneath the back side of an upper-level low pressure system that has moved east of our region into the Great Basin. However, in the northerly flow aloft, some lingering moisture will bring additional light snow showers to the Sierra Nevada until this afternoon. Probabilities for at least one more inch of snow in the Sierra are around 40-70 percent with much lower chances of 2 inches or greater. Thus, we will be ending the Winter Weather Advisory at 11 AM PDT this morning, as little precipitation is likely to occur through the remainder of today. Otherwise, low and mid- level clouds will persist today with cooler than average temperatures. A warming trend occurs starting Monday, with more noticeable warming by Tuesday. Daytime highs will remain slightly below average on Monday and rise slightly above average on Tuesday. Expect even warmer days on Wednesday and Thursday. The chances for a maximum temperature of at least 85 degrees will be 50 to 80 percent for both the SJ Valley and Kern County desert on Wednesday and Thursday, but will lower by Friday. In the meantime, an upper- level shortwave will provide enough lift for a slight chance of isolated thunderstorms over the Sierra Nevada into the Tehachapi Mountains, as well as the adjacent foothills on both Wednesday and Thursday during the afternoons and early evenings. However, this feature is not expected to provide any significant cooling. Another relatively cold low pressure system arrives by late Friday and will bring the chance for more widespread precipitation into the weekend. Preliminary snow levels will generally be above 6,000 feet with this system but will lower slightly by next Sunday. Latest outlooks from the Climate Prediction Center continue to show a 50 to 60 percent chance (6-10 day outlooks for above average precipitation, but have trended towards below average temperatures. As for the 8-14 day outlook, there remains a slight tilt in the odds towards above average precipitation (about a 35-40 percent chance) with seasonal temperatures. && .AVIATION...00Z Update: In the San Joaquin Valley and West Side Hills, VFR prevails, except for local MVFR due to low clouds until 18Z Monday. Across the Sierra Nevada, adjacent foothills and Tehachapi Mountains, MVFR ceilings with areas of mountain obscuring IFR lasting thru 18Z Mon. Otherwise VFR thru 18Z Mon. && .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 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...BSO aviation....JPK weather.gov/hanford