


Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
546 FXUS66 KHNX 161830 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 1130 AM PDT Wed Apr 16 2025 .KEY MESSAGES... 1. Temperatures are expected to cool to slightly below normal on Thursday. Warming begins again by Friday and will be back to above normal by the weekend. 2. Breezy conditions are expected for the Mojave Slopes on Thursday. 3. There is a chance for showers and a slight chance for thunderstorms across the Sierra Nevada today and Thursday. && .DISCUSSION...A closed upper level low pressure system continues to meander off the Socal coast and has pushed some low level moisture northward into our CWFA with low clouds prevailing over the Kern County portions of the San Joaquin Valley and West Side Hills as well as over the east side of the San Joaquin Valley and the lower Sierra Foothills. Temperatures are running 5 to 7 DEG F cooler than yday across much of the San Joaquin Valley as the result of the marine cooled air which has spilled over into the valley and areas impacted by low clouds have cooled by 8 to 11 DEG F since yday at this time. With the low progged to move slowly toward the coast on Thursday and inland on Thursday night, there will be increased instability over the Sierra Nevada which will result in chances of showers and a slight chance of afternoon and evening thunderstorms today and better chances on Thursday. QPF progs are indicating between a tenth and a quarter inch of rainfall for the higher Sierra Nevada, but due to the convective nature of the precipitation, it will very from location to location. Snow levels are progged to range from 8000 to 9000 feet with 1 to 3 inches of new snowfall above 9000 feet by Thursday evening. The cooling trend is also progged to continue with the probability for maximum temperatures remaining below 70 DEG F in the San Joaquin Valley between 25 and 60 percent on Thursday. Meanwhile, a cold upper trough is progged to drop southward over the Great Basin region on Thursday night and Friday which will provide for enough instability for chances of showers across the Sierra Nevada and Tulare County and across the Kern County mountains and deserts. It will also bring a period of increased winds to the Mojave Desert Slopes on Thursday evening. This trough is then progged to move into the central CONUS this weekend while and upper ridge nudges inland into CA. This will result in a warming and drying trend across our area this weekend with warmer than normal temperatures and dry conditions prevailing across our area from Saturday through the middle of next week. && .AVIATION...18Z: In the San Joaquin Valley and West Side Hills, Local MVFR in low clouds. Otherwise VFR thru 18Z Thu. In the Sierra Nevada and adjacent foothills, areas of MVFR in low clouds and showers with local mountain obscuring IFR thru 18Z Thu. Isolated thunderstorms possible thru 06Z Thu. In the Tehachapi Mountains, areas of mountain obscuring IFR in low clouds thru 18Z Thu. In the Kern County portion of the Mojave Desert, VFR will prevail thru 18Z Thu. && .AIR QUALITY ISSUES...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...DAS idss...EW weather.gov/hanford