Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
140 FXUS66 KHNX 161032 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 332 AM PDT Mon Sep 16 2024 && .KEY MESSAGES... 1. A Winter Weather Advisory is in effect through 5 PM this afternoon. There is a 45 percent probability of 3 inches of snow or more for Tioga Pass as snow levels fall to 7500 feet. 2. A Wind Advisory is in effect from 5 PM this afternoon through 5 AM Tuesday morning for Eastern Kern County. 3. There is a 15 to 40 percent probability of 0.05 inches or more of rain in the San Joaquin Valley north of Kern County today. A second upper level trough will slide through on Wednesday and Thursday bringing an additional chance for precipitation to the area. 4. Temperatures across Interior Central California will be 15 to 20 degrees below normal today and will remain below average through THursday before a weekend warmup. 5. There is a 40 to 50 percent probability of setting new record low maximum temperature records at Hanford, Bakersfield, Madera, and Merced this afternoon. && .DISCUSSION... An strong, deep, and cool upper low is moving into Central California early this morning. This system looks to bring mountain snow to the higher passes above 7500 feet today with a probability of 45 percent of 3 inches of snow or more. The other impact areas is the Mojave Slopes of the Kern County Desert where a 40 to 75 percent probability of wind gusts exceeding 35 mph exists late this afternoon through the overnight hours. A noteworthy fact is that there is a 40 to 55 percent probability of setting new record low maximum temperatures at select locations across the San Joaquin Valley today. Tuesday The strong upper low exits into the Northern Rockies and leaves behind a trough to keep temperatures on the cool side. Another strong shortwave is diving into the trough late in the period. The probability of temperatures remain below 80 degrees ranges from 25 to 75 percent for the San Joaquin Valley. Wednesday the shortwave deepens into another upper low and by evening reaches the Bay Area. This system is warmer for the Sierra Nevada with the cooler upper level temperatures moving south and west of the Sierra. This will keep the snow at the very highest elevations. The system is a bit more dynamic and provides a better probability of thunder for the region. Wednesday evening into early Thursday morning the probability of thunder is 5 to 10 percent for the San Joaquin Valley and 10 to 20 percent for the Sierra Nevada north of Tulare County. The probability of greater than 0.05 of an inch of precipitation for the San Joaquin Valley late Wednesday into Thursday ranges from 35 to 75 percent. The upper low weakens and slows down over Central California on Thursday. The probability of temperatures remaining below 80 ranges from 35 to 70 percent for the San Joaquin Valley. Friday the upper low lifts into the Great Basin and heights begin to rise in the upper levels this will bring a drying and warming trend to the region. The probability of temperatures exceeding the benchmark of 92 degrees for normal highs is less than 10 percent on Friday, 15 to 55 percent on Saturday, 50 to 60 percent on Sunday, and 60 to 70 percent next Monday. As we get into the weekend the spread of temperatures at any point location is approaching ten degrees, for example Fresno, the range on Monday is from 89 to 99. The primary issue is the persistent upper low over the southeastern US and its development and progression that will allow or deny the Pacific Ridge to translate further inland for warmer temperatures for California. && .AVIATION... VFR ceilings before 06Z AFT MVFR CIGS probable over the Sierra with isolated IFR/Mountain Obscurations (for more detailed information visit aviationweather.gov). Over the Valley CIGS ABV MVFR through the period. Areas of MVFR and local IFR visibilities near wildfires. && .AIR QUALITY ISSUES... ISSUED: 09/15/2024 15:01 EXPIRES: 09/16/2024 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 low. 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 until 5 AM PDT Tuesday for CAZ337>339. Winter Weather Advisory above 8000 feet until 5 PM PDT this afternoon for CAZ323-326>328. && $$ Operational Products...Proton DSS....................DCH weather.gov/hanford