Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
785 FXUS66 KHNX 100721 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 1221 AM PDT Mon Jun 10 2024 .KEY MESSAGES... 1. Temperatures will remain around several degrees above average today, though a warming trend begins. 2. A few strong thunderstorms are possible in the afternoons into the evenings through midweek along the Sierra Nevada crest. 3. A Heat Advisory has been issued for Tuesday and Wednesday, with probabilities of afternoon highs exceeding 100 degrees in the San Joaqin Valley around 65-90%. The probability of exceeding 105 degrees on Wednesday is less than 20% with the exception of Fresno and Visalia with about 30 to 45%. 4. The warm temperatures will allow increased snowmelt to continue over the Sierra Nevada, resulting in colder and higher flows along rivers and waterways. && .DISCUSSION...A weak upper-level low remains off the coast of Southern CA, per latest satellite imagery. Mainly clear skies prevail and will continue this week, with the exception of isolated afternoon and evening thunderstorms over the Sierra Nevada crest, mainly from Yosemite to Sequoia/Kings Canyon NP. Today`s highs will be a touch warmer than yesterday, or around 4 to 8 degrees above seasonal averages. Hotter temperatures return on Tuesday and Wednesday. Little changes in probabilistic guidance are shown compared to the previous runs. So, we`re still looking at highs above 100 degrees with chances at 65 to 90 percent throughout the SJ Valley and much lower chances (15 percent up to 40 percent) for a reading of at least 105 degrees. The weak upper-level low will persist offshore as high resolution guidance continues to show it as a cutoff low. The Heat Advisory will continue for much of the Central Valley and adjacent higher terrain to the west. By Thursday, temperatures start to moderate while the upper- level low moves closer to the Southern CA coast. In addition, the potential exists for at least breezy conditions to develop in the typical prone areas, such as the west side hills and Mojave Desert slopes in eastern Kern County. Chances for a triple digit reading lower to 20 percent or lower throughout the Central Valley and generally 35 to 70 percent for readings at or above 95 degrees, which would be around a few degrees above seasonal averages, or similar to observed highs over the last couple of days. Otherwise, the best chance for highs in the triple digits will be in the Kern County desert, mainly towards the Indian Wells Valley where the probabilities are at or above 60 percent. For now, guidance suggests generally minor changes through the weekend into early next week. The danger for cold and fast moving water will continue for at least the next several days, or as long as snow continues to melt from the higher elevations of the Sierra Nevada. Take special care if venturing into the water, including lakes, rivers, and waterways. && .AVIATION... VFR conditions will prevail across the Central CA interior for the next 24 hours. && .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... Heat Advisory from 11 AM Tuesday to 6 AM PDT Thursday for CAZ301>303-305>317-319-332. && $$ BSO weather.gov/hanford