Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
947 FXUS66 KHNX 010941 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 241 AM PDT Wed May 1 2024 .KEY MESSAGES... 1. High temperatures will change little today, remaining around climatological averages for this time of year. 2. Warming conditions are forecast for the end of the work week with highs around 3 to 7 degrees above normal on Friday. Probabilities of exceedance for 85 degrees in the San Joaquin Valley are around 50%. 3. Ensemble guidance is trending towards a weekend storm system bringing snowfall to the Sierra Nevada and periods of rainfall to the San Joaquin Valley. 4. High temperatures are forecast to cool to around 10 to 15 degrees below normal by Sunday. && .DISCUSSION... Strong wind gusts continue along the Mojave Desert Slopes where a High Wind Warning remains in effect until 5 AM this morning. The SFO-LAS pressure gradient increased to 12 mb, up from 10 mb 24 hours ago. The Mojave ASOS (KMHV) measured a peak wind gust of 64 mph last evening. A broad upper trough remains over the west with an upper ridge over the Eastern Pacific. Temperatures changed little on Tuesday with highs right around climatological normals for this time of year. A persistence forecast is for little changes again today. A subtle increase in heights and thickness values will translate into high temperatures around 2 to 4 degrees above normal. Short wave ridging on Friday nudges max temperatures to 3 to 7 degrees above normal. Probabilities for a high temperature of 84 degrees or higher in the San Joaquin Valley on Friday are generally from 50 to 75 percent. Ensemble analysis shows an upper low dropping down over northern California on Saturday then shifting east over the Great Basin on Sunday. Precipitation chances develop late Saturday morning and continue through Sunday afternoon. Snow levels begin above 8000 feet on Saturday then lower to 5000 to 6000 feet on Sunday. The Probabilistic Winter Storm Severity Index (WSSI-P) has a 50% chance for moderate winter storm impacts around Yosemite NP this weekend. The Excessive Rainfall Outlook (ERO) has marginal risk (5-14%) painted along the Sierra Foothills of Mariposa, Madera, and Fresno Counties on Saturday. But there is still quite a bit of uncertainty regarding the timing, track, and strength of this system. Based on the current track, temperatures are forecast to cool to 10 to 15 degrees below normal by Sunday. && .AVIATION... VFR conditions will prevail across central CA for at least 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... High Wind Warning until 5 AM PDT early this morning for CAZ338. && $$ DCH weather.gov/hanford