Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
605 FXUS66 KHNX 291036 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 336 AM PDT Wed May 29 2024 && .KEY MESSAGES... 1. A slight cooling trend will take place today then a warming trend will follow on Thursday and Friday which will result in afternoon highs of 5 to 10 degrees above normal. 2. There is a 70 to 90 percent probability for temperatures to reach or exceed 95 degrees on Friday in the San Joaquin Valley. 3. Gusty west winds are possible tonight and Thursday morning for the Mojave Desert Slopes and Kern County Desert. && .DISCUSSION... An upper level shortwave trough is currently passing through the Pacific Northwest region, extending south into central California. The approaching trough brought warmer than average temperatures to our area today as it shifted the synoptic flow aloft to the west. Afternoon maximums reached the low 90s, around five degrees above normal for this time of year. Stronger winds have cascaded into the San Joaquin Valley, with sustained winds around ten miles per hour and gusts around 20 miles per hour. The elevated winds across the region extend into the Mojave Desert Slopes where sustained winds of 20 to 30 miles per hour remain expected through the overnight hours with stronger gusts up to 45 miles per hour possible. A Wind Advisory will continue for this area until 8 AM PDT this morning. The aforementioned trough is anticipated to progress eastward further inland later today, shifting the synoptic flow over central California to the west to northwest. A slight cooling trend is in order as a result of the winds aloft. Short-term, high resolution ensemble guidance from the HREF indicates less than a 30% probability for temperatures to exceed 91 degrees today in the San Joaquin Valley. However, even with this cooling trend, maximums this afternoon will still be two to four degrees above seasonal averages. Elevated winds will be present again across central California Wednesday evening, with the aforementioned HREF ensemble suggesting a 70 to 80 percent probability for wind gusts greater than 20 miles per hour in the San Joaquin Valley. There are similar probabilities for wind gusts greater than 40 miles per hour in the Mojave Desert Slopes and an additional Wind Advisory may be considered. As the upper level trough continues into the central United States, winds over central California are expected to stagnate, with the synoptic pattern being on the borderline between ridging and zonal flow; a warming trend will set up as a result for Thursday and Friday. According to probabilistic guidance from the National Blend of Models, afternoon maximums on Friday have a likely chance (70 to 90 percent) of being the warmest temperatures so far this year. The current highest temperature recorded in 2024 is 95 degrees, occurring at both Hanford and Madera on May 12th. The NBM ensemble also suggests a low to moderate probability (10 to 40 percent) to exceed 100 degrees in the San Joaquin Valley on Friday, although Fresno has a slightly higher probability at 51 percent. Regardless of temperatures exceeding 100 degrees, afternoon maximums Friday will be up to fifteen degrees above season normals. An upper level shortwave trough will bring a cooling trend and provide some relief for the weekend, with temperatures returning near 90 degrees Sunday afternoon. However, these temperatures are projected to be short-lived as zonal flow returns to central California to begin next week. Cluster analysis indicates a strong upper level ridge will propagate over the region midweek, continuing another warming trend. NBM probabilistic guidance suggests a 60 to 70 percent probability to exceed 100 degrees in the San Joaquin Valley next Wednesday and Thursday. These conditions are further corroborated by the Climate Prediction Center, which gives a moderate (40 percent) risk for excessive heat for next Thursday, June 6th, through the following Monday. && .AVIATION...VFR conditions will prevail across the central CA interior over the next 24 hours. && .AIR QUALITY ISSUES... ISSUED: 05/28/2024 14:39 EXPIRES: 05/29/2024 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 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... Wind Advisory until 8 AM PDT this morning for CAZ338. && $$ public/aviation...SM IDSS.............VJP weather.gov/hanford