Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
131 FXUS66 KHNX 020916 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 216 AM PDT Tue Jul 2 2024 && .KEY MESSAGES... 1. Above average temperatures continue today, then rapidly warm up to around 15 degrees above normal by Wednesday. This is a dangerous, prolonged heat wave that will last several days with an Extreme Heat Risk. 2. An Excessive Heat Warning remains in effect from today through Monday, July 8th, and may need to be extended further as the week progresses. 3. The risk of grass fires will continue to increase with herbaceous fuel loading at or near 120% of normal. A long period of excessive heat, minimum relative humidities near 15% and poor overnight relative humidity recovery will add to the grass fire risk. && .DISCUSSION... This morning the upper level set up has a trough over the Norther Plains States and an upper low parked in the Gulf of Alaska. In between is a very strong upper ridge near 600 decameters for a 500 MB height over the far Eastern Pacific. This ridge will be the impact weather maker over the next ten days and probably even longer for Central California. As the day changes to Wednesday the ridge moves into the Golden State. The ridge then wobbles around however holds over California all the way into next Tuesday and beyond. The confidence in this pattern is very high looking at the clusters of 500 MB heights through day nine all telling similar stories for the region. The excessive heat warning starts at 11 AM this morning for portions of the forecast area mainly for the San Joaquin Valley and Kern County desert. The heat risk index is in the major to extreme category through the end of the forecast period. There is not a reason to disbelieve the guidance. This is a severe heat event. Looking at the length of consecutive days above 105 and 110 degrees for the region lead to an insight on this heat wave. Here is the longest streaks of consecutive days of greater than 105 degrees for the climate stations in the San Joaquin Valley. Bakersfield 26 days from July 5th-31st 1908 Fresno 14 days from July 16th-30th 1988 Merced 9 days from Aug 30th-Sep 9th 2022 Madera 13 days from July 8th-21st 1961 Hanford 12 days from July 2nd-13th 1931 Here is the longest streaks of consecutive days of greater than 110 degrees for the climate stations in the San Joaquin Valley. Bakersfield 15 days from July 16th-31st 1908 Fresno 6 days from July 25th-31th 1898 Merced 3 days from July 21st-24th 2006 Madera 8 days from July 17th-24th 1960 Hanford 7 days from July 20th-27th 1931 Here is a table of probabilities of exceeding 105 degrees over the next seven days. Location TUE WED THU FRI SAT SUN MON NEXT TUE Bakersfield 65% 98% 95% 85% 100% 100% 75% 80% Fresno 60% 95% 95% 85% 100% 98% 70% 75% Merced 60% 90% 80% 85% 97% 95% 60% 65% Madera 55% 85% 85% 85% 99% 96% 65% 65% Hanford 60% 90% 95% 85% 100% 98% 70% 75% Here is a table of probabilities of exceeding 110 degrees over the next seven days. Location TUE WED THU FRI SAT SUN MON NEXT TUE Bakersfield 2% 55% 35% 20% 75% 70% 35% 45% Fresno 2% 30% 25% 20% 60% 65% 25% 35% Merced 0% 15% 10% 10% 45% 50% 25% 25% Madera 0% 15% 10% 10% 45% 50% 20% 25% Hanford 0% 30% 25% 20% 65% 70% 25% 35% The confidence on the pattern continuing in the six to ten day and eight to fourteen day CPC forecast is fairly high with high probability of Above normal temperatures to continue. && .AVIATION... Continued areas of MVFR and local IFR visibility due to smoke at and around the Fresno County fires will continue in the Sierra Nevada and adjacent foothills. Otherwise, VFR conditions will prevail across the central California interior for the next 24 hours. && .FIRE WEATHER... Above normal temperatures, low relative humidities, poor overnight humidity recovery, and dry fuels will continue. The impact issue this afternoon and evenings starting Wednesday into the weekend will feature wind gusts into the teens for the region to add to the fire weather impacts. The best news is that the probability of thunder is near zero for the period ahead. && .AIR QUALITY ISSUES... ISSUED: 07/01/2024 14:37 EXPIRES: 07/02/2024 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 high. 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... Excessive Heat Warning from 11 AM this morning to 8 AM PDT Tuesday for CAZ300>322-324-332-334-336>339. && $$ public/aviation/fire weather...Proton IDSS....EW weather.gov/hanford