096 FXUS66 KHNX 062136 CCA AFDHNX Area Forecast Discussion National Weather Service Hanford CA 232 PM PDT Mon Sep 6 2021 .SYNOPSIS... Dry and unseasonably hot conditions will continue into the middle of the week. Temperatures will trend slowly downward after Thursday, and highs are expected to be near normal for this time of year by the start of next week. Moisture moving in from the south will bring a chance for some thunderstorms in the Sierra Nevada and Kern County mountains and desert Thursday and Friday. && .DISCUSSION... The heat up continues today across central California under the influence of the upper level high pressure ridge currently centered near the Great Basin area. 24 hr temperature trends across our area are currently running up around 2-5 degrees, with highs on track to top out around 10 degrees above normal this afternoon. If Fresno reaches 100 degrees or more, it will be the 64th day of triple digit highs this year, and will break the record of 63 days first set in 1984 and tied yesterday. With more than an 85 percent probability of reaching at least 100 degrees this afternoon, Fresno is a sure bet to break this record. The high pressure center is progged to gradually meander eastward to near the Four Corners area through Thursday and will continue to create unseasonably hot conditions across central California. High temperatures will continue to run around 10 degrees above seasonal averages in the SJ Valley and Coastal Range through Thursday, creating an increased risk for heat related illnesses. The Heat Advisory there is in effect for this afternoon and early evening, and has been extended through Thursday. Desert locations are also experiencing excessive heat under the ridge and an Excessive Heat Warning is in effect there through Wednesday. By Thursday, the probability of reaching 105 degrees at most desert locales drops significantly to near 25 percent, so the Excessive Heat Warning is not being extended to Thursday at this time. A weak trough tracking inland over the ridge Tuesday is progged to remain well to our north, with no impact on our temperatures but is expected to bring a slight increase in wind gusts across the coastal range, combining with the low humidity to create an elevated fire weather risk on Tuesday. Models solutions diverge for the end of the week into early next week, as additional incoming shortwave troughs attempt to weaken and displace the strong ridge. Blended model guidance for this period predicts a very slight drop in temperatures by Friday, followed by a continued downward trend through the weekend. By next Monday, forecast highs are a few degrees below normal. Dry conditions are expected to prevail through Wednesday. Then, as flow around the high pressure center becomes southeasterly across our area, moisture is likely to be pulled northward and there will be a chance for showers and some thunderstorms over the Sierra as well as the Kern County mountains Thursday and Friday, before the moisture is shunted eastward. && .AVIATION... In the Sierra Nevada and Kern County mountains, areas of MVFR visibilities, with local mountain obscured IFR visibilities, are expected due to smoke and haze near active wildfires through at least the next 24 hours. In the San Joaquin Valley, MVFR visibilities are likely at times due to haze. && .AIR QUALITY ISSUES... On Monday September 6 2021... Unhealthy in Fresno and Kern Counties. Unhealthy for sensitive groups in Kings... Madera and Tulare Counties and Sequoia National Park and Forest. Further information is available at Valleyair.org && .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 an/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 8 PM PDT this evening for CAZ179>189. Heat Advisory from noon to 8 PM PDT Tuesday for CAZ179>189. Heat Advisory from noon to 9 PM PDT Wednesday for CAZ179>189. Heat Advisory from noon to 8 PM PDT Thursday for CAZ179>189. Excessive Heat Warning until 9 PM PDT Wednesday for CAZ198-199. && $$ public...JEB aviation....JEB weather.gov/hanford