FXUS65 KVEF 191809 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 1109 AM PDT Tue Aug 19 2025 .KEY MESSAGES... * Hotter than normal temperatures are on tap for the region this week with Extreme Heat Warnings and Heat Advisories in effect Wednesday through Saturday. * Moisture will return to the region during the second half of the week, bringing increased precipitation chances to the area late week into the weekend. && .DISCUSSION...through next Tuesday. Temperatures will continue to increase each day through the end of the week as we find ourselves under higher than normal 500 mb heights courtesy of the Four-Corners High. Afternoon high temperatures will top out around 5 degrees above normal as temperatures peak on Thursday and Friday. While 5 degrees above normal might not sound too bad, there will be little overnight relief with this heatwave as overnight low temperatures will be around 6 to 12 degrees above normal each night during the second half of the week. This combination of hotter than normal temperature during the day and anomalous overnight temperatures will result in widespread Moderate (Level 2 of 4) to Major (Level 3 of 4) HeatRisk with pockets of Extreme (Level 4 of 4) HeatRisk during the second half of the week. As such, A Heat Advisory is in effect for Esmeralda County, central Nye County, the Spring Mountains, and the Sheep Range from 8:00 am Wednesday through 11:00 pm Saturday. An Extreme Heat Warning is in effect for the Owens Valley, Death Valley, San Bernardino County, Mohave County, Lincoln County, and Clark County from 8:00 am Wednesday through 11:00 pm Saturday. While the heat headlines run through Saturday, one potential caveat is that convective cloud cover and precipitation could limit afternoon temperatures for portions of the region. As the high pressure ridge settles over the Four Corners Region, we will find ourselves in our typical monsoonal pattern with southeasterly flow aloft helping to transport moisture into our area. Moisture will begin to increase today, but the only evidence of this moisture will be increased cloud cover for portions of the region. Precipitation chances will begin to increase in the eastern portions of Mohave County on Wednesday afternoon, slowly pushing further west on Thursday afternoon as moisture continues to increase. Chances for afternoon showers and thunderstorms will become more widespread across northwestern Arizona, southern Nevada, and southeastern California beginning Friday and continuing into the weekend. Lightning, gusty outflow winds, and localized heavy downpours will be threats with any convection that develops. Forecast confidence decreases as we head into next week due to discrepancies regarding a potential trough and the return of dry southwesterly flow. The timing of this shift to drier flow aloft will determine how long we will see moisture linger across the region as it recirculates beneath the ridge. && .AVIATION...For Harry Reid...For the 18Z Forecast Package... Winds largely remain diurnally driven through the period. Expect winds to gradually turn east/southeast by early afternoon with a southwest push this evening and overnight. Winds should generally remain 15 knots or less, although a period of gusts in the 15-20 knot range is apparent in the late afternoon to early evening. Winds will gradually diminish late this evening and overnight becoming variable. Another hot day is on tap with highs exceeding 100 degrees from 19z through 04z and highs peaking around 106 degrees. For the rest of southern Nevada, northwest Arizona and southeast California...For the 18Z Forecast Package...Winds will largely remain diurnal and 10-15 knots or less. The few exceptions will be KBIH, where gusty south/southeast windswill persist through the afternoon. Winds here will decrease after sunset, eventually becoming northwesterly overnight. KDAG will also experience its typical west/southwest gustiness. Each of these locations can expect a few gusts of 20-30 knots. Otherwise expect just a few passing mid and high level clouds through the period. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ DISCUSSION...Stessman AVIATION...Austin For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter