655 FXUS65 KVEF 152248 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 348 PM PDT Sun Jun 15 2025 .KEY MESSAGES... * Above-normal temperatures continue through the forecast period. An Extreme Heat Warning remains in effect through 10 PM this evening. * Breezy southwesterly winds will continue through tomorrow, resulting in increased fire danger. The Fire Weather Watch that was in effect has been upgraded to a Red Flag Warning, which will be in effect from 12 PM to 8 PM tomorrow. * Breezy winds peak once again late-week as temperatures decrease heading into the weekend. && .DISCUSSION...This afternoon through Saturday. High pressure centered over northern Mexico will continue to build across the Desert Southwest, resulting in temperatures 8 to 12 degrees above seasonal normals. An Extreme Heat Warning is in effect through 10 PM this evening for western San Bernardino County, Death Valley National Park, lower elevations of Clark County, far southern Nye County, southern Mohave County, and the Colorado River Valley (including the Lake Mead National Recreation Area). Those spending time outdoors this afternoon are encouraged to bring extra water & electrolytes, and avoid heavy meals before heading outdoors. Temperatures will remain elevated tomorrow with highs remaining close to today`s values. However, the "Major" HeatRisk area shrinks in size, so the Extreme Heat Warning was not extended into tomorrow. Temperatures are expected to cool by a few degrees on Tuesday, but then rebound on Wednesday and Thursday. If these trends continue, additional heat products may be needed for the mid-week period. The region will remain sandwiched between an area of low pressure in the Gulf of Alaska and the aforementioned area of high pressure over northern Mexico. As a result of this dry southwesterly flow aloft, expect breezy southwesterly winds each afternoon through the week. Winds tomorrow will be enhanced a bit more as a shortwave moves into the Desert Southwest. This will further increase the southwesterly winds to 30 to 35 mph across the western Mojave Desert, Owens Valley, and higher terrain across the forecast area. Isolated gusts to 40 mph are also possible, but these will be isolated in space and time, so I elected not to issue a Wind Advisory. However, these winds will be coupled with extremely low daytime RH values (less than 10 percent in many areas), which will heighten wildfire concerns. Therefore, the Fire Weather Watch that was issued earlier has been upgraded to a Red Flag Warning and will be in effect from 12 PM to 8 PM tomorrow. See the FIRE WEATHER discussion below for more details. Late in the week, ensemble guidance indicates that a Gulf of Alaska closed low will quickly push southward into the Great Basin. As the Desert Southwest remains sandwiched between this system and the northern Mexico high, pressure gradients will tighten substantially, resulting in a resurgence of the strong, gusty winds Thursday and Friday. As a low associated with this trough moves through our forecast area late in the week and over the weekend, 500mb heights are expected to fall, allowing temperatures to return to levels closer to seasonal normals. && .FIRE WEATHER...The Fire Weather Watch that was in effect from 12 PM to 8 PM on Monday across southern Nevada (Zones 462, 464, 465, 466) and northwestern Arizona (Zones 101, 102) has been upgraded to a Red Flag Warning. A shortwave trough will push into the region, resulting in gusty southwest winds. Speeds will generally range from 25 to 35 mph, with occasional gusts to 40 mph in the western Mojave Desert, Owens Valley, and the higher terrain of the forecast area. This will lead to an increased risk of wildfire starts and spreads due to these breezy southwest winds coupled with single-digit (5- 10%) minimum relative humidities and poor overnight recoveries (5- 15%). Tuesday and Wednesday are expected to have lighter wind speeds and marginally improved RHs, so a short-term extension to the warning is not anticipated at this time. However, winds will increase beyond Wednesday, and RH values will remain low, so additional Fire Products are possible for the second half of the week. Be sure to safely dispose of cigarette butts, avoid activities with sparks or flames (such as campfires, target practice, fireworks), and report any fire starts to local officials. && .AVIATION...For Harry Reid...For the 00Z Forecast Package...Breezy southerly to southwesterly winds will continue into the evening, before diminishing by 06Z. Winds will remain elevated overnight with sustained speeds of 10 to 12 knots expected. Gustiness will return after 16Z tomorrow, with a few gusts possible, reaching up to 25 knots, generally between 19Z and 02Z. VFR conditions will prevail through the TAF period with only a FEW clouds with bases AOA 20kft AGL through early evening, then mainly clear skies thereafter. Temperatures over 100F can be expected through 04Z, peaking around 108F around 00Z today. Tomorrow, temperatures in excess of 100F are likely between 16Z and 04Z, with a maximum temperature of 109F around 00Z. For the rest of southern Nevada, northwest Arizona and southeast California...For the 00Z Forecast Package...All areas, except for the lower Colorado River Valley, will see gusty winds out of the south to southeast into the evening. Winds in the river valley will be lighter, with winds generally remaining 12 knots or less. Overnight, winds are expected to diminish, but similar conditions are likely on Monday, with gusts in the 20 to 30 knot range anticipated at all regional TAF sites. VFR conditions will prevail through tomorrow with only a FEW clouds with bases AOA 15kft AGL expected, mainly over the northern half of the region. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ DISCUSSION/AVIATION/FIRE WEATHER...Planz For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter