648 FXUS65 KVEF 051131 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 430 AM PDT Thu Jun 5 2025 .SYNOPSIS...Isolated-to-scattered showers and thunderstorms are expected across southern Nevada and northwest Arizona this afternoon with lesser chances in southeastern California. Gusty outflow winds, frequent lightning, and moderate-to-heavy rain will be threats with any storms that develop. Things will begin to dry out and heat up as we head into the weekend. && .SHORT TERM...Today. Elongated troughing stretching from the eastern Pacific through southern California into southern Nevada and northwest Arizona will allow for vorticity advection into the region today. This advection combined with daytime heating and precipitable water values over 200% of normal will allow for another round of showers and thunderstorms across much of the area this afternoon. Convection will favor areas of higher terrain for development beginning later this morning. Showers and thunderstorms will move off the higher terrain, tending to move from west to east with the upper-level flow. Southern Nevada and northwest Arizona will have the best chances at seeing scattered showers and thunderstorms this afternoon as this is where CAPE values around 500 to 1,000 J/kg overlap with 0.75 to 1.0 inches of precipitable water. Convection in San Bernardino and Inyo counties will be more isolated in nature. Anomalous moisture across the area will allow for moderate-to-heavy rain capable of resulting in isolated flash flooding will be possible with stronger storms. Frequent and dangerous lightning and 30 to 40 mph outflow wind gusts will be possible with any storms that develop; 50 mph outflow wind gusts will be possible with stronger storms. With lower CAPE values than we had on Tuesday and lack of sufficient wind shear, 1 inch hail is not expected to be a threat today. However, more robust convection may produce graupel or small hail (pea, nickel, or dime sized). Convection will begin to die down across the region after sunset with the exception of northern Lincoln County where showers and thunderstorms may linger later into the evening. .LONG TERM...Friday through Wednesday. Friday through early next week, a return to more typical early June hot and dry conditions is on tap for southern Nevada, southeastern California and northwestern Arizona. Ensemble guidance and cluster analyses remain in good agreement regarding a strengthening ridge over the region, which will facilitate a decrease in moisture and gradually warming temperatures, with a return to above normal temperatures on Friday, warming to well above normal Sunday through at least Tuesday. Fairly widespread highs in the 90s and lower 100s are expected Sunday through Tuesday, with Monday and Tuesday looking to be the hottest days of the forecast. Along with the warming temperatures will be increasing HeatRisk, with "Major" HeatRisk returning to Death Valley and the Lower Colorado River Valley on Saturday, gradually expanding across other lower elevations through early next week, with "Extreme" HeatRisk possible for the lowest Valleys Monday and Tuesday. Thereafter, ensemble members begin to diverge, with some indications that a weak trough may try to undercut the ridge heading into midweek, but with little in the way of moisture, this trough would have little impact other than tempering the hot temperatures by a couple of degrees, and producing some breezy conditions. Stay tuned. && .AVIATION...For Harry Reid...For the 12Z Forecast Package...Light winds are expected throughout the morning before becoming southeast by midday. Thunderstorm chances return during the afternoon with storm development initiating over the mountain terrain after 18Z, then spreading into the Las Vegas Valley through the afternoon hours. These storms will bring a period of gusty and erratic winds, lightning, and brief heavy rain to the valley, with about a 30% chance of a storm directly impacting the terminal. The convection will end around sunset, followed by improving conditions overnight. Storms on Friday should remain north and east of the valley. Away from areas of precipitation, FEW to SCT clouds with bases AOA 10kft AGL can be expected. Near any storms, CIGs to 8kft AGL are possible. For the rest of southern Nevada, northwest Arizona and southeast California...For the 12Z Forecast Package...Generally, light winds with partly cloudy to mostly clear skies are expected through mid- morning. Thunderstorm Chances return this afternoon, with the highest concentration of activity over southern Nevada. A few isolated storms are also possible over the western Mojave Desert near KDAG and along the Sierra near KBIH. The chance of storms in the Colorado River Valley is minimal. Brief periods of heavy rain and gusty winds will be the main concerns with any storms. Otherwise, light southerly winds with speeds of 8 to 12 knots are expected. Away from areas of precipitation, FEW to SCT clouds with bases AOA 10kft AGL can be expected. Near any storms, CIGs to 8kft AGL are possible. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Stessman LONG TERM...Phillipson AVIATION...Planz For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter