000 FXUS65 KVEF 140952 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 252 AM PDT Mon Apr 14 2025 .SYNOPSIS...Today through midweek, expect similar temperatures as Sunday. Late-week, a dynamic weather system moves into the region, which will increase chances of precipitation, gusty winds, and will cool off temperatures substantially. && .SHORT TERM...Today and Tuesday. Through the day today, an upper-level low in the southeastern Pacific will continue to strengthen. As it does so, a shortwave will ride counter-clockwise around it, pushing into the Desert Southwest this evening. Moisture content associated with this shortwave is modest, with forecast PWATs between 100 and 140% of normal (normal PWAT this time of year is around 0.30"). Coupled with sub-optimal PWATs for measurable precipitation, forecast HRRR soundings show a pronounced inverted-V signature, indicating very dry low-levels. As such, not expecting widespread measurable precipitation, but this evening between about 7pm and 12am, a swath of sprinkles will push northward through the forecast area. Cannot rule out the occasional bolt of lightning, which would result in locally higher rain rates as well as erratic, gusty winds from its direction, but overall, not expecting impacts aside from a ruined car wash. Otherwise, heights over the region will remain elevated across the Desert Southwest through mid-week, so temperatures will continue to range 7 to 10 degrees above seasonal normals, with widespread "Minor" Heat Risk. .LONG TERM...Wednesday through Sunday. A notable pattern change arrives mid/late week as two systems phase together over our area. On Wednesday, ensemble guidance is in fairly good agreement with a shortwave moving south out of western Canada and a cutoff low moving onshore near Point Conception. As anomalous low-level moisture pools between the two systems, scattered showers and isolated storms are expected to develop across the Great Basin and Sierra on Wednesday. On Thursday and Friday, guidance merges the systems together, forming a single, closed low over the Great Basin and Mojave Desert. With lingering low-level moisture and cold air aloft, precipitation chances continue and spread southward across most of the area. Latest NBM has PoPs ranging anywhere from 30-50%, with the higher probabilities across the southern Great Basin. Thunderstorms will certainly be possible (10-30% chances) with this activity as well. The cold air aloft will also foster lower snow levels, particularly if the low moves directly overhead. This should result in late-season snow accumulations to the Sierra and Spring Mountains, where there is a ~50% chance of 4"+. Outside of the precipitation potential, the other main features of the late-week systems are the gusty winds and cooler temperatures. Winds are expected to be strongest on Wednesday and Thursday as the systems approach and begin to phase. Best chances (40-60%) of wind impacts are across western San Bernardino County, while the rest of the area ranges from 10-30%. As guidance moves the low overhead on Friday, winds weaken. This is also when temperatures will be their coldest. Forecast highs across the area go from 75-90 degrees on Wednesday to 55-75 degrees on Friday, some 10-15 degrees below-normal. Over the weekend, ensemble guidance has the low advancing eastward, pushing out of our area. As a result, precipitation chances wane while temperatures moderate toward seasonal values. && .AVIATION...For Harry Reid...For the 06Z Forecast Package... Light south or southwest winds expected through around 8-9z before uncertainty in a possible wind shift arrives. Winds may shift to the northeast at 6-9 knots or remain light and southerly through the remainder of the early morning hours. By daybreak, northeasterly winds will overspread the valley if they haven`t already with a few gusts to around 18 knots possible. Winds will ease through the day and shift back to the south by Monday evening with increasing mid and high level clouds with CIGS descending to around 15kft AGL. For the rest of southern Nevada, northwest Arizona and southeast California...For the 06Z Forecast Package... Tonight, the strongest northerly gusts of 15 to 25 knots are expected in the favored terrain areas from southern Lincoln County through the Laughlin/Bullhead City area. Winds are expected to become easterly to southeasterly over much of the region on Monday, with only spotty gusts over 20 knots. Mid level clouds will increase from south to north late in the afternoon, with spotty virga and gusty winds. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Soulat LONG TERM...Woods AVIATION...Outler For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter