The National Weather Service in Las Vegas has issued a weather forecast for the region that includes showers and thunderstorms, thanks primarily to a low pressure system dragging tropical moisture into the area. According to the NWS discussion released early this morning, "Showers and thunderstorms are expected across much of the forecast area starting today as low pressure pulls remnant tropical moisture into the region." The bulk of the upcoming rain is anticipated to hit northwestern Arizona the hardest tonight into Monday, coupled with a stretch of cooler temperatures across the board, before heating up again midweek.
The low, currently positioned west of Baja California, is anticipated to push moisture left from Tropical Storm Alvin towards the Las Vegas area. The forecast warns that although virga showers have begun to form, with moisture initially too scant to reach the parched desert soil, greater amounts are expected to push through later this evening. To potentially exacerbate conditions, "strong outflow winds are a possibility with any showers that form," as stated by the NWS. Flooding becomes the main concern as the atmosphere moistens, particularly in southern Mohave County where a Marginal Excessive Rainfall Outlook has been issued.
On the temperature front, Las Vegas and surrounds are looking at a 5 to 10 degree dip from previous highs, thanks to the increasing cloud cover and decreased atmospheric heights. This comes as a brief respite before the mercury is expected to spike back up, pushing levels to a possible 10 degrees above the seasonal norm by next work week. Death Valley, notorious for its scorching climate, is notably situated within a "Moderate" (Level 2) HeatRisk category for Monday.
Looking ahead, the NWS mentions that "a northwest flow will set up over the region mid-to-late week," which implies a continuation of wet weather into Thursday. This is due to a combo of lingering moisture from the current system and incoming shortwaves on the northwest flow, as well as gusty south-southwest winds. But as a new ridge of high pressure builds, temperatures will "continue to climb back to 4 to 6 degrees above seasonal normals heading into the weekend," with desert valleys ready to bake in the 100s again, signaling a return of significant heat risks.
For aviators, wind conditions may prove challenging. "South southwest winds should persist this morning, with spotty gusts of 15 to 20 knots not out of the question," the NWS cautions, suggesting that gusts of about 25 knots will become the norm into the afternoon. Thunderstorm threats, complete with gusty and unpredictable winds, are slated to move in this evening, diminishing somewhat but not completely by early Monday morning.
Finally, in this season of wayward weather, the NWS has called on spotters to be vigilant and report any significant or impactful weather events as they unfold. The original NWS advisory and full forecast can be found at National Weather Service Las Vegas.
