Area Forecast Discussion
Issued by NWS Las Vegas, NV
Issued by NWS Las Vegas, NV
655 FXUS65 KVEF 160833 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 133 AM PDT Thu May 16 2024 .SYNOPSIS...Warm and dry conditions are expected the rest of the work week, with heat peaking on Friday before a system to the north knocks temperatures backs lightly for this weekend. Gradual cooling and increasing winds will continue into next week as low pressure develops over the region. && .SHORT TERM...Through Friday Night. Weak ridging will build into the region today and Friday which will bring modest height rises as the area remains in a transition zone between an area of high pressure to the south and a low pressure system over the northwest US. This will result in dry conditions, afternoon breezes, and warming temperatures. The ridge is not overly strong with only slightly above normal 500mb height rises over the region, however we can still expected above normal temperatures in most locations. Today`s high temperatures will be a degree or two warmer than yesterday, and Friday temperatures will climb a few more degrees from there as better mixing with afternoon gusts of 15 to 25 MPH allows for temperatures to efficiently warm. Latest NBM probabilities of reaching 100 degrees has dropped back to 30% and Death Valley has a 20% chance of reaching 110. However, with prolonged above normal temperatures, heat risk climbs to moderate levels by Friday for many valley locations; including Death Valley, Las Vegas, and Daggett...as well as in the Colorado River Valley and the Lake Mead Recreation area. Heat of that level could affect anyone outdoors for a prolonged period of time who are not prepared, anyone who is not used to desert heat, as well as heat sensitive individuals. .LONG TERM...Saturday through next Thursday. A longwave trough will dive southward through the central United States this weekend, effectively squashing our eastern Pacific ridge and altering the synoptic pattern for the western United States. A shortwave trough will push into the Pacific Northwest on Saturday as it rides along this longwave, which will further reduce heights over the Desert Southwest. As the weekend progresses, the central US trough will dive southwestward into the Great Basin with a 100kt 250mb jet. Meanwhile, a weak closed low will push inland into the northern Baja, ushering modest moisture into the region. The trough axes associated with both systems are expected to pass through the Desert Southwest on Monday. There remains uncertainty regarding how much (if at all) these two systems phase with one another. If the closed low completely phases with the longwave trough, the Desert Southwest will be breezy. If the closed low holds onto its independent center of circulation, we could get a repeat of the last two days` weather (isolated convection and showery activity). Regardless, we can expect temperatures to moderate. That said, as mentioned in the previous discussion, the NBM4.2 maintains a robust temperature difference between the 25th and 75th percentile for high temps next week, which highlight the synoptic uncertainty. Details including to what degree temperatures moderate will become more clear as we progress through the remainder of this week. && .AVIATION...For Harry Reid...Quieter day across the region as any threat of convection remains well outside of our area and there is no threat of outflow boundaries. Overall winds will generally remain diurnal with light northeast winds late morning and afternoon up to 7 knots, becoming light southwest after sunset. Skies will remain mainly clear. For the rest of southern Nevada, northwest Arizona and southeast California...High pressure building over the region will keep winds over most TAF sites under 10 knots along with any threat of convection and associated outflow boundaries outside of the forecast area. Light winds and just a few clouds around 12k feet expected through the end of the week. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Nickerson LONG TERM...Varian AVIATION...Gorelow For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter