Area Forecast Discussion
Issued by NWS Las Vegas, NV
Issued by NWS Las Vegas, NV
978 FXUS65 KVEF 221825 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 1125 AM PDT Wed May 22 2024 .SYNOPSIS...Seasonal temperatures with periods of gusty winds expected through the weekend. Most locations remain dry, but isolated showers and storms will be possible in our northern areas Friday and Saturday. High pressure builds in next week, resulting in above-normal temperatures and dry conditions. && .DISCUSSION...through Tuesday. Persistent, long-wave troughing over the Western US with embedded shortwaves will keep things mildly active through Saturday. The first shortwave passes through the PacNW and Northern Great Basin today, spurring breezy conditions across most of the CWA. Peak wind gusts of 20-30 mph are forecast this afternoon as temperatures remain close to seasonal normals. Zonal flow behind this system brings a slight reduction in winds and temperatures Thursday, but another shortwave makes its approach on Friday. Unlike its predecessor, this trough is expected to extend down through our CWA, bringing a greater likelihood of impactful winds. Latest NBM probabilities paint the typical SW wind belt (I-15 and I-40 corridors) with widespread 40-80% chances of 40+ mph winds. When bumping that threshold up to 48 mph, probabilities drop below 20% outside of the high terrain, suggesting any wind impacts are likely to be minor in nature. However, any boaters getting an early start to the holiday weekend should be prepared for increased wave action on Friday. Given the warm and largely dry weather of late, there is also some concern for elevated fire weather conditions, primarily in the lower elevations of the Colorado River Valley and NW Arizona where fuels are beginning to cure. In the areas not expected to see gusty winds with the late-week system, we`ll be watching for scattered showers and isolated thunderstorms to develop. Friday afternoon, 10-30% PoPs stretch from Northern Inyo County to Lincoln County. Ensemble guidance has the trough dragging just enough moisture into the Southern Great Basin to spur this activity in conjunction with the colder air/forcing aloft. While ensemble mean PWATs are 120-150% of climatology, that isn`t saying much for late May around here. As a result, any impacts from this convection would be gusty outflow winds and lightning. On Saturday, this potential becomes focused in East-Central Nevada. As Sunday rolls around, the aforementioned system will be east of the Rockies. In its wake, 500mb heights rise rather quickly as ridging begins to build over the Western US. WPC Cluster Analysis suggests good ensemble agreement in a large-scale pattern shift taking hold next week as the ridge dominates the regional weather. ECMWF meteograms for Las Vegas show the entire ensemble temperature distribution above the 50th percentile of model climatology by the middle of next week, suggesting a high likelihood of above-normal temperatures. && .AVIATION...For Harry Reid...A period of moderate (8-15kts) southeast winds (140-170) is possible through 21Z before becoming southwest with gusts to around 20kts after 21Z. Expect the southwest winds to persist into tomorrow morning before turning to the north after 14Z. South to southwest winds should return after 22Z tomorrow. VFR conditions will prevail through the TAF period. For the rest of southern Nevada, northwest Arizona and southeast California...Las Vegas Valley TAF sites will follow similar trends to KLAS. KBIH will see south winds into mid-afternoon before turning more westerly after 21Z. North winds will return after 03Z and continue through Thursday morning. At KDAG, westerly winds will continue through the TAF period, with gusts over 20kts developing after 20Z. TAF sites in the Colorado River Valley will have mainly south to southwest winds through the period, with occasional gusts to 20kts this afternoon and again Thursday afternoon. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ DISCUSSION...Woods AVIATION...Planz For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter