Area Forecast Discussion
Issued by NWS Las Vegas, NV
Issued by NWS Las Vegas, NV
922 FXUS65 KVEF 261853 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 1153 AM PDT Wed Jun 26 2024 .SYNOPSIS...Monsoon moisture will continue to fuel showers and thunderstorms across the southern Great Basin and northwestern Arizona this afternoon. Highest flash flood threat remains in northwestern Arizona and highest damaging wind gust threat will be in the southwestern Great Basin. Precipitation chances will continue to dwindle through Friday as breezy winds return and hot temperatures persist heading into the next work week. && .SHORT TERM...Today. Another round of isolated showers and thunderstorms expected this afternoon with widespread PWATs in excess of 1 inch across the forecast area. That said, thunderstorm coverage will not be as widespread as yesterday. Convection today will favor the higher terrain of northwestern Arizona and the southern Great Basin in the absence of synoptic forcing. CAPE values range from 500-750 J/kg in these areas, though DCAPE approaches 1000 J/kg this afternoon in the southwestern Great Basin - according to forecast HRRR soundings. As such, the highest threat of flash flooding will remain across northwestern Arizona and the highest threat of damaging wind gusts will be across the southwestern Great Basin. Afternoon temperatures today will range from 5 to 7 degrees above seasonal averages. The monsoonal moisture in place has allowed overnight low temperatures to remain fairly warm - with Las Vegas low temperatures failing to drop below 90 degrees for the last 3 nights. .LONG TERM...Thursday through Tuesday. Shower and thunderstorm chances continue to dwindle on Thursday as a shortwave originating from the Pacific Northwest ushers dry air into the region. As the axis of this shortwave pushes through the Desert Southwest, breezy southwest wind gusts will pick up Thursday and Friday afternoons to between 25 and 35 mph. These winds coupled with this dry air will increase fire danger each afternoon - particularly along a strip from Barstow-Daggett through Las Vegas into St. George. A zonal flow will set up aloft over the weekend. Additional shortwave passages will result in breezy afternoons each day through the weekend into the start of next week. Monsoonal moisture will ebb and flow into Arizona, resulting in a fluctuation of PoPs for Mohave County through the weekend. Meanwhile, heat remains a persistent impact in the Desert Southwest. Temperatures will remain above- average through the entire forecast period with HeatRisk remaining "Moderate" or higher for desert valleys through the week and weekend. Las Vegas remains on-track for hottest June on-record. Current record hottest June is 2017 with an average temperature of 92.8 degrees. && .AVIATION...For Harry Reid...Southerly winds with a few gusts to 25kts are expected late this afternoon through early evening. Wind gusts should diminish after sunset with a chance (30%) that winds could fall below 10kts between 05Z and 09Z. Gusty south to southwest winds will redevelop tomorrow morning, with gusts to 25kts likely after 19Z. A few isolated thunderstorms are expected once again this afternoon and early evening. However, most of the activity should be concentrated away from the field over northwest Arizona, and only a slight chance of an outflow impacting the terminal exists today. Away from areas of convection, VFR conditions will prevail through tomorrow. For the rest of southern Nevada, northwest Arizona and southeast California...Breezy south-to-southwest winds with a few gusts to 25kts are expected at the Las Vegas and Colorado River TAF sites this afternoon and early evening. Winds will diminish overnight, potentially falling to below 10kts at times, before increasing again on Thursday. At KBIH, northerly winds will turn west to southwest by late afternoon but will swing back to the north after sunset. Winds at KDAG will favor a westerly direction through tomorrow, with gusts approaching 30kts by tomorrow afternoon. Scattered thunderstorms are expected to develop this afternoon and evening over northwest Arizona and the higher terrain of the southern Great Basin. This activity is not expected to impact any of the regional TAF sites, but gusty winds, lightning, and heavy rainfall obscuring terrain will be possible in and near storms that do develop. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ DISCUSSION...Soulat AVIATION...Planz For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter