Area Forecast Discussion
Issued by NWS Las Vegas, NV
Issued by NWS Las Vegas, NV
059 FXUS65 KVEF 010749 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 1249 AM PDT Mon Jul 1 2024 .SYNOPSIS...A dangerous long-duration heat wave is on the way to the Mojave Desert and southern Great Basin. Excessive Heat Warnings go into effect beginning Wednesday and Thursday and continue into next week. Monsoonal moisture will linger in northwest Arizona, bringing slight chances for thunderstorms in eastern Mohave County today and possibly Tuesday, before getting pushed away to the east. && .SHORT TERM...through Tuesday night. Midnight satellite loop showed mid level convective debris clouds over southern and eastern Mohave County and clear skies over the rest of our CWA. Area radars showed very weak returns in extreme southern Mohave County, most likely associated with either sprinkles or virga. Surface obs showed south to southwest breezes, with peak gusts of around 40 mph in the Spring Mountains, hot temperatures (still 100F at Bullhead City), and dewpoints several degrees higher than 24 hours ago, especially in the Las Vegas Valley. The stickiest surface air was in the southern Colorado River Valley, where Lake Havasu City had a dewpoint of 61F at midnight to go along with a 99F temperature. High resolution and coarser models agree that this moisture will not push much farther west (barring an unexpected outflow boundary) and could even get pushed east as early as Tuesday, so thunderstorm chances should remain confined to Mohave County, and perhaps even stay east of Kingman. High temperatures today should be similar to yesterday - maybe even a degree or two lower - before the warming trend begins Tuesday. More on this in the long term period. .LONG TERM...Wednesday through the weekend. A 500mb ridge just off the West Coast will begin to nose into Mojave Desert and Great Basin on Wednesday. By the weekend, most ensemble solutions place the ridge axis overhead or just to our west. This drives temperatures even further above normal, placing most of our lower deserts in the 105-120 degree range, and the southern Great Basin zones in the 95-110 range. Daily records will be in jeopardy, and a few climate sites may flirt with all-time temperature records. As a result, HeatRisk indices quickly climb to Major and Extreme, particularly across the western 2/3 of the Mojave Desert. The excessive heat sticks around through the weekend, producing what will likely be a long-duration heat wave, and a long-duration Excessive Heat Warning has been issued. An often overlooked aspect of these heat waves is the overnight low temperatures, which are crucial to providing relief from the daytime temperatures. For places like Las Vegas and the Colorado River Valley, lows may struggle to fall below 90 degrees, especially by the weekend. In terms of precipitation, well the chances don`t look very great. PoPs remain less than 10% across the entire area during this time. If any place in the CWA were to get an isolated shower/storm, it would be eastern Mohave County, but again chances are low. Long story short, July looks to be picking up where June left off: hot and predominantly dry. && .AVIATION...For Harry Reid...Though there will be periods of respite, expect gusty south-southwest winds to persist through the overnight period with gusts ranging from 15 to 25 kts. Gust speeds will increase to 20 to 30 kts through the afternoon before tapering off after sunset. Wind speeds will drop below 10 kts overnight Monday into Tuesday. No operationally significant cloud cover expected through the TAF period. For the rest of southern Nevada, northwestern Arizona, and southeastern California...Gusty south-southwest winds will continue for the Las Vegas Valley TAF sites through sunset tonight with speeds between 20 and 30 kts. Breezy north winds at KBIH will become southerly through the afternoon before returning northwesterly overnight with speeds between 8 and 12 kts. Gusty west winds will pick up through the afternoon at KDAG with gust speeds to 30 kts. Gusty south winds along the Colorado River Valley will bring gusts between 20 and 25 kts to KIFP and KEED through the afternoon before subsiding after sunset. No operationally significant cloud cover expected through the TAF period. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Morgan LONG TERM...Woods AVIATION...Soulat For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter