Area Forecast Discussion
Issued by NWS Las Vegas, NV
Issued by NWS Las Vegas, NV
196 FXUS65 KVEF 200923 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 223 AM PDT Thu Jun 20 2024 .SYNOPSIS...Increasing temperatures and the first influx of moisture associated with the North American Monsoon are expected in the coming days. Temperatures will climb to around 6-8 degrees above normal over the weekend while tropical moisture will increase over western Arizona, southern Nevada and eastern California Friday through early next week. This moisture will lead to an increase in shower and thunderstorm chances, while the hottest temperatures have shifted to next week when decreasing moisture is forecast. && .DISCUSSION...Through next Wednesday. There are few concerns over the next day or two with generally clear skies, warming temperatures, and afternoon breeziness. Hot conditions caused by rising temperatures are standard fare for the Desert Southwest in mid-late June. High temperatures today will rise above normal by a few degrees with moderate Heat Risk spreading into our southern desert areas including southern Mohave and southern San Bernardino counties, the lower portions of the Colorado River Valley, and Death Valley where temperatures around 110 degrees will be common this afternoon. Temperatures continue to increase on Friday and plateau over the weekend at about 6-8 degrees above normal. Moderate Heat Risk expands in areal coverage on Friday then becomes more widespread over the weekend with areas of major Heat Risk appearing in southeast Inyo County and southern Nye County over the weekend. Its likely the increasing moisture drawn northward from Alberto will produce enough cloud cover to maintain moderate Heat Risk across our southern deserts. For the past two days had some concern for `excessively hot` temperatures occurring over the weekend as a massive ridge currently over the eastern/central US migrated back west, repositioning itself over the Desert Southwest. Now with more moisture expected to advect into the region, NBM temperatures have moderated some. Yesterday, NBM probabilities of Las Vegas high temperatures 110+ were 60%-70%, today have now dropped to around 40%. In actual numbers, both Saturday and Sunday highs are now 2-3 degrees lower than yesterday. Therefore, not as many pockets of `Major` HeatRisk expected. But, again that heat will be offset by higher humidity values. With limited Heat Risk concerns through the weekend, we will be primarily focused on any potential impacts that a remnant tropical system could bring to the Desert Southwest. First taste of the North American Monsoon set to arrive in the coming days as guidance .AVIATION...For Harry Reid...Diurnal winds continue with light winds favoring southwest until mid-morning when northeast to east winds will prevail through midday when wind will transition though southeast settling on the south-southwest by 22Z. After the southwest shift, speeds will increase to 10 to 12 knots with a few gusts to 20kts possible through sunset when winds will relax a bit to 5-8kts and become more westerly. Skies will remain mainly clear through the TAF period. For the rest of southern Nevada, northwest Arizona and southeast California...Winds will follow a typical diurnal pattern through Thursday with light and, at times, variable winds during the morning hours. Winds will pick up from the south in the afternoon Thursday with the gusts of around 20kts up the Colorado River Valley and west- southwesterly gusts to 25 kts at KDAG. Skies will be clear through the TAF period at most sites with some high clouds AOA 15kft along the Sierra crest and over the northern Owens Valley including KBIH. region.continues to get more `bullish` on moisture advection into the region.which Tropical Storm Alberto, near the Mexican coast in the southwest Gulf of Mexico, is progged to move inland into mainland Mexico this morning. The remnants of Alberto will then continue to move west into the eastern Pacific along the southern periphery of a strong subtropical ridge expanding westward over the Desert Southwest. Moisture presently over west Texas, New Mexico and northern Mexico will advect westward underneath the ridge on east- southeast winds, arriving into eastern Arizona today. That moisture continues to move west into western Arizona, southern Nevada and eastern California Friday into early next week. As the remnants from Alberto cross into the eastern Pacific and southern Gulf of California it could induce a gulf surge transporting additional moisture into the lower Colorado River Valley. Both the GEFS and EPS both indicate precipitable water values peaking over the weekend into early next week with values ranging from 1` to 1.5` from around Las Vegas/Mesquite south through western Arizona and eastern California. Therefore, the chance for showers and thunderstorms has continued to increase, and expand further west from Friday into early next week. Initial storm conditions will likely support gusty winds and dry lightning potential, as moisture deepens storms should transition to seeing more rain reach the ground. && .AVIATION...For Harry Reid...Diurnal winds continue with light winds favoring southwest until mid-morning when northeast to east winds will prevail through midday when wind will transition though southeast settling on the south-southwest by 22Z. After the southwest shift, speeds will increase to 10 to 12 knots with a few gusts to 20kts possible through sunset when winds will relax a bit to 5-8kts and become more westerly. Skies will remain mainly clear through the TAF period. For the rest of southern Nevada, northwest Arizona and southeast California...Winds will follow a typical diurnal pattern through Thursday with light and, at times, variable winds during the morning hours. Winds will pick up from the south in the afternoon Thursday with the gusts of around 20kts up the Colorado River Valley and west- southwesterly gusts to 25 kts at KDAG. Skies will be clear through the TAF period at most sites with some high clouds AOA 15kft along the Sierra crest and over the northern Owens Valley including KBIH. region. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Salmen LONG TERM...Pierce AVIATION...Berc For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter