Area Forecast Discussion
Issued by NWS Las Vegas, NV
Issued by NWS Las Vegas, NV
414 FXUS65 KVEF 182004 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 104 PM PDT Wed Sep 18 2024 .SYNOPSIS...A trough of low pressure will swing across the western US during the second half of the week, bringing a chance of precipitation to the southern Great Basin and reinforcing the below- normal temperatures. Drier and warmer conditions will return over the weekend as a high-pressure ridge builds over the region. && .SHORT TERM...Through Friday. Continuing to watch the trends and potential precipitation impacts with a deepening upper level low that is expected to shift through the region Thursday and Friday. Models continue to slow down the eastward progression of the low, with the center of the low now expected to be situated over southern Nevada or western Arizona Friday afternoon. Thursday precipitation chance and amounts have decreased outside of northern Inyo County and Esmeralda County with this slower solution. In the areas where precipitation may fall Thursday, amounts remain unchanged with impacts mainly revolving around the potential for wet roads in the Owens Valley and the northwest corner of Esmeralda County. Despite increasing forcing Thursday with low moving into California, moisture will struggle so the potential for flash flooding Thursday is low. Thursday night into Friday the low will continue to swing inland. As previously mentioned, trends have slowed the system down and now with the low center sitting somewhere around southern Nevada, Friday afternoon precipitation chances have changes. With the cold core low overhead in the afternoon, scattered showers and even isolated thunderstorms will be possible over much of the region when before the low was further eats and there was less potential for precipitation. Friday afternoon precipitation chances have increase, especially in terrain of southern Nevada and around Mountain Pass, CA. Again, moisture will be lacking so not expecting widespread heavy rain or flash flooding, however anyone who was expecting Friday to be dry or only a low chance for precipitation may be surprised. Some hi-res models are slower still the the ensemble means for Friday afternoon so a continued slowing trend is still possible which would again change precipitation potential and amounts. Snow will remain in the very high terrain with snow levels remain at 9000ft or higher, though the first snowflakes of the season are possible Friday morning on the peaks of the Spring Mountains. With the center of the low moving across the region, winds are not expected to be impactful. This system will reinforce the cooler than normal temperatures we have been experiencing. Friday`s high temperatures are now cooler than previously forecasted with the low slowing down and increased precipitation and overall, temperatures will run 10-15 degrees below normal for mid to late September. .LONG TERM...Saturday through Tuesday. Picking up Saturday morning, model consensus is for the low to be exiting stage right, with any lingering precip chances limited to the eastern fringes of our CWA. As the low departs, the warming trend will begin, and high temps should be five to 10 degrees warmer Saturday than Friday, except in the far eastern CWA where clouds and precip chances will hold temps down one more day. Dry weather then takes hold for the rest of the period as high pressure builds in from the west, and highs rise another four to eight degrees from Saturday to Monday before plateauing on Tuesday. No significant winds are expected through the period. && .AVIATION...For Harry Reid...Light and variable winds will pick up and swing around to the southeast later this afternoon. These southeasterly winds will continue into the evening hours before decreasing slightly and swinging around to the southwest in a typical diurnal fashion. These southwesterly winds will become light and variable during the overnight period, continuing through the morning hours before picking up out of the southeast during the early afternoon. For the rest of southern Nevada, northwest Arizona and southeast California...The remaining Las Vegas Valley TAF sites will follow similar trends to KLAS with winds picking up and swinging around to the southeast later this afternoon before becoming light and diurnal through the overnight hours. KDAG will see light and variable winds continue into the evening when they will pick up and swing to the west-southwest through the overnight period. The Colorado River Valley TAF sites will favor a more southerly direction, varying between southwesterly and southeasterly, with sustained speeds of 10 knots or less. KBIH will tend to follow typical diurnal directional trends with sustained winds of 12 knots or less. Vicinity showers will begin to pop up in the higher terrain surrounding the Owens Valley later this afternoon with the potential for these showers to move off the terrain and into the terminal area during the evening and overnight hours. These showers will be accompanied by CIGS ranging from 6 to 10 kft. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ SHORT TERM...Nickerson LONG TERM...Morgan AVIATION...Stessman For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter