Area Forecast Discussion
Issued by NWS Las Vegas, NV
Issued by NWS Las Vegas, NV
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
109 FXUS65 KVEF 172326 AFDVEF Area Forecast Discussion National Weather Service Las Vegas NV 326 PM PST Mon Nov 17 2025 .KEY MESSAGES... * Widespread rain and mountain snow returns to the region today and tonight, with periods of locally heavy rainfall persisting into Tuesday night. * Wet soils and bursts of moderate to heavy rain will lead rapid runoff and area of flood potential in low lying and sensitive basins. * Heavy snow remains expected in the higher terrain of the Spring Mountains, Sierra, White Mountains, and peaks in the southern Great Basin. && .DISCUSSION...through Sunday. The active weather pattern continues as another rather deep closed low digs south into central California this afternoon. This 548dm low is spreading heavy snow into the Sierra at this hour with some light spillover rainfall reported into the Owens Valley and around Bishop as well. As the low drops further south tonight, increasing diffluent southerly flow will overspread the Mojave Desert and southern Great Basin, with showers and isolated thunderstorms breaking out prior to daybreak and spreading north in several rounds through the day. As the low slowly pivots east into the Mojave and Sonoran Deserts Tuesday night into Wednesday, precipitation will gradually shift eastward but some lingering light showers may persist into Wednesday under the cool wrap- around flow on the back side of the departing low. Following the widespread and locally heavy rainfall observed across much of the region over the weekend - soils are saturated and will have an added sensitivity to additional rainfall. Latest NBM/HREF probabilities favor Northwest Arizona and the Colorado River Valley with the highest 24 hour rainfall totals exceeding 1 inch, with probabilities ranging from 25-50 percent. Some pockets of heavier rainfall exceeding 2 inches are even suggested across parts of Mojave County. Meanwhile, probabilities for over 0.50 inches remain elevated across much of southern Nevada and much of Inyo County, with totals that could end up being comparable to the weekends wet storm system. Given some of the flood impacts witnessed over the weekend and the expectation for additional rainfall, drew a broad flood watch for much of the area starting late this evening and continuing through Wednesday morning. Finally, heavy snow continues to be a concern in the higher elevations. Overall, no major changes to the expectations in the Sierra/White Mountains, but trends towards slightly higher snow levels do have some implications for the Spring Mountains and southern Great Basin areas. Overall, snow level within the deep southerly flow Tuesday will climb to 7000-8000 feet across southern Nevada much of the day, resulting in a rain or rain-snow mix within that elevation range that will limit snow totals through the day. Cooler air will filter in after sunset Tuesday allowing snow levels to fall closer to 6000 feet, and when the more impactful snow accumulations are expected in the higher terrain. Specially, Kyle Canyon in the Spring Mountains may remain more rain than snow for most of the day before the snow level falls in the evening. After this system moves out Wednesday evening, another storm system will drop south behind it. Latest trends continue to suggest this system will trend further west and south, largely bypassing our forecast area - however, there remains the chance of some light showers and cooler temps as it moves off the coast. Meanwhile, a much anticipated break is expected by the weekend as ridging builds in temperatures slowly moderate. && .AVIATION...For Harry Reid...For the 00Z Forecast Package... Southeast breezes continue for a few more hours, weakening and turning more easterly after sunset. Precipitation moves in after midnight, bringing reduced visibilities and lowering CIGs throughout the night and Tuesday. Chances for CIGs below 6kft exceed 50% by 08z, with a 50% chance of CIGs below 3kft by 18z Tuesday. Probabilities for CIGs below 1kft are ~25% from 18z-00z. Precipitation chances above 50% from 12z to 03z. Winds tonight and tomorrow remain light, favoring an easterly direction. For the rest of southern Nevada, northwest Arizona and southeast California...For the 00Z Forecast Package...Southerly to easterly breezes continue this evening, particularly in the Owens Valley and southwestern Great Basin. Precipitation has already begun to move into our western zones, and will continue to push eastward overnight. Expecting widespread precipitation on Tuesday, mainly across southern Nevada, northwestern Arizona, and Inyo County. When precipitation is ongoing or nearby, expect reduced visibilities, low CIGs, and significant terrain obscuration. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ DISCUSSION...Outler AVIATION...Woods For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter