Moderate to High Chance of Rain and possible Thunderstorms throughout Southern Nevada through late Today and Monday.
SYNOPSIS: A Pacific system will begin to bring unsettled weather across the region later today through Monday bringing chances for showers and thunderstorms, breezy winds and cooler temperatures. Another weather system will quickly move across the Great Basin region Tuesday bringing more chances for showers and gusty winds to the area. This will be followed by at least a few days of tranquil weather with a warming trend the second half of the week. UPDATE: Not much change to the forecast through the afternoon. Decreased sky cover and slowed down the arrival of scattered precipitation based on current mesoscale trends. Don't think the offshore low will edge close enough to influence our weather until at least 00Z when diffluent forcing and a 300mb jet edge into San Bernardino county. Best chance for any precipitation late this afternoon and evening will be from Bishop to Daggett corridor, though activity will be scattered at best. Weak instability in Lincoln county could allow for a stray thunderstorm late this afternoon, otherwise don't anticipate an convection away from the precip associated with the incoming system as morning sounding showed very dry air place over much of the southwest US. High temperatures will be warmer than normal, but should not be as yesterday. DISCUSSION for Sunday through Saturday (Updated @ 2:57 am PST). Main story is the anticipated approaching closed low currently spinning off the SoCal coast near 30N/130W. This system will begin to effect the region later this afternoon bringing increased cloud cover, gusty west-southwest winds, slight chances for showers and thunderstorms and slightly cooler temperatures. As the low slides into southern CA this evening, a decent slug of moisture will begin to advect across the region. The better moisture will set up across Clark, southeast San Bernardino, and Mohave counties. With added forcing from the approaching closed low, the best chances for widespread precipitation will be across far southeastern San Bernardino, and Mohave counties Monday morning through the afternoon. Elsewhere, more scattered precip will be possible as vorticity maxima moves eastward with the closed low circulation through Monday. With this set-up in mind, the better storm totals will be across the eastern half of our CWA, especially across Mohave County. Valleys could see storm total amounts of Trace - 0.10", higher terrain could see storm total amounts of 0.30"-0.50" with isolated higher amounts up to 0.75"- 0.80" possible across far northeastern Mohave County. Isolated to scattered thunderstorms can be expected and could create flooding concerns if there are training storms. With added cloud cover, temperatures will decrease to slightly below normals Monday and Tuesday. As the low begins to lift off to the northeast sometime late Monday, an open-wave trough will begin to dig into the Intermountain West/Great Basin region mainly bringing gusty southwest winds Tuesday afternoon and more rain chances for eastern Nevada and northwest Arizona. Models have been trending downward with the magnitude of the winds across the region Tuesday afternoon, and still look to be sub-advisory level with the strongest winds setting up along the I-15 corridor. Behind the trough, expect dry zonal flow Wednesday and Thursday with another possible weather system developing sometime late next weekend. With large discrepancies between models, low confidence on the forecast details beyond Thursday.