Synopsis: After a few days of above normal temperatures, another closed low will drop south from the Pacific Northwest into western Nevada on Sunday.
Discussion: Looking at the big picture, the 18Z 250mb GFS shows a rather distinct closed low in the upper levels is expected to be situated near the Oregon/California/Nevada border. The 18Z 500mb GFS for Sunday morning shows this same closed low over the area with decent area of positive vorticity expected over much of California. So what all this means is western Nevada will be in a favorable location for showers and thunderstorms to develop over much of the area and expand east as the day progresses.
Precipitation: The latest NAM, GFS MOS and SREF plume data for Reno (not shown) suggest that amounts of less than one tenth of an inch is likely, however, the typically drier NAM has no precipitation with low chance probabilities. Looking at climatology and pattern recognition, total precipitation amounts as depicted in the GFS look reasonable, with heaviest amounts northwest of Reno. The ECMWF shows mainly just a few hundredths for the Carson City area and is in good agreement with the GFS. Due to the spotty nature of precipitation with these types of lows, some folks will see measurable rain and some folks will not.
Temperatures: Latest forecast MOS data is in good agreement in keeping highs in the low 80s on Saturday, with a significant cool down on Sunday into the upper 60s to low 70s. In fact, the NAM and GFS MOS data show Reno only getting to a high of 69. For Carson City, highs are typically a few degrees cooler, so expect highs in the upper mid to upper 60s.
Winds: Winds on Saturday will be out of the west at 15-25 mph becoming northwest at 10-15 mph on Sunday
Outlook: Once the low moves out of the area Sunday night, expect a gradual warming trend, with an end the showers. Highs are expected to be in the mid to upper 70s Monday, warming to the upper 80s to near 90 by the end of next week. No precipitation is expected at this time after Sunday night through the rest of next week.
Graphics are courtesy of NOAA Tropical Tidbits and Weatherbell Analyitics.