textproduct: Reno

KEY MESSAGES

* Anomalously warm and dry conditions persist through the weekend along with many areas reaching near-record high temperatures.

* A significant pattern change is expected next week bringing much cooler temperatures, stronger winds, and increasing chances for valley rain and mountain snow.

* Multiple rounds of precipitation are likely starting on Tuesday with snow levels dropping significantly by Wednesday.

DISCUSSION

Today and tomorrow will be the warmest days of the week as an upper level ridge slowly weakens with the approach of another low pressure system to the PacNW. This will lead to near-record temperatures again this weekend for western NV, NE CA and the Sierra. Afternoon highs will be in the upper 70s to low 80s for western NV and NE CA valleys, with Sierra valleys in the upper 50s to upper 60s. Typical afternoon westerly breezes are expected each day with gusts to 15-25 mph over exposed ridges and valleys. Moisture aloft will continue to move in as observed in the latest sounding. A very dry layer near the surface will continue in the forecast leading to virga through this afternoon, as many models persist to show light showers, especially over Mono county. The chances for showers and thunderstorms remain below 12%.

The pattern changes late on Sunday into Monday as the first upper trough pushes through the PacNW into the Northern Rocky Mountains with a weak shortwave trough and associated cold front stalling over northern NV. So, expect the first cool down, and gusty west winds with gusts potentially reaching 30-40 mph by Monday afternoon. Rain and high elevation mountain snow will be limited to NE CA, the Sierra and areas north of I-80 in western NV. However, probabilities remain low at 15-25%. Also, any accumulations are expected to be very light through Tuesday morning.

Tuesday through the end of the work week, we will be affected by a series of shortwaves with the main upper trough passing through late in the week. Model solutions are still diverging as is typical for this time of the year. Regardless, the forecast still calls for wetter and cooler conditions along with stronger winds. The main uncertainty resides in how much precipitation (rain/snow), how deep the snow levels will go down, and how strong the winds will be. At the moment, we are looking at seasonal to below normal temperatures, along with a 30-60% chance of precipitation with snow levels potentially starting at 7000-8000 ft Tuesday, and dropping to 4000-5000 ft Thursday night into Friday morning, with gusts likely exceeding 40 mph. However, I would recommend keeping an eye out to the model trend this weekend to better ascertain what will happen late next week.

If you are not happy about the late week forecast, well... next weekend's forecast is looking generally hot and dry with another high amplitude upper level ridge developing over the West Coast. Although some ensembles continue to show some weak disturbances in the flow that could lead to very light and isolated precipitation.

-HC

AVIATION

VFR conditions are expected through this weekend with FEW-BKN upper level cloud cover. Overall, winds will be light and VRB overnight and in the morning with typical westerly afternoon gusts to 15-25 kts.

-HC

REV Watches/Warnings/Advisories

NV...None. CA...None.