textproduct: Reno

KEY MESSAGES

* Unseasonably mild weather continues today with light winds and valley inversions persisting. High flows also continue on area streams/rivers.

* Shower chances expected today with a 15-30% chance for thunderstorms across NE California/NW Nevada during the afternoon and evening.

* Rain and high elevation snow chances Sunday and Monday with thunderstorm chances decreasing.

DISCUSSION

Temperatures as of this writing are capping out in the mid 60s for valleys and upper 50s for the Sierra. Current satellite imagery also shows a thick layer of upper level clouds pushing over the region, which may limit how warm those afternoon highs get. Those clouds may also limit the potential for storm development south of I-80 today (chances have decreased to <10% today).

Meanwhile, isolated showers are pushing their way into NE CA in Lassen county, as well as north central Washoe county and have already begun to produce lightning. Those showers are capable of becoming stronger as the low pressure system that's bringing these showers tracks more inland. Storms that develop today will be capable of producing gusty outflows and small hail or pellet showers. With snow levels over 9500' today, the predominant precipitation type will be rain.

Shower chances become more widespread Sunday through Monday as that aforementioned low pressure system tracks over the area. However, chances will be mostly between 25-50% for the Sierra and Sierra Front, with 15-30% chances in the Basin and Range. Snow levels drop throughout the day Sunday, bottoming out Monday morning below 6000'. For more details, please see the Avalanche discussion below. Amounts will be light, and keep continuing to trend lighter. This system will exit the region by late Monday, allowing for brief high pressure to build Tuesday before another trough impacts the region Wednesday, bringing light shower chances (15-45%) areawide.

A series of troughs will keep the latter half of next week interesting from a forecaster standpoint. Model confidence is low of the timing and placement of said troughs so check back here next week for more concrete details.

-Giralte

AVIATION

VFR conditions are expected today for all terminals. Shower and thunderstorm chances for all sites except KMMH have decreased to <10% today. WSW FL100 winds increase to 35-40 kts today, bringing periods of LLWS to Sierra terminals. Otherwise, patchy FG is possible again (20% chance) at KTRK after 08Z.

-Giralte

AVALANCHE

Light rain/snow showers will impact all avalanche center terrain mainly Sunday through Monday.

* Snow levels and amounts: Snow levels Sunday start out around 9000', dropping steadily to 7000-8000' by late Sunday night. Levels will plummet further to near or just below 6000' by sunrise Monday before increasing to 6750-7500' (locally higher part of that range for southern Mono county) by mid afternoon. That secondary peak in snow levels coincides with when the showers are expected to exit the region. Snow amounts will be light and predominantly along the highest peaks, with a trace to 0.5" in the Tahoe Basin and 1-2.5" for central Mono county (up to an inch for ESAC terrain).

* SLR and SWE: SLRs will start out 5:1 Sunday, increasing to 8-10:1 by Monday morning. SWE will be highest in the Tahoe Basin with 0.1-0.4" through Monday morning, with locally lower as you progress southward (up to 0.3" for BAC terrain and 0.2" for ESAC terrain).

* Wind gusts: Southwest ridgetop winds increase tonight, with gusts of 50-60 mph.

* Lightning: Thunderstorm chances generally <10%, peaking at a riveting 12% along the crest in the Tahoe Basin Sunday afternoon.

-Giralte

HYDROLOGY

All rivers and streams in the area have crested, but flows remain elevated and may respond quickly to additional snowmelt with warm temperatures and any weekend showers/thunderstorms, especially smaller creeks and steams.

Use extra caution near rivers and creeks. Prolonged high flows may lead to unstable banks and erosion.

No new flooding is forecast, check for river forecasts and observations at www.cnrfc.noaa.gov

-TB/HRICH

REV Watches/Warnings/Advisories

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