Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Reno Nevada
306 PM PST Monday Mar 2 2015
A trough across the region will increase cloud cover and provide
chances for snow showers especially along the Sierra into
tomorrow. Areas of snow showers with light snow accumulations
are possible across eastern Pershing and Churchill counties into
Tuesday morning as well. Dry northerly flow will develop Tuesday
and Wednesday followed by a warming trend for the end of the week.
Isolated snow showers have formed across the Sierra this afternoon
and will continue to develop through the evening. An additional
couple of inches of snow are possible in the higher terrain with
trace amounts for western Nevada. The showers will be convective,
similar to this past weekend, but not nearly as persistent.
However, if a strong storm develops then localized higher amounts
of snow may result.
A more distinct shortwave associated with the northward portion of
the trough will drop across Pershing and Churchill counties late
tonight. Models differ with the timing of the shortwave as the NAM
swings it through the Interstate 80 corridor from Reno eastward
during the 12-15z timeframe, while the GFS is a couple of hours
earlier. The hrrr shows the band strengthening south of Interstate 80
around 12z, and dropping quickly south which will help to limit
snow amounts. Although snow accumulations should remain around an
inch, locally heavier amounts will be possible under more well
developed showers through early Tuesday morning. Some enhancement
near area lakes will be possible since temperature differentials
between lake surfaces and the lower troposphere are greater than
5c. Fog may develop in areas north of Interstate 80 if the high
clouds clear out quickly enough, but the extent of the fog will be
localized and likely affect the typical locations, such as the
martis and Sierra valleys. Otherwise, high level clouds leftover
from the shortwave will limit radiational cooling resulting in
decreased chances for fog development Tuesday morning.
Very dry middle-level air will work its way into the Sierra and western
Nevada Tuesday/Wednesday ahead of the upper level ridge, which will
bring an end to chances for precipitation through the remainder of
the week. A warming trend will start midweek with temperatures
climbing into the high 60s for western Nevada and the middle 50s for
the Sierra by Friday. Weishahn
Long term...Thursday through Monday...
By Thursday the upper ridge re-establishes itself over the southwest
and remains over the area through the weekend. This will bring
mostly clear skies, light winds, and well above average
temperatures to the region for the weekend.
Daytime temperatures will rise 10 to 12 degrees above normal with
Sierra valleys easily reaching the upper 50's and possibly low
60's during the day. Western Nevada will see temperatures rise
back to the middle to upper 60's through the weekend. Clear skies and
increased snow cover will allow temperatures to remain cool overnight,
with near freezing temperatures in western Nevada and low 20's for
By the end of the weekend models are in good agreement with the mean
ridge amplifying over the eastern Pacific and allowing a large closed
low to develop under it around 150w. This could strengthen the
subtropical jet while a positive ridge anomaly builds southwest of
the Aleutian Islands during the next week. Models are indicating a
trough developing along the West Coast next week. Of course,
significant model inconsistencies remain about just how deep the
trough will be and especially how far south cold air will be
Scattered convective showers remain throughout the region with the
strongest showers west of the Sierra crest. Continued showers
remain possible at all terminals through 06z with brief periods of
mfvr conditions possible mainly at ktvl/ktrk. Surface winds will
remain erratic near convective showers with gusts of 20kts
possible. Current hrrr shows a second wave of convective showers
moving through northwest Nevada potentially impacting knfl around 10z.
Moderate middle-level clouds expected through Monday night, however any
possible clearing would allow fog to develop in Sierra valleys.
Light north surface winds with VFR conditions for Tuesday. Tolby
For more information from the National Weather Service visit...
http://weather.Gov/Reno (all lower case)