Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 041506
Area Forecast Discussion
National Weather Service Sacramento CA
806 AM PDT WED MAY 4 2016
Period of unsettled weather setting in through this weekend.
Scattered thunderstorms in this pattern will produce a few areas
of heavy rain and small hail, most numerous in the foothills and
Radar returns across interior Northern California this morning
show showers and isolated lightning strikes in heavier showers.
Storms are generally developing north of Sacramento. Short term
model guidance indicates that the northern portions of the
forecast area will have the better chances for shower and storms
through this evening. Updated the forecast to include the
thunderstorm mention this morning.
The approaching trough is splitting, with the southern end
forming a closed low off the central California coast. Most of the
showers and thunderstorms today are expected to occur generally
north of I-80. More widespread shower activity will develop across
the region Thursday and Friday as the low drifts very slowly to
the southeast toward SoCal, with wrap-around continuing over the
weekend as the lows shifts into the Desert Southwest.
The primary impact from the system will be a trend back to cooler
temperatures, but some strong storms will be possible later this
week which may be accompanied by brief heavy rain, hail and gusty
winds. Some light snowfall accumulations will also be possible
beginning Thursday along the crest of the northern Sierra and may
impact travel at times into the weekend across the higher passes.
.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)
Closed low over the Great Basin will continue to have wrap around
moisture that will impact our CWA on Sunday. Expect a chance of
valley showers along with possible mountain thunderstorms over
the Sierra on Sunday with daytime highs near to below average. On
Monday, the closed low moves eastward while high pressure ridging
builds over the Eastern Pacific Ocean. Our region will be between
these two systems on Monday causing a drier pattern with daytime
highs warming above normal into midweek. Slight chance of showers
may still persist over the higher elevations of the Sierra into
VFR conditions through this morning. The best chances for
thunderstorms today will be in the afternoon/evening, primarily
in the mountains, however, showers/thunderstorms are possible in
the valley, too, which could bring periods of MVFR conditions.
Winds will generally be 10 kts or less, but breezy periods
possible today, especially near any thunderstorms that develop.