Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 071204
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
404 AM PST Sat Dec 7 2013
A cold low pressure system has exited the region, although
scattered showers may be possible through the day mainly over the
Sierra. A very cold airmass will settle into Northern California
through the middle of next week, bringing overnight hard freeze
conditions. Low confidence in a weather system late next week.
A fairly vigorous weather front moved through Northern California
early this morning. While available moisture was less than
impressive, strong lift along the weather front more than made up
for it. Roughly 0.25 to 1.00 inches of precipitation fell, most of
it along the front itself. Low snow elevations were reported, with
snow levels of roughly 300 ft observed along the Northern
Sacramento Valley, and down to 600-800 ft east of Sacramento. 3 to
5 inches of snow were reported in Redding, with preliminary
estimates of 6 to 10 inches along the midslopes of the Sierra.
We`ll learn more about what happened at the highest elevations
Scattered showers continue behind the front...mainly along the
Sierra. This will likely continue through the afternoon, although
accumulations moving forward will be relatively light.
Temperatures this afternoon are expected to be on the cold side,
with low heights and thicknesses and areas of highly reflective
surfaces due to fresh snow. Look for highs only in the low to mid
40s across the Valley, with 10s to 30s over the mountains. These
highs are considerably colder than normal.
Overnight lows will be even colder. In fact, the coldest lows of
the year are likely the next few nights, and the coldest lows in
several years may be possible. Across the Valley, lows are
expected to be in the mid 10s to mid 20s. The coldest peaks and
mountain basins may go below zero. In those locales, frostbite may
become an issue with prolonged exposure.
The very cold airmass will remain in place through at least the
early parts of next week.
.Extended Discussion (Wednesday through Saturday)
Models continue to show little run to run consistency with
handling of waves moving into the EPAC ridge during the extended
period. Have leaned the forecast toward the drier side, but
confidence in the forecast is not high. With some cloudiness
spilling through the ridge and minimal precip chances, have edged
valley temperatures up a bit but colder areas will still be around
Cold front continues to work its way south and will exit NorCal
early this morning with precip ending in the valley and decreasing
winds. Snow showers will continue across the northern Sierra
Nevada today before tapering off this evening. Widespread ST with
IFR/MFR CIGS in the Central Valley will gradually erode from the
north today, clearing to about the SAC area by 00Z and then
completely by 06Z Sun. Widespread IFR conditions -SHSN/BR/FG
continue across the northern Sierra Nevada til about 06Z Sunday.
Winter Storm Warning until 4 pm pst this afternoon Motherlode...
West Slope Northern Sierra Nevada.
Hard Freeze Warning in effect from tonight through Tuesday morning
for the Sacramento Valley...Northern San Joaquin Valley...Southern
Lake County...Northeast Sierra Foothills...and the Motherlode
below 2000 ft.