Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Sacramento California
921 PM PDT Tue Mar 31 2015
cooler, but still above normal weather expected this week. Weak
weather systems may bring a few showers to the mountains Wednesday
and Wednesday night. Windy on Thursday. Another chance of
precipitation arrives this weekend.
clear skies this evening with much cooler temperatures. We still
have some colder air filtering into the region this evening that
has some local breezy conditions popping up in the valley. The
winds will continue out of the northwest to north direction
overnight but not as strong as they where earlier in the day.
Another shortwave will move through the area on Wednesday but the
greatest impact looks to be keeping temperatures cool and breezy
conditions over the region. Some showers look possible over the
mountain areas late in the day from around Plumas County northward
and along the coastal range from around Northern Lake County northward.
The same general area looks to keep shower threats through the
evening hours before any threat diminishes. Snow levels will be
lower so some showers down into Chester and will be possible late
in the day and evening with a mix of rain and snow down near
Quincy for the evening.
Winds will likely remain breezy overnight over the far north end
of the valley and along parts of the west side of the valley. On
Thursday with the system well east of US windy conditions look
likely over the valley with possible wind advisories being needed.
Northerly wind gusts 30 to 40 mph look likely within the valley
and Delta. Weak ridging building into the area Thursday night will
help to diminish the winds during the evening. The ridging will
lead to warmer temperatures for Friday with weaker winds. Another
trough setting up in the Gulf of Alaska for this weekend will
start to break down the ridge on Friday and reverse the wind flow
in the valley.
Extended discussion (saturday through tuesday)
A low pressure system will drop southeast from near Alaska into the pac
northwest this weekend into early next week. Several waves progged to
move along associated trough into norcal by overnight Saturday
into Tuesday. Models in decent agreement but still vary a bit in
timing and strength of individual waves as the system rotates
inland. Despite differences, increasing confidence for now in at
least a few chances for precipitation Sunday into midweek. Because
main parent low will remain removed far to the north, best chances
will reside across northern mountains and Sierra Nevada with
lesser of a chance in the valley. Have raised chances a bit in
this time frame. Regardless of precip chances and areal coverage,
system will bring cooler temperatures (closer to normal) and
increased cloud cover. Cooler nature of system would also bring
the potential for snow below pass levels. Will keep on eye on this
as system moves closer.
VFR conditions thru the forecast period. Skies will generally
remain mostly clear. Local breezy northerly winds with gusts to
around 25 kts possible through this evening and becoming more
widespread again during the day Wednesday.