Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 291209
Area Forecast Discussion
National Weather Service Sacramento CA
409 AM PST SUN NOV 29 2015
Freezing morning today and Monday. The next storm will arrive
late Wednesday into Thursday bringing cold, wet, and windy
weather to our region.
.SHORT TERM DISCUSSION (TODAY THROUGH TUESDAY)...
Most of the Valley is very near or below freezing as of 230 am.
The big temperature drop areas from yesterday are the north and
west side of the Sacramento Valley (12-17F cooler) due to light
to no wind. Tonight/Monday morning will be very cold as well, but
not quite as much as this morning. The mountains are even colder
with some single digits up near Lake Almanor and Lassen Park. More
record lows for Nov 29 may fall this morning, and with the
dewpoints from the teens to the mid 20s, there is plenty more room
to drop. The Redding area has already tied a record of 27F from
2010. Tomorrow morning will be another cold morning, but not quite
as cold as this morning.
A shortwave currently along 135W will weaken as it encounters the
West Coast ridge leaving only the coastal range with a chance of
showers over our forecast area on Mon. Ridging rebuilds on Tue
allowing for a moderation in temperatures. The ridge slides east
Wednesday with another Pacific shortwave approaching the West
Coast with a chance of light precipitation, mainly up north.
.EXTENDED DISCUSSION (Thursday THROUGH Sunday)
A moderately wet system will move through Thursday into Friday
bringing widespread rain, mountain snow, and gusty winds. Mainly
drier weather Saturday, followed by a weaker system Sunday, mainly
north of I80.
The main question for the Thursday system is in timing. The
latest ECMWF is slower now, bringing precipitation more in the
afternoon and peaking overnight into early Friday. This disagrees
somewhat with the GFS, with brings precip into the western side
of the area Thursday morning, and into the Sierra through the
afternoon, peaking by early evening. In either case, the potential
is improving for accumulating snow above 5000 feet, with up to a
foot of snow above 6000 feet. This combined with strong mountain
winds could cause significant travel difficulties. This system
also will bring a brief period of moderate rain and gusty
southerly winds to the Valley. This will bring down leaves, which
could clog drains and cause slippery conditions on area roads.
The wind may also bring down tree branches, causing local power
The system should be mainly out of the area by Friday evening.
Drier weather returns Saturday, except for perhaps the far
northern mountains. A weaker system moves in Sunday, but looks
like it will mainly affect areas north of I80, especially the
Coastal Range. EK
VFR conditions with generally light winds the next 24 hours.
Freeze Warning until 9 AM PST this morning for Carquinez Strait
and Delta-Central Sacramento Valley-Northern Sacramento Valley-
Northern San Joaquin Valley-Southern Sacramento Valley.