Scientific Forecaster Discussion
fxus66 ksto 162319
Area forecast discussion
National Weather Service Sacramento California
319 PM PST Sat Nov 16 2019
dry and mild conditions this weekend through early next week. Very
warm over the weekend and Monday with record highs possible in the
North Sacramento valley. Pattern change still on track around mid
week with breezy winds, cooler temperatures and maybe some
rain/snow mainly in the Sierra Nevada.
high pressure will remain over the region into next week. Light
winds tonight should allow for the redevelopment of fog for
places south of Marysville and into the Delta. Mainly through the
central parts of the valley and near waterways. Some record and
near record temperatures the next couple of days.
On Tuesday a low pressure area will drop down from the north and
over the state. This will bring cooler temperatures and breezy
north winds during the day for the valley. Offshore pressure
pattern increases Tuesday night into Wednesday when the stronger
winds are expected to develop. Some shower chances for Sierra
Nevada Tuesday night as the lows moves into the area but most
areas look to remain dry.
Extended discussion (wednesday through saturday)...
Main issue for the extended forecast period is continued concerns
for northerly winds, with some increase in confidence. Upper
level trough will drop down into a closed low over California mid
week. European model (ecmwf) ensembles means continue to indicate elevated
probabilities of wind gusts exceeding 35 mph for the valley and
the Sierra foothills Wednesday into early Thursday. Latest
guidance indicates wind gusts in the 30 to 40 mph range (locally
higher) could be possible Wednesday into early thursday; strongest
winds should be on Wednesday.
Despite not expecting excessively low humidity levels, fuels
remain at critically dry levels for this time of year due to
recent north wind events and little precipiation. Becuase of this
these gusty winds will bring some fire weather concerns. The main
areas of concern are currently expected to be along the west side
of the Sacramento Valley into Lake County, the northeast Sierra
foothills, and portions of the coastal range. Lighter winds are
expected Thursday afternoon as the npressure gradient relaxes.
In terms of precipitation, this system could bring some mountain
rain or snow showers mainly for areas along and/or south of I-80
per latest deterministic and ensemble output. European model (ecmwf) ensemble means
suggest modest probabilities of 24-hour quantitative precipitation forecast > 0.1" for those
Regarding temperatures, highs will be above average through the
period, with valley highs in the mid 60s to low 70s.
VFR conditions next 24 hours except local MVFR conditions
from ksmf southward returning again Sunday 12z-18z. North wind
up to 10 kts from 18z-01z in the valley.