Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Sacramento California
339 am PDT Mon may 25 2015
warmer temperatures with afternoon and evening showers and
thunderstorms expected through the middle of the week, mainly over
the mountains. High pressure dries things out by late in the week.
mostly clear to partly cloudy skies cover the region early this
morning. A thin area of marine stratus extends inland into the
Sacramento region from the Bay area as onshore gradients have
increased compared to 24 hours ago and the marine layer along the
coast is between 2500-3000 ft deep. Temperatures through much of
the valley are cooler than Sunday morning and are in the 50s to
lower 60s. The exception is the north end of the Sacramento Valley
where onshore flow has yet to reach and readings there are still
in the mid 60s to lower 70s.
High pressure will weaken a bit over norcal today as short-wave
energy moving around the upper low along the British Columbia/Washington border
drops down into the region. This will also lead to an increase in
showers and thunderstorms over the mainly the mountains later
today into this evening, though there is a chance some activity
may migrate down into the northern Sacramento Valley.
Little overall change to the pattern is expected through
Wednesday, though temperatures will begin to rise a little each
day as onshore flow weakens and the mountains see a little less
deep convection. By Thursday, temperatures are forecast to warm
significantly as the ridge over the eastern Pacific shifts
overhead norcal, with some areas of the valley possibly
approaching the century mark.
Extended discussion (friday through monday)...
high pressure ridge will be centered across norcal on Friday
making for what should be the warmest day of the period. Dry
weather is expected across the area with above normal afternoon
temperatures reaching into the upper 80s to mid 90s in the valley
and 60s to 70s in the mountains. Benign weather and mostly sunny
skies will continue through the weekend as high pressure remains
in control. As the ridge shifts east, increasing onshore flow will
cool temperatures a degree or two Saturday and a few more degrees
Sunday but still above normal for the end of may. Models hinting
at next system approaching norcal by next Monday/Tuesday with a
chance for precip across the north, but substantial differences
remain this far out. Ceo
generally VFR conditions expected for the next 24 hours. A few
showers and thunderstorms across higher terrain this afternoon and
evening may lead to local MVFR restrictions. Marine stratus has
intruded from the Delta as far west at kmhr early this morning and
MVFR cigs may continue through approx 18z before it Burns off.
Locally gusty winds will continue through the Delta with gusts to