Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 291650
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
950 AM PDT Fri May 29 2015
Above normal daytime temperatures today and Saturday as high
pressure slides across the west coast. Cooler early next week with
a slight chance of showers and thunderstorms over the northern
Sacramento valley and surrounding mountains as the tail end of a
Pacific trough brushes through. Warmer temperatures are expected
to return mid to late in the week.
Ridge of high pressure over the area today bringing mostly sunny
skies and above normal temperatures (by about 5 to 10 degrees).
The high pressure ridge helped decrease the depth of the marine
layer (to around 1500 ft this morning). The low clouds made it
inland from the bay area to only around Cordelia this morning. The
low clouds will return tomorrow morning to around Vallejo. Temperatures
this morning are running similar to yesterday. Afternoon
temperatures will be in the upper 80s to mid 90s in the Valley and
mid 60s to low 80s in the mountains. These temperatures are
generally around 5 to 10 degrees above normal for the end of may
and will be a little warmer than yesterday. The temperatures will
be close to what we saw at the beginning of the month and in some
places may be the warmest so far this year. Temperatures will be
similar to slightly cooler tomorrow as the ridge axis shifts to
the east and an upper level trough approaches the west coast.
The upper level trough and associated low pressure system will
strengthen the onshore flow and deepen the marine layer Sunday
into Monday bringing cooler temperatures and possibly some low
clouds into the Valley. This system will also bring some
instability for a chance of showers and thunderstorms over the
Northern Sacramento Valley and surrounding mountains Sunday
afternoon into Monday. High temperatures are expected to reach the
upper 70s to low 80s in the Valley and 50s and 60s in the
mountains on Monday which is about 5 to 10 degrees below normal
for the first of June.
.Extended Discussion (Tuesday through Friday)
Weak upper trough moves through Tuesday followed by weak upper
ridging Wednesday, then another weaker trough Thursday into Friday.
Slight chance of showers are possible over the Shasta and Plumas
mountains Tuesday, otherwise dry weather expected. High temperatures
forecast to gradually trend upward through the extended forecast
Upper level ridge over the area bringing VFR conditions except
stratus west of KSUU until 18z and returning again aft 08z. Local
southwest wind gusts to around 25 knots through Delta.