Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 191527
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
827 AM PDT Sun Oct 19 2014
High pressure will provide dry weather and seasonable temperatures
Sunday. Frontal system will provide cooler temperatures and
precipitation chances Monday and Monday night.
Ridge of high pressure will remain over the area today with
temperatures warming into the upper 70`s to lower 80`s for the
valley to the 50`s to mid 60`s for the mountains.
A weak cold front will move into the coastal range Monday
morning and spread through the interior during the day. the
southern end of the front will move through Sacramento during the
afternoon hours. The front this far south appears like it wont
hold together but may bring some showers this far south. Further
north looks like the better changes of rain. The central core of
the low will move through the interior Monday evening to keep a
threat of showers in the forecast. Once the low moves into the
Great Basin more stable air will filter in behind the system.
Instability does not look that great with this system but any
thunderstorms would likely be limited to the evening hours as the
core of the low moves inland and probably not that widespread.
Zonal flow aloft over the region for Tuesday with light northerly
winds. Cooler air will remain over the area to keep temperatures
in the lower to mid 70s for another day for the valley to the 50s
for the mountains. Some high cloudiness should be over the area
A large low will form in the Gulf of Alaska by Wednesday.
By Wednesday night and lasting through the remainder of the work
week the low will deepen and may bring some rain to interior
Northern California. The best chances will remain over the north
but will increase for the Sacramento area late Friday per the GFS
model which is more progressive with moving the low inland than
the other models.
.Extended Discussion (Thursday through Sunday)
For most of our CWA, the latter half of the week should be fairly
mild, dry weather with valley highs in the 70s to low 80s.
However, extended models continue to hint that the upper low in
the Gulf of Alaska could keep a slight chance of precipitation
along the Coastal range. The models diverge Friday into the
weekend as the GFS wants to track the low into the west coast and
spread the chance of precipitation across all of NorCal.
Meanwhile, the ECMWF keeps a weak ridge over NorCal. So have
blended the two solutions and kept mention of precipitation over
the Coastal range until models come into better agreement. JBB
VFR conditions and mainly light winds continue the next 24 hours.