Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 082237 CCA
Area Forecast Discussion
National Weather Service Sacramento CA
935 AM PST MON FEB 8 2016
...CORRECTED MORNING DISCUSSION...
DRY AND MILD WEATHER FOR INTERIOR NORCAL FOR THE NEXT WEEK.
NAEFS climate height percentiles and mean temp return intervals
indicate a 30(+) year max of values will prevail over/near the
CWA today and then shift mainly Ewd on Tue. Thus...there is a
continued potential for some record max temps again today...with
about a 25-50% percent chance of equaling or exceeding record
max temps at SAC (69 2006) and at DTS (72 2006) and about a
10-20% chance of the same at RBL (79 2006) and RDD (80 2006).
The major difference today is the lighter N winds in the N Valley
than yesterday and reduced adiabatic warming effects. However...
with temps running some 6-9 degrees warmer than yesterday over the
N Valley...it provides a good jump start to the diurnal range. LAMP
guidance shows temps slowing down through the day and falling just
shy of the record marks.
An impressive Ely pressure gradient of 12 mbs is resulting in
isolated strong gusty winds over the Siernev and Lake Co mtns. The
925 mbs winds are forecast to weaken substantially today...and the
katabatic winds over the Siernev should weaken accordingly as the
day wears on.
Omega Block/Strong high pressure along the W Coast will shift inland
as the deep cyclone over the Great Lakes/Ohio Valley swings up to
the NE. Energy from the Gulf of AK trof will weaken as it encounters
the blocking ridge so a dry and unseasonably warm week of wx is ahead
for Norcal. The chance of rain earlier forecast for the end of the week
looks less and less promising for Norcal...perhaps brushing the Nrn mtns
late Fri or Sat. The NCEP 45 day Total QPF ensemble plume for SAC paints
a dry picture until the end of the month before there is an uptick in
precip again. Not too unusual for dry/drier periods during wet El Nino
years as March has sometimes been a wet month as in the 1982-83 (strong)
and 1994-95 (moderate) El Nino years.
Although North Sac Valley temps will peak Sun/Mon...South Sac Valley
temps will will flirt with records through Wed before cooling...albeit
max temps will be above normal this week. Some patches of late night
and early morning valley fog will be possible as the week unfolds and
Nly winds subside. JHM
.EXTENDED DISCUSSION (Friday THROUGH Monday)
A weakening trough temporarily breaks down the ridge for a
minimal chance of precipitation Friday afternoon into Saturday
primarily north of Interstate 80. High pressure rebuilds Sunday
into early next week with continued warm and dry conditions.
GFS and ECMWF are hinting at a potentially more dynamic frontal
system impacting NorCal next Wednesday into Thursday.
Patchy IFR/LIFR shallow fog south of Marysville this morning,
otherwise VFR conditions today. Isolated northeast wind gusts up
to 25 kt over higher terrain through about 22z. Patchy fog returns