Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA

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090
FXUS66 KMTR 221155
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco Bay Area
355 AM PST Tue Jan 22 2019

.SYNOPSIS...High pressure will bring dry and tranquil weather to
the state the rest of this week and through the upcoming weekend.
The dry pattern may last through the end of the month with mild
days and cool nights.

&&

.DISCUSSION...as of 3:36 AM PST Tuesday...Recall that the pattern
turned wet around Thanksgiving and essentially for the last two
months we`ve been in a fairly active storm cycle with year to date
rainfall running 80-100% of normal. For the first time since late
November a strong and stable ridge is forecast to build over the
West Coast and California bringing a prolonged stretch of dry
weather at least for the next week and likely through the end of
the month.

In the short term skies are mostly clear with gusty northerly
winds in the hills to around 25-30 mph keeping the boundary layer
fairly well mixed with temperatures currently running in the upper
30s and 40s most areas with lower 50s in the city. Look for a few
degrees of warming today with highs into the lower 60s most
locations. This will be due to dry north/northeasterly flow and
modest 850 mb temp warming. This trend continues into Weds when
temps may warm into the mid 60s with plenty of sunshine
regionwide.

A weak ripple in the flow may knock 850 mb temps down slightly by
Thursday but those effects may be mitigated by another round of
light to moderate offshore flow. Sometimes during this time of
year the easterly flow can bring clammy tule fog from the Delta
into the Bay Area but that doesnt seem to be the case at this
time.

Upcoming weekend looks high and dry with the ECMWF building a 588
dm 500 mb ridge along the California coast. This will bring sunny
skies and seasonably mild highs in the 60s with even some 70s
possible for the Central Coast.

Right now confidence is above average that the ridge will keep dry
weather in place at least for the next 7 days. There have been and
continue to be signals that the ridge will break down by the end
of the month or early February with westerlies breaking through
once again. This is supported by the PNA teleconnection trending
negative and is showing up in the long range gfs ensembles as well
as the cfs for renewed precip chances by early Feb.

&&

.AVIATION...As of 4:00 AM PST Tuesday...Northerly flow is helping
to dry out the lower level of the atmosphere. High confidence of
VFR through Wednesday.

Vicinity of KSFO...VFR through the period. Northerly winds 5-10
mph.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR. Southeast drainage wind 5-10 mph in
the morning otherwise light winds.

&&

.MARINE...as of 03:48 AM PST Tuesday...Winds will decrease during
the day as a low pressure system over the High pressure building
over the southwest moves further east. High pressure will dominate
off the California coast and over the Great Basin through the
remainder of the week resulting in light  winds through the
period.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tday...SCA...Pigeon Pt to Pt Pinos 0-10 nm until 3 PM
             SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm until 3 PM
             SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm until 3 PM
             SCA...Pt Arena to Pigeon Pt 10-60 nm

&&

$$

PUBLIC FORECAST: RWW
AVIATION: W Pi
MARINE: W Pi

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