Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
FXUS66 KMTR 242036
Area Forecast Discussion
National Weather Service San Francisco Bay Area
136 PM PDT Mon Apr 24 2017
.SYNOPSIS...Look for a few light showers to continue into the
early evening hours followed by dry weather tomorrow. Another
chance of rain, mainly over the North Bay, is slated for
Wednesday, with dry and seasonably cool weather expected
elsewhere. Dry weather along with a warming trend is forecast
across the region from Thursday through the weekend as high
pressure builds in. Locally breezy conditions are likely from
Thursday and Friday.
.DISCUSSION...As of 1:35 PM PDT Monday...KMUX and Mount Vaca
Radars have indicated very few echoes through the day as a system
moved into the PacNW. HOwever, a few stations have reported tips
of the buckets with up to a tenth so far for the North Bay. Shower
chances will continue into the evening hours with any additional
amounts expected to be very light.
Dry weather will return by tonight as the system continues to
slide off to the east. In general temperatures will be similar to
today with degree or two increase likely. Look for 60s to lower
A second system will pass to our north on Wednesday and bring
another threat of light rain to our region. Again, the best chance
will be over the North Bay where locally up to a tenth can be
expected. For the rest of our CWA the only impact will be higher
The flow will transition to much more amplified starting on
Thursday and continuing into the weekend as an upper level low
sinks to the Four Corners and a strong ridge develops off the
coast. At the same time a ridge of high pressure will work into
our region allowing for stronger winds both at the surface and
aloft. By Friday afternoon and evening widespread gusts of 20 to
30 mph look likely with higher amounts forecast for higher
elevation spots plus locations with north/northwesterly exposures.
920 MB speeds off the ECMWF approach 45 KT both along the coast
plus sections of Monterey/San Benito counties. Still a few days
down the road, so more important at the moment to be aware of the
potential for gusty winds near by rather than trying to pin point
The building ridge will lead to warmer temperatures over the
weekend along with continued dry conditions. Highs for both
Saturday and Sunday will be 60s to lower 70s at the coast with 70s
to lower 80s inland. Many locations will be 4 to 8 degrees
warmer than normal.
Longer range outlook favors dry weather along with warmer then
normal temperatures through at least the first week of May. It
appears that our rainy season has come to an end for the first
half of 2017.
.AVIATION...as of 10:33 AM PDT Monday...For 18z Tafs. A weak
system moving in from the north that is spreading light rain and
low cigs this morning. KSTS is the only terminal reporting -ra as
of now, but a few showers may make down to OAK and SFO with
marginal confidence. Otherwise, a mix of MVFR to VFR expected
through this afternoon. Improving conditions expected overnight
with clearing of any low cigs. Winds will likely increase later
this afternoon as well.
Vicinity of KSFO...MVFR cigs through this afternoon with a brief
window of -shra. VFR expected overnight. West winds around 15 kt
anticipated to strengthen in the afternoon to 15 to 20 kt with
gusts to 25-30 knots possible.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals..VFR through much of the period. Southwest
winds around 5 kt will strengthen to around 10-15 kt with gusts
to 15-20 kt in the afternoon.
.MARINE...as of 10:29 AM PDT Monday...High pressure over the
Eastern Pacific and low pressure inland result in moderate
northwest winds along the Central Coast. Winds will be locally
strong south of point sur near the coast. Winds and seas will
increase Wednesday night into thursday as high pressure
strengthens over the eastern pacific resulting in a tighter
pressure gradient across the coastal waters.
.Tngt...SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
PUBLIC FORECAST: Bell
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