Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
FXUS66 KMTR 241725
Area Forecast Discussion
National Weather Service San Francisco Bay Area
1025 AM PDT TUE MAY 24 2016
.SYNOPSIS...A weak low pressure system will bring a slight chance
of showers and a thunderstorm or two to our region today.
Temperatures will be seasonably cool, but gradually warm later in
.DISCUSSION...as of 8:45 AM PDT Tuesday...Widespread cloud cover
over the region this morning with temperatures generally in the
50s. Meanwhile, a long wave trough extends down the Pacific
Northwest into northern and central California. Increased moisture
and weak disturbances riding along the trough will result in
chances for showers and thunderstorms over a portion of the region
again this afternoon. Have updated the ongoing forecast to
included convection over the Santa Lucia Mountains for this
afternoon along with the North and East Bay Hills/Mountains and
the higher terrain of San Benito County. Otherwise, cooler than
average temperatures expected for the remainder of the day with
most locations only warming into the 60s to lower 70s.
Note: Current visibility sensor at KSNS (Salinas Airport) has been
inaccurate since Monday morning. NWS Technicians are on site
looking into the problem this morning.
.PREVIOUS DISCUSSION...as of 3:30 AM PDT Tuesday...Widespread
clouds this morning across most of our CWA with a onshore west-to-
east gradient of 1.5 MB. Synoptically, a longwave trof extending
from Central Canada remains across our entire region. Similar to
yesterday a weak impulse will move through our cwa today and
likely trigger a few showers. Lifted values are forecast to drop
to below zero values over parts of the North Bay plus eastern
sections of the CWA, therefore still looks like a slight chance of
thunderstorms. The pattern also favors small hail with any of the
cells. The trof will start to progress to the east by Wednesday
afternoon which will effectively bring an end of precipitation.
Our string of cooler than normal conditions will continue through
at least Wednesday with many spots in the 60s to lower 70s. As a
ridge starts to build back starting on Thursday, temperatures will
warm back closer to normal values. That trend will continue into
weekend with the range in the mid 60s to the upper 70s. A few
lower 80s cannot be ruled out for far southern and eastern
Longer range outlook favors warmer than normal conditions next
week with mostly dry conditions.
.AVIATION...as of 10:19 AM PDT Tuesday...Tricky forecast the next
hour or two as morning stratus erodes and afternoon strato cu
develops. For the most part, MVFR transitioning to VFR in the
18-19z time frame. Expecting mostly VFR this afternoon with
elevated cu, but cigs may be borderline MVFR/near 3K feet. Moist
low level will allow for MVFR cigs tonight with a few pockets of
Vicinity of KSFO...Transition period as blue skies are starting
to show up on airport cams and visible satellite. Pushed clearing
for KSFO until 18z, but it will likely be a dirty clearing with
lingering clouds. KOAK will hold onto cigs slightly longer. VFR
this afternoon, but cannot rule out a passing BKN030 from time to
time. MVFR cigs develop overnight.
SFO Bridge Approach...Similar to KSFO. However, far southern end
of approach will see even less clouds in the short term.
Monterey Bay Terminals...Lingering MVFR cigs from 18-19z. Strato
cu this afternoon. MVFR cigs return again tonight.
.MARINE...as of 08:43 AM PDT Tuesday...Light to moderate winds and
small seas will persist today. Winds will increase tonight and
Wednesday as high pressure builds over the region. The winds will
be strongest north of Point Reyes.
PUBLIC FORECAST: RGass
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