-- Discussion containing changed information from previous version are highlighted. --
934
FXUS66 KMTR 220751
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1251 AM PDT Sat Jun 22 2024

...New SYNOPSIS, SHORT TERM, LONG TERM...

.SYNOPSIS...
-- Changed Discussion --
Issued at 1250 AM PDT Sat Jun 22 2024

Hot temperatures peak today with a Heat Advisory in effect later
this morning through the evening for the interior regions with a
moderate risk of heat-related illnesses. Temperatures moderate
through the early part of next week, but remain warm across the
interior.
-- End Changed Discussion --

&&

.SHORT TERM...
-- Changed Discussion --
(Today and tonight)
Issued at 1250 AM PDT Sat Jun 22 2024

Satellite imagery shows marine layer stratus developing across the
coastal regions with intrusions through the Golden Gate, across the
East Bayshore, into Napa County, across the Monterey Bay region and
down into the Salinas Valley. Right now, we`re not expecting as much
interior development tonight, as the marine layer has compressed
through the previous day, as exemplified by the Fort Ord profiler
showing a marine layer depth around 1000-1250 feet. Low temperatures
this morning range from the low 50s to near 60 in the lower
elevations, with the lower temperatures expected where there is
marine layer stratus tonight, up to the upper 60s to lower 70s in
the higher elevations.

The warmest temperatures of the brief heat event are expected to
develop later today. A Heat Advisory will come into effect later
this morning through the evening for the interior North Bay
mountains, interior East Bay, the Santa Clara Valley and eastern
Santa Clara hills, the interior Central Coast mountains, the
southern Salinas Valley, and the Santa Lucia mountains. Areas under
the Heat Advisory should expect highs from the mid 90s into the mid
100s, and a Moderate HeatRisk. This means that there is a risk of
heat-related illnesses for most people sensitive to heat, including
children, the elderly, pregnant women, those working or living
outside, and those with certain medical conditions. Elsewhere across
the region, high temperatures are expected to reach the upper 80s to
mid 90s in the inland North Bay valleys, the mid 70s to upper 80s in
the Bayshore and the northern Salinas Valley, and the 60s into the
low 70s for the Pacific coast.

Here are heat safety tips:

* Stay hydrated and drink plenty of fluids.
* Wear lightweight, light-colored clothing.
* Reduce time spent outdoors or stay in the shade.
* Never leave people or pets unattended in vehicles.
* Use sunscreen if going to the coast or the pool.
-- End Changed Discussion --

&&

.LONG TERM...
-- Changed Discussion --
(Sunday through Friday)
Issued at 1250 AM PDT Sat Jun 22 2024

Sunday should be noticeably cooler as an upper level trough to our
west begins to promote stronger onshore flow. High temperatures will
drop into the mid 80s to the low 90s in the interior valleys
(perhaps close to 100 in the warmest spots), the 70s into the lower
80s along the Bayshore, and the upper 50s to the 60s along the
coast. The ridge will begin to erode and shift eastward with an
upper level low approaching the Pacific Northwest, but the general
weather pattern should remain relatively unchanged, with perhaps a
few degrees of cooling towards the latter part of the next work
week. The latest CPC outlook continues to suggest temperatures near
or above seasonal averages, and precipitation at or below seasonal
averages (noting that at this point in the year, seasonal average
precipitation is very low) continue into the first days of July.
-- End Changed Discussion --

&&

.AVIATION...
(06Z TAFS)
Issued at 1040 PM PDT Fri Jun 21 2024

VFR tonight for inland terminals, while coastal terminals are
likely to see a brief period of low coastal clouds in the mid
morning (IFR CIGs), though confidence is only moderate on this.
Monterey Bay on the other hand is high confidence for developing
IFR CIGs, and dipping into LIFR territory overnight. Clearing is
expected in the mid to late morning of Saturday for all terminals
to VFR. Onshore and breezy winds return Saturday afternoon.

Vicinity of SFO...Currently VFR. VFR conditions last through the
majority of the night, though towards the mid morning of Saturday,
low clouds will begin to drift into the terminal vicinity. Current
thinking is that clouds may briefly and intermittently form IFR
CIGs, but confidence on this is only moderate. Winds overnight
expected to decrease and become light.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...IFR CIGs last through the majority of the
night, though are expected to decrease to become LIFR in the mid
morning as higher pressure begins to build over the region. Clouds
clear and begin to erode beyond sunrise, leading to widespread
VFR conditions. Breezy westerly winds return in the afternoon
Saturday.

&&

.MARINE...
(Tonight through next Thursday)
Issued at 622 PM PDT Fri Jun 21 2024

Fresh northwesterly winds continue into the weekend with strong
gusts over the northern outer waters. These stronger gusts may
pose hazardous for small craft. Significant wave heights of 10-12
feet are expected over the outer waters through the weekend, when
northwest winds increase once again over much of the waters.
Light southerly swell continues to move through the waters today,
accompanied by moderate NW swell.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CA...Heat Advisory from 11 AM this morning to 10 PM PDT this evening
     for CAZ504-510-513>518.

PZ...Small Craft Advisory until 9 PM PDT Sunday for Pt Arena to Pt
     Reyes 10-60 NM.

     Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt
     to Pt Pinos 10-60 NM.
-- End Changed Discussion --

&&

$$

SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Canepa
MARINE...AC

Visit us at www.weather.gov/sanfrancisco

Follow us on Facebook, Twitter, and YouTube at:
www.facebook.com/nwsbayarea
www.twitter.com/nwsbayarea
www.youtube.com/nwsbayarea