-- Discussion containing changed information from previous version are highlighted. --
004
FXUS66 KMTR 210426 AAA
AFDMTR

Area Forecast Discussion...UPDATED
National Weather Service San Francisco CA
926 PM PDT Thu Jun 20 2024

...New UPDATE, MARINE...

.SYNOPSIS...
Issued at 1019 AM PDT Thu Jun 20 2024

Gorgeous day across the interior today with temps on the rise.
Warming trend peaks Saturday...Heat Advisory in effect for inland
areas Saturday with moderate HeatRisk. Temps cool Sunday into
early next week.

&&

.UPDATE...
-- Changed Discussion --
Issued at 925 PM PDT Thu Jun 20 2024

The short term forecast is in good shape with no real changes
needed. The only thing we`ll need to be mindful of tonight,
sensible weather wise is the potential for more widespread fog. At
this time, the boundary layer appears to be a bit too turbulent
for widespread dense fog (and thus more in the way of low
stratus), but trends will be monitored.

The main weather headline will be the above normal heat over the
next couple of days. With the marine layer being rather
compressed, we`ll see temperatures climb quickly on Friday and
into Saturday...particularly farther away from the coast. High
temperatures on Friday across the interior will climb into the mid
to upper 90s with a few locations across San Benito, Monterey,
and far northern Sonoma county topping 100 degrees. Saturday will
be the hottest day with highs climbing up toward 105. Be sure you`re
practicing your heat safety and NEVER leave children or pets
unattended in vehicles! In addition, with the hot conditions,
grasses will still remain receptive to burning as we`ve seen
across the area over the last few weeks. Do your part and avoid
activities that could spark a wildfire.
-- End Changed Discussion --


&&

.SHORT TERM...
(This afternoon through Friday)
Issued at 1115 AM PDT Thu Jun 20 2024

No major change in the forecast today. Ample sun for areas away
from the coast and temperatures a couple of degrees warmer today
compared to yesterday. Some high clouds across northern portions
of the CWA as some residual upper level moisture swings through
associated with the decaying trough. By Friday afternoon, 500 mb
heights rise rapidly as the trough fully decays and the ridge sets
in. This will likely result in the most drastic day-to-day
temperature change of the week with high temps Friday generally
5-10 degrees warmer than today. Marine layer compression due to
large scale subsidence into the weekend will also result in
clearer conditions for coastal areas this weekend.

&&

.LONG TERM...
(Saturday through next Wednesday)
Issued at 1115 AM PDT Thu Jun 20 2024

Saturday is expected to be the warmest day of this short heat
event with another 4-7 degree increase from Friday`s temps.
Generally looking like the lower 100s for far inland areas, a
spread in the 90s for most of the North Bay, South Bay, and
interior valleys around Monterey Bay, and the 60s to mid 70s for
coastal areas. A Heat Advisory is in effect Saturday for interior
areas of the North Bay, East and South Bay (including San Jose),
and the interior Central Coast. HeatRisk will be in the "moderate"
category for these areas, which means that the heat will affect
most individuals sensitive to heat...especially those without
effective cooling or adequate hydration. You may think you`re used
to the heat, but it`s still relatively early in the season and
your body may think otherwise. Take care of yourself and others.
There is some degree of relief noted in overnight lows,
especially at elevations where most people live. Coastal and Bay
Area locations will see lows in the 50s, while further inland
places will be in the lower 60s. Locations above about 2000 feet
may struggle to cool lower than the low 70s overnight Friday and
Saturday nights. A notable cool down by about 8-10 degrees will
take place Sunday, but warmer weather persists through early next
week.

&&

.AVIATION...
(00Z TAFS)
Issued at 410 PM PDT Thu Jun 20 2024

Marine stratus continues to linger just offshore and is expected
to eventually spread eastward far enough inland for ceilings
hovering between IFR/MVFR to develop later this evening and
continue through the overnight for a most of our terminals.

Vicinity of SFO...MVFR low stratus CIGs are expected develop in
the early evening hours and will eventually become IFR as stratus
fill in farther inland. IFR CIGs will last through the overnight
hours into early Friday, with VFR expected by late morning.

SFO Bridge Approach...similar to SFO.

Monterey Bay Terminals...CIGs are expected to remain at least MVFR
through the forecast period, with IFR expected to develop this
evening through late morning on Friday.

&&

.MARINE...
-- Changed Discussion --
(Tonight through next Wednesday)
Issued at 905 PM PDT Thu Jun 20 2024

  Moderate to fresh northwesterly winds persist tonight and
prevail into the weekend, with strong gusty winds over the
northern outer  waters. These stronger gusts may pose hazardous
for small craft.  Significant wave heights of 6-8 feet will
persist until the end of the week, then build back up to 10-12
feet over the outer waters  for 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.
-- End Changed Discussion --

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory from 11 AM to 10 PM PDT Saturday for CAZ504-510-
     513>518.

PZ...Small Craft Advisory until 3 AM PDT Friday for Pt Arena to Pt
     Reyes 0-10 nm.

     Small Craft Advisory until 3 AM PDT Saturday for Pt Arena to Pt
     Reyes 10-60 NM.

&&

$$

UPDATE...Bain
SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...JM
MARINE...SO

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