533
FXUS66 KMTR 011752
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1052 AM PDT Mon Jul 1 2024

...New AVIATION...

.SYNOPSIS...
Issued at 255 AM PDT Mon Jul 1 2024

The warm up begins today and will ramp up on Tuesday with excessive
heat across the interior through the upcoming weekend. Increased
fire danger this week as well with temperatures well above normal
and dry conditions through out the forecast period.

&&

.UPDATE...
Issued at 937 AM PDT Mon Jul 1 2024

Starting off the day a few degrees cooler compared to 24 hours ago
across lower elevations. That will quickly change going into
tomorrow as the marine layer continues to compress under the
strong high pressure aloft. These changes can already be seen in
the higher elevations, as these areas are starting the day slight
warmer than 24 hours ago. As such, will leave today`s forecast
temps alone in anticipation of the strong warming aloft this
evening into tomorrow.

A notable change this morning...The City of San Francisco has been
added to the Heat Advisory for Tuesday and Wednesday as forecast
high temps are being nudged slightly higher. Current forecast for
the city each day calls for highs in the mid-80s, but the 90th
percentile high temp is around 89-91 each day. The higher temps
being in the southern and eastern parts of the city. As such,
HeatRisk is moderate for the eastern portion of the city Tuesday
and Wednesday.

&&

.SHORT TERM...
(Today and tonight)
Issued at 255 AM PDT Mon Jul 1 2024

The much anticipated warm up begins today with temperatures across
the interior warming into the mid-to-upper 90`s with a few spots
reaching the triple digits. Meanwhile, coastal areas will remain
cool for another day with maximum temperatures warming into the 60`s
and 70`s as a shallow marine layer remains in place. Elsewhere, look
for high temperatures to be in the upper 70`s to lower 90`s just
inland away from the coast. For tonight, expecting minimum
temperatures to cool only into the mid 50`s to mid 60`s in most
major urban areas with upper 60`s to mid 70`s in the hills and
potentially lower 80`s in the peaks.

&&

.LONG TERM...
(Tuesday through Sunday)
Issued at 255 AM PDT Mon Jul 1 2024

A more robust warming trend begins on Tuesday as a strong ridge of
high pressure builds over the West Coast. This looks to continue
through much of the week if not into next week under the influence
of the high pressure. No major changes to the Heat Advisory or
Excessive Heat Warning other than to extend it out into Saturday
evening. Inland areas within the Warning, especially the higher
terrain, will see limited overnight relief with temperatures
remaining in the 70`s to 80`s while lower elevations cool more
sufficiently.

Heat Safety and Impacts:

By now youre well aware that it is going to be extremely hot this
week with well-above normal temperatures; now lets talk about the
impacts of excessive heat and actions we can take to minimize those
impacts: With extreme heat, and especially prolonged heat events, it
is a marathon, and not a sprint. Our bodies, infrastructure, pets,
and livestock will be under duress from heat over the span of days
as opposed to just a day or two. Given that there is little
overnight relief expected throughout this event, this is where it
really becomes a marathon, and precautionary measures are
necessitated in order to prevent adverse results such as heat
exhaustion and stroke. This is not just for individuals sensitive to
heat, but rather, the entire population. Heat for this duration and
at these temperatures can be dangerous for everyone. Do your body a
favor and if you can, suspend outdoors activities between the hours
of 10am and 7pm on days where Heat Advisories or Excessive Heat
Warnings are in effect. Remain in air conditioning if you have that
available to you in your residence, or seek out air conditioned
environments such as stores, movie theaters, restaurants, libraries,
and cooling shelters.

If you cannot access air conditioned environments, must be outside,
work outdoors, or otherwise, there are other precautionary measures
you can take to keep yourself and your loved ones safe (including
pets!) during excessive heat. Take frequent breaks in the shade and
ensure that you are drinking plenty of cool water, or other
hydrating beverages such as sports drinks with electrolytes. Avoid
DEHYDRATING drinks such as alcohol or caffeinated beverages. That
aside, visiting your city public pool or a lake, river, or ocean can
also help keep you cool, but dont forget the life jacket! If
planning on swimming, stick to where there is a lifeguard, and know
the ocean or river conditions before you get in. Although outside of
our area, its worth repeating: rivers can run fast and cold with
snowmelt in the Sierra Nevada mountains, and cold water shock can
set in quickly, which can lead to loss of muscle control, and
ultimately, drowning. Cold water shock can also set in for ocean-
goers. Have fun at the water, but be smart, be safe, and Know Before
You Go!

Finally, if you do not have air conditioning or cannot access it,
and also cannot access a body of water to stay cool: consider taking
cold showers or baths, turn on those sprinklers or garden hose and
have a fun time in your own makeshift water park, or lay a damp,
cool towel across your head or body. Even just dipping your hands
and feet in cool water can help to abate feelings of excessive heat.
For pets and livestock, make sure they have access to shade
structures or areas, and have clean water freely available to them
at all times. They do not have the same resources or ability to
notify of feeling heat-stressed as we do, so check in on them! If
theyre permanently outdoors, consider giving them a quick rinse-
down with the hose or set up misters, as the evaporation will help
to keep them cool as well.

&&

.AVIATION...
(18Z TAFS)
Issued at 1051 AM PDT Mon Jul 1 2024


VFR through the TAF period for all terminals except Monterey Bay.
Onshore and breezy winds return this afternoon for all terminals,
then ease into the night to become light. Winds will shift overnight
to develop very light northerly or offshore flow. Monterey Bay
terminals will be under LIFR CIGs through the nighttime.

Vicinity of SFO...VFR through the TAF period. W/NW winds resume in
the afternoon to become moderate, and with a few gusts nearing 25
knots. Winds then diminish into the nighttime to become light. Some
light offshore flow is expected in the morning of Tuesday.

SFO Bridge Approach...FEW low clouds will develop over the SF bay in
the early morning of Tuesday, but are expected to clear in the late
morning.

Monterey Bay Terminals...VFR through the early evening today with
breezy W/NW winds, then developing IFR CIGs. IFR CIGs are expected
to quickly lower to LIFR within a couple hours of stratus pushing
into terminal vicinities. Winds ease to become light in the late
night. LIFR CIGs and lowered visibilities then linger through
sunrise Tuesday. VFR returns by the late morning of Tuesday.

&&

.MARINE...
(Today through Saturday)
Issued at 937 AM PDT Mon Jul 1 2024

  Strong northwesterly breezes continue over the outer waters
through the midweek. Winds become more northerly this afternoon
and gale force to near gale force gusts become more widespread
over the outer waters as high pressure builds. Winds will
gradually weaken by mid to late week and become moderate to fresh.
Significant wave heights generally build to 10-12 feet through
mid-week before abating by the late week. Portions of the northern
outer waters may see peak wave heights between 12-16 feet through
mid-week.

&&

.FIRE WEATHER...
Issued at 901 PM PDT Sun Jun 30 2024

...A Red Flag Warning is in effect from Monday evening through
Tuesday evening for the East Bay Hills, Marin and Sonoma Coastal
Ranges, and the North Bay interior mountains Monday evening
through late Wednesday afternoon.

A Red Flag Warning has been added to the list of hazards along
with the Excessive Heat Warning which remains in place for most
of our interior locations, and a Heat Advisory for some locations
closer to the shoreline that may still see minimal influence of
the Marine Boundary Layer. Minimum RH values inland for the
upcoming week and beyond will mostly be in the teens, with some
single digit values in areas of higher elevation. Overnight RH
recover will be poor to non-existent as the heat wave persists
through the week, and potentially into next weekend. The hot and
dry conditions continue to move ERCs into the 70-80 percent range.
With the long holiday weekend, and the many outdoor activities
expected, people need to be careful with any campfires, and
fireworks should not be used. Any wildfire that ignites will have
the potential for rapid spread. Lightning is the only natural
ignition for wildfires and there are no thunderstorms in the
forecast.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory from 11 AM Tuesday to 7 PM PDT Wednesday for
     CAZ006.

     Red Flag Warning from 11 PM this evening to 11 PM PDT Tuesday
     for CAZ502-503-515.

     Excessive Heat Warning from 11 AM Tuesday to 8 PM PDT Saturday
     for CAZ502>504-506-510-512>518.

     Red Flag Warning from 11 PM this evening to 5 PM PDT Wednesday
     for CAZ504.

     Heat Advisory from 11 AM Tuesday to 8 PM PDT Saturday for CAZ508-
     528-529.

PZ...Small Craft Advisory until 3 AM PDT Tuesday for Pigeon Pt to Pt
     Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm.

     Small Craft Advisory until 9 PM PDT this evening for Pt Pinos to
     Pt Piedras Blancas 0-10 nm.

     Small Craft Advisory until 3 PM PDT this afternoon for Pt Arena
     to Pt Reyes 10-60 NM.

     Gale Warning from 3 PM this afternoon to 3 PM PDT Tuesday for Pt
     Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...AC
MARINE...AC

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