922
FXUS66 KMTR 042109
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
209 PM PDT Thu Jul 4 2024

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

.SYNOPSIS...
Issued at 1217 AM PDT Thu Jul 4 2024

Day 3 of the heat wave. Extremely hot conditions will continue
through the middle of next week for inland areas. Excessive Heat
Warnings, Heat Advisories, and Red Flag Warnings are in effect.

&&

.UPDATE...
Issued at 924 AM PDT Thu Jul 4 2024

The forecast remains on track this morning. The Excessive Heat
Warning across our interior remains in effect until Wednesday of
next week, highlighting the extent of this heat wave. Today will
actually be a few degrees cooler in some locations than yesterday,
but temperatures bump right back up tomorrow. The warm overnight
lows and modest increase of temperatures again tomorrow will
compound the effects of the building heat on sensitive
populations. Please limit outdoor activity from late morning
through early evening, stay hydrated and check on friends, family
and neighbors including pets. Red Flag Warnings remain in effect
for some of our higher elevation area in coastal ranges and
interior peaks and hills. Any fire that gets ignited over our
grassland areas will likely spread rapidly. Fireworks should not
be used.

&&

.SHORT TERM...
(This evening through Friday)
Issued at 207 PM PDT Thu Jul 4 2024

The center of the dome of high pressure responsible for our extended
heat wave has begun moving onshore and will continue to gradually
shift east and south over the coming days. Today will be the
`coolest` day until possibly the middle of next week, but will offer
no relief as the high heat keeps on building, and the impacts will
only continue to compound. Elevated locations away from the
immediate shoreline are seeing little to no relief wrt overnight
temperatures with lows in the 80s, even some higher spots in the
90s. This is something campers and hikers need to be aware of as we
continue through the holiday weekend. Temperatures at or just along
the immediate shoreline will offer the best chance at beating the
heat with highs in the 60s and 70s, otherwise do everything you can
to reduce your heat risk. Read below at the bottom of the Long Term
forecast for more on how to keep yourself safe.

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 207 PM PDT Thu Jul 4 2024

Saturday appears to be the peak of the heat wave wrt maximum
temperatures, but will still be days away from marking the end of
the event. Elevated areas across southern Monterey and San Benito
Counties will be at or slightly above 115 degrees. There is no end
in sight to heat wave in the official extended forest out to next
Thursday (July 11th), but looking out at next weekend, troughing is
established along the West Coast on the back side of the meandering
high as it moves farther inland. As heights and thickness values
gradually decrease, so will temperatures, but until then please take
note of the following information to keep yourself, family, friends
and pets safe from this historic heat wave.

Heat is the number 1 weather related killer in the United States.
Unfortunately lives will be lost during this heat wave. Follow these
tips to protect yourself, your loved ones, and your animals.

-Stay inside in an air conditioned environment between 10am and 7pm.
-Suspend unnecessary outdoor activities during the extreme heat, but
if you must be outdoors, take frequent breaks in the shade  or AC
and drink cool water.
-Know the signs and symptoms of Heat Exhaustion vs. Heat Stroke!
Heat Stroke can be deadly if not treated immediately by a medical
professional. Call 911 if you suspect someone is suffering from Heat
Stroke.
-Wear a lifejacket, swim near a lifeguard, and check conditions
before entering the water if going to a river or ocean to cool off.
Rivers and the ocean are extremely cold, and Cold Water Shock can
turn into paralysis and drowning if you are not careful.
-Use a cool and damp towel on your body if you do not have AC and
are feeling hot. Or, take a cool shower or bath.
-Do not leave kids or pets in a parked car.
-Ensure pets and livestock have access to shade and water.

&&

.AVIATION...
(18Z TAFS)
Issued at 1026 AM PDT Thu Jul 4 2024

Clear skies over our area with some stratus off the coast. The high
pressure has caused some drying of stratus, but some low clouds
return along the coast that will travel close to the Monterey Bay
terminals overnight. Confidence is high that the remainder of the
terminals will remain clear. Therefore, VFR through the TAF period
for all terminals, except KSNS. Winds will build this afternoon, but
will turn light to variable overnight.

Vicinity of SFO...High confidence that VFR will prevail through
the TAF period. NW/W winds will become breezy this afternoon up to
12 knots before becoming light to moderate overnight.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR through the TAF period for KMRY,
whereas the model signal and persistence forecast shows KSNS
receiving a LIFR ceiling.

&&

.MARINE...
(Today through Tuesday)
Issued at 1026 AM PDT Thu Jul 4 2024

  Light to moderate winds persist into the weekend. Waves start to
diminish this morning, bringing relatively calm conditions over
the waters into Friday before winds begin to become gusty in the
southern waters.

&&

.FIRE WEATHER...
Issued at 257 PM PDT Wed Jul 3 2024

Red Flag Warnings are in effect for the North Bay Interior
Mountains, East Bay Hills, and Santa Cruz Mountains until 9 PM
Saturday. Red Flag Warnings are in effect for the Marin and Sonoma
Coastal Range until 5 AM Friday. Red Flag Warnings are in effect
for the Santa Lucia Mountains, San Benito County, and the Southern
Salinas Valley from 9 AM Friday through 9 PM Saturday.

This heat wave will bring very low RH and the long duration will
cure and dry the fuels. ERC values are exceeding or approaching
the max moving average for a number of regions. Thankfully the
winds won`t be very strong, but with such high temps, low RH and
critically dry fuels, it only takes 6-11 mph winds to trigger RFW
criteria. Conditions are dangerous, and we urge extreme caution.
Please rethink the use of any fireworks this year, including the
safe and sane, or even those seemingly-innocuous sparklers and
pop-its. Perhaps consider not lighting them off at all this year,
and instead enjoy a professional display in your community, or
even on TV. Its not worth the risk. Don`t Be the Spark!

&&

.BEACHES...
Issued at 1224 AM PDT Wed Jul 3 2024

Beaches will be a popular destination over the Holiday and as one
of the few places to escape the oppressive inland temperatures.
Fortunately the waves are relatively low energy, but that doesn`t
alleviate all beach safety concerns. Ocean temperatures are in
the mid-50s. This cold water may catch some off-guard. Cold water
shock can set in very quickly. Wear a life jacket, dress
appropriately, limit time in the water, swim near a lifeguard and
follow their instructions.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 5 AM PDT Friday for CAZ006-506-508.

     Heat Advisory until 7 PM PDT this evening for CAZ006.

     Excessive Heat Warning until 11 PM PDT Wednesday for CAZ502>504-
     506-510-512>518.

     Red Flag Warning until 5 AM PDT Friday for CAZ502-503.

     Red Flag Warning until 9 PM PDT Saturday for CAZ504-512-515.

     Heat Advisory until 11 PM PDT Wednesday for CAZ508-528-529.

     Red Flag Warning from 9 AM Friday to 9 PM PDT Saturday for
     CAZ516>518.

PZ...Small Craft Advisory from 3 PM Friday to 3 AM PDT Saturday for
     Pt Pinos to Pt Piedras Blancas 0-10 nm.

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...SO
MARINE...SO

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