252
FXUS66 KMTR 072104
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
204 PM PDT Sun Jul 7 2024

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

.SYNOPSIS...
Issued at 1236 AM PDT Sun Jul 7 2024

Day 6 of the inland heat wave. The peak of the event is finally
behind us and some minor relief is on the way this week before a
more substantial cool-down next weekend.

&&

.SHORT TERM...
(This evening through Monday)
Issued at 203 PM PDT Sun Jul 7 2024

Twenty-four hour temperature trends are a welcomed indication that
we`re beginning to emerge from the heat wave. However, we have kept
the Excessive Heat Warning and Heat Advisories intact because we`re
not out of the woods yet. Todays highs will still be well into the
90s and low-100s across the interior and elevated locations, along
with 80s and 90s in lower lying areas as you get closer to the
coast. The near coast environment is relatively normal, and
continues to offer the best chance at relief from the heat, as the
marine boundary layer has begun to bounce back behind the ridge axis
that has shifted to the east. Temperatures take another gradual step
lower tomorrow, but will still be well above normal outside of the
coastal environment. The forecast trends have been cooler, but
todays heat is still dangerously high and have decided to maintain
consistent messaging of that threat, with the overnight crew or
tomorrow`s day shift reassessing impacts across our area. Please
read the following to limit your risks to the 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.

&&

.LONG TERM...
(Monday night through next Saturday)
Issued at 203 PM PDT Sun Jul 7 2024

Although the end of the heat wave may be in sight, it is by no means
the end of the above normal temperatures expected through the work
week. We currently have the Excessive Heat Warning out until
Wednesday night (same for locations under the Heat Advisory).
However, the forecast for the progress of the upper level ridge
responsible for all the heat has been gradually shifting more south
than east, likely in response to how Beryl has taken a turn north
helping to block the ridges eastward momentum. As a result,
temperatures across our eastern interior, especially the
south/southeast portions of our interior have jumped up for Thursday
and Friday. Ultimately there`s lots of uncertainty beyond midweek,
wrt to how the dome of high pressure reorganizes over the Four
Corners region in the wake of the remnants of Beryl exiting off the
East Coast.

&&

.AVIATION...
(18Z TAFS)
Issued at 1145 AM PDT Sun Jul 7 2024

Satellite and surface observations show nearly continuous stratus
and fog /LIFR-IFR/ along the immediate coast, inland it`s MVFR-VFR
with localized haze reducing surface visibilities. There may also
be reduced slant range visibility due to wildfire smoke/haze aloft,
otherwise recent high resolution rapid refresh model output shows
general improvement in visibility from later today to tonight.

The marine layer depth varies from a few hundred feet deep along
the North Bay to approx 1000 feet deep Marin Headlands to the
north Central Coast. Stratus and fog /LIFR-IFR/ return inland on
onshore breezes prevailing tonight and Monday morning, currently
the SFO-SAC pressure gradient is 2.2 mb, there`s an ongoing SMX-SFO
pressure gradient currently 1.5 mb and the ACV-SFO northerly gradient
is far less than it was since early last week, currently less than
1 mb and the STS-UKI gradient is currently 2.2 mb supporting a
southerly breeze.

Vicinity of SFO...VFR. West to northwest breezes increasing to 18
to 25 knots during the afternoon and evening, easing tonight and
Monday morning to around 10 knots.

SFO Bridge Approach...Similar to SFO. Reduced slant range
visibility possible due to wildfire smoke/haze aloft, otherwise
generally improving conditions per recent high resolution model
output through later today and tonight.

Monterey Bay Terminals...Stratus and fog /LIFR-IFR/ along the
northern Monterey Bay, elsewhere it`s VFR. Stratus and fog /LIFR-IFR/
redeveloping and moving inland tonight and Monday morning. Stratus
and fog mixing out by late Monday morning and/or early afternoon.
West to northwest winds 5 to 15 knots with a few afternoon and early
evening gusts nearing 20 knots.

&&

.MARINE...
(Today through Friday)
Issued at 1109 AM PDT Sun Jul 7 2024

High pressure continues over the Pacific Ocean with gentle to
moderate northwest winds persisting into the early work week.
Fresh  to the occasional strong gusts will briefly develop over
the  northern outer coastal waters Monday before diminishing into
Tuesday. Widespread fresh to strong northwest winds return across
the coastal waters by mid-week. Significant wave heights will
build to 10-14 feet in the outer waters beginning Wednesday.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Warning until 11 PM PDT Wednesday for CAZ502>504-
     506-510-512>518.

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

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

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...Canepa
MARINE...Canepa

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