411
FXUS66 KMTR 051749
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1049 AM PDT Fri Jul 5 2024

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 1232 AM PDT Fri Jul 5 2024

Dangerous heat continues inland as high pressure prevails through
the middle of next week. Red Flag Warnings remain in effect
through Saturday night, and heat hazard highlights through
Wednesday.

&&

.UPDATE...
Issued at 940 AM PDT Fri Jul 5 2024

No changes to the forecast for this mornings update. Red Flag
Warnings for Marin and Sonoma Coastal Ranges were allowed to
expire earlier this morning, but the RFW`s across North Bay
Interior Mountains, East Bay Hills and Santa Cruz Mountains continue
until 9pm Saturday. Red Flag Warnings are also in effect for the
Santa Lucia Mountains, San Benito County, and the Southern Salinas
Valley until 9 PM Saturday. We`re not expecting to update the
Excessive Heat Warning or current Heat Advisories today or
tomorrow (the hottest day of the heat wave), but there are signals
in the extended guidance that H50 troughing begins to weaken the
backside of the ridge over our area for the beginning of next
week, which would help bring temperatures down.

&&

.SHORT TERM...
(Today and tonight)
Issued at 1232 AM PDT Fri Jul 5 2024

A touch warmer today across inland areas, but much of the same
across lower elevations and coastal areas. Day 4 of the heat wave
now, and the next couple of days look like they`ll represent our
secondary peak. Still no major synoptic driver of widespread
offshore winds, so expect the marine layer to remain mostly in
place. This is the reason many coastal areas have been largely
spared from the record-breaking and deadly heat that we are
seeing inland. Red Flag Warnings are still in effect into the
weekend. As of writing, no major incidents that we are aware of.
However, while monitoring overnight satellite, there have been
dozens of small fires and flare ups from the Delta to the South
Bay and into the Central Valley.

&&

.LONG TERM...
(Saturday through Thursday)
Issued at 1232 AM PDT Fri Jul 5 2024

I`ll start with the good news for those dealing with the heat. It
looks like we`re getting over the peak this weekend, and there has
been a consistent trend in "cooling off" late next week. The bad
news? It`s going to warm up into Saturday, and we still have a
few days of upper 90s and lower 100s to go. By Saturday, we should
see temps in northern Napa/Sonoma and far eastern Contra
Costa/Alameda approaching 110 once again, while temps in southern
Monterey County may push the 115-118 mark. These locations are
looking at temperatures 20-25 degrees above normal for this time
of year. Cluster analysis still strongly supports a ridge pattern
that promotes above average temperatures through the forecast
period, but those temps are expected to be closer to 5-10 degrees
above normal by the end of next week. At this time, we have chosen
to not extended the heat highlights beyond their current
expiration of Wednesday night.

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 1048 AM PDT Fri Jul 5 2024

Stratus near Monterey Bay has lifted, leaving the region with
clear skies over the terminals. With the continuation of the high
pressure system influence, expect VFR to prevail through the TAF
period for most terminals, except Monterey Bay. Winds build this
afternoon and will turn onshore, before returning to moderate to
light and variable overnight, with the exception of KSFO.

Vicinity of SFO...High confidence that VFR will prevail through
the TAF period. Breezy and gusty NW/W winds will build this
afternoon up and will diminish to moderate overnight before a
return of breezy conditions Saturday afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR through the remainder of the day, but
with the shallow marine layer, IFR/LIFR conditions are anticipated
to return tonight for both KSNS and KMRY. Timing is a bit uncertain
but expect after 09Z. Clearing should occur near 15Z.

&&

.MARINE...
(Today through Wednesday)
Issued at 1048 AM PDT Fri Jul 5 2024

Light winds persist over much of the waters into the weekend.
Fresh to strong breeze developing over the southern waters near
Point Sur today through the weekend. Winds increase to a fresh
breeze over the rest of the outer waters by the beginning of next
week.

&&

.FIRE WEATHER...
Issued at 940 AM PDT Fri Jul 5 2024

Red Flag Warnings remain in effect for the North Bay Interior
Mountains, East Bay Hills and Santa Cruz Mountains until 9 PM
Saturday. Red Flag Warnings are also in effect for the Santa Lucia
Mountains, San Benito County, and the Southern Salinas Valley until
9 PM Saturday as well

Despite easing surface winds, this prolonged heat wave will
continue to bring very low RH that will cure and dry the fuels.
ERC values are exceeding or approaching the max moving average for
a number of regions. 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...Excessive Heat Warning until 11 PM PDT Wednesday for CAZ502>504-
     506-510-512>518.

     Red Flag Warning until 9 PM PDT Saturday for CAZ504-512-515>518.

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

PZ...Small Craft Advisory until 9 AM PDT Saturday for Pt Pinos to Pt
     Piedras Blancas 0-10 nm.

&&

$$

SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...SO
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