884
FXUS66 KMTR 080826
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
126 AM PDT Mon Jul 8 2024

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

.SYNOPSIS...
Issued at 111 AM PDT Mon Jul 8 2024

Day 7 of the inland heat wave. There will be a decent cooling
trend through Tuesday before temperatures increase again Wed-Fri.
More substantial cooling is on the way this weekend.

&&

.SHORT TERM...
(Today and tonight)
Issued at 111 AM PDT Mon Jul 8 2024

Inland temperatures were roughly 5-15 degrees cooler on Sunday,
compared to the peak of the heat wave on Saturday. As the ridge
continues to slide east, temperatures will continue to decrease.
Monday will be another 5 degrees cooler than Sunday was. This is
welcome relief and the HeatRisk product has moved out of the major
and extreme categories we saw for much of the last week, into
minor and moderate for Mon-Tue. As such, we have decided to
downgrade many of the Excessive Heat Warnings to Heat Advisories.
That`s the good news. The bad news is we extended many of the new
heat advisories through Friday. More information in the long term
section.

&&

.LONG TERM...
(Tuesday through Sunday)
Issued at 111 AM PDT Mon Jul 8 2024

The much anticipated cool-down will continue through Tuesday,
with inland max temperatures staying in the low to mid 90s. The
forecast gets a little more uncertain starting Wednesday. The
strong ridge will gradually flatten out as the jet stream
transitions from a very stable meridional block to more zonal
flow. While the ridge leaving is certainly a good thing to help
end this heat wave, the new pattern with higher pressure inland
could support offshore winds later in the week. Most guidance
agrees the current cooling trend will reverse, and Wednesday-
Thursday will be roughly 10 degrees warmer than Tuesday for
inland areas. This brings inland areas back to Moderate/Major
HeatRisk for the second half of the work week. Fortunately there
is a more substantial cool-down arriving next weekend, and we may
even see temperatures get close to normal by the middle of next
week. There is still a lot of model disagreement beyond the
weekend. The GFS continues cooler while ECMWF stays steady. Either
way, this week will be cooler than last week, and next week will
be cooler than this week. It`s just that after all that cooling,
we may still be above normal.

&&

.AVIATION...
(06Z TAFS)
Issued at 1045 PM PDT Sun Jul 7 2024

Mix of VFR and LIFR conditions expected overnight. Stratus is
expected to be more widespread tonight with stratus reaching all
stations except SFO, SJC, and LVK. Haze may reduce visibility at LVK
to 6SM but is not expected to cause a change in flight category.
Onshore flow persists through the TAF period with light overnight
flow becoming more moderate to gusty during the day. Increased fog
potential remains for STS with CIG height and visibility expected to
drop rapidly.

Vicinity of SFO...VFR through the TAF period. Guidance indicates
some potential for stratus to reach SFO but, given persistence and a
similar setup to this morning, leaning towards stratus not reaching
SFO. Onshore flow from the west to northwest continues through the
TAF period with moderate gusty winds returning during the day.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...LIFR conditions overnight before VFR
returns during the day. Night Fog shows both MRY and SNS socked in
with stratus which is expected to persist through the mid to late
morning. Onshore flow out of the west continues with winds becoming
more moderate during the day. Stratus looks to return by late
tomorrow evening with a slight reduction in visibility possible.

&&

.MARINE...
(Tonight through next Saturday)
Issued at 1045 PM PDT Sun Jul 7 2024

Surface high pressure over the Pacific Ocean will continue  to be
the dominating feature through the period. Northwesterly  breezes
will prevail through the period, increasing Wednesday as  the
pressure gradient tightens. Significant wave heights begin to
build to 10-14 feet in the outer waters by Thursday.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory until 8 PM PDT Friday for CAZ502>504-506-510-
     512>516-528.

     Heat Advisory from 11 AM Wednesday to 8 PM PDT Friday for CAZ508.

     Excessive Heat Warning until 8 PM PDT Friday for CAZ517-518.

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

     Small Craft Advisory from 9 PM this evening to 3 AM PDT Tuesday
     for Pt Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...Flynn
LONG TERM....Flynn
AVIATION...Sarment
MARINE...Sarment

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