330
FXUS66 KMTR 121017
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
317 AM PDT Fri Jul 12 2024

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

.SYNOPSIS...
Issued at 315 AM PDT Fri Jul 12 2024

Heat highlights remain in effect through this evening. A nice cool
down this weekend, with near normal temps by early next week.
Otherwise fairly quiet weather through the forecast period.

&&

.SHORT TERM...
(Today and tonight)
Issued at 315 AM PDT Fri Jul 12 2024

The persistent high pressure responsible for all the recent heat is
currently centered over Utah and will slowly migrate east today and
tomorrow towards the Four Corners region. A weak offshore upper
level low on the eastern periphery of the high, will gradually slide
north over the next couple of days from SoCal to the Central Coast
latitude. Todays highs will continue to be well above normal with
the Excessive Heat Warning and Heat Advisories remaining intact
until 8pm later tonight. Interior temperatures will remain in the
90s to low 100s with some elevated locations approaching 110. A
welcomed cooling trend in temperatures begins on Saturday with many
interior locations seeing a 10 degrees drop in highs from today to
tomorrow afternoon. The offshore upper level low will advect cooler
low level temperatures and moisture as slowly lifts north.

&&

.LONG TERM...
(Saturday through Thursday)
Issued at 315 AM PDT Fri Jul 12 2024

The slow moving upper level low on the western periphery of high
pressure centered over the Four Corners region on Sunday, will
continue to help moderate temperatures in the wake of the recent
heat wave. Mostly zonal flow to our north will begin to buckle and
absorb the upper level low as it moves up the coast of the Pacific
Northwest for the first half of next. Unfortunately, as the upper
low/trough shifts north over water, the persistent area of high
pressure over the desert southwest begins to amplify again across
western CONUS. A warming trend can be seen for the end of next week,
and may be more pronounced than currently progged if the signal for
amplification gets stronger, which allows for the center of the high
to retrograde back to the west closer to central California.

&&

.AVIATION...
(06Z TAFS)
Issued at 1133 PM PDT Thu Jul 11 2024
IFR and LIFR CIGS are along the immediate coast and over the
Monterey Bay terminals and last into the mid morning. Winds reduce
into the late night, becoming light for most areas. Later into the
night, fog looks to affect the Monterey Bay terminals. CIGs erode
into mid Friday morning as moderate winds build. Winds ease into
Friday evening as CIGs return to the coast and Monterey Bay
terminals.

Vicinity of SFO...VFR through the TAF period. Winds reduce into the
night, becoming light. Expect winds to stay light into Friday
afternoon before more moderate to breezy northwesterly winds arrive.
Winds weaken again into Friday night.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...LIFR CIGs and mist last into the mid
morning. Expect pockets of fog to form in  the area through much of
the morning. CIGs erode in the mid morning north and westerly winds
build.

&&

.MARINE...
(Today through Wednesday)
Issued at 315 AM PDT Fri Jul 12 2024

Breezy to gusty north to northwest winds continue over the
northern outer waters through Saturday afternoon before
diminishing. Significant wave heights between 10 to 12 ft
continue over the outer coastal waters with peak wave heights
between 12 to 14 ft expected over the far northern outer coastal
waters. Significant wave heights, sustained winds, and wind gusts
begin to subside below small craft advisory criteria by the late
weekend.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory until 8 PM PDT this evening for CAZ502-503-506-508-
     512-516-528.

     Excessive Heat Warning until 8 PM PDT this evening for CAZ504-
     510-513>515-517-518.

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

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...Murdock
MARINE...Murdock

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