764
FXUS66 KMTR 192114
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
214 PM PDT Sat Oct 19 2024

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

.SYNOPSIS...
Issued at 212 PM PDT Sat Oct 19 2024

Surface winds will continue to ease through the evening hours,
however we still have a very dry airmass across our region with near
record fuel levels that support rapid fire growth if any fires do
start, avoid any activities that could spark a wildfire.

&&

.SHORT TERM...
(This evening through Sunday)
Issued at 212 PM PDT Sat Oct 19 2024

Surface winds have begun to gradually ease this afternoon and will
continue to do so through the evening hours. A weak offshore surface
low under H50 ridging will help inhibit marine layer development
overnight. With mostly clear skies across our area and easing winds
we`ll see radiational cooling drop temperatures into the 40s and 50s
area wide. Some isolated spots in the valleys of southern Monterey
County may drop into the 30s once again tomorrow morning. High
temperatures across the North Bay and East Bay tomorrow will cool 5-
10 degrees from today, but otherwise remain similar for the rest
of our area.


&&

.LONG TERM...
(Sunday night through next Friday)
Issued at 212 PM PDT Sat Oct 19 2024

The dry airmass over our area this weekend will remain in place
through midweek with weak shortwaves embedded in mostly zonal flow
aloft helping to produce unorganized surface flow along the coast
and continue to hold back redevelopment of the marine layer. Both
ensemble and deterministic lack certainty in the timing and location
of the next synoptic trough for the end of the week into next
weekend. Rain chances across the North Bay and Bay Area have trended
drier over the past couple of updates as ridging over the Baja of
California has become more prominent. However, temperatures will
return closer to normal by the end of next week with lowering H50
heights and thickness values.

&&

.AVIATION...
(18Z TAFS)
Issued at 1047 AM PDT Sat Oct 19 2024

VFR for the 18z TAFs. The WMC-SFO, ACV-SFO and SAC-SFO pressure
gradients are 12.4 mb, 5.1 mb and 0.6 mb respectively, supporting
offshore winds. Local influxes of onshore wind developing nearest
the coastline today. Surface high pressure over far northern
California and the Great Basin weakens tonight and Sunday.

Vicinity of SFO...VFR. Light north to northeast wind becoming west
10 to 12 knots in the afternoon. Light and variable wind tonight
and Sunday morning.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR. Light and variable winds except
southeast near 10 knots in the Salinas Valley this morning. Winds
becoming onshore 5 to 10 knots in the afternoon and early evening.
Southeast winds 5 to 10 knots tonight and Sunday morning.

&&

.MARINE...
(Today through Thursday)
Issued at 1035 AM PDT Sat Oct 19 2024

Surface high pressure over the offshore waters and far northern
California will weaken tonight and Sunday. Winds and seas will
continue to decrease through the weekend. High pressure
temporarily rebuilds early next week then weakens mid to late
week.

&&

.FIRE WEATHER...
Issued at 407 AM PDT Sat Oct 19 2024

Red Flag conditions continue to be observed across the region this
morning with multiple weather stations recording relative
humidity as low as 11% and wind gusts as high as 35-50 mph, Mt.
St. Helena recorded the strongest gust at 76 mph. While
northeasterly winds will decrease through the day, poor daytime
relative humidity will still support elevated fire weather
conditions. A Red Flag Warning is in effect through 5 PM Saturday
for the Bay Area and Central Coast with the exception of coastal
Marin, Monterey, and Sonoma Counties. Sustained northeasterly
winds largely on the order of 25-35 mph can be expected with gusts
to 50 mph, and isolated gusts to 65 mph across the highest
terrain and ridgetops and through gaps and passes. Every
precaution should be taken to prevent a wildfire spark always,
but especially today.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Red Flag Warning until 5 PM PDT this afternoon for CAZ006-
     502>504-506-508>510-512>518-528-529.

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

&&

$$

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

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