643
FXUS66 KMTR 151942
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1242 PM PDT Sat Jun 15 2024

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

.SYNOPSIS...
Issued at 1238 PM PDT Sat Jun 15 2024

Dry and windy with elevated fire concerns into early next week.
Seasonal temps and quiet weather midweek. Potential warming trend
for late next week.

&&

.SHORT TERM...
(This evening through Sunday)
Issued at 1238 PM PDT Sat Jun 15 2024

Clear skies continue into the evening with drier conditions compared
to yesterday evening. N-S gradient continues to strengthen bringing
some occasional gusty strong winds, especially over the hills,
coastal gaps, and mountain ranges, into the late evening. The winds
will mostly have impacts over our marine zones where winds can reach
up to 45-55 mph, especially along the Big Sur coast. With this
strong gradient and drier air conditions, clouds will remain mixed
out going into Sunday, giving us a break from the June-Gloom. With
the clear skies, expect a few degrees lower tonight, compared to
last night as radiative cooling goes into effect. Minimum
temperatures will get down to mid 40s to mid 50s across the region.
As we low pressure system off the Pacific NE move closer inland
and sit over Washington and Oregon state on Sunday, expect another
day of cooler temperatures. Inland areas are looking to see high
70s to low 80s, with the coastline seeing max temperatures in the
60s. Strong northerly winds will also support cooler temperatures
going into Sunday.

&&

.LONG TERM...
(Sunday night through next Friday)
Issued at 1238 PM PDT Sat Jun 15 2024

As we move into the beginning of the work week, we will start to see
that low pressure system gradually dip down even further into our
area, allowing for some strong gusty winds to persist Sunday into
Monday. This does bring some fire concerns as the minimum relative
humidity values are expected to get down to the teens in certain
parts of the region. Although there are some areas in our region
that bring elevated fire concerns, no RFW have been issued as the
overall conditions have not met warning criteria for our area at
this moment. Fire conditions will be closely monitored, especially
if the north/northeast winds linger and low relative humidity
continues beyond Monday afternoon. (See Fire Weather discussion
below for more details)

As we move into Tuesday, we will start to see the N-S gradients to
gradually decrease as the upper level pattern start to transition
into a zonal/weak ridging pattern. This will bring a warming trend
starting Thursday with temperatures in the upper 80s and 90s going
into the weekend with some chances of triple digit values. CPC and
WPC outlooks also show portions of our area for excessive heat with
a 50-60% above normal temperatures.

&&

.AVIATION...
(18Z TAFS)
Issued at 1051 AM PDT Sat Jun 15 2024

Currently VFR at all terminals. High confidence in VFR through the
TAF period at all terminals as strong winds are allowing for the
marine layer to stay thoroughly mixed out. Strong winds will
impact all terminals through the TAF period, particularly
terminals within close proximity to the coast or within a
northwest-southeast oriented valley. While below LLWS criteria,
it will likely be bumpy getting out of the area.

Vicinity of SFO...Currently VFR with westerly flow. VFR through the
TAF period. AWW in effect from 21Z this afternoon through 06Z
tonight for strong westerly winds in excess of 35 knots. Westerly
winds will somewhat diminish overnight before approaching the AWW
criteria of 35 knots again tomorrow afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently VFR with northwesterly flow at
both terminals. VFR through the TAF period. Low probability and low
confidence of ceilings developing through the TAF period as the
strong winds are keeping the marine layer thoroughly mixed out, but
if ceilings were to develop they would likely be IFR-MVFR in the
early morning hours, around 12Z or so. Winds will prevail out of
the west through the TAF period, becoming gusty this afternoon.

&&

.MARINE...
(Today through Thursday)
Issued at 1051 AM PDT Sat Jun 15 2024

A tight pressure gradient over the waters will allow for strong
northwesterly breezes and widespread gale force gusts to persist
through the weekend. Significant wave heights will be 12-17 feet
through the weekend before beginning an abating trend Monday.
Hazardous conditions will linger into early next week as winds
remain strong and seas remain elevated.

&&

.FIRE WEATHER...
Issued at 345 AM PDT Sat Jun 14 2024

...Elevated Fire Weather Conditions Through The Weekend...

*Increasing northerly winds, especially higher terrain
*Lowering relative humidity values day and night

Forecast remains on track as northerly flow ramps up across the
district. Gusts of 30-50 mph will be more common along the coast,
higher terrain, and inland gaps/passes. Have already seen a few
isolated inland passes reach close to 60 mph as well. These
stronger winds will persist through early Monday. It should be
noted that they will not be strong the entire time, more like
bursts of stronger winds. The northerly flow has also ushered in
much drier air across the region too. 24 hour trends show some
locations 40-70% drier than 24 hours ago. While there are a few
isolated stations that may "technically" reach Red Flag criteria
conditions are not widespread enough to warrant a fire weather
zone wide Red Flag warning. Therefore, still best to message
elevated fire weather conditions through the weekend.

Regardless, individuals with outdoor activities planned this
weekend should be fire weather aware. Be mindful and don`t be
"that spark".

MM

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PDT this evening for SF Bay N of
     Bay Bridge.

     Small Craft Advisory from 3 PM Sunday to 3 AM PDT Monday for SF
     Bay N of Bay Bridge.

     Small Craft Advisory until 3 AM PDT Monday for Mry Bay.

     Gale Warning until 3 AM PDT Monday for Pigeon Pt to Pt Pinos 0-
     10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-
     10 nm-Pt Arena to Pt Reyes 10-60 NM-Pt Pinos to Pt Piedras
     Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

&&

$$

SHORT TERM...SO
LONG TERM....SO
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