ca discuss
Office: EKA
FXUS66 KEKA 061002
AFDEKA
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
202 AM PST Sat Dec 6 2025
.SYNOPSIS...Light rain possible for Humboldt and Del Norte late
through the weekend into early next week. King tides combined
with tidal anomaly will continue to bring the threat of coastal
flooding in low- lying areas around Humboldt Bay Saturday. A
series of frontal systems moving north of the area will bring a
chance of light rain across the northern portion of the area
through the weekend.
&&
.DISCUSSION...Dense fog developed Friday evening as radiational
cooling had a few hours of activity. Similar behavior is possible
Saturday morning with moisture being deposited from stratiform
saturated profiles near ground. The deep marine layer lifted as
the cold front approached as prefaced by the previous forecasts.
Light rain/drizzle is expected to continue into early next week.
High pressure continues to slowly weakening and "flattening",
while a series of shortwaves trough and frontal systems embedded
to the Aleutian Low continues to move toward the Pacific Northwest
this weekend. Northwest flow aloft will bring additional light
showers across Del Norte and Humboldt counties on Saturday. On
Sunday, another shortwave and frontal system is expected to move
north of our area. The flow aloft will become more zonal, bringing
additional chances of light rain across the northern portion,
especially for Del Norte and northern Humboldt counties.
Elsewhere, partly to mostly cloud skies is expected to continue.
The 500 mb ridge appears to slowly build back early next through
mid next week. WPC ensemble clusters do show about an even split
(50%) of clusters that are "drier" (at least for the North Coast)
than the grand ensemble mean. The ensemble mean is by no stretch
very wet with 0.10-0.25 inches of rain in 24 hours everyday from
Monday through Wednesday, mostly for Del Norte. It could be wet
or it could be dry or both. Stay tuned. -ZVS /EYS
&&
.AVIATION...(06Z TAFS)...A front will continue through Northwest
California early Saturday morning. Most of the drizzle and light
rain has moved through the area, but IFR/LIFR ceilings will continue
for coastal terminals of Humboldt and Del Norte counties.
Southeast flow ahead of another frontal passage to the north may
aide in lifting ceilings and visibilities around sunrise. For
areas to the south and east, including UKI, only a few high clouds
are expected with generally light winds. There is around a slight
chance for MVFR stratus impacts early Saturday to around sunrise
at UKI Saturday. Any low clouds and fog will lift and scatter
shortly after sunrise. JB
&&
.MARINE...Winds and seas continue to ease north of Cape Mendocino as
a weak front moves through the area. Winds and steep seas will
continue to ease early Saturday morning. Generally light winds are
forecast this weekend, with south winds forecast north of Cape
Mendocino and west-northwest winds forecast south of the Cape.
Despite light winds, seas will elevate as a mid-period northwest
swell fills in Saturday. This will peak at around 7-9 ft at 12
seconds. Wave heights peak Saturday night and early Sunday morning,
and combined seas could briefly reach or exceed 10 ft. Seas subside
Sunday and Monday as this swell decays. Light winds continue into
early next week, but seas will remain elevated as a series of mid-
period northwest swells fill in from systems to the north. JB
&&
.COASTAL FLOODING...King tides are predicted to continue this
weekend. High tides are forecast to be at 8.63 feet at the North
Spit tide gauge at around 11:44 AM local time. High tides
combined with surge and tidal anomaly will result in water levels
between 8.9 to 9.2 feet MLLW (Mean Lower Low Water). Minor
coastal flooding around Humboldt Bay, including King Salmon and
Jackson Ranch Road in the Arcata Bottoms, will be likely between
10 AM and 1 PM. A Coastal Flooding Advisory will be in effect
from 10 AM to 1 PM on Saturday. High tides are predicted to be at
8.24 feet at 12:35 PM on Sunday. At this point, coastal flooding
looks marginal for Sunday with high tides diminishing. -ZVS
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
Coastal Flood Advisory from 10 AM this morning to 1 PM PST
this afternoon for CAZ103.
NORTHWEST CALIFORNIA COASTAL WATERS...
Coastal Flood Advisory from 10 AM this morning to 1 PM PST
this afternoon for PZZ415.
&&
$$
NOTE: The full forecast discussion is now regularly issued between
10 am/pm and 1 pm/am. Additional updates will be issued as needed.
Visit us at https://www.weather.gov/eureka
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https://www.facebook.com/NWSEureka
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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png
Office: HNX
FXUS66 KHNX 061206
AFDHNX
Area Forecast Discussion
National Weather Service Hanford CA
406 AM PST Sat Dec 6 2025
.UPDATE...
Updated Aviation Section.
&&
.KEY MESSAGES...
1. Fog and low clouds will continue each night and morning across
the San Joaquin Valley into early next week. Dense fog will also
develop at times in the lower Sierra foothills, coastal ranges, and
the Grapevine.
2. A gradual warming trend will occur in the mountains and
desert until next week, as the high pressure pattern continues
over the region.
&&
.DISCUSSION...
A ridge of high pressure will strengthen and move further
inland. This will allow temperatures to rise, at least in the
mountains and desert. However, fog and stratus will persist over the
Central Valley as well as the coastal ranges, lower Sierra
foothills, and the Kern County mountains for at least the next few
days. Dense fog will continue at times tonight into Saturday along
major highways, such as Interstate 5 through the Grapevine in Kern
County and Highway 152 through Pacheco Pass. It is also possible
dense fog will occur anywhere that the stratus deck touches the
lower Sierra foothills and Tehachapi Mountains, including at
elevations around 1,500 to 2,500 feet. Otherwise, the Central Valley
may fog back up anywhere the stratus deck clears. Currently, short
term high resolution guidance shows a 40-50 percent chance of dense
fog anywhere in the Central Valley and lower chances (about 20-30
percent) towards the foothills and coastal ranges through the late
morning hours on Saturday.
This dry and stable pattern will last until next week and beyond.
The latest CPC outlooks have the Valley, the Sierra Nevada, and the
Mojave Desert under a 70 to 90 percent chance of above average
temperatures due to the persisting ridge. However, the outlooks show
a shift from a 40 to 50 percent probability of below average
precipitation to a 33 to 40 percent probability of above average
precipitation for the much of the Valley and Sierra Nevada.
&&
.AVIATION...
IFR ceilings and visibilities are expected to prevail through
20Z Saturday before improving to MVFR. LIFR conditions will also
persist in the coastal ranges, Sierra foothills, and the Kern
County mountains due to the low stratus deck.
&&
.AIR QUALITY ISSUES...
On Saturday December 6 2025, Fireplace/Wood Stove Burning
Status is: No Burning Unless Registered in Fresno, Kern, Kings,
Madera, Merced, and Tulare Counties. Burning Discouraged in
Kern (Greater Frazier Park Area) and Sequoia National Park and
Forest.
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is medium.
The level of certainty for days 3 through 7 is medium.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.html for additional information
and/or to provide feedback.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until noon PST today for CAZ300-335.
&&
$$
public/aviation....BSO/EW
weather.gov/hanford
Office: LOX
FXUS66 KLOX 061519
AFDLOX
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
719 AM PST Sat Dec 6 2025
.SYNOPSIS...05/441 PM.
Light offshore winds will weaken through tonight. Benign weather
will continue through the weekend with a low chance of morning
coastal low clouds and fog. A significant warming trend will
begin Sunday with temperatures well above normal Monday through
next Friday, peaking Tuesday through Thursday. Offshore winds will
increase Sunday and Monday and continue into much of the week.
&&
.SHORT TERM (TDY-MON)...06/1242 AM.
A Chamber of Commerce weekend is on tap for Srn CA. A ridge poking
in from the west bringing hgts around 582 dam. Weak offshore flow
should keep the low clouds away, but there is about a 10 percent
chc that the LA south coast and SBA county west coast will see
some morning low clouds and dense fog. There may be some local
canyon winds in the morning, but nothing near advisory levels.
Max temps will be the main talking point. Weaker offshore flow
this morning will bring some cooling to the VTA/LA csts and vlys.
But the rest of the area will see warming esp the Antelope Vly
where the lack of cool air advection will bring 8 to 10 degrees of
warming. On Sunday, sunny skies, higher than normal hgts and the
offshore flow will all combine to bring 3 to 6 degrees of warming
to the csts/vly S of Pt Conception and 1 to 2 degrees of warming
elsewhere. Sunday's max temps will be 3 to 5 degrees above normal
at the csts and 5 to 10 degrees inland.
Stronger offshore flow will bring 20 to 25 mph canyon gusts to
some areas in the morning. Hgts rise to 584 dam and this along
with the better offshore flow will allow max temps to rise 3 to 6
degrees to the csts/vly S of Pt Conception and 1 to 2 elsewhere.
This warming will bring some max temps up into the lower 80s in
the warmest LA/VTA vly areas. Most areas away from the coast will
end up 10 to 12 degrees above normal.
.LONG TERM (TUE-FRI)...06/255 AM.
The GFS has now trended towards the warmer EC solution and it
seems pretty certain that all of next week will be a very warm
one. Upper level high pressure will sit atop of the state and hgts
will vary between 584 dam and 586 dam. These hgts are about 15 dam
higher than the normal value of 571 dam. Offshore flow will
continue through the period with a peak on Tuesday.
Cannot rule out some morning low clouds in the LGB-LAX area on any
given morning but right now it looks like the chance of this
happening is under 50 percent.
There will be some canyon winds but the only chance of advisory
level gusts will be Tuesday morning and they will be more from the
north than the NE.
Max temps will be the name of the game for the entire week.
Coastal temperatures will vary the most heating or cooling
depending on the sfc gradient trends. The current thinking for
coastal temps is for for a 3 to 5 degree rise on Tuesday bring max
temps into the mid 70s to lower 80s (lower 70s right at the
beaches). A degree or two of cooling each day Wed and Thu will
bring the temps down into the upper 60s and 70s. Most coastal max
temps S of Pt Conception will be 4 to 8 degrees above normal. The
Central Coast will exceed that with temps coming 10 to 15 degrees
over normal. The interior will see two days of warming Tue and Wed
and then little change Thu and Fri. People can expect to see 80s
in the vlys (with a 30 to 40 percent chc of some lower 90s). The
lower elevations of the mtns and all of the far interior will have
max temps in the 70s. These max temps are 12 to 18 locally 20 degrees
above normal.
Looking further ahead it appears that there will be some cooling
next weekend but max temps will remain well above normal.
&&
.AVIATION...06/1040Z.
At 0910Z, there was no marine layer depth at KLAX, but there is a
surface-based inversion up to around 2000 feet with a temperature
around 17 degrees Celsius.
VFR conditions are expected through at least 03Z Sunday, but there
is a very low chance of VLIFR to LIFR conditions through 16Z at
coastal terminals. After 03Z Sunday at coastal terminals, there
is a low-to-moderate chance of VLIFR to LIFR conditions through
08Z Sunday increasing to a moderate chance of VLIFR to LIFR
conditions after 08Z Sunday.
KLAX...There is a less than 10 percent chance of VLIFR to LIFR
conditions through 16Z, otherwise VFR conditions are expected.
There is a 20 percent chance of VLIFR to LIFR conditions after 03Z
Sunday increasing to a 30 percent chance after 08Z Sunday. Any
east winds should remain less than 7 knots.
KBUR...VFR conditions are expected through the period. No wind
impacts are expected at this time.
&&
.MARINE...06/717 AM.
For the waters southwest through northwest of the Channel Islands
beyond 10 NM offshore of the Central Coast, low-end Small Craft
Advisory conditions expected at times through much of next week,
especially across the north and western portions of PZZ670/673
during the afternoon and evening hours.
Inside the southern California bight, high chance of winds and
seas remaining below SCA levels through Monday night. Moderate
chance of offshore winds from Ventura through Santa Monica through
Tuesday afternoon. Guidance suggests winds and seas should remain
below SCA levels thereafter through the work week.
There is a moderate chance of dense fog over the coastal waters
tonight through tomorrow. Likely south of Point Conception.
Confidence remains low on timing and coverage.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 11 AM PST this
morning for zones 87-349-350-354-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PST Monday for
zones 670-673. (See LAXMWWLOX).
&&
$$
PUBLIC...Rorke
AVIATION...Hall
MARINE...Black
SYNOPSIS...Lewis/CMC
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox
Office: STO
FXUS66 KSTO 052117
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
117 PM PST Fri Dec 5 2025
.KEY MESSAGES...
- Periods of clouds, mist, or fog continue in the Central Valley
for the next few mornings
- Seasonable temperatures and light winds are forecast over the
next several days
- Tonight - Early Sat. AM's rain chances for Shasta County have
lowered with only a 10-30% of measurable rain.
&&
.DISCUSSION...
...Today...
Current GOES-West visible satellite imagery illustrates the
blanket of stratus in the Central Valley gradually eroding, with
some high clouds passing overhead from the north. Visibilities
have improved across the Central Valley this afternoon, but still
see swaths of low clouds/stratus clouds over the Valley. We can
expect another round of patchy dense fog and low clouds once again
tonight into Saturday morning with best chances from Marysville
southward again. Dry weather and seasonable temperatures are
forecasted for the region, with 50s to 60s in the Valley and
foothills, and 40s to 60s in the mountains for the daytime highs.
Highs are trending several degrees cooler than initially
forecasted due to the persistence of the fog/low clouds, keeping
max temperatures from being fully actualized.
...Tonight-Sunday...
A weak system passing to the north over the weekend may bring
some isolated, light showers to the Shasta County mountains,
however little to no impacts or accumulations are expected.
Elsewhere, dry conditions will persist over the weekend with daily
chances for fog, mist and low clouds especially in the Valley.
High temperatures are forecast to be in the 40s to 60s across
interior NorCal.
...Next Week...
High pressure builds across the region next week, allowing for a
gradual warming trend with high temperatures warming to the 50s
to near 70 (mainly for areas outside of stratus/fog
development). Dry conditions will continue through next week.
Some ensembles are indicating a pattern change in mid December but
there is a large amount of uncertainty as it is too far out in
time.
&&
.AVIATION...
Lingering low cigs and mist across the Central Valley this
afternoon and evening, although some sites may briefly return to
VFR conditions. Another round of BF/FG and low stratus returns
tonight after 03Z-12Z Saturday, with areas of MVFR/IFR
conditions, locally IFR, particularly from Sacramento southward.
Light and variable surface winds less than 12kts.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Office: SGX
FXUS66 KSGX 061020
AFDSGX
Area Forecast Discussion
National Weather Service San Diego CA
220 AM PST Sat Dec 6 2025
.SYNOPSIS...
Warmer this weekend with the potential for patchy dense fog near
the coast tonight and again Sunday night. Much warmer next week
with highs 10-15 degrees above normal and periods of weak to
locally moderate Santa Ana winds, strongest on Tuesday.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Skies remain clear this morning with light winds across the
region. Pressure gradients will be nearly neutral to the local
deserts through Sunday morning, allowing for a weak sea breeze to
develop this afternoon. With the return of this weak onshore
flow and a forecasted weak coastal eddy tonight, we could see a
development of dense fog over the coastal waters and locally into
the coastal areas tonight into Sunday morning. Weak offshore flow
kicks back in on Sunday morning, helping to clear out any fog.
Patchy dense fog may briefly return again Sunday evening before
slightly stronger offshore flow develops Sunday night. Aside from
that, there will be gradual warming through the weekend as an
upper level ridge of high pressure begins to build in from the
west. High temperatures today will be around 3-7 degrees above
normal, increasing to around 5-10 degrees above normal for Sunday.
Next week can be summed up with warm and dry. The upper high
slowly shifts east through the week, directly overhead by Friday.
At the surface, mostly weak Santa Ana winds will prevail, becoming
locally moderate on Tuesday morning as surface gradients peak.
With no upper level support, winds will remain confined to the
usual passes, canyons, and coastal slopes and follow a diurnal
pattern, strongest in the mornings and then weakening during the
afternoon. On Tuesday morning, northeast to east gusts in the
wind prone locations will generally peak around 30-45 mph. Monday
and Wednesday through Friday will see peak gusts closer to 20-35
mph. Only minor daily fluctuations in temperatures is expected,
with highs generally 10-15 degrees above normal each day Monday
through Saturday. Dry air and weak winds overnight will allow for
decent cooling, so HeatRisk remains low. For the valleys and
deserts it will very much be a winter in the morning, summer
(highs in the low 80s) for a few hours in the early afternoon,
and fall in the evening sort of pattern.
The forecast becomes a little more uncertain towards next weekend
with the upper high potentially beginning to weaken or break down,
influencing how much cooling we'll see and whether or not onshore
flow will return. Still no signs of precipitation around here
until the second half of the month.
&&
.AVIATION...
061000Z....Predominately clear skies and VFR conditions through the
TAF period. Chances for some patchy fog for TAF sites along the
immediate coast after 03Z Sunday. The San Diego County coast line
will see chances around 10-20% through 12Z Sunday and Orange County
will see slightly higher chances around 30-40% through 19Z.
Confidence is not high enough in VIS restrictions below VFR to
include fog in the TAFs at coastal sites at this time.
&&
.MARINE...
No hazardous marine conditions are expected through Thursday.
&&
.BEACHES...
High tides are around 6 to 7 ft this weekend. Otherwise, no beach
hazards are expected through Thursday.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&
$$
PUBLIC...SS
AVIATION/MARINE/BEACHES...Villafane
Office: MTR
FXUS66 KMTR 061132
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
332 AM PST Sat Dec 6 2025
...New SHORT TERM, LONG TERM...
.KEY MESSAGES...
Updated at 250 AM PST Sat Dec 6 2025
- Persistent forecast through the next seven days with benign
conditions and no precipitation expected
- Impacts from Tule Fog in the North Bay and interior East Bay
valleys
- Next chance for rain towards the middle of the month
&&
.SHORT TERM...
Issued at 250 AM PST Sat Dec 6 2025
(Today and tonight)
Satellite imagery overnight reveals a different scenario than the
last few nights. Tule Fog remains persistent across the Central
Valley, West Delta, and far East Bay Valleys. The change is a
redevelopment of the marine layer as high pressure builds
overhead. There is stratus along portions of the coastal waters
and Bay Area with the Central Coast remaining cloud free. There
was a Cold Weather Advisory in effect for portions of the North
Bay, but an influx of low level moisture/stratus limited
widespread temps below 36 degrees. In fact, a few places saw an
increase in temperatures once the stratus developed. Therefore,
cancelled the advisory. Another interesting note are the temp
spreads across the N Bay from valley to mts with upper 30s coldest
in the valleys and low 50s highest peaks. The warmer temps are
likely being enhanced by NE winds above the stratus deck. One
weather impact that hasn't changed is patchy dense fog impacting
the N Bay and E Bay Valleys. It's patchy and not widespread enough
to warrant a dense fog advisory as of this writing.
Rest of today and tonight: clouds across the Bay Area will be slow
to clear through late morning. A cool and damp start to the day in
those locations. Outside of the stratus, temperatures are colder,
but not as cold as yesterday. Slightly warmer temps likely due to
some weak offshore flow as well. For this afternoon expect a few
clouds passing overhead as a weak front to the north washes out
against the ridge of high pressure. Given lingering stratus and
Tule fog went on colder side of guidance for Max Temps in the N
and E Bay with Upper 50s to 60s. Elsewhere, generally 60s to a
few near 70. For tonight the ridge overhead strengthens a little.
This will help to compress the marine layer. In the big picture,
not a lot of change expected in overall sensible weather with
clouds and fog impacting N and E Bay and some of the Bay Area.
&&
.LONG TERM...
Issued at 330 AM PST Sat Dec 6 2025
(Sunday through Friday)
Solid agreement with model guidance through at least Friday as
high pressure dominates CA. A gradual warming trend is expected
with peak warmth Wed-Fri as temperatures soar above normal with
interior highs reaching the upper 60s to mid 70s. The challenge
next week will be N and E Bay temps and potential Tule fog impacts
keeping temperatures colder. There continues to be a few weak
systems passing well to the north, which may lead to some drizzle
over the coastal waters but land areas remain dry.
Friday and beyond - We'll continue to monitor a lowered end chance
for a pattern change. Cluster analysis has a few clusters
breaking down the ridge. However, operational ensemble guidance
keep the ridge locked in or flattens it with zonal flow. We'll see
how this changes over the coming days.
&&
.AVIATION...
(06Z TAFS)
Issued at 953 PM PST Fri Dec 5 2025
An odd mixture of stratus along the coast and IFR/Tule fog moving
into eastern portions of the CWA. Leaned on HREF guidance to capture
stratus moving in along the coast with moderate confidence that
stratus/MVFR conditions will persist through much of the overnight
period. For areas impacted by stratus, not anticipating visibilities
to drop much. For areas impacted by Tule Fog, visibilities will be
around 1-2SM with the potential for dense fog (1/4SM) to develop in
the North Bay. APC is likely to see some impact from Tule Fog
tonight but confidence is lower as to how long fog will be over the
airport. Followed persistence forecast for the timing of when
conditions will improve tomorrow (generally looking at late
morning/early afternoon clearing). Moderate onshore winds redevelop
tomorrow afternoon/evening before weakening and becoming variable to
lightly offshore overnight.
Vicinity of SFO...MVFR through much of the overnight period. Models
did not have a good grasp on the reemerging marine layer and
accompanying marine stratus tonight with only HREF guidance showing
the stratus that is currently over SFO. HREF guidance keeps low
clouds in the vicinity of SFO through the rest of tonight so opted
to utilize the HREF timing. Not anticipating fog to develop at SFO
with CIGs expected to predominantly be on the MVFR-IFR border
overnight. Winds remain light and slightly offshore overnight before
more moderate onshore winds return during the day tomorrow.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR. HREF guidance is best depicting the
current marine stratus setup with stratus to stay offshore tonight.
There is some potential for low clouds to reach MRY after 12Z but no
major impacts are expected at the airport. Winds remain light
overnight before more moderate onshore winds return during the
afternoon.
&&
.MARINE...
(Tonight through next Thursday)
Issued at 924 PM PST Fri Dec 5 2025
Northwesterly winds have increased to fresh to strong offshore
with localized near gale force gusts possible across the outer
waters. Winds remain elevated through the weekend and into next
week but there may be brief periods where winds weaken across the
coastal waters. Moderate seas with wave heights between 6 to 8
feet continue through the weekend. Moderate, long-period
northwesterly swell returns by mid next week with wave heights to
build.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 3 PM PST Sunday for CAZ006-506-508-
529-530.
PZ...Small Craft Advisory until 3 AM PST early this morning for Pt
Arena to Pt Reyes 0-10 nm.
Small Craft Advisory from 9 AM this morning to 3 AM PST Sunday
for Pt Pinos to Pt Piedras Blancas 0-10 nm.
Small Craft Advisory until 9 AM PST this morning for Pt Arena to
Pt Reyes 10-60 NM.
Small Craft Advisory until 9 AM PST Sunday for Pigeon Pt to Pt
Pinos 10-60 NM.
&&
$$
SHORT TERM...MM
LONG TERM....MM
AVIATION...Kennedy
MARINE...Kennedy
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FXUS66 KMTR 061144
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
344 AM PST Sat Dec 6 2025
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 250 AM PST Sat Dec 6 2025
- Persistent forecast through the next seven days with benign
conditions and no precipitation expected
- Impacts from Tule Fog in the North Bay and interior East Bay
valleys
- Next chance for rain towards the middle of the month
&&
.SHORT TERM...
Issued at 250 AM PST Sat Dec 6 2025
(Today and tonight)
Satellite imagery overnight reveals a different scenario than the
last few nights. Tule Fog remains persistent across the Central
Valley, West Delta, and far East Bay Valleys. The change is a
redevelopment of the marine layer as high pressure builds
overhead. There is stratus along portions of the coastal waters
and Bay Area with the Central Coast remaining cloud free. There
was a Cold Weather Advisory in effect for portions of the North
Bay, but an influx of low level moisture/stratus limited
widespread temps below 36 degrees. In fact, a few places saw an
increase in temperatures once the stratus developed. Therefore,
cancelled the advisory. Another interesting note are the temp
spreads across the N Bay from valley to mts with upper 30s coldest
in the valleys and low 50s highest peaks. The warmer temps are
likely being enhanced by NE winds above the stratus deck. One
weather impact that hasn't changed is patchy dense fog impacting
the N Bay and E Bay Valleys. It's patchy and not widespread enough
to warrant a dense fog advisory as of this writing.
Rest of today and tonight: clouds across the Bay Area will be slow
to clear through late morning. A cool and damp start to the day in
those locations. Outside of the stratus, temperatures are colder,
but not as cold as yesterday. Slightly warmer temps likely due to
some weak offshore flow as well. For this afternoon expect a few
clouds passing overhead as a weak front to the north washes out
against the ridge of high pressure. Given lingering stratus and
Tule fog went on colder side of guidance for Max Temps in the N
and E Bay with Upper 50s to 60s. Elsewhere, generally 60s to a
few near 70. For tonight the ridge overhead strengthens a little.
This will help to compress the marine layer. In the big picture,
not a lot of change expected in overall sensible weather with
clouds and fog impacting N and E Bay and some of the Bay Area.
&&
.LONG TERM...
Issued at 330 AM PST Sat Dec 6 2025
(Sunday through Friday)
Solid agreement with model guidance through at least Friday as
high pressure dominates CA. A gradual warming trend is expected
with peak warmth Wed-Fri as temperatures soar above normal with
interior highs reaching the upper 60s to mid 70s. The challenge
next week will be N and E Bay temps and potential Tule fog impacts
keeping temperatures colder. There continues to be a few weak
systems passing well to the north, which may lead to some drizzle
over the coastal waters but land areas remain dry.
Friday and beyond - We'll continue to monitor a lowered end chance
for a pattern change. Cluster analysis has a few clusters
breaking down the ridge. However, operational ensemble guidance
keep the ridge locked in or flattens it with zonal flow. We'll see
how this changes over the coming days.
&&
.AVIATION...
(12Z TAFS)
Issued at 337 AM PST Sat Dec 6 2025
Tule fog impacts continue this morning for North Bay and East Bay
terminals. Some fog and stratus making its way into other parts of
the Bay a bit less certain due to terrain interaction and mixing
of dry air above the marine layer. The overall pattern remains
fairly stagnant, so persistence forecast is the name of the game
through this TAF period. Anticipating another round of Tule fog
again tonight for North Bay and Bay Area terminals.
Vicinity of SFO...Patchy stratus this morning thanks to the
influence from Tule fog and light offshore wind. Some terrain-
induced mixing and weak perturbations above the marine layer will
cause some periodic clearing amongst the stratus through sunrise.
Going into tonight, reasonable to anticipate much of the same as
last night/this morning.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR. Light offshore flow from Tule fog
pattern owing to drier air due to downslope off the Gabilan Range
and Santa Lucia. This pattern will very likely repeat tonight,
allowing VFR to persist through the period.
&&
.MARINE...
(Today through Thursday)
Issued at 337 AM PST Sat Dec 6 2025
Fresh northwesterly winds persist through this weekend and into
the middle of next week. Moderate seas with wave heights 6 to 8
feet across the outer waters this weekend. A new, long period
northwesterly swell is anticipated by Wednesday of next week.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 3 PM PST Sunday for CAZ006-506-508-
529-530.
PZ...Small Craft Advisory from 9 AM this morning to 3 AM PST Sunday
for Pt Pinos to Pt Piedras Blancas 0-10 nm.
Small Craft Advisory until 9 AM PST this morning for Pt Arena to
Pt Reyes 10-60 NM.
Small Craft Advisory until 9 AM PST Sunday for Pigeon Pt to Pt
Pinos 10-60 NM.
&&
$$
SHORT TERM...MM
LONG TERM....MM
AVIATION...Behringer
MARINE...Behringer
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