ca discuss
Office: EKA
FXUS66 KEKA 091951
AFDEKA
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1151 AM PST Tue Dec 9 2025
.SYNOPSIS...Periodic coastal drizzle continues for areas of the
North Coast through mid week. A generally dry and warm weather
pattern is expected to prevail across NW CA mid to late week, with
record warmth likely for the interior.
&&
.DISCUSSION...Satellite imagery shows areas of stratus and fog in
many of the interior valleys late this morning. Low cloud cover
will gradually lift and scatter out today, giving way to a fairly
pleasant December afternoon. The main exception will be at the
northern Humboldt and Del Norte coasts, where stratus and drizzle
is likely to return this afternoon and evening. Precipitation
amounts are minimal with up to a few hundredths of an inch of
drizzle possible in Del Norte.
The persistent ridge of high pressure responsible for blocking
Pacific storm systems will strengthen and nose eastward through
the week. Significant warming for the interior will occur as a
result. The current forecast yields interior high temperatures
reaching 10-20F above climatological norms midweek through the
weekend. NBM shows a high probability (70% or higher) for the
warmer interior valleys, including Ukiah and much of Lake County,
to exceed 70 F Thursday and Friday. NBM probabilities for
exceeding 75F around Ukiah is around 50% for Thursday and Friday.
This would break the high temperature record of 72F from 1958 for
Ukiah on Friday if the forecast holds.
Ensembles and clusters are hinting at the weakening of the
stubborn ridge through the weekend. Precipitation chances start to
increase through the latter portion of the weekend. However, any
meaningful breakdown of the ridge or zonal flow may not occur
until early next week.
&&
.AVIATION...(18Z TAFs)...Fog and stratus have started to lift and
scatter across the area, ushering in MVFR to VFR conditions for
the terminals. An approaching front to the north will bring a
chance for drizzle or light rain, and likely gradually bring
ceilings down to MVFR or IFR for the coastal terminals. The weak
marine inversion could lead to scattering near sunrise at ACV, but
shallow ground fog is still a possibility. LIFR fog and stratus
may return for the interior valleys, including UKI, again tonight.
Any stratus and fog is likely to lift and scatter by mid-morning
Wednesday. JB
&&
.MARINE...Northerly winds are forecast to ramp up south of Cape
Mendocino this afternoon and evening and persist through at least
Friday. Wind gusts peak around 20-30 kts in the lee of Cape
Mendocino, with breezy winds reaching nearshore areas at times.
Steep wind waves of 5-7 ft are possible with these winds. North
of Cape Mendocino, winds remain light and southerly through at
least Thursday. North winds return late Thursday into Friday and
could be breezy in the outer waters. The sea state remains
dominated by mid-period northwest swells, with additional swells
filling in tonight into Wednesday and again Thursday. These will
keep the sea state elevated and combined seas could exceed 10 ft
at times, especially south of the Cape where the swell will
combine with the steep wind waves. Winds ease this weekend as high
pressure weakens. JB
&&
.BEACH HAZARDS...An increased threat of sneaker waves is expected
for the Del Norte, Humboldt, and Mendocino coastlines this Thursday.
A mid-period westerly swell generated by a storm currently located
near 45N,160W will enter the coastal waters early Thursday
morning. A lack of local wind waves will allow this swell to
dominate the sea state over an existing swell, creating beach
conditions that could look deceivingly calm. Forecast confidence
will grow as the swell passes NOAA/NDBC buoys Wednesday morning.
Remember to never turn your back to the ocean, and to avoid steep
beaches, jetties, outcroppings, and rocks during these events. DS
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
Beach Hazards Statement from Thursday morning through
Thursday evening for CAZ101-103-104-109.
NORTHWEST CALIFORNIA COASTAL WATERS...
Small Craft Advisory from 3 PM Wednesday to 10 AM PST
Thursday for PZZ455.
Small Craft Advisory from 3 PM Wednesday to 2 AM PST Friday
for PZZ475.
&&
$$
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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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png
Office: HNX
FXUS66 KHNX 091818
AFDHNX
Area Forecast Discussion
National Weather Service Hanford CA
1018 AM PST Tue Dec 9 2025
.KEY MESSAGES...
1. Fog and low clouds will continue each night and morning across
the San Joaquin Valley this 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 across the mountains and
desert this week, as the high pressure pattern continues over
the region.
&&
.DISCUSSION...
Central California saw very little change in the last 24 hours
as low clouds covered the San Joaquin Valley. The stagnant
weather pattern is still in place over the Southwest as the
region remains dry. While outside of the San Joaquin Valley,
temperatures across the Mountains and Kern Desert have seen a
slow rise conditions warm under the ridge of high pressure. Over
the next 2 to 3 days, probability of seasonal normal values
across the valley struggle to reach any percentage higher than
20 percent. On the contrary, outside of the San Joaquin Valley,
the probability of reaching 65 degrees for elevations below
6,000 feet sits between 60 and 90 percent. With these high
percentage value showing up for much of the week, will expect
little change in the stratus plaguing the San Joaquin Valley.
In the realm of precipitation, ensemble moisture analysis is
showing the blocking high maintaining its position over the
Eastern Pacific, and placing the steering current in the
direction of the Pacific Northwest. With little change in the
next 5 day, Central California will remain dry and covered in
low clouds. Longer range ensemble analysis does show a change in
the pattern with a hint toward the introduction of precipitation
as early as next Tuesday (16 Dec 2025). Ensemble analysis still
hints toward precipitation around the middle to late next week.
Yet, uncertainty is still too high on the actual magnitude of
the next storm. Further analysis is needed to gauge the next
storm potential.
&&
.AVIATION...
IFR to MVFR ceilings and visibilities are expected to prevail
for much of the San Joaquin Valley during the next 24 hours.
LIFR conditions will also persist in the coastal ranges, Sierra
foothills, and the Kern County mountains due to the low stratus
deck. Otherwise, VFR conditions will prevail in the Sierra
Nevada and in the Kern County mountain and desert areas over
the next 24 hours.
&&
.AIR QUALITY ISSUES...
On Tuesday December 9 2025, Unhealthy for Sensitive Groups in
Fresno and Kern Counties. Fireplace/Wood Stove Burning Status
is: No Burning For All in Fresno and Kern Counties. No Burning
Unless Registered in 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 high.
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 11 AM PST this morning for CAZ300-304-
308-313-316>322-334>336.
&&
$$
Public/Aviation....Molina
weather.gov/hanford
Office: LOX
FXUS66 KLOX 092143
AFDLOX
Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
143 PM PST Tue Dec 9 2025
.SYNOPSIS...09/133 PM.
Benign weather will continue through this week, with a warming
trend continuing through Thursday. High temperatures will be well
above normal through at least Friday. Offshore flow will produce
locally gusty canyon winds in the mornings.
&&
.SHORT TERM (TDY-FRI)...09/140 PM.
Enjoyable weather is expected through the short-term period. A
590 dam ridge of high pressure is centered about 700 miles west of
Point Conception. This feature is expected to remain nearly
stationary & gradually weaken through the week. Offshore gradients
from the north and east have peaked Today and are expected to
weaken Wednesday through Friday. KSBP-KBFL & KSMX-BFL gradient
values will be similar late tonight into early tomorrow morning.
However, there will not be support up to 850 mb that we had this
morning. Thus, winds should remain below wind advisory criteria,
but cannot rule out a local gust to 45 mph. Gusty winds are
expected through and below passes and canyons in the usual Santa
Ana wind prone areas through Thursday morning. Local gusts to 45
mph is possible across the Santa Susana mountains through Wed
morning, with a 20% chance of a wind advisory.
The combination of offshore flow and the upper high will result in
clear skies and well above normal temps across the area through
likely Friday. Maximum Temps are expected to warm 2 to 4 degrees
Wednesday, except for the coast and inland coast areas which should
remain similar.
Overall, this will make Wednesday the warmest day across our area.
Inland coastal areas will see highs in the upper 70s to mid 80s
& valley locations well into the 80s. The warmest locations will
be across the San Fernando, Santa Clarita, Ojai, & Santa Ynez valley
floors. Max T departures are expected to be 12 to 18 degrees above
normal. Some local areas over 20 degrees.
Most sites should stay below record values. However, our forecasted
numbers are within a couple degrees of daily records such as:
Ojai (1958) and Lancaster (1975).
The ridge and offshore flow will weaken some Thursday into Friday
which will result in 3 to 6 degrees of cooling across csts/vlys
thanks to earlier and stronger seabreeze. The far interior should
remain near the same as the previous day. Coastal areas will see
more cooling on Friday as offshore gradients continue to relax.
Most areas should remain about the same, except for SLO interior
which could see 2 to 4 degrees of warming.
.LONG TERM (SAT-TUE)...09/141 PM.
A shortwave trough is expected to arrive to the area on Saturday
reducing 500mb heights to around 578 dam. Also, gradients look to
increase to near neutral according to ECMWF guidance. About 50%
of ensembles have weak onshore flow which would be sufficient for
night through morning low clouds and fog (likely dense) to return
to some of the coasts. More support on Sunday.
Max Temperatures are expected to cool 1 to 3 degrees on Saturday.
Another 3 to 6 degrees of cooling is expected on Sunday. However,
we will stay above normal by 3 to 6 degrees across csts/vlys and
6 to 12 degrees across the interior. There is decent agreement
on reinforcing ridging early next week which would likely result
in offshore flow, less clouds, and another increase in temps.
The ECWMF/AI show some support for troffing and rain chances to
return after the 20th, but its minimal and low confidence at this
time.
&&
.AVIATION...09/1903Z.
At 18Z at KLAX, There was no marine layer.
High confidence in VFR TAFs.
KLAX...High confidence in TAF. Any east wind component will
be less than 7 knots.
KBUR...High confidence in VFR TAF.
&&
.MARINE...09/1103 AM.
NE winds of 15 to 25 knots will affect wind prone areas at times
through Wednesday morning. This includes portions of the Central
Coast and from Ventura to Santa Monica. These winds will likely
reach low-end Small Craft Advisory (SCA) levels for the nearshore
waters of San Luis Obispo County.
Some dense fog will form in the coastal waters by Thursday or
Friday, but low confidence on when and where.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 10 AM PST Wednesday for
zones 645-670-673. (See LAXMWWLOX).
&&
$$
PUBLIC...Black
AVIATION...Munroe
MARINE...RM/RK/BL
SYNOPSIS...Ciliberti/KL
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox
Office: STO
FXUS66 KSTO 092148
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
148 PM PST Tue Dec 9 2025
.KEY MESSAGES...
- Periods of low clouds, mist, fog and unseasonably cool high
temperatures continue in the Central Valley, Delta and lower
foothills this week with little change
- Increasingly mild temperatures with sunny skies and dry
weather are expected over higher terrain this week
- Potential for a pattern change next week with light
precipitation, but uncertainty is high and might be limited to
the far northern area in Shasta County
&&
.DISCUSSION...
...Today - Sunday... Eastern Pacific high pressure ridging
continues a stagnant pattern across the region, with a strong
inversion keeping mist, fog and low stratus over the Valley and
Delta and into the lower foothills. Patchy fog has primarily been
observed over the northern Sacramento Valley and in the foothills
(1500-2000 feet) where low clouds are intersecting with the
terrain. Fog in the northern Sacramento Valley has diminished
this afternoon, but lingers in the foothills. This pattern is
expected to continue with low clouds persisting and some patchy
fog reforming in the Valley again tonight, most likely around the
Redding area. Winds remain generally light and variable.
This pattern is expected to persist through the week and even into
the weekend as the high pressure ridge continues to build. Dry
weather continues across the region. The exception to this is
periods of mist and drizzle at times with the low clouds and fog,
which may wet the ground. The low clouds continue to keep
high temperatures unseasonably cool in the Valley and Delta,
generally 10-14 degrees below normal, while higher terrain
experiences sunny skies and above normal temperatures (10-20
degrees above normal). The building high will bring further warming
temperatures to the area over higher terrain, generally for
locations above 1500 feet. Stratus and fog will prevent this
warming for portions of the Valley and Delta that remain covered,
though, so little change in is expected in those areas this week,
with unseasonably cool temperatures persisting. The northern
Sacramento Valley has the best potential for seeing some clearing
due to a thinner cloud deck and some light northerly winds late in
the week, which could bring a gradual increase in temperatures
there locally.
...Next Week...
A pattern change is projected for early next week, but there
remains quite a bit of uncertainty in the timing and intensity of
this system. Current forecast shows the potential for
precipitation north of I-80, especially for the mountains. The
best chances expected over the mountains of Shasta County, but
little to no impacts are expected at this point. This system could
potentially end this stagnant pattern. Stay tuned for forecast
updates.
&&
.AVIATION...
Lingering low cigs and mist across the Central Valley continue
into this evening with IFR/LIFR conditions, although some sites
may very briefly see MVFR/VFR visibility around 22-24Z, mainly for
TAF sites north of Sacramento. Another round of BF/FG and low
stratus returns after 03Z-06Z with areas of IFR/LIFR ceilings once
again expected to persist through the day. Light and variable
surface winds less than 12kts.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Office: SGX
FXUS66 KSGX 092111
AFDSGX
Area Forecast Discussion
National Weather Service San Diego CA
111 PM PST Tue Dec 9 2025
.SYNOPSIS...
Warm and dry conditions with periods of weak Santa Ana winds this
week. Above average temperatures expected into next week, with the
most significant departure from normal expected today through
Thursday. Mostly clear skies are expected through at least Thursday,
with low clouds and fog returning to coastal areas as early as
Friday or Saturday morning.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Temperatures at 1 PM were running 3 to 8 degrees warmer than 1 PM
yesterday for most locations expect the mountains where they were
running up to 11 degrees warmer than yesterday. A few additional
degrees of warming is expected for inland areas Wednesday and
Thursday, with some cooling at the coast. The surface high pressure
over the Great Basin will remain in place through Friday, continuing
periods of weak Santa Ana winds. Strongest winds will remain
confined to coastal mountain slopes, foothills, and below passes
with gusts 25 to 35 mph. The airmass getting pushed into Southern
California from the Great Basin is quite dry, with minimum afternoon
relative humidity for inland areas falling to 10 to 20% each
afternoon through Thursday, bringing periods of elevated fire
weather conditions.
Skies are expected to remain mostly clear through Thursday. Chances
of low clouds and fog returning to the coast begin to increase
Friday with higher chances over the weekend. High resolution
guidance is showing the development of a coastal eddy Thursday night
into Friday, which would increase the chances of low clouds and fog
returning to coastal areas. The first night or two that marine layer
low clouds and fog return, the fog has the potential to be dense
especially as ridging aloft remains over the area.
Highs for the weekend into early next week will remain above
average, but not quite as warm as this week. Highs along the coast
through Monday will be about 5 degrees above average and 8 to 12
degrees above average for inland areas. For the early to middle part
of next week there starts to become some uncertainty in the upper
level pattern. By next Tuesday, 65% of ensemble clusters are showing
the ridge continuing over the West Coast, with 20% showing the ridge
weakening due to an incoming trough, and 15% showing the ridge
present but over the Eastern Pacific.
&&
.AVIATION...
092100Z...Beautiful clear skies with VFR conditions will continue
through the TAF period at all sites. Breezy northeast winds in the
foothills and locally into the adjacent valleys with gusts up to 25-
30 kts will be possible through 18Z Wednesday with winds beginning
to trend down after 20Z.
&&
.MARINE...No hazardous marine conditions are anticipated through
Sunday.
&&
.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...CO
AVIATION/MARINE...Villafane
Office: MTR
FXUS66 KMTR 092057
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1257 PM PST Tue Dec 9 2025
...New SHORT TERM, LONG TERM...
.KEY MESSAGES...
Updated at 1256 PM PST Tue Dec 9 2025
- Tule fog and stratus return tonight for Bay Area valleys.
- Quiet weather continues, with high temperatures increasing
through Friday.
- Light rain remains possible early next week.
&&
.SHORT TERM...
Issued at 1256 PM PST Tue Dec 9 2025
(This evening through Wednesday)
Another day of watching the stratus slowly erode across the Bay
area. The North Bay Valleys seem to be on track to erode by mid to
late afternoon, which should keep high temperatures fairly chilly up
there. It's been fun, yet challenging and humbling experience to try
and nail the stratus erosion timing and high temperature forecast.
This will continue to be the trend into Wednesday, though hopefully
we get a little more compression from the high pressure system and
perhaps slightly stronger offshore flow. If that happens, we could
see warmer temperatures than forecast; however, I trended with a
slightly more pessimistic forecast for Wednesday. If your'e outside
the East and North Bay areas, warmer weather is on tap for
Wednesday.
The area area to watch will be interior Central Coast temperatures
tonight. Ended up tweaking the values in these area based on the
past few nights being a touch colder than expected.
&&
.LONG TERM...
Issued at 1256 PM PST Tue Dec 9 2025
(Wednesday night through next Monday)
Heights will build into for the later portion of the work week,
leading to high temperatures climbing a few degrees each day. The
question will be, what does that mean for our friends who have been
stuck with stratus? The ridge should limit the spread of the stratus
and fog, due to the marine layer compressing. If any clouds and fog
do form, they should at least erode faster leading to smaller
warming trend for these areas. High temperatures falter a few
degrees as we head towards the weekend as upper level ridging slides
eastwards. The next chance for rain may occur early next week. The
dates of when this occurs seem to continue to be pushed back, so
stay tuned.
&&
.AVIATION...
(18Z TAFS)
Issued at 934 AM PST Tue Dec 9 2025
Another messy start to the day with low clouds and some fog
impacting the N, E, S, and SF Bay. Monterey Bay on the other hand
is VFR. Expect another slow clearing of cigs for the greater Bay
Area again, but still expecting some SCT late this afternoon.
Another repeat for cigs again tonight in the N and E Bay, but an
uptick in drying NE winds at 2500 ft will keep less clouds in SF
Bay. Could even see some marginal LLWS for KOAK early tomorrow.
Vicinity of SFO...IFR conditions remain with cigs and some haze.
Cams and satellite show some clearing farther out in the Bay, but
slow going for the terminal itself. Will keep cigs through 19-20Z.
Tonight and tomorrow less conf, but VFR at the moment with drier
offshore flow.
SFO Bridge Approach...Same as SFO.
Monterey Bay Terminals...VFR
&&
.MARINE...
(Today through Sunday)
Issued at 921 AM PST Tue Dec 9 2025
High pressure off the California coast will maintain northerly
flow over the coastal waters. Winds are locally stronger south of
Point Pinos leading to hazardous conditions today. Winds will
strengthen across all outer waters later this week. A new, long
period northwesterly swell is expected by midday Wednesday,
lasting into the early weekend.
&&
.BEACHES...
Issued at 132 AM PST Tue Dec 9 2025
Long period swell will impact the coast Wednesday - Friday. This
energy brings strong rip currents, an increased risk for sneaker
waves, and large breaking waves. NW swell around 8 feet with a 15
second period will translate to breaking waves up to 15-20 feet.
These conditions may warrant a Beach Hazards Statement, particularly
with the warm weather likely luring more people to the Beach.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement from Wednesday morning through Friday
evening for CAZ006-505-509-529-530.
PZ...Small Craft Advisory until 9 PM PST this evening for Pt Pinos to
Pt Piedras Blancas 0-10 nm.
&&
$$
SHORT TERM...KR
LONG TERM....KR
AVIATION...MM
MARINE...MM
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