Air Resources Laboratory banner image
Air Resources Laboratory web site National Oceanic and Atmospheric Administration (NOAA)

ca discuss


Office: EKA
FXUS66 KEKA 070826
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
1226 AM PST Sun Dec 7 2025

.SYNOPSIS...Cloudy and misty conditions expected this morning. A
warm front with light rain and drizzle passes over Del Norte and
Humboldt counties today. Generally dry weather conditions is
expected to prevail across NW CA this coming week, with periods of
light rain/drizzle for the North Coast.

&&

.DISCUSSION...A stubborn high pressure center has been sitting off
the California coast for a few weeks now. The strength of the high
pressure has been keeping the storm track far to the north of NW CA
for the last few weeks. This slower start to winter will continue
this week with increased moisture, yet not enough forcing will be
present to create meaningful precipitation amounts as most of the
vertical vorticity of a frontal system to the north will be
focused in Oregon, only briefly and periodically clipping NW CA.
The increased atmospheric moisture will create fog and low clouds
along the coast and in the inland valleys. Increased cloud
coverage will keep nighttime temperatures on the warmer side for
the season.

A passing warm front will bring light rain and/or drizzle across
mostly Del Norte and Humboldt counties later today. Total storm
precipitation amounts will be minimal and mostly north of Humboldt
Bay and West of the Klamath River. REFS probabilities shows only a
20-30% chance of wetting rain in Del Norte and a 0-15% chance of
wetting rain in northern Humboldt Co. Elsewhere, drier weather
conditions will prevail with morning valley fog, mist and low
clouds.

High pressure slowly builds back over the area next week in the wake
of the frontal passages. The general consensus between the ensemble
and operational models is dry weather conditions across much of
Northwest California, with intermittent light rain/drizzle in Del
Norte County through Thursday at the earliest. The dry weather
allows for a gradual warming trend through the week, with interior
high temperatures warming up to mid 60s to mid 70s late in the week
peaking on Thursday.

Some ensembles are indicating a pattern change by mid December but
there is a large amount of uncertainty as it is too far out in time
to have any true meaning for the forecasts.
-ZVS/DES


&&

.AVIATION...(06Z TAFS)...Periods of LIFR to IFR stratus will
continue into early Sunday for coastal areas ahead of an approaching
front. Light rain is possible over Humboldt and Del Norte starting
early Sunday morning around 12Z. Some interior valleys may see
stratus and fog again tonight, but confidence at UKI is lower. JB


&&

.MARINE...Northerly winds and seas have eased as front moves in
north of our area. Generally light winds are forecast this weekend,
with south winds forecast north of Cape Mendocino and west-northwest
winds forecast south of the Cape. A mid period northwest swell will
continue and peak at around 7-9 ft at 12 seconds. Wave heights peak
early Sunday morning. Combined seas could briefly reach or exceed 10
ft, especially if the swell fills in higher than forecast. 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


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
None.
&&

$$

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

Follow us on Facebook and Twitter at:
https://www.facebook.com/NWSEureka
https://www.twitter.com/NWSEureka

For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.png



Office: HNX FXUS66 KHNX 071824 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 1024 AM PST Sun Dec 7 2025 && .KEY MESSAGES... 1. Fog and low clouds will continue each night and morning across the San Joaquin Valley into 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 in the mountains and desert until next week, as the high pressure pattern continues over the region. && .DISCUSSION... Conditions today remain in a "rinse and repeat" pattern, with low clouds spanning across the San Joaquin Valley and areas of fog and reduced visibilities in the foothill areas where these clouds encounter the local terrain. This pattern comes as the result of a strong temperature inversion extending to 6000 feet above ground level which is trapping saturated air between 1000 and 2000 feet. In fact, the warmer temperatures are anomalously warm for this time of year, running around five degrees celsius above average. Without warmer temperatures and/or drier conditions at the surface, or increased winds to mix out the low clouds, our valley stratus will look to continue at least through midweek. As the mid to late week period approaches, the high pressure ridge over the eastern Pacific driving our stable conditions is projected to slide eastward, based on current ensemble forecasts. This pattern change is expected to cause increasingly anomalous temperatures, especially for the Sierra Nevada and surrounding foothills, and in the Kern County Desert. Probabilistic guidance shows areas including Lake Isabella, Oakhurst, and Yosemite Valley have more than a 90 percent probability for maximum temperatures to exceed 70 degrees this coming Friday, when these locations average 50 to 60 degrees. It will remain to be seen what this system does for the San Joaquin Valley. Warmer temperatures caused by the ridge will bring afternoon highs nearer to season averages, which could lead to clearing conditions during the day, however the subsidence aloft caused by the high pressure would keep moisture trapped in the lower levels. These warm and dry conditions are likely to remain into the extended period, as the Climate Prediction Center expresses a 70 to 80 percent chance for above average temperatures and 33 to 50 percent chance for below average precipitation. && .AVIATION... IFR to MVFR ceilings and visibilities are expected to prevail for much of the San Joaquin Valley. These conditions will continue through 18Z Sunday. 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 Mountains and Desert over the next 24 hours. && .AIR QUALITY ISSUES... ISSUED: 12/06/2025 15:02 EXPIRES: 12/07/2025 23:59 On Sunday December 7 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 CAZ300-335. && $$ public/aviation..McCoy weather.gov/hanford
Office: LOX FXUS66 KLOX 071913 AFDLOX Area Forecast Discussion...UPDATED National Weather Service Los Angeles/Oxnard CA 1113 AM PST Sun Dec 7 2025 .SYNOPSIS...07/1212 AM. Benign weather will continue through the weekend with a small chance of morning low clouds and fog along the Los Angeles coast. A significant warming trend will begin today with temperatures well above normal Monday through next Friday, peaking Tuesday through Thursday. Offshore winds will increase Sunday and Monday, and are expected to persist through much of the week. && .SHORT TERM (TDY-TUE)...07/801 AM. ***UPDATE*** Latest satellite and surface observations indicate clear skies across the area this morning. Weak offshore gradients are generating some locally gusty north to northeast winds in the 15-25 mph range. Forecast-wise for the immediate short term, no issues are expected. Sunny skies will prevail for all areas through the day. Looking at morning TEMP STUDY data, boundary layer is a bit warmer and offshore pressure gradients are a bit stronger. So today will be about 2-5 degrees than Saturday across the area. The weak offshore winds will remain weak throughout the day. Overall, current forecast has good handle on the immediate short term. So, no significant updates are expected. ***From Previous Discussion*** Benign weather on tap for the short term an beyond. Weak upper level ridging will continue and hgts will rise from 582 dam today to 586 dam on Tuesday. Offshore flow will also continue through the period, peaking on Tuesday. Skies should be mostly clear through the period with the exception of a 30 percent chc of some low clouds in the KLAX-KLGB area this morning and a more likely chc (~70 percent) chance on Monday morning. There will be local offshore winds each morning. Offshore flow increases each day and peaks on Tuesday. There is no chc of advisory level gust today and Monday but low end advisory level gusts look possible Tuesday morning through and below the Santa Lucia Range and the western LA vlys and eastern VTA vlys. Temperatures will be the main story. Rising hgts, offshore flow and sunny skies will all combine to bring 2 to 4 locally 5 degrees of warming each day. Max temps across the csts/vlys will rise from the upper 60s and 70s today to the the upper 70s to mid 80s by Tuesday. Most max temps will be 10 to 15 degrees above normal on Tuesday. Min temps will be warmer than normal in the windier areas, but the dry air and clear skies will bring lower than normal temps in the wind sheltered areas. .LONG TERM (WED-SAT)...07/300 AM. The GFS and EC as well as their ensembles all agree that the ridging from the west will continue through Friday. The upper high does weaken some and hgts will slowly fall during the 3 day period. The onshore flow which peaked on Tuesday will also slowly relax during the period. While there will be some morning canyon winds they will not be of much consequence. Still this forecast is all about the temps. Tuesday will be the warmest day for the csts of LA/VTA county as the relaxed offshore flow will lead 1 or 2 degrees of cooling on Wednesday. For the rest of the area, however, Wednesday will be the warmest day with max temps rising another 2 to 3 degrees over Tuesday's already super warm temps. Almost all areas will cool 1 to 2 degrees on Thursday as the high relaxes. Despite this cooling, most max temps will still end up 10 to 15 degrees over normal (4 to 8 for the nearshore area south of Pt Conception). Friday's temps will be similar to Thursday's. Not the best agreement on the pattern/fcst for next weekend, but in general the high should continue to weaken and offshore flow should weaken further. Some mdls show a return of the marine layer as well. Some cooling each day is likely, but how much is still a bit of a mystery. && .AVIATION...07/1912Z. At 1822Z at KLAX, the marine layer was 500 feet deep. The top of the inversion was 2500 feet with a temperature of 19 C. Moderate to high confidence in KSBA, KOXR, KSMO, KLAX, and KLGB after 03Z Monday, otherwise high confidence for all TAFs. There is a 30% chance of conds remaining VFR through the period at KLAX. There is a 30% chance of VLIFR to LIFR conds at the specified aforementioned sites, with conds potentially arriving as early as 03Z Mon for KSMO, KLAX, and KLGB and around 09Z for KOXR and KSBA. KLAX...Good confidence in TAF. There is a 30% chance of VFR conds persisting through the period, otherwise LIFR-IFR conds could arrive as early as 03Z Mon. Any easterly winds will remain less than 7 knots. KBUR...High confidence in VFR TAF. && .MARINE...07/800 AM. For the outer waters, there is a 40-60% chance of low-end Small Craft Advisory (SCA) conditions through the week, especially across the western portions of the waters north of Santa Cruz Island during the afternoon and evening hours. For the inner waters including the southern California bight and the nearshore waters along the Central Coast, there is a 30-50% of local northeast SCA level wind gusts from Ventura to Santa Monica as well as from Pismo Beach to Point Piedras Blancas each night and morning through Tuesday, and a 30% chance of reoccurring on Wednesday. Otherwise, winds and seas should remain below SCA levels. There is a moderate chance of dense fog over the coastal waters through Monday morning. Confidence remains low on timing and coverage. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...Small Craft Advisory in effect until 3 AM PST Tuesday for zones 670-673. (See LAXMWWLOX). && $$ PUBLIC...Rorke/Thompson AVIATION...Lund MARINE...Hall/Lund SYNOPSIS...Black/Ciliberti weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox
Office: STO FXUS66 KSTO 062110 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 110 PM PST Sat Dec 6 2025 .KEY MESSAGES... - Periods of low 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 && .DISCUSSION... ...Today - Sunday... Stratus/Low clouds were more of the story this morning vs. fog dominating the forecast yesterday but still impacting much of the Central Valley and adjacent lower foothills. Out forecast remains on repeat with another round of low clouds/fog tonight into tomorrow morning with best chances Sacramento northward although fog is possible throughout all of the Valley. Dry weather and seasonable temperatures are forecasted for the region, with upper 40s to 50s 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. ...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 weak 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 continues into this evening, although some sites may very briefly return to VFR conditions around 22-24Z. Another round of BF/FG and low stratus returns tonight after 03Z and continues through Sunday, with areas of MVFR/IFR conditions. Areas of LIFR in fog and low ceilings around 12-18Z, particularly in the Central Valley from Sacramento southward. Lingering low ceilings in stratus expected to persist through the day. Light and variable surface winds less than 12kts. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$
Office: SGX FXUS66 KSGX 071726 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 926 AM PST Sun Dec 7 2025 .SYNOPSIS... Warm and dry conditions with periods of Santa Ana winds expected this week. The peak of the heat is expected to be mid-week. Patchy low clouds could develop overnight into Monday morning near the coast. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Mostly clear skies are being observed across the area as of 9 AM. A few patches of low clouds developed off the coast overnight, but weak easterly winds and a prevailing offshore pressure gradient kept the clouds offshore. For tonight into Monday morning there is a 10 to 20 percent chance of patchy low clouds and dense fog developing along the coast, with slightly higher chances of dense fog developing over the coastal waters. Mostly clear skies will prevail from Monday afternoon through the middle of the week due to periods of weak to moderate Santa Ana winds. A persistent surface high pressure over the Great Basin is predicted to remain in place through Saturday. This will bring weak to locally moderate Santa Ana winds to the area. With no upper level support, the strongest winds will remain confined to coastal mountain slopes and below passes. The strongest winds are expected on Tuesday with gusts 25 to 40 mph. A secondary peak in winds is expected on Friday. The airmass getting pushed into Southern California from the Great Basin will be on the drier side, with minimum afternoon relative humidity for inland areas falling to 12 to 20% each afternoon through Friday, bringing periods of elevated fire weather conditions. An upper level ridge over the East Pacific will strengthen over the US West Coast through Tuesday, bringing an uptick in high temperatures. High temperatures on Tuesday will be 15 to 20 degrees above average. Widespread highs in the low to mid 80s are forecast across the inland coastal areas into the valleys as well as the low deserts. Weaker Santa Ana winds and a weakening in the upper level ridge will allow for minor cooling on Wednesday and Thursday mainly for coastal areas. The secondary uptick in Santa Ana winds on Friday is expected to bring additional warming to areas west of the mountains with high temperatures expected to run up to 20 degrees above average for inland areas. Nights and mornings will remain cool, especially in the wind-sheltered areas, minimizing any heat impacts. A few degrees of cooling is expected into next weekend as weak onshore flow returns, but temperatures will continue to run above average. && .AVIATION... 071630Z...Clear skies and VFR prevail region-wide through this afternoon. Some HZ currently near the surface. After 01z Mon, 10-20% chance for very patchy fog developing within 5 miles of the coast with very patchy VIS reductions. Offshore E/NE winds gusting 25-35 kts to pick up through mountain passes and Santa Ana mountain coastal slopes after 13z Mon, clearing out any leftover fog. && .MARINE... Tonight, 20-30% chance of patchy dense fog with visibility 1 nautical mile or less through early Monday before sunrise. && .BEACHES... Morning high tide is predicted to be 6.5 to 7 ft at 10 AM this morning in La Jolla and at 9:50 AM in Newport Beach. Astronomically high tides may result in tidal overflow in normally dry beach areas. High tide is predicted to fall below 6 ft by Monday. && .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/BEACHES...Westerink
Office: MTR FXUS66 KMTR 072019 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1219 PM PST Sun Dec 7 2025 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Updated at 1218 PM PST Sun Dec 7 2025 - Benign conditions through the next seven days with no precipitation expected and a gradual warming trend through the later part of the week - Impacts from Tule Fog continue in the North Bay and interior East Bay valleys, with potential for expansion across the rest of the Bay Area overnight - Next chance for rain lies slightly beyond the 7-day outlook && .SHORT TERM... Issued at 1218 PM PST Sun Dec 7 2025 (This evening through Monday) Today is looking to be very similar to yesterday, right down to the satellite imagery showing outgrowth from the Tule Fog across the Bay Area, slowly dissipating south of the Golden Gate and west of the Berkeley-San Leandro Hills and the eastern Santa Clara Mountains, and lingering across the North Bay and interior East Bay valleys. Indeed, if you compared the current satellite image and the one from yesterday, you could only them apart by the lack of coastal stratus today. As a point of curiosity, while there are no radiosonde observations over the Central Valley, aircraft soundings from the region suggest that the saturated lower atmosphere -- the "Tule fog" layer, if you will -- extends 1500-2000 feet above the ground. The Central Coast remains mainly clear. The remarkably similar evolution of the stratus from yesterday through today has lowered confidence in the clearing of stratus from the Santa Rosa Plain and the rest of the North Bay valleys. I've tamped down the high temperatures today even further in those regions, into the upper 40s to the lower 50s, and even then the expected highs are still a little warmer than the observed highs yesterday. Across the rest of the region, temperatures range from the middle 50s to lower 60s across the Bayshore, the Bay Area Pacific Coast and the Santa Clara Valley, while the sun-blessed Central Coast sees highs in the lower to middle 60s in the Monterey Bay region and the Hollister area, and the upper 60s to lower 70s inland. Tomorrow, the ridge over the West Coast will strengthen and continue a general warming trend across the region. For the Central Coast, the temperature forecast should be similar to today's. The uncertainty increases across the Bay Area and especially in the North and East Bays, where the impacts of the building ridge on the Tule Fog remain uncertain. In general, a building ridge will tend to compress the inversion layer, and limit the extent that the Tule Fog can extend across the region. (We see this happen during our marine layer season as well, when building ridges compress the marine layer and prevent it from coming inland.) If the inversion layer does compress enough, the Tule Fog could find itself hitting a proverbial wall before it reaches the Bay Area. On the flip side, for those areas still impacted by the Tule Fog, ceilings and visibilities will tend to drop. This makes the temperature forecasts highly uncertain. For now, tamped down the temperatures slightly so that the North and East Bay valleys see highs in the middle 50s to lower 60s, while the rest of the Bay Area valleys see highs in the lower to middle 60s, but this might be quite optimistic indeed. && .LONG TERM... Issued at 1218 PM PST Sun Dec 7 2025 (Monday night through next Saturday) Ridiculously resilient ridging will dominate the weather pattern through the rest of the week with the ridge crawling through the Western United States, such that over the next 6 days the ridge axis moves from just off the coast of the Pacific Northwest to the Oregon- Idaho border area. Over the Central Coast the impacts are most certain with a gradual warming trend in the forecast. The warmest days are expected Wednesday through Saturday with highs reaching the upper 60s to the middle 70s across the inland valleys. The Bay Area in general and the North and East Bay valleys in particular remain tied to the evolution of the Tule Fog. Impacts are expected to persist into the early part of the work week before diminishing with the continuing ridging across the region. The pattern change for the middle of the month is beginning to come into the very end of the 7 day outlook. The early indications are pointing more towards a zonal flow pattern for the Western United States and any rain storms that develop generally being deflected into the Pacific Northwest. Beyond the 7-day outlook, the ensemble model clusters suggest that a return to a wetter pattern is possible around 9-10 days out, and the CPC's 8-14 day outlook shows a slight lean towards rainfall totals above seasonal averages for the third week of December. I have heard that before this month... && .AVIATION... (18Z TAFS) Issued at 955 AM PST Sun Dec 7 2025 Tough forecast given the Tule fog and associated stratus have not been handled well by the models. In fact, most of them for today are fairly optimistic, which seems unlikely for much of our service Bay Area terminals. The marine layer looks to be 1000-1500ft, with the Valley being socked in as of this discussion. Expect cloudy conditions to prevail for most sites, with CIGS varying from LIFR to IFR. The exception might be KOAK, KSFO, and KSJC where onshore flow might be able to mix things out. Where skies are clear, KHAF, elevations above 1500ft, and the majority of the Central Coast, VFR conditions will prevail. Vicinity of SFO...Low to medium confidence in the forecast here as most models have indicated some clearing by now and what we have seen so far is a slight lift in CIGs. Satellite imagery shows some clearing over the San Francisco Bay, but outside of that there doesn't appear to be much movement. The most pessimistic of forecasts looks to be the MOS guidance from the EC, which has loosely been incorporated in the TAF for clearing around 21Z. After that, opted to keep the previous forecaster's TAFs in shape if the onshore flow pans out. Should it not, and we stay socked in. The question if that happens will be how long do we stay with IFR cigs? Low to medium confidence on this forecast. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Light and variable offshore winds become onshore by this afternoon, before circling back to offshore or light variable tonight. No VIS or CIG concerns, thus VFR prevail. && .MARINE... (Today through Friday) Issued at 900 AM PST Sun Dec 7 2025 Moderate to fresh north to northwest winds hold for much of the waters today with strong gusts focused on the southern waters. Moderate seas with wave heights 6 to 8 feet across the outer waters today, subsiding to around 4 to 6 feet for Monday. Winds increase on Tuesday, with strong to near gale force gusts possible for much of the waters. A new, long period northwesterly swell is anticipated by Wednesday of next week. && .MARINE... (Today through Friday) Issued at 900 AM PST Sun Dec 7 2025 Moderate to fresh north to northwest winds hold for much of the waters today with strong gusts focused on the southern waters. Moderate seas with wave heights 6 to 8 feet across the outer waters today, subsiding to around 4 to 6 feet for Monday. Winds increase on Tuesday, with strong to near gale force gusts possible for much of the waters. 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 this afternoon for CAZ006- 506-508-529-530. PZ...Small Craft Advisory from 3 PM Monday to 3 AM PST Tuesday 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. Small Craft Advisory until 9 PM PST this evening for Pigeon Pt to Pt Pinos 0-10 nm. Small Craft Advisory until 3 AM PST Tuesday for Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory until 9 PM PST this evening for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...DialH LONG TERM....DialH AVIATION...KR MARINE...KR Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, X, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea