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FXUS66 KMTR [Monterey CA] 111214 AFDMTR 

FXUS66 KMTR 111214
AFDMTR [HEAD]

National Weather Service San Francisco Bay Area 5:14am PDT Sat Jul 11 2020 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
514 AM PDT SAT JUL 11 2020 [HEAD]

Synopsis. High pressure will continue to dominate the weather pattern over the region resulting in very warm temperatures across the interior. Continued onshore flow will keep conditions near the coast cooler, yet still mild. A subtle cooling trend is on track to occur early next week. 

.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER
PATTERN OVER THE REGION RESULTING IN VERY WARM TEMPERATURES ACROSS
THE INTERIOR. CONTINUED ONSHORE FLOW WILL KEEP CONDITIONS NEAR
THE COAST COOLER, YET STILL MILD. A SUBTLE COOLING TREND IS ON
TRACK TO OCCUR EARLY NEXT WEEK. [DISC]

Discussion. As of 03:16am PDT Saturday… mostly clear sky conditions prevail over the region this morning in response to a compressed marine layer. Currently, the marine layer appears to be only a few hundred feet in depth per the Fort Ord profiler [instrument designed to measure horizontal winds directly above its location, and thus measure the vertical wind profile. Profilers operate on the same principles as Doppler radar.]. That said, do see indications of patchy stratus/fog developing around the Monterey Bay on GOES [Geostationary Operational Environmental Satellite]-17 satellite imagery. Given the lack of more widespread cloud cover this morning, temperatures are generally a few degrees cooler compared to 24 hours ago. Any low clouds and/or fog that does develop will likely dissipate by mid/late morning. 

.DISCUSSION...AS OF 03:16 AM PDT SATURDAY...MOSTLY CLEAR SKY
CONDITIONS PREVAIL OVER THE REGION THIS MORNING IN RESPONSE TO A
COMPRESSED MARINE LAYER. CURRENTLY, THE MARINE LAYER APPEARS TO BE
ONLY A FEW HUNDRED FEET IN DEPTH PER THE FORT ORD PROFILER. THAT
SAID, DO SEE INDICATIONS OF PATCHY STRATUS/FOG DEVELOPING AROUND
THE MONTEREY BAY ON GOES-17 SATELLITE IMAGERY. GIVEN THE LACK OF
MORE WIDESPREAD CLOUD COVER THIS MORNING, TEMPERATURES ARE
GENERALLY A FEW DEGREES COOLER COMPARED TO 24 HOURS AGO. ANY LOW
CLOUDS AND/OR FOG THAT DOES DEVELOP WILL LIKELY DISSIPATE BY
MID/LATE MORNING. [DISC]

The mid/upper level ridge centered over the desert southwest will maintain a very warm and dry air mass over central California through the remainder of the weekend. Thus, look for more widespread 90s across the interior with some of the region's warmest locations reaching between 100–104°F. Meanwhile, weak onshore surface flow will persist and keep temperatures in check near the coast with upper 60s to 70s most likely. Overnight temperatures will generally cool into the 50s for most urban locations while 60s to even lower 70s will be likely in the higher elevations. 

THE MID/UPPER LEVEL RIDGE CENTERED OVER THE DESERT SOUTHWEST WILL
MAINTAIN A VERY WARM AND DRY AIR MASS OVER CENTRAL CALIFORNIA
THROUGH THE REMAINDER OF THE WEEKEND. THUS, LOOK FOR MORE WIDESPREAD
90S ACROSS THE INTERIOR WITH SOME OF THE REGION`S WARMEST LOCATIONS
REACHING BETWEEN 100-104 DEG F. MEANWHILE, WEAK ONSHORE SURFACE FLOW
WILL PERSIST AND KEEP TEMPERATURES IN CHECK NEAR THE COAST WITH
UPPER 60S TO 70S MOST LIKELY. OVERNIGHT TEMPERATURES WILL GENERALLY
COOL INTO THE 50S FOR MOST URBAN LOCATIONS WHILE 60S TO EVEN LOWER
70S WILL BE LIKELY IN THE HIGHER ELEVATIONS. [DISC]

Both heat and fire weather concerns are generally being mitigated by the lack of stronger offshore flow. However, poor humidity recoveries are likely in the region's higher elevations through the remainder of the weekend along with critically low humidity each afternoon across the interior. Thus, elevated fire weather concerns will persist. 

BOTH HEAT AND FIRE WEATHER CONCERNS ARE GENERALLY BEING MITIGATED BY
THE LACK OF STRONGER OFFSHORE FLOW. HOWEVER, POOR HUMIDITY
RECOVERIES ARE LIKELY IN THE REGION`S HIGHER ELEVATIONS THROUGH THE
REMAINDER OF THE WEEKEND ALONG WITH CRITICALLY LOW HUMIDITY EACH
AFTERNOON ACROSS THE INTERIOR. THUS, ELEVATED FIRE WEATHER CONCERNS
WILL PERSIST. [DISC]

A subtle cooling trend is likely to occur early next week as onshore flow increases in response to troughing over the Pacific Northwest. This will likely bring interior temperatures back closer to seasonal averages by Monday and/or Tuesday. This pattern would also likely allow for a better defined marine layer to develop with night/morning coastal clouds returning. For the remainder of next week, little day-to-day change is anticipated as troughing persist over the northwest while the ridge of high pressure shifts eastward over Texas. 

A SUBTLE COOLING TREND IS LIKELY TO OCCUR EARLY NEXT WEEK AS ONSHORE
FLOW INCREASES IN RESPONSE TO TROUGHING OVER THE PACIFIC NORTHWEST.
THIS WILL LIKELY BRING INTERIOR TEMPERATURES BACK CLOSER TO SEASONAL
AVERAGES BY MONDAY AND/OR TUESDAY. THIS PATTERN WOULD ALSO LIKELY
ALLOW FOR A BETTER DEFINED MARINE LAYER TO DEVELOP WITH
NIGHT/MORNING COASTAL CLOUDS RETURNING. FOR THE REMAINDER OF NEXT
WEEK, LITTLE DAY-TO-DAY CHANGE IS ANTICIPATED AS TROUGHING PERSIST
OVER THE NORTHWEST WHILE THE RIDGE OF HIGH PRESSURE SHIFTS EASTWARD
OVER TEXAS. [DISC]

Aviation. As of 5:14am PDT Saturday… it's clear (VFR [Visual Flight Rules]) except for a few patches of fog and/or stratus over the Monterey Bay. A compressed marine layer continues at 500 feet deep. In many spots over land surface winds are calm which is more supportive of dew forming on cooler surfaces versus a light wind causing fog and/or stratus to form. Even with a marine layer temperature inversion and a clear sky favorable for night-time outgoing radiative cooling coastal fog and stratus is still mostly reluctant to form. Conditions are not quite ideal mainly due to an intrusion of mid-latitude drier surface air flowing over the top of chilly sea surface temperatures early this morning; meso-scale models are over-forecasting boundary layer humidity. As it appears it's favorable for VFR [Visual Flight Rules] to continue today. Would expect tonight to favor at least patchy development, but it's a tough call as a period of NW winds and drying could develop over the North Bay later today and tonight; dynamical model output shows this however statistical guidance does not. The models continue to under-forecast the northerly ACV [Arcata/Eureka CA]-SFO [San Francisco CA] pressure gradient and wind and consequently the amount of drying arriving from the north entraining into the marine layer. 

.AVIATION...AS OF 5:14 AM PDT SATURDAY...IT`S CLEAR /VFR/ EXCEPT
FOR A FEW PATCHES OF FOG AND/OR STRATUS OVER THE MONTEREY BAY. A
COMPRESSED MARINE LAYER CONTINUES AT 500 FEET DEEP. IN MANY SPOTS
OVER LAND SURFACE WINDS ARE CALM WHICH IS MORE SUPPORTIVE OF DEW
FORMING ON COOLER SURFACES VERSUS A LIGHT WIND CAUSING FOG AND/OR
STRATUS TO FORM. EVEN WITH A MARINE LAYER TEMPERATURE INVERSION
AND A CLEAR SKY FAVORABLE FOR NIGHT-TIME OUTGOING RADIATIVE COOLING
COASTAL FOG AND STRATUS IS STILL MOSTLY RELUCTANT TO FORM. CONDITIONS
ARE NOT QUITE IDEAL MAINLY DUE TO AN INTRUSION OF MID-LATITUDE DRIER
SURFACE AIR FLOWING OVER THE TOP OF CHILLY SEA SURFACE TEMPERATURES
EARLY THIS MORNING; MESO-SCALE MODELS ARE OVER-FORECASTING BOUNDARY
LAYER HUMIDITY. AS IT APPEARS IT`S FAVORABLE FOR VFR TO CONTINUE
TODAY. WOULD EXPECT TONIGHT TO FAVOR AT LEAST PATCHY DEVELOPMENT,
BUT IT`S A TOUGH CALL AS A PERIOD OF NW WINDS AND DRYING COULD
DEVELOP OVER THE NORTH BAY LATER TODAY AND TONIGHT; DYNAMICAL MODEL
OUTPUT SHOWS THIS HOWEVER STATISTICAL GUIDANCE DOES NOT. THE MODELS
CONTINUE TO UNDER-FORECAST THE NORTHERLY ACV-SFO PRESSURE GRADIENT
AND WIND AND CONSEQUENTLY THE AMOUNT OF DRYING ARRIVING FROM THE
NORTH ENTRAINING INTO THE MARINE LAYER. [AVIA]

Vicinity of KSFO [San Francisco CA]VFR [Visual Flight Rules], west to northwest wind increasing to 20–30 knots [23–35 mph] by early afternoon. Wind easing tonight and Sunday morning. 

VICINITY OF KSFO...VFR, WEST TO NORTHWEST WIND INCREASING TO 20 TO
30 KNOTS BY EARLY AFTERNOON. WIND EASING TONIGHT AND SUNDAY MORNING. [AVI2]

SFO [San Francisco CA] bridge approach… similar to KSFO [San Francisco CA]

SFO BRIDGE APPROACH...SIMILAR TO KSFO. [AVI2]

Monterey Bay terminals… a patch or two of VLIFR [Very Low Instrument Flight Rules]-IFR [Instrument Flight Rules] otherwise VFR [Visual Flight Rules] through today. Calm winds shifting to west to northwest 10–15 knots [12–17 mph] by early afternoon. VFR [Visual Flight Rules] forecast tonight and Sunday morning, however there still could be a few patches of fog and/or stratus. 

MONTEREY BAY TERMINALS...A PATCH OR TWO OF VLIFR-IFR OTHERWISE VFR
THROUGH TODAY. CALM WINDS SHIFTING TO WEST TO NORTHWEST 10 TO 15
KNOTS BY EARLY AFTERNOON. VFR FORECAST TONIGHT AND SUNDAY MORNING,
HOWEVER THERE STILL COULD BE A FEW PATCHES OF FOG AND/OR STRATUS. [AVI2]

Marine. As of 3:16am PDT Saturday… a strong surface high pressure system over the eastern Pacific will keep moderately strong northwesterly winds going over the coastal waters through the weekend. Fresh short period swells from the northwest and longer period southerly swells will result in hazardous conditions especially for small craft. 

.MARINE...AS OF 3:16 AM PDT SATURDAY...A STRONG SURFACE HIGH
PRESSURE SYSTEM OVER THE EASTERN PACIFIC WILL KEEP MODERATELY
STRONG NORTHWESTERLY WINDS GOING OVER THE COASTAL WATERS THROUGH
THE WEEKEND. FRESH SHORT PERIOD SWELLS FROM THE NORTHWEST AND
LONGER PERIOD SOUTHERLY SWELLS WILL RESULT IN HAZARDOUS CONDITIONS
ESPECIALLY FOR SMALL CRAFT. [AVIA]

MTR Watches/Warnings/Advisories

  • Today: Small Craft AdvisoryPt Reyes [San Francisco CA] to Pigeon Pt [Pescadero CA] 0–10 nm [11 miles] until 3pm Small Craft AdvisoryPigeon Pt [Pescadero CA] to Pt Pinos [Monterey CA] 0–10 nm [11 miles] until 3pm Small Craft AdvisoryPt Arena [Mendocino CA] to Pigeon Pt [Pescadero CA] 10–60 nm [69 miles] Small Craft AdvisoryPt Arena [Mendocino CA] to Pt Reyes [San Francisco CA] 0–10 nm [11 miles] Small Craft AdvisoryPt Pinos [Monterey CA] to Pt Piedras Blancas [San Simeon CA] 0–10 nm [11 miles] Small Craft AdvisoryPigeon Pt [Pescadero CA] to Pt Piedras Blancas [San Simeon CA] 10–60 nm [69 miles] 
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 3 PM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 3 PM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM [WARN]

Public Forecast: Rgass; Aviation/Marine: Canepa 

PUBLIC FORECAST: RGASS
AVIATION/MARINE: CANEPA [CRED]
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO [LINK]

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Point Forecast

Half Moon Bay CA

11 Jul 06:20am PDT

Today Sunny, with a high near 66°. Light west wind becoming WSW 5 to 9 mph in the morning.
Tonight Partly cloudy, with a low around 49°. West wind 5 to 9 mph becoming light.
Sunday Sunny, with a high near 68°. WSW wind 6 to 9 mph.
Sunday Night Partly cloudy, with a low around 50°. WSW wind 7 to 9 mph.
Monday Mostly sunny, with a high near 66°. WSW wind 9 to 11 mph.
Monday Night Partly cloudy, with a low around 50°.
Tuesday Mostly sunny, with a high near 69°.
Tuesday Night Partly cloudy, with a low around 51°.
Wednesday Sunny, with a high near 68°.
Wednesday Night Partly cloudy, with a low around 52°.
Thursday Mostly sunny, with a high near 69°.
Thursday Night Partly cloudy, with a low around 52°.
Friday Mostly sunny, with a high near 68°.
Today
Sunny, with a high near 66. Light west wind becoming west southwest 5 to 9 mph in the morning.
Tonight
Partly cloudy, with a low around 49. West wind 5 to 9 mph becoming light.
Sunday
Sunny, with a high near 68. West southwest wind 6 to 9 mph.
Sunday Night
Partly cloudy, with a low around 50. West southwest wind 7 to 9 mph.
Monday
Mostly sunny, with a high near 66. West southwest wind 9 to 11 mph.
Monday Night
Partly cloudy, with a low around 50.
Tuesday
Mostly sunny, with a high near 69.
Tuesday Night
Partly cloudy, with a low around 51.
Wednesday
Sunny, with a high near 68.
Wednesday Night
Partly cloudy, with a low around 52.
Thursday
Mostly sunny, with a high near 69.
Thursday Night
Partly cloudy, with a low around 52.
Friday
Mostly sunny, with a high near 68.

This page is generated dynamically from the National Weather Service's NWS point forecast and Area Forecast Discussion, reformatted for readability. NWS glossary; about point forecasts. For more information, visit the Lobitos Weather Project home page. Comments and corrections are welcome: