Area Forecast Discussion
FXUS66 KMTR [Monterey CA] 012059 AFDMTR ∨
FXUS66 KMTR 012059 AFDMTR [HEAD]
National Weather Service San Francisco Bay Area 1:59pm PDT Wed Apr 1 2015 ∨
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 159 PM PDT WED APR 1 2015 [HEAD]
Synopsis. A weak Pacific storm system moving inland to our north will maintain cool… dry and breezy conditions through Thursday. A slight warming trend is then expected for late week as a brief ridge develops over the region. A stronger system will then approach the Northern California coast and bring chances for precipitation back to the region from Sunday into early next week. ∨
.SYNOPSIS...A WEAK PACIFIC STORM SYSTEM MOVING INLAND TO OUR NORTH WILL MAINTAIN COOL...DRY AND BREEZY CONDITIONS THROUGH THURSDAY. A SLIGHT WARMING TREND IS THEN EXPECTED FOR LATE WEEK AS A BRIEF RIDGE DEVELOPS OVER THE REGION. A STRONGER SYSTEM WILL THEN APPROACH THE NORTHERN CALIFORNIA COAST AND BRING CHANCES FOR PRECIPITATION BACK TO THE REGION FROM SUNDAY INTO EARLY NEXT WEEK. [DISC]
Discussion. As of 01:59pm PDT Wednesday… a mid/upper level trough continues to push into the Pacific Northwest this afternoon with high level clouds ahead of the system streaming across the region. Temperatures are also cooler at this hour compared to 24 hours ago as a result of the colder air mass associated with this system. Meanwhile… dry weather conditions continue region-wide with any precipitation remaining well to our north. While a much colder air mass is expected to advect into the region overnight… increased wind speeds should help prevent frost development over most interior locations of the North Bay. However… can not rule out patchy frost in a few of the most sheltered locations early Thursday and Friday mornings when temperatures bottom out in the mid 30s. Daytime temperatures will slowly rebound Thursday through Saturday as the aforementioned trough shifts inland and a weak ridge builds over the state. ∨
.DISCUSSION...AS OF 01:59 PM PDT WEDNESDAY...A MID/UPPER LEVEL TROUGH CONTINUES TO PUSH INTO THE PACIFIC NORTHWEST THIS AFTERNOON WITH HIGH LEVEL CLOUDS AHEAD OF THE SYSTEM STREAMING ACROSS THE REGION. TEMPERATURES ARE ALSO COOLER AT THIS HOUR COMPARED TO 24 HOURS AGO AS A RESULT OF THE COLDER AIR MASS ASSOCIATED WITH THIS SYSTEM. MEANWHILE...DRY WEATHER CONDITIONS CONTINUE REGION-WIDE WITH ANY PRECIPITATION REMAINING WELL TO OUR NORTH. WHILE A MUCH COLDER AIR MASS IS EXPECTED TO ADVECT INTO THE REGION OVERNIGHT...INCREASED WIND SPEEDS SHOULD HELP PREVENT FROST DEVELOPMENT OVER MOST INTERIOR LOCATIONS OF THE NORTH BAY. HOWEVER...CAN NOT RULE OUT PATCHY FROST IN A FEW OF THE MOST SHELTERED LOCATIONS EARLY THURSDAY AND FRIDAY MORNINGS WHEN TEMPERATURES BOTTOM OUT IN THE MID 30S. DAYTIME TEMPERATURES WILL SLOWLY REBOUND THURSDAY THROUGH SATURDAY AS THE AFOREMENTIONED TROUGH SHIFTS INLAND AND A WEAK RIDGE BUILDS OVER THE STATE. [DISC]
A deeper mid/upper level system is forecast to drop southward out of the Gulf of Alaska late in the week into the upcoming weekend. Moisture advection will increase across our region ahead of this system Saturday night into Sunday and with the approach of a frontal boundary… chances for precipitation will increase over the northern half of the region by Sunday morning. Lingering showers will be possible through Monday afternoon with a cooler… more unstable airmass aloft. At this time… rainfall amounts are forecast to remain low (generally less than 1/10 of an inch). ∨
A DEEPER MID/UPPER LEVEL SYSTEM IS FORECAST TO DROP SOUTHWARD OUT OF THE GULF OF ALASKA LATE IN THE WEEK INTO THE UPCOMING WEEKEND. MOISTURE ADVECTION WILL INCREASE ACROSS OUR REGION AHEAD OF THIS SYSTEM SATURDAY NIGHT INTO SUNDAY AND WITH THE APPROACH OF A FRONTAL BOUNDARY...CHANCES FOR PRECIPITATION WILL INCREASE OVER THE NORTHERN HALF OF THE REGION BY SUNDAY MORNING. LINGERING SHOWERS WILL BE POSSIBLE THROUGH MONDAY AFTERNOON WITH A COOLER...MORE UNSTABLE AIRMASS ALOFT. AT THIS TIME...RAINFALL AMOUNTS ARE FORECAST TO REMAIN LOW (GENERALLY LESS THAN 1/10 OF AN INCH). [DISC]
With the main upper level feature remaining off of the Pacific Northwest coast early next week… rain chances will continue over portions of the region into Tuesday. The latest models show the trough slowly pushing inland on Monday with precipitation progressing southward down into the Monterey Bay region Monday night into Tuesday morning. This is when the best chances for widespread rainfall are expected. The WPC 7 day QPF [Quantitative Precipitation Forecast] predictions continue to show 1/4–1/2 inch rainfall amounts over much of the region with higher totals across the North Bay hills/mountains. Along with the rain chances… cooler temperatures are also expected Sunday into early next week as these systems impact the region. The medium range models then show a brief drying trend for the middle of next week followed by another mid/upper level system that could potentially bring additional precipitation to portions of the San Francisco/Monterey Bay region late next week. ∨
WITH THE MAIN UPPER LEVEL FEATURE REMAINING OFF OF THE PACIFIC NORTHWEST COAST EARLY NEXT WEEK...RAIN CHANCES WILL CONTINUE OVER PORTIONS OF THE REGION INTO TUESDAY. THE LATEST MODELS SHOW THE TROUGH SLOWLY PUSHING INLAND ON MONDAY WITH PRECIPITATION PROGRESSING SOUTHWARD DOWN INTO THE MONTEREY BAY REGION MONDAY NIGHT INTO TUESDAY MORNING. THIS IS WHEN THE BEST CHANCES FOR WIDESPREAD RAINFALL ARE EXPECTED. THE WPC 7 DAY QPF PREDICTIONS CONTINUE TO SHOW 1/4 TO 1/2 INCH RAINFALL AMOUNTS OVER MUCH OF THE REGION WITH HIGHER TOTALS ACROSS THE NORTH BAY HILLS/MOUNTAINS. ALONG WITH THE RAIN CHANCES...COOLER TEMPERATURES ARE ALSO EXPECTED SUNDAY INTO EARLY NEXT WEEK AS THESE SYSTEMS IMPACT THE REGION. THE MEDIUM RANGE MODELS THEN SHOW A BRIEF DRYING TREND FOR THE MIDDLE OF NEXT WEEK FOLLOWED BY ANOTHER MID/UPPER LEVEL SYSTEM THAT COULD POTENTIALLY BRING ADDITIONAL PRECIPITATION TO PORTIONS OF THE SAN FRANCISCO/MONTEREY BAY REGION LATE NEXT WEEK. [DISC]
Aviation. As of 10:23am PDT Wednesday… VFR [Visual Flight Rules] conditions. The only real hiccup could be some patchy low clouds around the Monterey Peninsula tomorrow. A few of the high-resolution models suggest patchy clouds. Conf is not high enough and therefore did not include in KMRY [Monterey CA] or KSNS [Salinas CA] TAF [Terminal Aerodrome Forecast]. ∨
.AVIATION...AS OF 10:23 AM PDT WEDNESDAY... VFR CONDITIONS. THE ONLY REAL HICCUP COULD BE SOME PATCHY LOW CLOUDS AROUND THE MONTEREY PENINSULA TOMORROW. A FEW OF THE HI-RES MODELS SUGGEST PATCHY CLOUDS. CONF IS NOT HIGH ENOUGH AND THEREFORE DID NOT INCLUDE IN KMRY OR KSNS TAF. [AVIA]
Vicinity of KSFO [San Francisco CA]… VFR [Visual Flight Rules]. West winds. Afternoon peak gusts up to 30 kt [35 mph]. ∨
VICINITY OF KSFO...VFR. WEST WINDS. AFTERNOON PEAK GUSTS UP TO 30 KT. [AVI2]
SFO [San Francisco CA] bridge approach… similar to KSFO [San Francisco CA]. ∨
SFO BRIDGE APPROACH...SIMILAR TO KSFO. [AVI2]
Monterey Bay Area terminals… VFR [Visual Flight Rules]. West winds. Afternoon peak gusts around 20 kt [23 mph]. ∨
MONTEREY BAY AREA TERMINALS...VFR. WEST WINDS. AFTERNOON PEAK GUSTS AROUND 20 KT. [AVI2]
Marine. As of 10:23am PDT Wednesday… another windy day over the coastal waters as high pressure continues to produce gusty northerly winds. Local gale force gusts will be possible. Building northwest swell in conjunction with building fresh swell and mixed seas will lead to hazardous maritime conditions along the Central Coast. ∨
.MARINE...AS OF 10:23 AM PDT WEDNESDAY...ANOTHER WINDY DAY OVER THE COASTAL WATERS AS HIGH PRESSURE CONTINUES TO PRODUCE GUSTY NORTHERLY WINDS. LOCAL GALE FORCE GUSTS WILL BE POSSIBLE. BUILDING NORTHWEST SWELL IN CONJUNCTION WITH BUILDING FRESH SWELL AND MIXED SEAS WILL LEAD TO HAZARDOUS MARITIME CONDITIONS ALONG THE CENTRAL COAST. [AVIA]
.MTR WATCHES/WARNINGS/ADVISORIES... .TNGT...SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 5 AM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 5 AM SCA...PT ARENA TO PT REYES 10-60 NM SCA...PT REYES TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PINOS 10-60 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM SCA...PT ARENA TO PT REYES 0-10 NM SCA...PT REYES TO PIGEON PT 0-10 NM SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 3 AM SCA...MONTEREY BAY UNTIL 11 PM [WARN]
Public Forecast: Rgass; Aviation/Marine: MM ∨
PUBLIC FORECAST: RGASS AVIATION/MARINE: MM [CRED]
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2:02pm PDT Apr 1 2015
This Afternoon Sunny, with a high near 58°. Breezy, with a NW wind around 23 mph, with gusts as high as 29 mph.
Tonight Mostly clear, with a low around 48°. Breezy, with a NW wind 21 to 26 mph decreasing to 9 to 14 mph after midnight. Winds could gust as high as 32 mph.
Thursday Sunny, with a high near 62°. North wind 10 to 15 mph, with gusts as high as 18 mph.
Thursday Night Mostly clear, with a low around 48°. WNW wind 11 to 18 mph, with gusts as high as 23 mph.
Friday Sunny, with a high near 60°. NW wind 10 to 18 mph, with gusts as high as 23 mph.
Friday Night Mostly clear, with a low around 49°.
Saturday Mostly sunny, with a high near 58°.
Saturday Night Mostly cloudy, with a low around 47°. Breezy.
Sunday A slight chance of showers. Mostly cloudy, with a high near 57°.
Sunday Night Mostly cloudy, with a low around 47°.
Monday A chance of showers. Cloudy, with a high near 58°.
Monday Night A chance of showers. Mostly cloudy, with a low around 48°.
Tuesday A slight chance of showers. Partly sunny, with a high near 59°.
Sunny, with a high near 58. Breezy, with a northwest wind around 23 mph, with gusts as high as 29 mph.
Mostly clear, with a low around 48. Breezy, with a northwest wind 21 to 26 mph decreasing to 9 to 14 mph after midnight. Winds could gust as high as 32 mph.
Sunny, with a high near 62. North wind 10 to 15 mph, with gusts as high as 18 mph.
Mostly clear, with a low around 48. West northwest wind 11 to 18 mph, with gusts as high as 23 mph.
Sunny, with a high near 60. Northwest wind 10 to 18 mph, with gusts as high as 23 mph.
Mostly clear, with a low around 49.
Mostly sunny, with a high near 58.
Mostly cloudy, with a low around 47. Breezy.
A slight chance of showers. Mostly cloudy, with a high near 57.
Mostly cloudy, with a low around 47.
A chance of showers. Cloudy, with a high near 58.
A chance of showers. Mostly cloudy, with a low around 48.
A slight chance of showers. Partly sunny, with a high near 59.