229  
FXUS66 KMTR 261558  
AFDMTR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA  
858 AM PDT TUE JUL 26 2016  
   
SYNOPSIS
 
A WARMING TREND REMAINS ON TRACK FOR THE INLAND AREAS  
BEGINNING TODAY AND PERSISTING THROUGH LATE WEEK AS HIGH PRESSURE  
BUILDS IN FROM THE DESERT SOUTHWEST. HOWEVER, TYPICAL COOL SUMMER  
CONDITIONS WILL PREVAIL ALONG COAST. A COOLING TREND IS  
ANTICIPATED FOR THE UPCOMING WEEKEND AS AN UPPER LEVEL TROUGH  
DEVELOPS OFF OF THE PACIFIC NORTHWEST COAST.  
 

 
   
DISCUSSION...AS OF 08:55 AM PDT TUESDAY
 
LOW CLOUD REMAINED  
CONFINED MOSTLY TO THE COAST THIS MORNING AND ONLY SPREAD LOCALLY  
INLAND, ESPECIALLY AROUND THE MONTEREY BAY REGION WHERE PATCHY  
DENSE FOG WAS OBSERVED AS WELL. THIS IS A RESULT OF A MUCH MORE  
COMPRESSED MARINE LAYER THAT IS NOW AROUND 1000 FEET IN DEPTH THIS  
MORNING. AS TEMPERATURES ALOFT WARM IN RESPONSE TO THE BUILDING  
MID/UPPER LEVEL HIGH PRESSURE, EXPECTING A ROBUST WARMING TREND TO  
TAKE PLACE TODAY. MOST INLAND AREAS WILL BE 6-10 DEGREES WARMER  
COMPARED TO YESTERDAY WHILE CONTINUED ONSHORE FLOW WILL RESULT IN  
LITTLE CHANGE ALONG THE COAST. VERY WARM AND DRY CONDITIONS WILL  
ALSO PERSIST IN THIS HILLS/MOUNTAINS AS WELL AS THE INLAND VALLEY  
LOCATIONS WHERE A FEW SPOTS WILL EXCEED THE 100 DEGREE MARK THIS  
AFTERNOON. AS A RESULT OF LIGHT AND VARIABLE WINDS OFF THE  
SURFACE, SMOKE FROM THE SOBERANES FIRE WILL CONTINUE TO IMPACT  
MUCH OF THE REGION TODAY. THUS, HAVE INCREASED COVERAGE OF SMOKE  
AND HAZE IN THE OFFICIAL FORECAST ACROSS MUCH OF THE SAN FRANCISCO  
BAY AREA AND MONTEREY BAY REGION. THE ONGOING FORECAST REMAINS ON  
TRACK AND NO MAJOR CHANGES ARE NEEDED AT THIS TIME.  
 

 
   
PREV DISCUSSION...AS OF 3:09 AM PDT TUESDAY
 
BUILDING HIGH  
PRESSURE IS COMPRESSING THE MARINE LAYER THIS MORNING AS INDICATED  
BY THE FORT ORD PROFILER WHICH IS SHOWING A MARINE LAYER DEPTH OF  
JUST UNDER 1000 FEET. THE COMPRESSED MARINE LAYER IS RESULTING IN  
LOW CLOUDS, CEILINGS AROUND 200 FEET, ALONG THE COAST AND PATCHY  
DENSE FOG IN THE MONTEREY AREA. THE CURRENT IR SATELLITE FOG  
PRODUCT CONTINUES TO SHOW LOW CLOUDS OVER THE COASTAL WATERS,  
STRETCHING INTO THE SALINAS VALLEY. THE HEAT SIGNATURE ASSOCIATED  
WITH THE SOBERANES FIRE IS ALSO EVIDENT ON THE FOG PRODUCT.  
 
THE 0000Z ECMWF AND GFS20 HAVE INITIALIZED WELL WITH THE CURRENT  
SYNOPTIC WEATHER PATTERN AND REMAIN IN GOOD AGREEMENT THROUGH  
ROUGHLY SATURDAY, BUILDING THE FOUR CORNERS HIGH TO 594DM. AS THE  
HIGH PRESSURE BUILDS 850MB TEMPERATURES HEAT UP. IN FACT 850MB  
TEMPERATURES ARE FORECAST TO REACH 25 TO 26C TODAY AND 26 TO 27C  
WEDNESDAY AND THURSDAY. THIS TRANSLATES TO HOT INLAND TEMPERATURES  
REACHING INTO THE MID TO UPPER 90S. THE HOTTEST AREAS WILL BE IN  
INTERIOR MONTEREY AND SAN BENITO COUNTIES WHERE LOW 100S WILL BE  
COMMON. PINNACLES NATIONAL MONUMENT IS EXPECTED TO REACH A HIGH OF  
107 TODAY AND TOMORROW BEFORE COOLING TO 106 ON THURSDAY. IN  
ADDITION TO THE HEAT THE 0000Z GFS20 IS ALSO INDICATING THAT SOME  
MONSOON MOISTURE WILL BEGIN TO MOVE INTO SOUTHERN MONTEREY  
WEDNESDAY. AT THIS POINT THE ATMOSPHERE DOES NOT LOOK UNSTABLE  
ENOUGH TO SUPPORT CONVECTION, BUT WE WILL CONTINUE TO MONITOR THIS  
MOISTURE AS IT MOVES INTO THE AREA. A COOLING TREND REMAINS ON  
TRACK FOR THE WEEKEND AS A TROUGH OF LOW PRESSURE BEGINS TO SWING  
INTO THE PACIFIC NORTHWEST.  
 

 
   
AVIATION...AS OF 4:30 AM PDT TUESDAY
 
A SLIGHTLY COMPRESSED  
MARINE LAYER COMPARE TO 24 HOURS AGO. LOW CLOUDS ARE MAINLY  
IMPACTING MONTEREY BAY. LINGER SMOKE PARTICULATES AND COMPRESSED  
MARINE LAYER MAY HAVE HELPED TO PRODUCE DENSE FOG FOR MRY AND SNS.  
OTHER LOCATIONS WILL LIKELY HAVE SOME HAZE/SMOKE TODAY. CURRENT  
OBS SHOW SOME AIRPORTS REPORTING CIGS NEAR 8K, WHICH IS LIKELY A  
SMOKE LAYER. OVERALL CONF IS LOW TO MODERATE GIVEN LINGERING SMOKE  
AND POSS HAZE/SMOKE.  
 
VICINITY OF KSFO...WILL CONTINUE TO FORECAST VFR WITH POSS MVFR  
DUE HAZE FROM SMOKE. THE SMOKE COULD ALSO HAVE IMPACTS ON  
SLANTWISE VIS IN SF BAY THIS MORNING.  
 
SFO BRIDGE APPROACH...SIMILAR TO KSFO.  
 
MONTEREY BAY TERMINALS...DENSE FOG WITH LIFR TO VLIFR THIS  
MORNING. MVFR/VFR THIS AFTERNOON WITH FU POSS FROM NEARBY FIRE.  
CIGS RETURN TONIGHT.  
 

 
   
FIRE WEATHER...AS OF 3:09 AM PDT TUESDAY
 
THE MARINE LAYER HAS  
COMPRESSED TO AROUND 900 FEET THIS MORNING. ALTHOUGH RELATIVE  
HUMIDITY RECOVERIES HAVE BEEN GOOD BELOW A 1000 FEET TONIGHT, MAX  
RELATIVE HUMIDITY ABOVE 1000 FEET REMAINS POOR. SURFACE WINDS OVER  
THE WATERS ALONG THE BIG SUR COAST ARE ANTICIPATED TO BE AROUND 10  
MPH AND OUT OF THE NORTH. GENERALLY LIGHT AND VARIABLE WINDS, 4  
TO 8 MPH, ARE ANTICIPATED OVER SANTA LUCIA MOUNTAIN AND LOS PADRES  
NATIONAL FOREST. THIS WILL RESULT IN ANOTHER DAY OF SMOKEY  
CONDITIONS FOR THE MONTEREY AREA.  
 

 
   
MARINE...AS OF 08:55 AM PDT TUESDAY
 
LIGHT TO MODERATE NORTHERLY  
WINDS WILL CONTINUE OVER THE COASTAL WATERS AS A SFC RIDGE LINGERS  
OFFSHORE OF THE PACNW AND HIGH PRESSURE REMAINS ALOFT OF THE  
REGION. THE STRONGEST WINDS WILL BE OVER THE NORTHERN OUTER  
WATERS AND IN LOCALIZED AREAS OF THE NORTHERN SAN FRANCISCO BAY.  
HAZARDOUS CONDITIONS FROM SQUARED SEAS WILL ALSO BE POSSIBLE IN  
THE NORTHERN OUTER WATERS. WINDS WILL TAPER OFF THROUGH THE WEEK  
AS A MIXED SWELL MOVES THROUGH THE COASTAL WATERS.  
 

 
   
MTR WATCHES/WARNINGS/ADVISORIES
 
 
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM  
SCA...SF BAY FROM 11 AM  
 

 
 

 
 
PUBLIC FORECAST: RGASS  
AVIATION: MM  
MARINE: MM  
FIRE WEATHER: LARRY  
 
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO  
 
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