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000
FXUS66 KSTO 151530
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
830 AM PDT SAT JUN 15 2013


.SYNOPSIS...NEAR NORMAL TEMPERATURES WITH DRY WEATHER THROUGH
MONDAY. A PACIFIC LOW PRESSURE SYSTEM WILL BRING COOLER
TEMPERATURES AND A SLIGHT CHANCE OF SHOWERS TO NORTHERN SHASTA
COUNTY FOR TUESDAY AND WEDNESDAY.

&&

.UPDATE...
UPPER RIDGE SHIFTS EAST TODAY AS DEEP LOW OVER THE GOA DROPS A BIT
FURTHER SOUTH OVER THE EPAC. MORNING SOUNDINGS INDICATE THAT TEMPS
OVER THE INTERIOR AND HIGHER ELEVATIONS WILL REMAIN QUITE WARM
TODAY...AND MAY EVEN BE A FEW DEGREES WARMER THAN FRIDAY...WHILE
GRADUALLY STRENGTHENING ONSHORE FLOW AND A DEEPENING MARINE LAYER
WILL LEAD TO SOME COOLING IN THE DELTA AND SOUTH VALLEY. APPEARS
RISK FOR DEEP CONVECTION WILL REMAIN NORTH OF SHASTA COUNTY TODAY.
UPDATES OUT SHORTLY.

&&

.SHORT TERM DISCUSSION...THE UPPER LEVEL RIDGE AXIS HAS SHIFTED
EASTWARD WITH SOUTHWEST FLOW SETTING UP OVER THE REGION. A WEAK
DISTURBANCE WILL PASS TO THE NORTH THIS AFTERNOON BRINGING UNSTABLE
CONDITIONS TO FAR NORTHERN CALIFORNIA. CONVECTIVE SHOWERS SHOULD
REMAIN NORTH OF THE FORECAST AREA WITH JUST SOME AFTERNOON CUMULUS
BUILDING OVER THE MOUNTAINS OF SHASTA COUNTY. SUNNY AND DRY WEATHER
IS EXPECTED ELSEWHERE. TEMPERATURES WILL GENERALLY BE SIMILAR TO
THOSE SEEN ON FRIDAY. THE DELTA SHOULD BE SEVERAL DEGREES COOLER
WITH DELTA FLOW INCREASING THROUGH THE DAY INTO THE EVENING.
SATURDAY NIGHT/SUNDAY MORNING TEMPERATURES IN THE DELTA AND
SACRAMENTO METRO AREA WILL BE NOTICEABLY COOLER AS A RESULT. LOWS
ELSEWHERE MAY ACTUALLY GO UP A LITTLE.

SUNDAY AND MONDAY SHOULD BE PROGRESSIVELY A LITTLE COOLER AS AN
UPPER LOW OFF THE PACIFIC NORTHWEST COAST GRADUALLY MOVES EASTWARD.
A MORE SIGNIFICANT CHANGE IS EXPECTED BY TUESDAY WITH HIGHS 5 TO 10
DEGREES BELOW NORMAL. SHORTWAVE ENERGY WITH SOME INSTABILITY WILL
BRUSH THE NORTHERN PORTION OF THE FORECAST AREA. THIS WILL GENERALLY
MEAN AN INCREASE IN CLOUDS. THERE IS A SLIGHT CHANCE OF SHOWERS FOR
NORTHERN SHASTA COUNTY THROUGH WEDNESDAY BUT RAIN AMOUNTS SHOULD BE
RELATIVELY LIGHT. EK

&&

.EXTENDED DISCUSSION (WEDNESDAY THROUGH SATURDAY)...
BY WEDNESDAY THE UPPER LOW COULD BE MAINLY EAST OF THE AREA (GFS
MODEL) OR BRUSHING THROUGH THE NORTH (EUROPEAN MODEL). WILL LEAN
TOWARD THE EUROPEAN FOR NOW WITH LINGERING SHOWERS POSSIBLE OVER THE
NORTHERN SHASTA COUNTY MOUNTAINS INTO THE EARLY EVENING. DRY WEATHER
IS LIKELY FOR THE REST OF THE WEEK AS THE LOW DEPARTS AND DRY
NORTHWEST FLOW SETS UP. ZONAL/WEAK RIDGING SHOULD LEAD TO GRADUALLY
WARMER TEMPERATURES FOR THE END OF THE WEEK WITH ABOVE NORMAL HIGHS
FOR FRIDAY AND SATURDAY EXPECTED. EK

&&

.AVIATION...
MAINLY VFR CONDITIONS THE NEXT 24 HOURS. SCT010 POSSIBLE IN THE
DELTA AFTER 06Z SUNDAY. WINDS GENERALLY LESS THAN 15 KNOTS EXCEPT
THROUGH THE DELTA 10 TO 20 GUSTS TO 25 KNOTS.

&&

.STO WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$