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AREA FORECAST DISCUSSION

 
 FXUS66 KEKA 271128
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
428 AM PDT MON APR 27 2015

.SYNOPSIS...A RIDGE OF HIGH PRESSURE OVER THE WEST COAST WILL
BRING DRY WEATHER AND INTERIOR TEMPERATURES WELL ABOVE NORMAL
TODAY. EXPECT INTERIOR TEMPERATURES TO COOL TUESDAY AND WEDNESDAY
AS THE RIDGE SHIFTS INLAND AND A TROUGH PASSES OVER THE PACIFIC
NORTHWEST. INTERIOR TEMPERATURES WILL TREND UPWARD THE SECOND HALF
OF THE WEEK AS HIGH PRESSURE DOMINATES THE WEATHER PATTERN.

&&

.DISCUSSION...A RIDGE OF HIGH PRESSURE OVER THE WEST COAST WILL
BRING DRY WEATHER TO NORTHWEST CALIFORNIA TODAY. WITH THE RIDGE
NEARLY OVERHEAD INTERIOR TEMPERATURES WILL CONTINUE TRENDING
UPWARD TODAY, RISING WELL ABOVE NORMAL ALONG WITH SOME HIGH LEVEL
CLOUDS. WIDESPREAD VALLEY TEMPERATURES IN THE 80S ARE FORECASTED
TODAY AND A FEW 90S ARE NOT OUT OF THE QUESTION. THE COAST CAN
EXPECT SEASONAL TEMPERATURES IN THE 50S AND 60S. THOUGH, THE
IMMEDIATE REDWOOD COAST MAY STAY UNDER STRATUS MOST OF TODAY DUE
TO WEAK NORTHWEST FLOW. SOME CLEARING IS POSSIBLE FOR A SHORT TIME
THIS AFTERNOON, BUT UNCERTAINTY IS HIGH AND CLOUDS WILL PROBABLY
RETURN TONIGHT. INTERIOR TEMPERATURES WILL BEGIN TRENDING DOWNWARD
ON TUESDAY AS THE RIDGE SHIFTS INLAND AND A TROUGH APPROACHES FROM
THE PACIFIC. BUT EVEN WITH THE TEMPERATURES TRENDING DOWNWARD,
THEY WILL REMAIN A FEW DEGREES ABOVE NORMAL ON TUESDAY. THE TROUGH
WILL APPROACH ON TUESDAY AND AN ASSOCIATED VERY WEAK DISTURBANCE
WILL PASS TO OUR NORTH TUESDAY MORNING. THIS WILL BRING US SOME
HIGH LEVEL CLOUDS AND A SLIGHT CHANCE OF VERY LIGHT RAIN SHOWERS
TO DEL NORTE COUNTY. WILL EMPHASIZE THE ODDS OF THIS ARE LOW, BUT
NOT ZERO. ANY QPF WILL BE BARELY MEASURABLE. MODELS SHOW THE
TROUGH MOVING OVER US LATE TUESDAY INTO WEDNESDAY, BRINGING COOLER
TEMPERATURES. NO PRECIPITATION IS EXPECTED. AS A RESULT, POPS
REMAIN BELOW CLIMO DURING THIS TIME PERIOD. ZONAL FLOW DEVELOPS
THURSDAY AND CONTINUES THROUGH THE END OF THE WEEK. THOUGH, THE
MODELS HINT AT A CUTOFF LOW DEVELOPING OFF THE COAST OF SOUTHERN
CALIFORNIA TOWARDS THE END OF THE WEEK. WILL KEEP AN EYE ON THIS
AS IT COULD LEAD TO SHOWERS OR MAYBE THUNDERSTORMS LATE THIS WEEK.
BUT IT`S TOO FAR OUT TO KNOW FOR SURE AT THIS POINT. OTHERWISE,
THE CONSMODEL WAS USED FOR TEMPERATURES DURING THAT TIME PERIOD
AND IT HAS THEM REMAINING SEASONAL ALONG THE COAST AND TRENDING
BACK UP (ABOVE NORMAL) ACROSS THE INTERIOR.

&&

.AVIATION...AFTER A MORNING OF PATCHY LOW CLOUDS ALONG THE COAST,
CIGS SHOULD LIFT ALLOWING FOR A VFR DAY. HIGH CLOUDS WILL BE
STREAMING OVER NW CAL TODAY AS WEAK HIGH PRESSURE BEGINS TO SHIFT
TO THE EAST. VFR WILL PREVAIL ACROSS NW CAL THROUGH TONIGHT WITH
EXCEPTION OF THE COASTAL AREAS. MODELS SHOW AN ONSHORE PUSH
DEVELOPING THIS EVENING AND THE BOUNDARY LAYER MOISTURE INCREASING
AS WE GO INTO TONIGHT. THIS SHOULD BRING IN SOME LOW CLOUDS ACROSS
COASTAL AREAS. WITH A DEEPENING MARINE LAYER DUE TO THE
APPROACHING FRONT, THERE COULD BE DEEPER PENETRATION OF THE LOW
CLOUDS UP THE RIVER VALLEYS. SOMETHING TO WATCH FOR THIS EVENING.
BFG

&&

.MARINE...HIGH PRESSURE WILL SHIFT OFF TO THE EAST TODAY AHEAD OF
AN APPROACHING UPPER TROUGH AND ITS WEAK SURFACE FRONT. THIS FRONT
IS FORECAST TO CLIP THE NORTHERN WATERS TUESDAY EVENING, BRINGING
SOUTHERLY WINDS WHILE LEAVING NORTHERLY WINDS ACROSS THE SOUTHERN
WATERS. IF THE FRONT COMES IN A BIT STRONGER WINDS WILL SHIFT TO
THE SOUTH ACROSS ALL COASTAL WATERS, BUT MODELS ARE FAIRLY
CONSISTENT YIELDING MODERATE TO HIGH CONFIDENCE. A NW SWELL WILL
BEGIN TO BUILD INTO THE WATERS ON TUESDAY, GENERATED FROM A BROAD
AREA OF LOW PRESSURE SPINNING IN THE GULF OF ALASKA. LOOK FOR
HEIGHTS TO BUILD TO AROUND 8 TO 11 FT AT ABOUT 12 SECONDS LATE
TUESDAY INTO WEDNESDAY. SMALL CRAFT ADVISORIES WILL LIKELY BE
NEEDED SOMETIME TUESDAY FOR MOST OF THE WATERS. THIS DEPENDS ON
HOW FAST THE WINDS INCREASE AND WHEN THE SWELL ARRIVES.
REGARDLESS, AS HIGH PRESSURE SURGES IN BEHIND TUESDAYS WEAK FRONT
NORTHERLY CONDITIONS WILL INCREASE SHARPLY. SMALL CRAFT ADVISORIES
WILL BE NEED FOR ALL WATERS BY WEDNESDAY MORNING DUE TO SEAS. AT
THIS POINT, WE ARE LOOKING AT THE POTENTIAL OF GALE CONDITIONS
DEVELOPING BY THURSDAY AFTERNOON ACROSS THE OUTER WATERS. WE WILL
NEED TO SEE HOW MODELS HANDLE THIS OVER THE COMING CYCLES, BUT WE
MAY NEED TO ISSUE A GALE WATCH FOR THURSDAY. HIGH PRESSURE IS
EXPECTED TO MAINTAIN FRESH TO STRONG WINDS OVER THE OUTER WATERS
THROUGH THE WEEKEND WHILE THE INNER WATERS WILL BE IN MORE OF A
DIURNAL TREND WITH HIGHER WINDS EACH AFTERNOON AND EVENING. BFG

&&

.EKA WATCHES/WARNINGS/ADVISORIES...

CA...NONE.

NORTHWEST CALIFORNIA COASTAL WATERS...NONE.

&&




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