000
FXUS66 KEKA 252231
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
331 PM PDT SAT MAY 25 2013
.SYNOPSIS...A WEAK SYSTEM WILL BRING LIGHT RAIN TO AREAS NORTH OF
CAPE MENDOCINO TONIGHT INTO SUNDAY MORNING. MORE WIDESPREAD AND
HEAVIER RAINFALL IS EXPECTED SUNDAY NIGHT THROUGH MONDAY AS A
STRONGER STORM SYSTEM MOVES THROUGH THE REGION.
&&
.DISCUSSION...MOSTLY CLEAR SKIES ACROSS THE REGION DEVELOPED TODAY
IN ASSOCIATION WITH SUBSIDENCE IN AN UPPER LEVEL RIDGE AHEAD OF AN
ADVANCING SHORTWAVE TROUGH. THIS TROUGH WILL BRING LIGHT RAIN TO
THE NORTHERN HALF OF THE CWA BEGINNING THIS EVENING THROUGH THE
MORNING HOURS. RAINFALL WILL RANGE FROM A TRACE IN COASTAL
SOUTHERN HUMBOLDT COUNTY TO OVER A QUARTER INCH IN DEL NORTE
COUNTY.
THIS SHORTWAVE WILL MOVE EAST OF THE AREA DURING THE DAY SUNDAY WITH
WEAK UPPER LEVEL RIDGING BUILDING OVER NORTHWEST CALIFORNIA FOR
SUNDAY AFTERNOON AND EVENING. THIS SHOULD ALLOW SOME OF THE LOWER
CLOUDS TO DISSIPATE LEAVING MID AND HIGH CLOUDS SPREADING OVER THE
AREA AHEAD OF THE NEXT MUCH STRONGER SYSTEM. DIVERGENT FLOW ALOFT
WILL SPREAD OVER NORTHWEST CALIFORNIA IN THE EVENING AT THE SAME
TIME AS WEAK WARM AIR ADVECTION BEGINS TO DEVELOP. THIS SHOULD ALLOW
LIGHT RAIN TO SPREAD OVER AREAS NORTH OF CAPE MENDOCINO BY AROUND
MIDNIGHT. A STRONG UPPER LEVEL JET AND SHORTWAVE WILL BEGIN TO
INFLUENCE THE REGION EARLY MONDAY MORNING ENHANCING THE RAINFALL AND
EXPANDING THE RAIN OVER ALL OF NORTHWEST CALIFORNIA. MODELS HAVE
TRENDED TOWARD HEAVIER RAINFALL THEN WAS PREDICTED IN PREVIOUS
RUNS...SO HAVE INCREASED THE QPF FORECAST FOR THE REGION IN LINE
WITH THE RFC. THE HEAVIEST RAINFALL WILL LIKELY OCCUR NORTH OF CAPE
MENDOCINO IN THE MOUNTAINS OF HUMBOLDT AND DEL NORTE COUNTIES
DURING MONDAY MORNING. A COLD FRONT WILL PUSH INLAND DURING THE
DAY MONDAY WITH RAINFALL DECREASING THROUGH THE EVENING. RAINFALL
TOTALS WILL RANGE FROM 0.15 INCHES IN FAR SOUTHERN INTERIOR
MENDOCINO COUNTY TO OVER AN INCH IN DEL NORTE COUNTY. SNOW LEVELS
WILL REMAIN ABOVE 6000 FEET.
COLD AIR ADVECTION AND RIDGING WILL REDEVELOP OVER THE REGION ON
TUESDAY BRINGING A BRIEF PERIOD OF DRIER CONDITIONS...HOWEVER WITH
ONSHORE FLOW STILL ANTICIPATED HAVE KEPT CHANCE POPS IN THE
FORECAST. A FINAL SHORTWAVE WILL MOVE THROUGH TUESDAY NIGHT INTO
WEDNESDAY MORNING BRINGING A LAST SHOT OF RAINFALL TO THE REGION
BEFORE A LARGE UPPER LEVEL RIDGE BUILDS BACK OVER THE WEST COAST
FOR THE REMAINDER OF THE WEEK. RPA
&&
.AVIATION...VFR CONDITIONS, PARTLY CLOUDY SKIES AND LIGHT TO MODERATE
WINDS WILL CONTINUE AT KCEC AND KACV THROUGH THE EARLY EVENING.
CLOUDINESS WILL INCREASE, SHOWERS WILL MOVE THROUGH THE AREA AT
TIMES AND PATCHY FOG WILL OCCUR OVERNIGHT AND EARLY SUNDAY MORNING
AT KCEC AND KACV REDUCING CEILINGS AND VISIBILITIES TO MVFR AND
TEMPORARY IFR CONDITIONS. VFR CONDITIONS WILL CONTINUE AT KUKI
THROUGH SUNDAY.
&&
.MARINE...LIGHT TO MODERATE WINDS AND MODERATE SEAS WILL PREVAIL
ACROSS THE WATERS THROUGH THE MIDDLE OF NEXT WEEK. THE WINDS AND
SEAS WILL INCREASE WEDNESDAY NIGHT AND THURSDAY AS A WEAK COLD FRONT
MOVES THROUGH THE REGION AND A HIGH PRESSURE SYSTEM STRENGTHENS
BEHIND THE FRONT INCREASING THE PRESSURE GRADIENT.
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...NONE.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV
HTTP://WWW.TWITTER.COM/NWSEUREKA
000
FXUS66 KEKA 251608
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
908 AM PDT SAT MAY 25 2013
.UPDATE...DECREASED CHANCES OF PRECIP IN DEL NORTE COUNTY THIS
AFTERNOON AS MODELS HAVE TRENDED TOWARD A LATER ARRIVAL OF
PRECIPITATION. OTHERWISE THE GOING FORECAST REMAINS ON TRACK AND
THE PREVIOUS DISCUSSIONS ARE INCLUDED BELOW.
&&
.PREV DISCUSSION... /ISSUED 433 AM PDT SAT MAY 25/
SYNOPSIS...A SERIES OF DISTURBANCES PASSING THROUGH THE AREA
SHOULD BRING SHOWERS TO LOCATIONS MAINLY NORTH OF MENDOCINO COUNTY
FROM LATE THIS AFTERNOON THROUGH SUNDAY MORNING. A STRONGER STORM
WILL BRING RAIN TO ALL OF NORTHWEST CALIFORNIA LATE SUNDAY NIGHT
THROUGH MEMORIAL DAY. SHOWERS SHOULD GRADUALLY DIMINISH TUESDAY
AND WEDNESDAY.
DISCUSSION...SATELLITE SHOWS CLOUDS OVER MOST OF HUMBOLDT COUNTY
AND PARTS OF DEL NORTE AND TRINITY COUNTIES. SURFACE OBSERVATIONS
AREN`T SHOWING ANY RAIN OR DRIZZLE. HOWEVER, SINCE THE LOCAL RADAR
I BROKEN IT`S DIFFICULT TO KNOW IF ANY SHOWERS ARE OCCURRING.
EXPECT CLOUDS TO START TO DIMINISH THIS MORNING ONLY FOR MORE TO
BUILD IN BY THIS AFTERNOON AS A DISTURBANCE PASSES THROUGH THE
AREA. THIS DISTURBANCE SHOULD BRING SHOWERS TO LOCATIONS MAINLY
NORTH OF MENDOCINO COUNTY FROM LATE THIS AFTERNOON THROUGH SUNDAY
MORNING. RAISED POPS AND QPF SOME TO REFLECT THE LATEST MODEL
RUNS, ESPECIALLY ALONG THE CA/OR BORDER AND THE REDWOOD COAST.
PERHAPS AROUND 0.25 INCH MAY OCCUR IN THE SHOWERS NEAR THE CA/OR
BORDER THROUGH SUNDAY, DECREASING AS ONE HEADS SOUTH. MONDAY IS
THE WETTEST DAY OF THE HOLIDAY WEEKEND AS AN UNSEASONABLY STRONG
STORM MOVES THROUGH, BRINGING WIDESPREAD RAIN TO NORTHWEST
CALIFORNIA. MODELS REMAIN IN GOOD AGREEMENT WITH THE TIMING,
LOCATION, AND QPF AMOUNTS SO BUMPED UP POPS AND QPF TO REFLECT
THIS. A 0.25 TO 0.5 INCH IS POSSIBLY NORTH OF MENDOCINO COUNTY
LATE SUNDAY THROUGH MONDAY WITH LESSER AMOUNTS ACROSS MENDOCINO
COUNTY. THE RAIN TRANSITIONS TO SHOWERS MONDAY NIGHT AND THEN
CONTINUES THROUGH THE MIDDLE OF NEXT WEEK WITH POPS GRADUALLY
LOWERING TO CLIMO AS WE HIT DAY 7.
AVIATION...LOW CLOUDINESS HAS DEVELOPED N OF CAPE MENDO AND
FARTHER INLAND OVER INLAND VALLEYS. HOWEVER...KCEC REMAINS CLEAR
AS OF 4 AM. IMPROVEMENTS IN CONDITIONS ARE EXPECTED LATER TODAY AS
CLOUDS LIFT AND THIN...BUT A MORE WIDESPREAD CLOUD DECK FROM
FARTHER OFFSHORE IS EXPECTED TO ADVECT INLAND LATE TODAY AND
TONIGHT AS BOUNDARY LAYER FLOW INCREASES SLIGHTLY AND BECOMES MORE
ONSHORE. /SEC
MARINE...TIGHTER PRESSURE GRADIENT BETWEEN AN INLAND LOW PRESSURE
TROF AND HIGH PRESSURE SW OF THE AREA WILL PERSIST A BIT LONGER
THAN PREVIOUSLY EXPECTED. AS A RESULT...THE SMALL CRAFT ADVISORY
FOR THE S OUTER MARINE LEG HAS BEEN EXTENDED THRU NOON TODAY. SFC
WINDS WILL DROP OFF THIS AFTERNOON AND LIGHTER WINDS WILL PERSIST
THRU SUN. S FLOW IS STILL EXPECTED TO INCREASE BRIEFLY ON MON
AHEAD OF AN APPROACHING FRONT. /SEC
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL NOON PDT TODAY PZZ475.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV
HTTP://WWW.TWITTER.COM/NWSEUREKA
000
FXUS66 KEKA 251133
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
433 AM PDT SAT MAY 25 2013
.SYNOPSIS...A SERIES OF DISTURBANCES PASSING THROUGH THE AREA
SHOULD BRING SHOWERS TO LOCATIONS MAINLY NORTH OF MENDOCINO COUNTY
FROM LATE THIS AFTERNOON THROUGH SUNDAY MORNING. A STRONGER STORM
WILL BRING RAIN TO ALL OF NORTHWEST CALIFORNIA LATE SUNDAY NIGHT
THROUGH MEMORIAL DAY. SHOWERS SHOULD GRADUALLY DIMINISH TUESDAY
AND WEDNESDAY.
&&
.DISCUSSION...SATELLITE SHOWS CLOUDS OVER MOST OF HUMBOLDT COUNTY
AND PARTS OF DEL NORTE AND TRINITY COUNTIES. SURFACE OBSERVATIONS
AREN`T SHOWING ANY RAIN OR DRIZZLE. HOWEVER, SINCE THE LOCAL RADAR
I BROKEN IT`S DIFFICULT TO KNOW IF ANY SHOWERS ARE OCCURRING.
EXPECT CLOUDS TO START TO DIMINISH THIS MORNING ONLY FOR MORE TO
BUILD IN BY THIS AFTERNOON AS A DISTURBANCE PASSES THROUGH THE
AREA. THIS DISTURBANCE SHOULD BRING SHOWERS TO LOCATIONS MAINLY
NORTH OF MENDOCINO COUNTY FROM LATE THIS AFTERNOON THROUGH SUNDAY
MORNING. RAISED POPS AND QPF SOME TO REFLECT THE LATEST MODEL
RUNS, ESPECIALLY ALONG THE CA/OR BORDER AND THE REDWOOD COAST.
PERHAPS AROUND 0.25 INCH MAY OCCUR IN THE SHOWERS NEAR THE CA/OR
BORDER THROUGH SUNDAY, DECREASING AS ONE HEADS SOUTH. MONDAY IS
THE WETTEST DAY OF THE HOLIDAY WEEKEND AS AN UNSEASONABLY STRONG
STORM MOVES THROUGH, BRINGING WIDESPREAD RAIN TO NORTHWEST
CALIFORNIA. MODELS REMAIN IN GOOD AGREEMENT WITH THE TIMING,
LOCATION, AND QPF AMOUNTS SO BUMPED UP POPS AND QPF TO REFLECT
THIS. A 0.25 TO 0.5 INCH IS POSSIBLY NORTH OF MENDOCINO COUNTY
LATE SUNDAY THROUGH MONDAY WITH LESSER AMOUNTS ACROSS MENDOCINO
COUNTY. THE RAIN TRANSITIONS TO SHOWERS MONDAY NIGHT AND THEN
CONTINUES THROUGH THE MIDDLE OF NEXT WEEK WITH POPS GRADUALLY
LOWERING TO CLIMO AS WE HIT DAY 7.
&&
.AVIATION...LOW CLOUDINESS HAS DEVELOPED N OF CAPE MENDO AND
FARTHER INLAND OVER INLAND VALLEYS. HOWEVER...KCEC REMAINS CLEAR
AS OF 4 AM. IMPROVEMENTS IN CONDITIONS ARE EXPECTED LATER TODAY AS
CLOUDS LIFT AND THIN...BUT A MORE WIDESPREAD CLOUD DECK FROM
FARTHER OFFSHORE IS EXPECTED TO ADVECT INLAND LATE TODAY AND
TONIGHT AS BOUNDARY LAYER FLOW INCREASES SLIGHTLY AND BECOMES MORE
ONSHORE. /SEC
&&
.MARINE...TIGHTER PRESSURE GRADIENT BETWEEN AN INLAND LOW PRESSURE
TROF AND HIGH PRESSURE SW OF THE AREA WILL PERSIST A BIT LONGER
THAN PREVIOUSLY EXPECTED. AS A RESULT...THE SMALL CRAFT ADVISORY
FOR THE S OUTER MARINE LEG HAS BEEN EXTENDED THRU NOON TODAY. SFC
WINDS WILL DROP OFF THIS AFTERNOON AND LIGHTER WINDS WILL PERSIST
THRU SUN. S FLOW IS STILL EXPECTED TO INCREASE BRIEFLY ON MON
AHEAD OF AN APPROACHING FRONT. /SEC
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY FOR PZZ475.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV
HTTP://WWW.TWITTER.COM/NWSEUREKA
000
FXUS66 KEKA 242350 CCA
AFDEKA
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE EUREKA CA
449 PM PDT FRI MAY 24 2013
.SYNOPSIS...A SERIES OF DISTURBANCES PASSING THROUGH THE REGION
SHOULD BRING SHOWERS TO LOCATIONS MAINLY NORTH OF CAPE MENDOCINO
SATURDAY EVENING INTO SUNDAY MORNING. RAIN IS EXPECTED ON MONDAY
FOLLOWED BY SHOWERS THROUGH THE MIDDLE OF NEXT WEEK.
&&
..DISCUSSION...BROAD UPPER LEVEL TROUGHING CONTINUES TO DOMINATE THE
WEST COAST WEATHER WITH A WEAK SHORTWAVE TROUGH BRINGING INCREASED
CLOUD COVER TODAY INTO TONIGHT. THIS SHOULD HELP KEEP TEMPERATURES A
FEW DEGREES WARMER OVERNIGHT...ALONG WITH SLIGHTLY WARMER
TEMPERATURES ALOFT...TO NOT REQUIRE ANY FROST ADVISORIES. LOW
TEMPS WILL RANGE FROM THE UPPER 30S TO MID 40S FOR MOST VALLEY
LOCATIONS.
ANOTHER MORE POTENT SHORTWAVE TROUGH WILL MOVE TOWARD NORTHWEST
CALIFORNIA ON SATURDAY BRINGING SOME ENHANCED UPLIFT AND CLOUD COVER
TO AREAS PRIMARILY NORTH OF CAPE MENDOCINO. MODELS ARE IN GENERAL
AGREEMENT ON A TRACE TO 0.30 INCHES OF RAIN FOR HUMBOLDT AND DEL NORTE
COUNTIES SATURDAY EVENING INTO EARLY SUNDAY MORNING. THE HIGHEST
AMOUNTS WILL BE IN UPSLOPING LOCATIONS OF DEL NORTE COUNTY. WEAK
SHORTWAVE RIDGING WILL THEN BUILD OVER NORTHWEST CALIFORNIA SUNDAY
INTO SUNDAY NIGHT BRINGING A BRIEF PERIOD OF DRIER WEATHER.
A MUCH STRONGER SYSTEM NOW CURRENTLY LOCATED IN THE ALEUTIAN ISLANDS
WILL REACH NORTHWEST CALIFORNIA ON MONDAY. MODELS INDICATE THE
DIFFLUENT FLOW ALOFT AND SHORTWAVE WILL SPREAD OVER THE WEST COAST
EARLY MONDAY MORNING WITH RAIN BEGINNING ALONG THE HUMBOLDT AND DEL
NORTE COASTS BY MIDDAY...POSSIBLY EARLIER. WIDESPREAD RAINFALL WILL
THEN EXPAND OVER THE CWA AS ZONAL ONSHORE FLOW AND STRONG UPPER
LEVEL JET STREAK AIM AT NORTHWEST CALIFORNIA. MODELS INDICATE
BETWEEN A QUARTER TO A HALF INCH OF RAINFALL CAN BE EXPECTED FOR THE
ENTIRE AREA WITH LOCALLY HIGHER AMOUNTS THROUGH MONDAY NIGHT. THERE
IS THE POSSIBILITY THAT SOUTHERN MENDOCINO COUNTY MAY SEE LIGHTER
AMOUNTS OF RAINFALL SO HAVE KEPT CHANCES OF PRECIP IN THE 60S FOR
UKIAH.
ONSHORE FLOW ON THE SOUTH SIDE OF AN UPPER LEVEL LOW IN THE
NORTHEAST PACIFIC WILL CONTINUE TO BRING CHANCES OF RAINFALL THROUGH
MID WEEK. CONFIDENCE IN THE FORECAST FOR MID TO LATE NEXT WEEK
DECREASES SIGNIFICANTLY WITH GFS INDICATING CONTINUED TROUGHING OVER
THE WEST COAST WHILE THE ECMWF IS SHOWING SIGNS OF A RIDGE. HAVE
KEPT WITH CLIMO POPS FOR THE FAR EXTENDED FORECAST. RPA
&&
.AVIATION...VFR CONDITIONS, PARTLY CLOUDY TO MOSTLY CLOUDY SKIES AND
LIGHT TO MODERATE WINDS WILL CONTINUE AT KCEC, KACV AND KUKI THROUGH
THE EARLY EVENING. CLOUDINESS WILL INCREASE OVERNIGHT AT KCEC AND
KACV AND PATCHY FOG WILL DEVELOP EARLY SATURDAY MORNING THEREFORE
CEILINGS AND VISIBILITIES WILL DECREASE TO MVFR CONDITIONS. ONCE THE
PATCHY FOG DISSIPATES CEILINGS AND VISIBILITIES WILL INCREASE AND
VFR CONDITIONS WILL PREVAIL AT KCEC AND KACV ON SATURDAY. VFR
CONDITIONS WILL CONTINUE AT KUKI FOR THE NEXT FEW DAYS.
&&
.MARINE...THE PRESSURE GRADIENT HAS RELAXED ACROSS THE WATERS.
SUBSEQUENTLY THE WINDS AND SEAS WILL CONTINUE TO GRADUALLY DIMINISH
ACROSS THE WATERS INTO SATURDAY. A SMALL CRAFT ADVISORY REMAINS IN
EFFECT THROUGH EARLY SATURDAY MORNING ACROSS THE SOUTHERN OUTER
WATERS AS THE WINDS AND SEAS CONTINUE NEAR SMALL CRAFT CRITERIA
BEFORE SLOWLY DIMINISHING ON SATURDAY.
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY UNTIL 6 AM PDT SATURDAY PZZ475.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV
HTTP://WWW.TWITTER.COM/NWSEUREKA
000
FXUS66 KEKA 242256
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
356 PM PDT FRI MAY 24 2013
.SYNOPSIS...A SERIES OF DISTURBANCES PASSING THROUGH THE REGION
SHOULD BRING SHOWERS TO LOCATIONS MAINLY NORTH OF CAPE MENDOCINO
SATURDAY EVENING INTO SUNDAY MORNING. RAIN IS EXPECTED ON MONDAY
FOLLOWED BY SHOWERS THROUGH THE MIDDLE OF NEXT WEEK.
&&
..DISCUSSION...BROAD UPPER LEVEL TROUGHING CONTINUES TO DOMINATE THE
WEST COAST WEATHER WITH A WEAK SHORTWAVE TROUGH BRINGING INCREASED
CLOUD COVER TODAY INTO TONIGHT. THIS SHOULD HELP KEEP TEMPERATURES A
FEW DEGREES WARMER OVERNIGHT...ALONG WITH SLIGHTLY WARMER
TEMPERATURES ALOFT...TO NOT REQUIRE ANY FROST ADVISORIES. LOW
TEMPS WILL RANGE FROM THE UPPER 30S TO MID 40S FOR MOST VALLEY
LOCATIONS.
ANOTHER MORE POTENT SHORTWAVE TROUGH WILL MOVE TOWARD NORTHWEST
CALIFORNIA ON SATURDAY BRINGING SOME ENHANCED UPLIFT AND CLOUD COVER
TO AREAS PRIMARILY NORTH OF CAPE MENDOCINO. MODELS ARE IN GENERAL
AGREEMENT ON A TRACE TO 0.30 INCHES OF RAIN FOR HUMBOLDT AND DEL NORTE
COUNTIES SATURDAY EVENING INTO EARLY SUNDAY MORNING. THE HIGHEST
AMOUNTS WILL BE IN UPSLOPING LOCATIONS OF DEL NORTE COUNTY. WEAK
SHORTWAVE RIDGING WILL THEN BUILD OVER NORTHWEST CALIFORNIA SUNDAY
INTO SUNDAY NIGHT BRINGING A BRIEF PERIOD OF DRIER WEATHER.
A MUCH STRONGER SYSTEM NOW CURRENTLY LOCATED IN THE ALEUTIAN ISLANDS
WILL REACH NORTHWEST CALIFORNIA ON MONDAY. MODELS INDICATE THE
DIFFLUENT FLOW ALOFT AND SHORTWAVE WILL SPREAD OVER THE WEST COAST
EARLY MONDAY MORNING WITH RAIN BEGINNING ALONG THE HUMBOLDT AND DEL
NORTE COASTS BY MIDDAY...POSSIBLY EARLIER. WIDESPREAD RAINFALL WILL
THEN EXPAND OVER THE CWA AS ZONAL ONSHORE FLOW AND STRONG UPPER
LEVEL JET STREAK AIM AT NORTHWEST CALIFORNIA. MODELS INDICATE
BETWEEN A QUARTER TO A HALF INCH OF RAINFALL CAN BE EXPECTED FOR THE
ENTIRE AREA WITH LOCALLY HIGHER AMOUNTS THROUGH MONDAY NIGHT. THERE
IS THE POSSIBILITY THAT SOUTHERN MENDOCINO COUNTY MAY SEE LIGHTER
AMOUNTS OF RAINFALL SO HAVE KEPT CHANCES OF PRECIP IN THE 60S FOR
UKIAH.
ONSHORE FLOW ON THE SOUTH SIDE OF AN UPPER LEVEL LOW IN THE
NORTHEAST PACIFIC WILL CONTINUE TO BRING CHANCES OF RAINFALL THROUGH
MID WEEK. CONFIDENCE IN THE FORECAST FOR MID TO LATE NEXT WEEK
DECREASES SIGNIFICANTLY WITH GFS INDICATING CONTINUED TROUGHING OVER
THE WEST COAST WHILE THE ECMWF IS SHOWING SIGNS OF A RIDGE. HAVE
KEPT WITH CLIMO POPS FOR THE FAR EXTENDED FORECAST. RPA
&&
.AVIATION...VFR CONDITIONS, PARTLY CLOUDY TO MOSTLY CLOUDY SKIES AND
LIGHT TO MODERATE WINDS WILL CONTINUE AT KCEC, KACV AND KUKI THROUGH
THE EARLY EVENING. CLOUDINESS WILL INCREASE OVERNIGHT AT KCEC AND
KACV AND PATCHY FOG WILL DEVELOP EARLY SATURDAY MORNING THEREFORE
CEILINGS AND VISIBILITIES WILL DECREASE TO MVFR CONDITIONS. ONCE THE
PATCHY FOG DISSIPATES CEILINGS AND VISIBILITIES WILL INCREASE AND
VFR CONDITIONS WILL PREVAIL AT KCEC AND KACV ON SATURDAY. VFR
CONDITIONS WILL CONTINUE AT KUKI FOR THE NEXT FEW DAYS.
&&
.MARINE...THE PRESSURE GRADIENT HAS RELAXED ACROSS THE WATERS.
SUBSEQUENTLY THE WINDS AND SEAS WILL CONTINUE TO GRADUALLY DIMINISH
ACROSS THE WATERS FRIDAY AND SATURDAY. A SMALL CRAFT ADVISORY WILL
BE IN EFFECT THIS AFTERNOON THROUGH EARLY SATURDAY MORNING ACROSS
THE SOUTHERN OUTER WATERS AS THE WINDS AND SEAS CONTINUE NEAR SMALL
CRAFT CRITERIA BEFORE SLOWLY DIMINISHING ON SATURDAY.
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY UNTIL 6 AM PDT SATURDAY PZZ475.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV
HTTP://WWW.TWITTER.COM/NWSEUREKA
000
FXUS66 KEKA 241137
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
437 AM PDT FRI MAY 24 2013
.SYNOPSIS...A TROUGH OVER THE WEST COAST WILL BRING COOL
TEMPERATURES AND NORTHWEST WINDS TO NORTHWEST CALIFORNIA TODAY. A
SERIES OF DISTURBANCES PASSING THROUGH THE TROUGH SHOULD BRING
SHOWERS TO LOCATIONS MAINLY NORTH OF CAPE MENDOCINO SATURDAY AND
SUNDAY. RAIN IS EXPECTED ON MONDAY FOLLOWED BY SHOWERS THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...SATELLITE SHOWS CLOUDS OVER MOST OF HUMBOLDT, DEL
NORTE, AND TRINITY COUNTIES. DRIZZLE WAS BEING REPORTED IN EUREKA,
BUT RADAR WAS NOT PICKING IT UP SINCE IT WAS SO SHALLOW. EXPECT
PATCHY DRIZZLE INTO THIS MORNING BEFORE SKIES CLEAR. ADDITIONALLY,
TEMPERATURES ACROSS TRINITY COUNTY ARE NOT AS COLD AS ORIGINALLY
FORECAST, PROBABLY DUE TO THE HIGH CLOUDS PASSING OVER THE AREA.
AS A RESULT, DROPPED THE FROST ADVISORY FOR ZONE 4. TEMPERATURES
ARE IN THE 30S AND 40S ACROSS MENDOCINO COUNTY. SOME FROST MAY
DEVELOPS IN SOME OF THE COLDEST VALLEYS, BUT AREAL COVERAGE WAS
NOT ENOUGH TO WARRANT A FROST ADVISORY. EXPECT SKIES TO CLEAR AND
TEMPERATURES TO WARM UP TODAY, BUT THEY SHOULD REMAIN A FEW
DEGREES BELOW NORMAL. TEMPERATURES TONIGHT SHOULD BE A FEW DEGREES
WARMER, SO WIDESPREAD FROST IS NOT EXPECTED. THINGS GO DOWNHILL
FROM THERE AS A SERIES OF DISTURBANCES PASS THROUGH THE TROUGH
THIS WEEKEND. EXPECT SHOWERS NORTH OF ORICK ON SATURDAY WITH SOME
MORE SHOWERS OVER THE HIGHER TERRAIN ACROSS THE INTERIOR. SATURDAY
NIGHT INTO SUNDAY SHOULD SEE THE SHOWERS INCREASE IN AREAL
COVERAGE, WITH SHOWERS EXPECTED NORTH OF MENDOCINO COUNTY. POPS
ARE THE HIGHEST ALONG THE CA/OR BORDER, GRADUALLY DECREASING TO
THE SOUTH. PERHAPS UP TO 0.25 INCH MAY OCCUR IN THE SHOWERS NEAR
THE CA/OR BORDER BOTH OF THESE DAYS, DECREASING AS ONE HEADS
SOUTH. MONDAY IS THE WETTEST DAY OF THE HOLIDAY WEEKEND AS AN
UNSEASONABLY STRONG FRONT MOVES THROUGH, BRINGING WIDESPREAD RAIN
TO NORTHWEST CALIFORNIA. MODELS ARE GENERALLY IN GOOD AGREEMENT
WITH THE TIMING, LOCATION, AND AMOUNTS SO BUMPED UP POPS A LOT TO
REFLECT THIS. A 0.25 INCH ACROSS THE ENTIRE AREA IS POSSIBLE ON
MONDAY. THE RAIN TRANSITIONS TO SHOWERS MONDAY NIGHT AND THEN
CONTINUES THROUGH THE MIDDLE OF NEXT WEEK WITH POPS GRADUALLY
LOWERING TO SLIGHTLY ABOVE CLIMO AS WE APPROACH DAY 7. WILL ALSO
NEED TO MONITOR THE THUNDERSTORM POTENTIAL ACROSS TRINITY COUNTY
ON SUNDAY, BUT CONFIDENCE IS MARGINAL.
&&
.AVIATION...AFTER BRIEF PERIOD OF MVFR CIGS WITH LIGHT RAIN
SHOWERS EARLY THIS MORNING AT COASTAL TAF SITES...MOSTLY VFR
CONDITIONS ARE EXPECTED. /SEC
&&
.MARINE...A BRIEF TIGHTENING OF THE PRESSURE GRADIENT BETWEEN HIGH
PRESSURE W OF THE AREA AND A LOW PRESSURE TROF OVER NW CA WILL
LEAD TO LOW END SMALL CRAFT ADVISORY CONDITIONS OVER THE OUTER
WATERS S OF CAPE MENDO LATE THIS AFTERNOON INTO EARLY SAT MORNING.
OTHERWISE...SUB-ADVISORY CRITERIA EXPECTED FOR THE WEEKEND. S
WINDS ARE EXPECTED TO INCREASE EARLY NEXT WEEK AHEAD OF AN
APPROACHING FRONTAL SYSTEM. /SEC
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY FOR PZZ475.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV
HTTP://WWW.TWITTER.COM/NWSEUREKA
000
FXUS66 KEKA 232223
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
323 PM PDT THU MAY 23 2013
.SYNOPSIS...
COOL AIR WILL CONTINUE TO FLOW INTO NORTHWEST CALIFORNIA THROUGH
THURSDAY. INTERIOR AREAS WILL NOT BE AS COLD TONIGHT. A LITTLE LIGHT
RAIN WILL BE POSSIBLE AT EARLY FRIDAY MORNING AND AGAIN SATURDAY
NIGHT NORTH OF TRINIDAD OTHERWISE IT IS LOOKING LIKE A DRY WEEKEND. A
MORE WIDESPREAD RAIN WILL ARRIVE MONDAY.
&&
.DISCUSSION...
TEMPERATURES ON AVERAGE ARE RUNNING 5 TO 10 DEGREES WARMER THAN
YESTERDAY INLAND, AND CONDITIONS ARE A BIT MILDER ON THE COAST AS
WELL. SFC HIGH PRESSURE RIDGING HAS ACTUALLY SHIFTED NORTHWARD INTO
SRN OREGON TODAY AS THE UPPER LOW CENTERED OVER WASHINGTON STATE
CONTINUES TO FILL. THIS HAS HELPED PROMOTE MOSTLY SUNNY SKIES ALL
THE WAY UP THE COAST, JUST ABOUT TO CAPE BLANCO. THE NORTH COAST
INTERIOR HAS SEEN SOME CUMULUS BUILD-UPS OVER THE HIGHER TERRAIN
WITH DAYTIME HEATING. SUSPECT THERE COULD STILL BE AN ISOLATED
SHOWER OVER THE SISKIYOUS OF ERN DEL NORTE OR ERN HUMBOLDT COUNTY
EARLY THIS EVENING. KBHX RADAR HAS NOT PICKED UP ANYTHING...SO IF
THERE ARE ANY WEAK SHOWERS OUT THERE NOW, THEY ARE BEING OVERSHOT
BECAUSE THE TOPS ARE SO LOW.
THE FINAL SHORTWAVE ROUNDING THE UPPER LOW WILL APPROACH THE NORTH
COAST THIS EVENING BUT AS THE LOW CONTINUES TO FILL, ANY
PRECIPITATION WILL NEED TO BE FORCED IN THE SHALLOW MOISTURE AND
INSTABILITY WITH ONSHORE FLOW WITHIN A FEW THOUSAND FEET OF THE
SURFACE. AS THE BOUNDARY LAYER STABILIZES OVERNIGHT NEAR THE COAST
SUSPECT THAT ANYTHING THAT DOES DEVELOP FROM PERHAPS ORICK NORTHWARD
MAY BE IN THE FORM OF LIGHT DRIZZLE. THIS COULD LINGER INTO EARLY
FRIDAY MORNING...OTHERWISE FRIDAY IS LOOKING LIKE ANOTHER MOSTLY
SUNNY AND DRY DAY WITH SLIGHTLY WARMER TEMPERATURES. THAT SAID, IT
WILL STILL BE COLD ACROSS THE INTERIOR TONIGHT, THOUGH NOT AS COLD
AS LAST NIGHT. ISSUED A FROST ADVISORY FOR TRINITY COUNTY. GUIDANCE
INDICATES THAT TEMPERATURES SHOULD BE AT LEAST COLD ENOUGH FOR FROST
THERE...AND PERHAPS IN THE DEEPER VALLEYS OF NORTHERN MENDOCINO AND
EASTERN HUMBOLDT COUNTY AS WELL.
THE WEEKEND GENERALLY LOOKS DRY ALTHOUGH THERE WILL BE A PESKY
TROUGH MOVING THROUGH SATURDAY NIGHT INTO SUNDAY MORNING. THINKING
THERE WILL BE ENOUGH SUBSIDENCE AND DRY AIR IN THE LOWER LEVELS TO
LIMIT SHOWERS TO NEAR THE OREGON BORDER. BETTER SHOT AT ISOLATED
SHOWERS AND MAYBE EVEN A RUMBLE OF THUNDER WILL BE WITH ANY
BUILD-UPS OVER THE SISKIYOUS OR YOLLA BOLLYS.
A MORE DEFINED STORM SYSTEM WILL APPROACH SUNDAY NIGHT. MODELS ARE
CONVERGING ON A PERIOD OF WIDESPREAD RAINFALL...PERHAPS OVER A
HALF-INCH...CENTERED ON MONDAY. NOT IDEAL BARBECUE WEATHER
UNFORTUNATELY.
&&
.AVIATION...VFR CONDITIONS, CLEAR TO PARTLY CLOUDY SKIES AND LIGHT
TO MODERATE WINDS WILL CONTINUE AT KCEC, KACV AND KUKI THROUGH THE
EARLY EVENING. MODERATE TO MODERATE AND GUSTY WINDS WILL CONTINUE
THROUGH THE EARLY EVENING NEAR THE COAST THEN LIGHT TO CALM WINDS
WILL PREVAIL ACROSS KCEC, KACV AND KUKI OVERNIGHT TONIGHT AND EARLY
FRIDAY MORNING. CLOUDINESS WILL INCREASE OVERNIGHT AT KCEC AND KACV
REDUCING CEILINGS, HOWEVER CEILINGS WILL REMAIN AT VFR CONDITIONS.
&&
.MARINE...THE PRESSURE GRADIENT WILL CONTINUE TO RELAX AND
SUBSEQUENTLY THE WINDS AND SEAS WILL GRADUALLY DIMINISH ACROSS THE
WATERS THROUGH THIS WEEKEND. LIGHT TO MODERATE WINDS AND MODERATE
SEAS WILL PREVAIL ACROSS THE WATERS FRIDAY THROUGH EARLY NEXT WEEK.
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...FROST ADVISORY FROM 2 AM TO 8 AM PDT FRIDAY CAZ004.
NORTHWEST CALIFORNIA COASTAL WATERS...NONE.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV
HTTP://WWW.TWITTER.COM/NWSEUREKA
000
FXUS66 KEKA 231630
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
930 AM PDT THU MAY 23 2013
.UPDATE...
QUICKLY UPDATED TO REFLECT CLEARER SKIES ACROSS MOST OF THE
FORECAST AREA AND LIMIT SHOWER CHANCES. TODAY WILL BE SIMILAR TO
YESTERDAY EXCEPT WITH SFC RIDGE PUSHING A BIT FURTHER NORTH SKIES
WILL BE NOTICEABLY SUNNIER NORTH OF THE KLAMATH, COMPARED TO
YESTERDAY. WE WILL BE IN BETWEEN SHORTWAVES WITH LIMITED MOISTURE
SO ANY SHOWER ACTIVITY WILL BE WEAK AND ISOLATED TO THE HIGHER
TERRAIN OF THE NORTH COAST INTERIOR LATER THIS AFTERNOON. EVEN
THIS MAY BE ASKING A LOT, WITH DECREASING LAPSE RATES AND DRIER
AIR ALOFT...BUT WITH CU ALREADY POPPING UP AND NOT MUCH OF A CAP
YET AND UPPER LOW STILL NEARBY, DECIDED NOT TO RULE IT OUT. NEXT
SHORTWAVE MAY BRING SOME LIGHT SHOWERS OR DRIZZLE TO THE NORTH
COAST LATE TONIGHT/EARLY FRI AM...OTHERWISE LOOKS LIKE A NICE
COUPLE OF DAYS WITH GRADUALLY MILDER TEMPS. AAD
&&
.PREV DISCUSSION... /ISSUED 457 AM PDT THU MAY 23 2013/
SYNOPSIS...AN UPPER LEVEL LOW CENTERED OVER THE PACIFIC NORTHWEST
WILL BRING A SLIGHT CHANCE OF SHOWERS TO MAINLY HUMBOLDT AND DEL
NORTE COUNTIES THROUGH FRIDAY MORNING. INLAND TEMPERATURES WILL
REMAIN BELOW NORMAL TODAY...AND THEN WARM UP SLIGHTLY ON FRIDAY
AND SATURDAY.
DISCUSSION...WATER VAPOR IMAGERY SHOWED AN UPPER LOW CENTERED
OVER WASHINGTON STATE EARLY THIS MORNING. A WEAK TROUGH
PIN-WHEELING AROUND THE SOUTHERN PERIPHERY OF THE LOW WAS MOVING
OVER NORTHERN CA EARLY THIS MORNING. IT WAS NOT GENERATING MUCH
IF ANY PRECIP. IT WAS PRODUCING A FAIR AMOUNT OF CLOUD COVER AS
WELL AS GUSTY NW WINDS OVER THE HIGHER TERRAIN AND RIDGES. AS A
RESULT...TEMPERATURES THIS MORNING WERE NOT AS COLD AS LAST NIGHT.
THERE WAS SOME CLEARING EVIDENT ON THE BACK SIDE OF THIS TROUGH.
TEMPERATURES WERE RUNNING IN THE MID 30S IN THE COLDEST VALLEYS OF
TRINITY AND INTERIOR MENDOCINO COUNTIES. WITH A SEVERAL MORE HOURS
OF LONG-WAVE COOLING AND PARTLY CLEARING SKIES...TEMPS SHOULD
DROP TO 32F OR LESS RIGHT BEFORE DAYBREAK. THUS WILL MAINTAIN THE
FREEZE WARNINGS AND FROST ADVISORIES. ANOTHER TROUGH WILL PIVOT
AROUND THE UPPER LOW TONIGHT AND COULD PRODUCE A FEW SHOWERS FOR
NW CA. THIS ONE LOOKS TO TAKE A TRACK FARTHER TO THE NORTH AND
EAST OF THE FORECAST AREA. THUS CLOUD COVER AND NW GUSTY WINDS MAY
NOT BE AS GREAT OF A FACTOR...BUT THE AIR MASS WILL BE WARMER.
ANOTHER FROST ADVISORY WILL LIKELY BE NECESSARY FOR THE COLDEST
VALLEYS OF NORTHERN MENDO...EASTERN HUMBOLDT AND ALL OF TRINITY
COUNTIES.
THE COLD UPPER LEVEL LOW THAT HAS PERSISTED OVER THE PAC NW ALL
THIS WEEK WILL BEGIN TO FILL AND LIFT OUT ON FRIDAY. THE AIR MASS
WILL WARM OVER NW CA AND THE GUSTY NW WINDS WILL ABATE. MODELS
CONTINUE TO INDICATE WEAK UPPER LEVEL TROUGHINESS LINGERING OVER
THE AREA THIS WEEKEND HOWEVER. THE SHOWER POSSIBILITIES DO NOT
LOOK ALL THAT GREAT ON SAT AS A SHORT-WAVE MOVES ACROSS THE AREA.
IT MAY GENERATE SOME ISOLATED SHOWERS OVER THE HIGHER TERRAIN SAT
AFTN AND EVE COUPLED WITH THE DAYTIME HEATING.
MODELS DIVERGE SLIGHTLY ON SUNDAY. THE GEM AND ECWMF WERE
A LITTLE STRONGER AND WETTER WITH ANOTHER SHORT-WAVE EXPECTED
TO MOVE TOWARD THE AREA ON SUNDAY. THE GFS HAS A WEAK SHORT-WAVE
RIDGE BUILDING AND INDICATES CONTINUED WARMING AND DRYING. THE
NAM12 WAS SIMILAR. CONSIDERING THESE DIFFERENCES AND AMBIGUITIES
IN THE MODELS...WILL GO WITH JUST A CHANCE OF SHOWERS ACROSS THE
NORTHERN ZONES INTO SUN NIGHT.
THE MODELS HAVE ANOTHER TROUGH MOVING TOWARD THE AREA WITH
PERHAPS A CLOSED LOW FORMING OVER OR JUST OFFSHORE THE NORTH
COAST BY TUE. THERE HAS BEEN FAIRLY GOOD RUN TO RUN CONTINUITY
AND AGREEMENT BETWEEN THE VARIOUS MODELS. IT IS LOOKING UNSETTLED
WITH PERIODIC SHOWERS MON THROUGH WED NEXT WEEK. BEEFED UP THE
PRECIP CHANCES SLIGHTLY FOR MON AS THAT MAY BE THE WETTER DAY.
ISOLD TSTMS SEEM POSSIBLE AS WELL...WITH WARMER BOUNDARY LAYER
TEMPS AND COOLING ALOFT. FOR NOW WILL HOLD OFF AS THE STRONG
WESTERLY AND SOUTHWESTERLY FLOW MAY STIFLE TSTM DEVELOPMENT.
AVIATION...UPPER LEVEL LOW CONTINUES TO SPIN OVER THE PACIFIC
NORTHWEST. WEAK SHORTWAVES WILL CONTINUE ROTATE AROUND THIS LOW
TODAY AND TONIGHT. A WEAK SHORTWAVE MOVING AROUND THE LOW MAY BRING
A FEW MORE SHOWERS TO THE AREA THIS MORNING. THIS MAY BRING SOME
BRIEF MVFR RESTRICTIONS AIRPORTS NORTH OF CAPE MENDOCINO THIS
MORNING...ALTHOUGH THE SHOWER COVERAGE IS EXPECTED TO REMAIN FAIRLY
LIMITED. WITH THE COLD LOW ALOFT THERE WILL BE LITTLE TO NO MARINE
INVERSION TO TRAP MOISTURE AND ALLOW COASTAL LOW CLOUDS AND FOG TO
DEVELOP. NORTHERLY WINDS OF 10 TO 15 KT ARE EXPECTED ONCE AGAIN
THIS AFTERNOON...MAINLY ALONG THE COAST. MKK
MARINE...AN UPPER LEVEL LOW TO THE NORTH OF THE AREA CONTINUES TO
SPIN AND REMAIN FAIRLY STATIONARY. THIS CONTINUES TO BRING LIGHT TO
MODERATE NORTHERLY WINDS TO THE AREA AND NORTHWEST WAVES OF 10 TO 12
FT AT 11 SECONDS. THE WAVES ARE REMAINING ELEVATED SLIGHTLY OVER
WHAT SWAN HAS...BUT EXPECT THEY WILL DIMINISH THIS MORNING. HAVE
EXTENDED THE SMALL CRAFT ADVISORIES THROUGH 9AM TO ACCOUNT FOR THIS.
ONCE THE SEAS DIMINISH TO 7 TO 8 FT BY LATE TODAY CONDITIONS SHOULD
REMAIN FAIRLY PERSISTENT THROUGH SATURDAY.
A LONG PERIOD NORTHWEST SWELL IS ALSO EXPECTED TO BEGIN BUILDING
INTO THE AREA TODAY. IT LOOKS TO BEGIN AROUND A FOOT AT 18 SECONDS
TODAY BUILDING TO AROUND 4 FEET AT 15 SECONDS TOMORROW. THIS WILL
THEN SLOWLY DIMINISH THROUGH THE WEEKEND.
LATE SUNDAY INTO MONDAY MODELS ARE SHOWING A FAIRLY DECENT SYSTEM
BRINGING A PERIOD OF SOME SOUTHERLY WINDS TO THE REGION. THE MODELS
ARE STILL STRUGGLING TO TO NAIL DOWN THE EXACT TIMING OF THIS
SYSTEM...SO MAINLY LEFT THE FORECAST EARLY NEXT WEEK THE SAME. THIS
WILL NEED TO BE MONITORED WITH THE NEXT THE NEXT FORECAST PACKAGE.
MKK
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 2 PM PDT THIS AFTERNOON PZZ455-475.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV
HTTP://WWW.TWITTER.COM/NWSEUREKA
000
FXUS66 KEKA 231157
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
457 AM PDT THU MAY 23 2013
.SYNOPSIS...AN UPPER LEVEL LOW CENTERED OVER THE PACIFIC NORTHWEST
WILL BRING A SLIGHT CHANCE OF SHOWERS TO MAINLY HUMBOLDT AND DEL
NORTE COUNTIES THROUGH FRIDAY MORNING. INLAND TEMPERATURES WILL
REMAIN BELOW NORMAL TODAY...AND THEN WARM UP SLIGHTLY ON FRIDAY
AND SATURDAY.
&&
.DISCUSSION...WATER VAPOR IMAGERY SHOWED AN UPPER LOW CENTERED
OVER WASHINGTON STATE EARLY THIS MORNING. A WEAK TROUGH
PIN-WHEELING AROUND THE SOUTHERN PERIPHERY OF THE LOW WAS MOVING
OVER NORTHERN CA EARLY THIS MORNING. IT WAS NOT GENERATING MUCH
IF ANY PRECIP. IT WAS PRODUCING A FAIR AMOUNT OF CLOUD COVER AS
WELL AS GUSTY NW WINDS OVER THE HIGHER TERRAIN AND RIDGES. AS A
RESULT...TEMPERATURES THIS MORNING WERE NOT AS COLD AS LAST NIGHT.
THERE WAS SOME CLEARING EVIDENT ON THE BACK SIDE OF THIS TROUGH.
TEMPERATURES WERE RUNNING IN THE MID 30S IN THE COLDEST VALLEYS OF
TRINITY AND INTERIOR MENDOCINO COUNTIES. WITH A SEVERAL MORE HOURS
OF LONG-WAVE COOLING AND PARTLY CLEARING SKIES...TEMPS SHOULD
DROP TO 32F OR LESS RIGHT BEFORE DAYBREAK. THUS WILL MAINTAIN THE
FREEZE WARNINGS AND FROST ADVISORIES. ANOTHER TROUGH WILL PIVOT
AROUND THE UPPER LOW TONIGHT AND COULD PRODUCE A FEW SHOWERS FOR
NW CA. THIS ONE LOOKS TO TAKE A TRACK FARTHER TO THE NORTH AND
EAST OF THE FORECAST AREA. THUS CLOUD COVER AND NW GUSTY WINDS MAY
NOT BE AS GREAT OF A FACTOR...BUT THE AIR MASS WILL BE WARMER.
ANOTHER FROST ADVISORY WILL LIKELY BE NECESSARY FOR THE COLDEST
VALLEYS OF NORTHERN MENDO...EASTERN HUMBOLDT AND ALL OF TRINITY
COUNTIES.
THE COLD UPPER LEVEL LOW THAT HAS PERSISTED OVER THE PAC NW ALL
THIS WEEK WILL BEGIN TO FILL AND LIFT OUT ON FRIDAY. THE AIR MASS
WILL WARM OVER NW CA AND THE GUSTY NW WINDS WILL ABATE. MODELS
CONTINUE TO INDICATE WEAK UPPER LEVEL TROUGHINESS LINGERING OVER
THE AREA THIS WEEKEND HOWEVER. THE SHOWER POSSIBILITIES DO NOT
LOOK ALL THAT GREAT ON SAT AS A SHORT-WAVE MOVES ACROSS THE AREA.
IT MAY GENERATE SOME ISOLATED SHOWERS OVER THE HIGHER TERRAIN SAT
AFTN AND EVE COUPLED WITH THE DAYTIME HEATING.
MODELS DIVERGE SLIGHTLY ON SUNDAY. THE GEM AND ECWMF WERE
A LITTLE STRONGER AND WETTER WITH ANOTHER SHORT-WAVE EXPECTED
TO MOVE TOWARD THE AREA ON SUNDAY. THE GFS HAS A WEAK SHORT-WAVE
RIDGE BUILDING AND INDICATES CONTINUED WARMING AND DRYING. THE
NAM12 WAS SIMILAR. CONSIDERING THESE DIFFERENCES AND AMBIGUITIES
IN THE MODELS...WILL GO WITH JUST A CHANCE OF SHOWERS ACROSS THE
NORTHERN ZONES INTO SUN NIGHT.
THE MODELS HAVE ANOTHER TROUGH MOVING TOWARD THE AREA WITH
PERHAPS A CLOSED LOW FORMING OVER OR JUST OFFSHORE THE NORTH
COAST BY TUE. THERE HAS BEEN FAIRLY GOOD RUN TO RUN CONTINUITY
AND AGREEMENT BETWEEN THE VARIOUS MODELS. IT IS LOOKING UNSETTLED
WITH PERIODIC SHOWERS MON THROUGH WED NEXT WEEK. BEEFED UP THE
PRECIP CHANCES SLIGHTLY FOR MON AS THAT MAY BE THE WETTER DAY.
ISOLD TSTMS SEEM POSSIBLE AS WELL...WITH WARMER BOUNDARY LAYER
TEMPS AND COOLING ALOFT. FOR NOW WILL HOLD OFF AS THE STRONG
WESTERLY AND SOUTHWESTERLY FLOW MAY STIFLE TSTM DEVELOPMENT.
&&
.AVIATION...UPPER LEVEL LOW CONTINUES TO SPIN OVER THE PACIFIC
NORTHWEST. WEAK SHORTWAVES WILL CONTINUE ROTATE AROUND THIS LOW
TODAY AND TONIGHT. A WEAK SHORTWAVE MOVING AROUND THE LOW MAY BRING
A FEW MORE SHOWERS TO THE AREA THIS MORNING. THIS MAY BRING SOME
BRIEF MVFR RESTRICTIONS AIRPORTS NORTH OF CAPE MENDOCINO THIS
MORNING...ALTHOUGH THE SHOWER COVERAGE IS EXPECTED TO REMAIN FAIRLY
LIMITED. WITH THE COLD LOW ALOFT THERE WILL BE LITTLE TO NO MARINE
INVERSION TO TRAP MOISTURE AND ALLOW COASTAL LOW CLOUDS AND FOG TO
DEVELOP. NORTHERLY WINDS OF 10 TO 15 KT ARE EXPECTED ONCE AGAIN
THIS AFTERNOON...MAINLY ALONG THE COAST. MKK
&&
.MARINE...AN UPPER LEVEL LOW TO THE NORTH OF THE AREA CONTINUES TO
SPIN AND REMAIN FAIRLY STATIONARY. THIS CONTINUES TO BRING LIGHT TO
MODERATE NORTHERLY WINDS TO THE AREA AND NORTHWEST WAVES OF 10 TO 12
FT AT 11 SECONDS. THE WAVES ARE REMAINING ELEVATED SLIGHTLY OVER
WHAT SWAN HAS...BUT EXPECT THEY WILL DIMINISH THIS MORNING. HAVE
EXTENDED THE SMALL CRAFT ADVISORIES THROUGH 9AM TO ACCOUNT FOR THIS.
ONCE THE SEAS DIMINISH TO 7 TO 8 FT BY LATE TODAY CONDITIONS SHOULD
REMAIN FAIRLY PERSISTENT THROUGH SATURDAY.
A LONG PERIOD NORTHWEST SWELL IS ALSO EXPECTED TO BEGIN BUILDING
INTO THE AREA TODAY. IT LOOKS TO BEGIN AROUND A FOOT AT 18 SECONDS
TODAY BUILDING TO AROUND 4 FEET AT 15 SECONDS TOMORROW. THIS WILL
THEN SLOWLY DIMINISH THROUGH THE WEEKEND.
LATE SUNDAY INTO MONDAY MODELS ARE SHOWING A FAIRLY DECENT SYSTEM
BRINGING A PERIOD OF SOME SOUTHERLY WINDS TO THE REGION. THE MODELS
ARE STILL STRUGGLING TO TO NAIL DOWN THE EXACT TIMING OF THIS
SYSTEM...SO MAINLY LEFT THE FORECAST EARLY NEXT WEEK THE SAME. THIS
WILL NEED TO BE MONITORED WITH THE NEXT THE NEXT FORECAST PACKAGE.
MKK
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...FROST ADVISORY UNTIL 8 AM PDT THIS MORNING CAZ002-003.
FREEZE WARNING UNTIL 8 AM PDT THIS MORNING CAZ004-076.
NORTHWEST CALIFORNIA COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 9 AM PDT THIS MORNING
PZZ450-455-470-475.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.EUREKA.GOV
HTTP://WWW.TWITTER.COM/NWSEUREKA
|
