River Flood Advisory 4, NWS Seattle, WA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
940 AM PST WED MAR 9 2011

.SYNOPSIS...A SERIES OF PACIFIC STORMS WILL BRING WET AND UNSETTLED
WEATHER TO THE REGION THIS WEEK. THE FIRST STORM WILL BRING GUSTY
WINDS TO THE AREA TODAY AS WELL AS LOCALLY HEAVY SNOW TO THE
MOUNTAINS. A STRONGER SYSTEM WILL BRING A THREAT OF HIGH WINDS TO
THE COAST AND NORTHWEST INTERIOR ON THURSDAY. ANTICIPATE MORE
SETTLED CONDITIONS ON FRIDAY BETWEEN SYSTEMS.

&&

.SHORT TERM...SURFACE OBS SHOW THE COLD FRONT MOVED THROUGH THE
COASTAL WATERS BUOYS...TATOOSH AND DESTRUCTION ISLAND AND BUOY
041...AT 15Z. FRONT IS ALONG THE COAST AT 17Z AND WILL CONTINUE TO
MOVE INLAND MOVING THROUGH THE INTERIOR MIDDAY AND INTO THE CASCADES
IN THE AFTERNOON. STRONGEST WINDS ALONG THE COAST AND OVER THE
NORTHWEST INTERIOR WILL BE AHEAD OF AND WITH THE FRONT. SATELLITE
IMAGERY SHOWS MOST OF THE SHOWER ACTIVITY BEHIND THE FRONT WRAPPING
AROUND THE LOW WHICH IS JUST SOUTHWEST OF HAIDA GWAII. THE NEXT
SYSTEM FORECASTED TO MOVE INTO WESTERN WASHINGTON BEGINNING TO
DEVELOP BACK OUT NEAR 41N/138W. SURFACE LOW ASSOCIATED WITH THIS
FEATURE EXPECTED TO DEEPEN DOWN INTO THE LOW TO MID 990 MB RANGE AS
IT TRACKS NORTHEAST IN THE NEXT 24 HOURS. BY 12Z THURSDAY THE LOW
WILL BE ABOUT 200 NM W OF KHQM WITH THE PRECIPITATION ASSOCIATED
WITH THE FRONT SPREADING OVER WESTERN WASHINGTON TONIGHT. SURFACE
LOW CONTINUING TO TRACK NORTHEAST INTO SOUTHERN BRITISH COLUMBIA
THURSDAY AFTERNOON. WILL STAY WITH THE HIGH WIND WATCH FOR THE COAST
AND NORTHWEST INTERIOR. WINDS INCREASING FOR THE CENTRAL AND
SOUTHERN INTERIOR THURSDAY AFTERNOON WITH THE KOLM-KBLI GRADIENTS
STILL FORECASTED TO BE NEAR PLUS 6 MB BY 00Z FRIDAY. IF THIS TREND
CONTINUES WILL ISSUE A WIND ADVISORY FOR PORTIONS OF THE INTERIOR
WITH THE AFTERNOON PACKAGE. A BRIEF BREAK IN THE ACTION STILL IN
STORE FOR LATER THURSDAY NIGHT INTO FRIDAY AS THE NEXT SYSTEM,
STALLS OFFSHORE WITH THE TROUGH WITH THE FRONT DIGGING SOUTH TO OFF
THE NORTHERN CALIFORNIA COAST. CURRENT FORECAST HAS THE TRENDS
COVERED. NO UPDATE THIS MORNING. FELTON

.LONG TERM...PREVIOUS DISCUSSION FOLLOWS.
A SERIES OF PAC STORMS WILL CONTINUE TO AFFECT THE REGION DURING
THIS PERIOD...RESULTING IN A WET AND UNSETTLED WEATHER PATTERN.

&&

.HYDROLOGY...A SERIES OF FRONTS WILL MOVE THROUGH WESTERN WASHINGTON
IN THE NEXT WEEK. IT STILL DOES NOT APPEAR THAT A MAJOR
FLOOD-PRODUCING PATTERN WILL DEVELOP DUE TO THE PROGRESSIVE NATURE
OF THE FRONTS AND THE RELATIVELY LOW FREEZING LEVELS.

HEAVY RAINFALL ON THE SOUTH SLOPES OF THE OLYMPICS IN THE NEXT 24
HOURS COULD PUSH THE SKOKOMISH RIVER UP TO NEAR FLOOD STAGE. CURRENT
GUIDANCE PUTS THE RIVER JUST A FEW INCHES BELOW FLOOD STAGE THURSDAY
MORNING. WILL KEEP AN EYE ON THE RIVER TODAY AND ISSUE AN ADVISORY
IF NEEDED LATER THIS AFTERNOON.

FLOODING IS NOT EXPECTED ON ANY OF THE OTHER AREA RIVERS
/EXCEPT POSSIBLY THE SKOKOMISH/...INCLUDING THE GREEN...DURING THE
NEXT TEN DAYS. FELTON

&&

.AVIATION...STRONG FNTL SYS MOVG THRU WRN WA TDY. DEEP LOW PRES WELL
OFFSHORE WILL MOVE NE AND FILL. STRONG SLY FLOW ALF WILL DIMINISH BY
EVENING. THE AIR IS STABLE AND MOIST. AT THE SURFACE STRONG
SOUTHEASTERLY GRADIENTS WILL CONTINUE TODAY...THEN TURN MORE SW AND
DIMINISH THIS EVENING. ANOTHER ROUND OF BLUSTERY WINDS THURSDAY AS
THE NEXT FNTL SYS AND LOW PRES CENTERED THIS MORNING NEAR 40N 140W
MOVES THRU THE REGION. AREAS OF MVFR CIGS AND VSBY WITH RAIN THIS
MORNING...TURNING TO SCATTERED SHOWERS THIS AFTERNOON. ANOTHER ROUND
OF RAIN TURNING TO SHOWERS WITH THE FROPA THU. 19

KSEA...SLY WIND WITH RAIN THIS MORNING TURNING TO SCATTERED SHOWERS
THIS AFTERNOON. ANOTHER FNTL SYS ON THU AND BLUSTERY SLY WINDS
DEVELOPING IN THE AFTERNOON. THE SLY GRADIENT COULD BE STRONGER THU
AFTERNOON WITH GUSTS TO ARND 30KT PM THU.

&&

.MARINE...SEEMS LIKE THE SECOND WEEK OF NOVEMBER. ONE GALE MOVG THRU
THIS MORNING AND ANOTHER WILL MOVE THRU WRN WA ON THU. TODAYS SYSTEM
IS MORE OF A SE SUCKER WITH THE DEEP 983MB LOW CENTER AT 51N 133W AT
8AM THIS MORNING...IT MOVES NE AND FILLS. THE NEXT SFC LOW IS NOT AS
DEEP BUT IT TRACKS MUCH CLOSER AND THE BENT BACK TROF WILL GIVE WRN
WA STRONG SLY GRADIENTS THU AFTERNOON AND EVENING...WITH GALES ALSO
LIKELY ON PUGET SOUND BY THAT TIME. 19

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WINTER STORM WARNING IN EFFECT FOR THE CASCADES ABOVE 3500 FT
     TODAY.

     A WINTER WEATHER ADVISORY IS IN EFFECT FOR THE OLYMPICS ABOVE
     3500 FT TODAY.

     HIGH WIND WATCH IN EFFECT FOR THE COAST AND NORTHWEST INTERIOR
     THU.

     A WIND ADVISORY IN IN EFFECT FOR THE NORTHWEST INTERIOR UNTIL
      NOON.

PZ...A GALE WARNING IS IN EFFECT FOR THE COASTAL WATERS...ENTRANCES
     TO THE STRAIT OF JUAN DE FUCA...NORTHERN INLAND WATERS...
     AND ADMIRALTY INLET.

     SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE REMAINING
     WATERS.

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