Winter Storm Warning 7, NWS Seattle, WA

292 
WWUS46 KSEW 302155
WSWSEW

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE SEATTLE WA
255 PM PDT MON SEP 30 2013

WAZ518-519-011300-
/O.CON.KSEW.WS.W.0007.000000T0000Z-131001T1300Z/
WEST SLOPES NORTHERN CASCADES AND PASSES-
WEST SLOPES CENTRAL CASCADES AND PASSES-
255 PM PDT MON SEP 30 2013

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 AM PDT
TUESDAY...

* SOME AFFECTED LOCATIONS...PARADISE MOUNT RAINIER...MOUNT BAKER.

* SNOW ACCUMULATIONS...ANOTHER 5 TO 10 INCHES OF SNOW IS EXPECTED
  TO FALL AT THE HIGHER ELEVATIONS OF THE CASCADES THROUGH
  TONIGHT. THE SNOW TURNED TO RAIN AT STEVENS PASS TODAY...BUT
  WILL LIKELY TURN BACK TO SNOW TONIGHT WITH SEVERAL INCHES OF
  SNOW POSSIBLE THERE. SNOQUALMIE PASS WILL REMAIN BELOW THE SNOW
  LEVEL TONIGHT AND SHOULD SEE RAIN SHOWERS. THE HEAVIEST SNOW
  WILL CONTINUE TO FALL ON THE HIGHER PEAKS.

* MAIN IMPACT...TRAVEL MAY BECOME DIFFICULT AT TIMES IN THE HIGH
  CASCADE PASSES. THOSE PLANNING ON ACTIVITIES IN THE BACKCOUNTRY
  SHOULD BE PREPARED FOR COLD WET WEATHER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS WINTER STORM WARNING IS FOR THE FIRST SUBSTANTIAL WINTER WEATHER
OF THE SEASON IN THE CASCADES.

&&

$$

WAZ513-011300-
/O.CON.KSEW.WW.Y.0020.000000T0000Z-131001T1300Z/
OLYMPICS-
255 PM PDT MON SEP 30 2013

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 AM PDT
TUESDAY...

* SNOW ACCUMULATIONS...SEVERAL INCHES OF ADDITIONAL SNOW
  ACCUMULATION ARE LIKELY TONIGHT.

* MAIN IMPACT...THOSE PLANNING ON HIKING OR HUNTING SHOULD BE 
  PREPARED FOR COLD...WET WEATHER. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS WINTER WEATHER ADVISORY IS FOR THE FIRST SIGNIFICANT WINTER
WEATHER OF THE SEASON IN THE OLYMPICS.

&&

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
915 PM PDT SUN SEP 29 2013

.SYNOPSIS...A DEEP LOW PRESSURE CENTER WILL MOVE INLAND OVER
VANCOUVER ISLAND THIS EVENING. THIS IS EXPECTED TO BRING STRONG
WINDS TO PARTS OF WESTERN WASHINGTON TONIGHT. A SHOWERY PATTERN WILL
THEN CONTINUE THROUGH WEDNESDAY WITH A BROAD UPPER TROUGH OVER THE
AREA. A DRIER PERIOD IS POSSIBLE AROUND THURSDAY AND FRIDAY AS HIGH
PRESSURE BUILD OVERHEAD.

&&

.SHORT TERM...A DEEP SURFACE LOW IS CURRENTLY MAKING LANDFALL OVER
VANCOUVER ISLAND...SOMEWHERE BETWEEN COMOX AND PORT HARDY. A
TRAILING COLD IS ALSO MOVING THROUGH THE INTERIOR OF WESTERN
WASHINGTON WITH RAIN CHANGING TO SHOWERS BEHIND THE FRONT. THERE
WERE SOME BRIEF HIGHS WINDS AT THE COAST EARLIER THIS EVENING WITH
THE FRONT. THERE WERE ALSO SOME SPOTTY HIGH WINDS EARLIER AHEAD OF
THE FRONT IN THE NORTHWEST INTERIOR.

THE BIG QUESTION TONIGHT IS HOW MUCH WIND WE WILL GET OVER THE
INTERIOR...ESPECIALLY OVER THE CENTRAL SOUND AND SEATTLE AREA. THE
SURFACE LOW IS MAKING LANDFALL FURTHER NORTH AND WEST THAN EARLIER
EXPECTED. THIS DIMINISHES THE HIGH WIND THREAT FOR THE INTERIOR
TONIGHT AND CONFIDENCE THAT HIGH WINDS WILL VERIFY IS NOT TOO HIGH
ANYMORE. NONETHELESS...WITH THE FRONT JUST MOVING THROUGH AND
SOUTHERLY GRADIENTS RAPIDLY INCREASING...IT DOES NOT SEEM PRUDENT TO
DROP ANY OF THE EXISTING WARNINGS JUST YET. BESIDES THE INCREASING
PRESSURE GRADIENTS...THERE ARE SOME STRONG WINDS JUST OFF THE
SURFACE WHICH COULD MIX DOWN IN THE UNSTABLE AIR BEHIND THE FRONT.

A SECOND LESSER CONCERN WITH THIS SYSTEM IS SNOW IN THE MOUNTAINS.
ELEVATIONS ABOVE ABOUT 5000 FEET PICKED UP A FEW INCHES EARLY TODAY.
SNOW LEVELS HAVE TEMPORARILY RISEN THIS EVENING BUT THEY SHOULD FALL
AGAIN TO 4500 OR 5000 FEET LATER TONIGHT AND MONDAY. MOIST UNSTABLE
ONSHORE FLOW WILL CONTINUE DURING THIS PERIOD. THE HIGHEST PASSES
AND SKI AREAS COULD SEE SEVERAL MORE INCHES OF SNOWFALL MONDAY AND
MONDAY NIGHT.

A THIRD CONCERN TONIGHT IS RIVER FLOODING. SEE THE HYDROLOGY SECTION
BELOW FOR MORE DETAILS.

OTHERWISE...MONDAY WILL BE BREEZY AND SHOWERY IN THE WAKE OF TODAYS
STORM WITH A BROAD UPPER TROUGH OVER THE AREA AND STRONG MOIST
UNSTABLE ONSHORE FLOW. TUESDAY WILL BE ABOUT THE SAME AS MONDAY
ALTHOUGH ONSHORE GRADIENTS AND WINDS WILL BE EASING. THE AIR MASS
WILL BE UNSTABLE ENOUGH FOR A SMALL CHANCE OF THUNDERSTORMS BOTH
DAYS. SCHNEIDER

.LONG TERM...PREVIOUS DISCUSSION...AN UPPER LOW WILL QUICKLY DIVE SE
THROUGH THE PAC NW ON WED...BRINGING THE COOLEST AIR MASS SO FAR
THIS FALL AND SHOWERS. UPPER RIDGING BUILDS IN FROM THE WEST ON
THURSDAY WITH THE RIDGE AXIS PASSING ACROSS ON THURSDAY NIGHT. A
DRIER PERIOD WITH COLDER NIGHTS WILL BE THE RESULT. WESTERLY FLOW
PICKS UP AGAIN NEXT WEEKEND WITH AN OPEN AND PROGRESSIVE UPPER
TROUGH SWING BY OVER THE WEEKEND. THEREFORE...CHANCE OF RAIN GOES
BACK UP NEXT WEEKEND.       HANER

&&

.HYDROLOGY...BRIEF SHOT OF HEAVY RAIN AS THE FRONT MOVES THROUGH THE
AREA THIS EVENING. STORM TOTAL RAINFALL AMOUNTS THROUGH 8 PM TODAY
IN THE MOUNTAINS RANGE FROM 3 TO ALMOST 9 INCHES. MOUNT BAKER
COMBINED RAINFALL FOR THE TWO SYSTEMS IS AT 7.79 INCHES AT 8 PM.
CUSHMAN DAM NEAR THE OLYMPICS IS REPORTING 8.40 INCHES SO FAR. IN
THE LOWLANDS THE SOUTHWEST INTERIOR WAS THE HARDEST HIT WITH A GAUGE
IN THE WILLAPAS 6 MILES SOUTH OF PE ELL REPORTING 8.68 INCHES.
NUMEROUS OTHER SITES IN THE SOUTHWEST INTERIOR HAVE GOTTEN 3 TO 6
INCHES OF RAIN OVER THE WEEKEND. OLYMPIA HAS SET A RECORD FOR THE
WETTEST SEPTEMBER ON RECORD IN THE LAST COUPLE OF HOURS. ANOTHER
INCH OR SO OF RAIN IS POSSIBLE IN THE CASCADES AS THE FRONT MOVES
THROUGH. THE RAINFALL RATES WILL DIMINISH SIGNIFICANTLY LATER THIS
EVENING.

FLOOD WARNING WILL REMAIN IN EFFECT FOR THE SKOKOMISH RIVER IN MASON
COUNTY AND FOR THE NEWAUKUM IN LEWIS COUNTY. WHILE THE PUYALLUP NEAR
ORTING IS ON THE RISE THIS EVENING AT THIS POINT IT LOOKS LIKE THE
RIVER WILL CREST BELOW FLOOD STAGE AND THE WARNING WILL DROPPED
WITHIN THE HOUR. THE FLOOD WATCH WILL REMAIN IN EFFECT UNTIL THE
FRONT CLEARS THE AREA. UNLESS RAINFALL AMOUNT COME IN SIGNIFICANTLY
HIGHER THAN EXPECTED THE WATCH WILL BE ENDED FOR MOST OF THE AREA
LATER TONIGHT. WITH THE HEAVY RAIN OVER THE SOUTHWEST INTERIOR THERE
IS STILL A THREAT OF MINOR FLOODING ON THE LOWER CHEHALIS RIVER LATE
MONDAY OR TUESDAY. FELTON

&&

.AVIATION...A 970 MB LOW MOVING ONSHORE OVER NORTH CENTRAL VANCOUVER
ISLAND WILL MOVE NE TONIGHT. THE LOW DEEPENED MORE THAN EARLIER
EXPECTED AND CURVED MORE TO THE NORTH. THIS IS SPARING WESTERN
WASHINGTON THE WORST OF THE WIND ASSOCIATED WITH THIS LOW. STILL
SWLY PRES GRADIENTS ARE RAPIDLY INCREASING THIS EVENING AND IT WILL
BE QUITE WINDY AND SHOWERY ACROSS THE AREA TONIGHT. KATX RADAR SHOWS
45 TO 50 KT SWLY WIND AT 1500 FT THIS EVENING. SOME OF THESE WINDS
WILL MIX DOWN TO THE SURFACE IN GUSTS THROUGH THE EARLY MORNING
HOURS. 45 TO 50 KT SW TO W FLOW AT 3000 FT OVER THE COASTAL WATERS
WILL GIVE STRONG GUSTS IN THE COASTAL ZONES OVERNIGHT AS WIND MIXES
DOWNWARD WITH COLD AIR ADVECTION.

CEILINGS IMPROVED LATE THIS AFTERNOON AS LOW LEVEL PRES GRADIENTS
WENT OFFSHORE WITH THE APPROACH OF THE OFFSHORE FRONT. WITH THE
FRONT NOW MOVING THROUGH...FLOW IS TURNING SWLY...SO EXPECT MAINLY
MVFR CONDITIONS THRU MONDAY WITH 3-5SM SHRA BKN015-025 AND BKN
LAYERS ABOVE. THE MOUNTAINS WILL BE MAINLY OBSCURED THRU MON.
ALBRECHT

KSEA...MVFR CONDITIONS WILL DOMINATE WITH VIS 4SM SHRA CIGS
BKN015-020. S TO SW WIND 30G40 KT THROUGH ABOUT 06Z WILL GRADUALLY
DECREASE TO SW 25G35KT LATE TONIGHT AND SW 15G25KT ABOUT 15Z MON
ONWARD. SW WIND 50 KT AT FL 020 AT 04Z WILL EASE TO 40-45 KT AFTER
MIDNIGHT AND FALL TO 30-35 KT AT 020 BY 15Z MON. ALBRECHT

&&

.MARINE...A DEEP 970 MB LOW IS MOVING INLAND OVER NORTH CENTRAL
VANCOUVER ISLAND. WINDS OVER THE COASTAL WATERS ARE SW 35 TO 45 KT
WITH GUSTS AROUND 50 KT. THESE WESTERLY WINDS WILL SPREAD IN THROUGH
THE STRAIT OF JUAN DE FUCA THIS EVENING. STORM FORCE SE WIND GUSTS
WERE REPORTED AHEAD OF THE FRONT EARLIER THIS EVENING OVER THE
NORTHERN INLAND WATERS...WINDS HAVE EASED SOMEWHAT AT 04Z...AND WILL
SHIFT TO SW AND INCREASE TO 30 TO 40 KT WITH GUSTS TO 50 KT AS THE
LOW TO THE NORTH MOVES OFF TO THE NE. SLY PRES GRADIENTS ARE RAPIDLY
INCREASING OVER PUGET SOUND AT 04Z AND WINDS ARE INCREASING TO GALE
FORCE AT THIS TIME.

SINCE GRADIENTS ARE CURRENTLY INCREASING RAPIDLY AND THE FRONT OVER
PUGET SOUND IS MOVING INLAND...WILL MAINTAIN STORM WARNINGS FOR ALL
WATERS THIS EVENING AND WILL LIKELY ISSUE A FULL MARINE UPDATE
AROUND 11 PM AS THE PICTURE EVOLVES.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...HIGH WIND WARNING FOR THE COAST...WESTERN STRAIT...OLYMPICS...
     THE NORTH INTERIOR...AND THE EVERETT AND SEATTLE AREAS.

     WIND ADVISORY FOR THE TACOMA AREA...SOUTHWEST INTERIOR...
     LOWER CHEHALIS VALLEY AND EASTERN STRAIT OF JUAN DE FUCA.

     FLOOD WATCH ENTIRE AREA EXCEPT ISLAND AND SAN JUAN COUNTIES.

     HIGH SURF WARNING FOR THE COAST.

     WINTER WEATHER ADVISORY FOR THE MOUNTAINS ABOVE 5000 FEET.

PZ...STORM WARNING ALL WATERS.

     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SEATTLE WA
1227 AM PDT MON SEP 30 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0604 PM     HIGH SUST WINDS  6 WSW FERNDALE          48.82N 122.71W
09/29/2013  M40.00 MPH       WHATCOM            WA   MESONET

0728 PM     NON-TSTM WND GST HURRICANE RIDGE         48.00N 123.48W
09/29/2013  M85.00 MPH       CLALLAM            WA   PARK/FOREST SRVC

0818 PM     HIGH SUST WINDS  WESTPORT                46.89N 124.11W
09/29/2013  M42.00 MPH       GRAYS HARBOR       WA   OTHER FEDERAL

            SUSTAINED WINDS OF 40 TO 50 MPH AT TIMES BETWEEN 8 P.M.
            AND 10 P.M. PDT. WIND GUST TO 60 MPH AT 824 P.M. PDT.

&&

WWW.WEATHER.GOV