WIND ADVISORY
Issue Date: 917 PM PST FRI DEC 25 2009
Expiration: 400 PM PST SAT DEC 26 2009

...AIR STAGNATION ADVISORY REMAINS IN EFFECT FOR THE SEATTLE-
BREMERTON AND TACOMA AREAS UNTIL 10 AM PST SATURDAY...
...WIND ADVISORY IN EFFECT FOR THE EAST PORTIONS OF THE SEATTLE
AND TACOMA METRO AREAS FROM MIDNIGHT TONIGHT TO 4 PM PST
SATURDAY...
THE NATIONAL WEATHER SERVICE IN SEATTLE HAS ISSUED A WIND
ADVISORY FOR THE EAST PORTIONS OF THE SEATTLE AND TACOMA METRO
AREAS...WHICH IS IN EFFECT FROM MIDNIGHT TONIGHT UNTIL 4 PM PST
SATURDAY. AN AIR STAGNATION ADVISORY REMAINS IN EFFECT UNTIL 10 AM
PST SATURDAY.
* EAST WINDS OF 25 TO 35 MPH WITH GUSTS TO NEAR 50 MPH WILL
  DEVELOP LATE TONIGHT MAINLY EAST OF STATE ROUTES 167 AND 161.
  THE STRONG WINDS WILL THEN PERSIST THROUGH SATURDAY MORNING
  BEFORE DIMINISHING IN THE AFTERNOON. THERE IS A POSSIBILITY THAT
  WINDS COULD GUST AS HIGH AS 55 MPH SATURDAY MORNING.
* AREAS MOST PRONE TO STRONG EAST WINDS ARE RENTON...KENT...
  AUBURN...AND SUMNER.
* THOSE...ESPECIALLY WITH HIGH PROFILE VEHICLES...PLANNING TRAVEL ON
  STATE ROUTES 161 AND 167 SHOULD BE PREPARED FOR SUDDEN...STRONG
  CROSS WINDS LATER TONIGHT AND SATURDAY.
* A STRONG LOW LEVEL INVERSION WILL PREVENT MUCH MIXING FROM
  OCCURRING OVER THOSE AREAS NOT PRONE TO STRONG EAST WINDS. THIS
  WILL ALLOW POLLUTANTS LIKE WOOD SMOKE AND INDUSTRIAL EMISSIONS
  TO ACCUMULATE AND REDUCE AIR QUALITY.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A WIND ADVISORY IS ISSUED WHEN SUSTAINED WINDS OF 30 TO 39 MPH OR
GUSTS OF 45 TO 57 MPH ARE LIKELY. WINDS THIS STRONG CAN SNAP
SMALL TREE BRANCHES...TOPPLE SMALL OR SHALLOW-ROOTED TREES...AND
CAUSE LOCAL POWER OUTAGES.
AN AIR STAGNATION ADVISORY IS ISSUED WHEN LOCALLY ESTABLISHED
CRITICAL VALUES OF TRANSPORT WINDS...MIXING HEIGHT...AND
VENTILATION ARE EXPECTED TO PERSIST FOR AT LEAST 72 HOURS. CHECK
WITH YOUR LOCAL AIR QUALITY AGENCY FOR POSSIBLE RESTRICTIONS IN
YOUR AREA.
&&
$$

HIGH WIND WARNING
Issue Date: 917 PM PST FRI DEC 25 2009
Expiration: 400 PM PST SAT DEC 26 2009

...HIGH WIND WARNING IN EFFECT FOR THE EAST WIND PRONE AREAS OF
THE EAST PUGET SOUND LOWLANDS UNTIL 4 PM PST SATURDAY...
...AIR STAGNATION ADVISORY IS CANCELLED...
THE NATIONAL WEATHER SERVICE IN SEATTLE HAS ISSUED A HIGH WIND
WARNING...WHICH IS IN EFFECT UNTIL 4 PM PST SATURDAY. DUE TO
IMPROVED MIXING IN RESPONSE TO INCREASING EAST WINDS...THE AIR
STAGNATION ADVISORY ISSUED EARLIER FOR THE EAST PUGET SOUND
LOWLANDS HAS BEEN CANCELLED.
* DAMAGING WINDS OF 40 TO 50 MPH WITH GUSTS NEAR 65 MPH WILL
  DEVELOP OVERNIGHT ACROSS THOSE AREAS PRONE TO EAST WINDS. THE
  HIGH WINDS WILL THEN PERSIST THROUGH SATURDAY MORNING BEFORE
  WINDING DOWN IN THE AFTERNOON.
* SOME AREAS MOST PRONE TO DAMAGING EAST WINDS ARE NORTH BEND...
  BLACK DIAMOND...ENUMCLAW...BUCKLEY...AND ORTING.
* A SPOTTER IN NORTH BEND HAS ALREADY MEASURED EAST WINDS OF 40
  MPH WITH GUSTS NEAR 50 MPH. THE HIGH WINDS WILL BECOME MORE
  WIDESPREAD OVERNIGHT ACROSS THOSE AREAS FAVORABLE TO EAST WINDS.
* THOSE...ESPECIALLY WITH HIGH PROFILE VEHICLES...TRAVELLING ON
  NORTH- SOUTH ORIENTED HIGHWAYS SUCH AS PORTIONS OF STATE ROUTE
  169 SHOULD BE ALERT FOR SUDDEN AND VERY STRONG CROSS WINDS.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A HIGH WIND WARNING MEANS THAT A HAZARDOUS WIND EVENT IS IMMINENT
OR OCCURRING. HIGH WINDS CAN TOPPLE TREES...DOWN POWER LINES...
AND DESTROY PROPERTY.
&&
$$

AIR STAGNATION ADVISORY
Issue Date: 438 PM PST FRI DEC 25 2009
Expiration: 1000 AM PST SAT DEC 26 2009

...AIR STAGNATION ADVISORY REMAINS IN EFFECT UNTIL 10 AM PST
SATURDAY...
AN AIR STAGNATION ADVISORY REMAINS IN EFFECT UNTIL 10 AM PST
SATURDAY.
STRONG HIGH PRESSURE ALOFT WILL PERSIST OVER THE REGION THROUGH
SATURDAY...TRAPPING COLD AIR NEAR THE SURFACE UNDER WARM AIR
ALOFT. THE RESULTING LACK OF ATMOSPHERIC VENTILATION WILL ALLOW
POLLUTANTS LIKE WOOD SMOKE AND VEHICLE AND INDUSTRIAL EMISSIONS
TO ACCUMULATE...DEGRADING AIR QUALITY. THE MOST LIKELY PLACES TO
EXPERIENCE REDUCED AIR QUALITY ARE ALONG THE I-5 CORRIDOR OF
THURSTON AND PIERCE COUNTIES.
WINDS WILL PREVENT STAGNATION ALONG THE COAST...THE STRAIT OF
JUAN DE FUCA AND ALSO ACROSS THE SAN JUAN ISLANDS. THE OLYMPIC
AND CASCADE MOUNTAINS WILL ALSO BE ABOVE THE STAGNANT INVERSION
LAYER. THEREFORE THESE AREAS ARE NOT INCLUDED IN THE ADVISORY.
GAP WINDS THROUGH THE CASCADE PASSES ARE EXPECTED THROUGH
SATURDAY. AS A RESULT...GOOD AIR QUALITY IS EXPECTED NEAR THE
CASCADE FOOTHILLS...EAST PUGET SOUND LOWLANDS... AND SOME OTHER
AREAS FROM KING COUNTY NORTHWARD.
CHECK WITH YOUR LOCAL AIR QUALITY AGENCY FOR POSSIBLE
RESTRICTIONS IN YOUR AREA.
$$