Weather Blog

Saturday Storm Blog

Saturday Storm Blog

Here are the latest events from the storm that's rolling through on Oct. 17:

4:45 p.m.: Here is time lapse video of one cell as it moved over Seattle, taken from our tower camera atop the Columbia Center building.

4:40 p.m.: Big storms up north in Whatcom County too:

...SIGNIFICANT WEATHER ADVISORY FOR WESTERN WHATCOM AND EXTREME NORTHWESTERN SKAGIT COUNTIES UNTIL 530 PM PDT...

AT 439 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM NEAR ACME...MOVING NORTHEAST AT 35 MPH.

WIND GUSTS TO 50 MPH ARE LIKELY WITH THIS STORM. FUNNEL CLOUDS ARE ALSO A POSSIBILTY WITH THESE STORMS. 

* LOCATIONS IMPACTED INCLUDE... VAN ZANDT...DEMING AND LAWRENCE... MAPLE FALLS... GLACIER...

3:55 p.m.: Storm near Bothell might have rotation for funnel cloud!

...SIGNIFICANT WEATHER ADVISORY FOR WESTERN SNOHOMISH AND NORTHWESTERN KING COUNTIES UNTIL 430 PM PDT... 
 
AT 349 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM NEAR BOTHELL...MOVING NORTHEAST AT 35 MPH. 

HAIL UP TO A HALF INCH IN DIAMETER AND WIND GUSTS TO 45 MPH ARE LIKELY WITH THIS STORM. THIS STORM HAS WEAK ROTATION AND MAY PRODUCE A FUNNEL CLOUD IF THE STORM STRENGTHENS FURTHER.
 
* LOCATIONS IMPACTED INCLUDE... 
  CATHCART...CLEARVIEW AND SILVER LAKE-FIRCREST... 
  SNOHOMISH... 
  MONROE... 
  VERLOT AND ROBE... 

3:45 p.m.: Well, that was a nice dousing. A storm cell developed just west of Seattle and drenched the area with a very brief but powerful rain.  The storm continues to intensify as it races NE toward Woodinville and Snohomish.

3:35 p.m.: Big Storm Forms Near Cinebar:

EAST PUGET SOUND LOWLANDS-WEST SLOPES CENTRAL CASCADES AND PASSES-
331 PM PDT SAT OCT 17 2009

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN LEWIS...CENTRAL PIERCE AND EXTREME SOUTHEASTERN THURSTON COUNTIES UNTIL 430 PM PDT...

AT 328 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 6 MILES NORTHEAST OF CINEBAR...MOVING NORTHEAST AT 35 MPH.

HAIL UP TO A HALF INCH IN DIAMETER AND WIND GUSTS TO 45 MPH ARE LIKELY WITH THIS STORM.

* LOCATIONS IMPACTED INCLUDE... ALDER AND MINERAL...  ELBE...  EATONVILLE... KAPOWSIN... WILKESON... THIS STORM MAY INTENSIFY. MONITOR LOCAL RADIO OR TV STATIONS FOR THE LATEST INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

2:30 p.m.: Beware the "Sucker Sunbreaks" over Seattle right now. The pattern is shifting from the widespread rains of this morning to more scattered showers and sunbreaks this afternoon with the "showers" that could become thunderstorms.  If anything, the sun just adds fuel to the fire as the heat will help provide additional lift for storms to form. We're still fairly quiet as of 2:30, but we're seeing more showers in their infant stages start to generate to our southwest and the storms today have been developing pretty quickly, so keep an eye to that radar!

2:00 p.m.:  While we wait for the fireworks to reenergize, our weather situation has captured the attention of the National Weather Service's Storm Prediction Center in Norman, Oklahoma. (They're in charge of issuing Severe Thunderstorm or Tornado Watches across the U.S.) Typically, we're not even on their radar (no pun intended), but today, they're keeping an eye on our weather too.  They don't think it'll be bad enough to warrant a Severe Thunderstorm Watch (which, if it happens, would be the first time -- I believe ever -- that the Puget Sound area would be in one of those) but they'll keep an eye on it.

Here is their discussion -- it's not exactly in Weather 101 speak, but weather geeks here will like it -- http://www.spc.noaa.gov/products/md/md2115.html

Loosely translated, it says conditions are ripe for scattered thunderstorms generating between now and 4 p.m., and marginal for severe thunderstorms, mainly characterized by large hail.

12:55 p.m.: Good sized squall line of thunderstorms has formed, but it waited until it got close to the Cascade foothills to really fire up, so it's missing most of the populated areas. Once that line races off into the mountains, looks like we've got another relative lull here for a while until the unstable air moves in. But these storms form fast and move fast, so keep an eye out.

12:30 p.m.: Lull over. Atmosphere firing up with several showers/thunderstorms now developing. At this point, they are primarily east of I-5 heading toward Cascades. Also good cell between Seattle and Federal Way, heading toward I-405 corridor.

11:55 a.m.: Aside from thunderstorm moving through east King County toward North Bend and lingernig heavy rain on the Olympic Peninsula, we're in a relative lull, but storms are expected to refire as we get into the early afternoon with peak storm times between 2-5 p.m.

11:00: Big storm with 3/4" hail heading toward East King County:

EAST PUGET SOUND LOWLANDS-WEST SLOPES CENTRAL CASCADES AND PASSES- 
1057 AM PDT SAT OCT 17 2009 
 
...SIGNIFICANT WEATHER ADVISORY FOR KING AND NORTHERN PIERCE COUNTIES UNTIL 1145 AM PDT... 
 
AT 1056 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 5 MILES SOUTH OF COVINGTON-SAWYER-WILDERNESS... MOVING NORTHEAST AT 60 MPH. 
 
THIS STORM HAS ALREADY PRODUCED HAIL UP TO THREE QUARTERS OF AN INCH IN DIAMETER. WIND GUSTS TO 45 MPH ARE ALSO POSSIBLE WITH THIS STORM. 
 
* LOCATIONS IMPACTED INCLUDE...  SELLECK AND PALMER...  CEDAR FALLS...  NORTH BEND AND SNOQUALMIE...  SKYKOMISH... 

THIS STORM MAY INTENSIFY. MONITOR LOCAL RADIO OR TV STATIONS FOR THE LATEST INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE. 

10:50 a.m.: Storm totals from Friday/Saturday Rain:

  • Poulsbo: 2.00" , 12 hrs from 7pm to 7am
  • Bellingham: 2.39", 24 hr total at 7 am
  • Nr Bremerton: 2.69", 24hr total at 8 am
  • Sudden Valley (Whatcom Co): 2.14", 24hr total at 8am
  • Edmonds: 1.54", 24 hrs at 8 am
  • Anacortes: 1.25" since midnight
  • Montesano: 2.14" 24hr at 8am
  • Forks: 2.70" 18hrs at 10am

10:35 a.m.: DOT Crews close ramp from SB I-405 to I-90 due to standing water.

10:35 a.m.: 1/4" hail reported in Yelm

10:30 a.m.: Significant Weather Advisory issued for Pierce County until 11:15 a.m.:

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL PIERCE COUNTY UNTIL 1115 AM PDT...

AT 1029 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM NEAR ROY...MOVING NORTHEAST AT 30 MPH.

HAIL UP TO A HALF INCH IN DIAMETER AND WIND GUSTS TO 45 MPH ARE POSSIBLE WITH THIS STORM.

* LOCATIONS IMPACTED INCLUDE...
  FREDERICKSON...ELK PLAIN...GRAHAM...SPANAWAY AND PARKLAND... SOUTH HILL...ORTING AND SUMMIT...  SUMNER...PUYALLUP...PRAIRIE RIDGE...NORTH PUYALLUP AND SOUTH PRAIRIE...

THIS STORM MAY INTENSIFY. MONITOR LOCAL RADIO OR TV STATIONS FOR THE LATEST INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

10:00 a.m.: National Weather Service Issues Special Weather Statement for Severe Weather:

...STRONG THUNDERSTORMS POSSIBLE THIS AFTERNOON...

A RATHER STRONG EARLY FALL COLD FRONT WILL SWEEP NORTHEAST ACROSS WESTERN WASHINGTON LATE THIS MORNING AND EARLY THIS AFTERNOON. THE FRONT WILL BE ACCOMPANIED BY A LINE OF HEAVY SHOWERS AND POSSIBLY A FEW THUNDERSTORMS.

BEHIND THE FRONT...THE AIR MASS WILL BECOME UNSTABLE AS COOLER AIR MOVES IN ALOFT MAKING THE REGION RIPE FOR THE DEVELOPMENT OF THUNDERSTORMS. THIS INSTABILITY WILL BE COMBINED WITH STRONG WIND SHEAR IN THE MID LEVELS OF THE ATMOSPHERE. THAT COMBINATION BRINGS ABOUT THE POTENTIAL FOR ROTATION TO DEVELOP IN ANY STRONG THUNDERSTORMS THAT DO DEVELOP DURING THE AFTERNOON HOURS.

ALTHOUGH TORNADOES ARE RARE IN WESTERN WASHINGTON...WHEN WE DO GET THEM IT IS NORMALLY UNDER SITUATIONS SIMILAR TO THIS WHEN THEY HAPPEN...BUT EVERYTHING HAS TO COME TOGETHER JUST RIGHT. 

THE NATIONAL WEATHER SERVICE WILL BE MONITORING THE SITUATION CLOSELY THROUGH THE EVENING HOURS AND WILL ISSUE STATEMENTS AND WARNINGS AS NEEDED. WE ARE ACTIVATING THE SKYWARN SPOTTER NETWORK AT THIS TIME FOR THE POTENTIAL AFTERNOON CONVECTION AND ARE ASKING FOR CALLS RELATED TO UNUSUAL CONVECTIVE ACTIVITY.