Weekly Weather, Jan 22nd - 28th

Warmest and coldest days are based on average temperature of the entire day, starting at midnight.  Averages are based on the whole week.

Warmest day: 45.9ºF (Tied between Monday and Tuesday)

Coldest day: 41.7ºF (Thursday)

Rainiest day: 0.26 inches (Monday)

Average temperature: 44.0ºF

Highest temperature: 52.2ºF (Wednesday)

Lowest temperature: 37.0ºF (Thursday)

Total Rainfall: 0.43 inches.

Highest humidity: 100%

Lowest humidity: 81%

Average humidity: 100%

High pressure: 29.884 inches

Low pressure: 29.323 inches

Average pressure: 29.657 inches.

Weather highlights this week:

-0.26 inches of rain on Monday.

Weather for the coming week:

-Possible lowland snow on Sunday morning, or maybe late Saturday night.  Nothing wide spread.  Shoreline and Lake Forest Park may completely be missed by this event.

-Continued more dry weather, however cooler temperatures.

Weekly Weather, Jan 15th - 21st, 2011.

Warmest and coldest days are based on average temperature of the entire day, starting at midnight.  Averages are based on the whole week.

Warmest day: 52.4ºF (Sunday)

Coldest day: 36.9ºF (Wednesday)

Rainiest day: 0.59 inches (Saturday)

Average temperature: 43.8ºF

High temperature: 54.9ºF (Sunday)

Low temperature: 32.5ºF (Thursday)

Total rainfall: 1.63 inches

High humidity: 100% (Every day)

Low humidity: 73% (Wednesday)

Average humidity: 98%

High pressure: 29.943 inches (Wednesday)

Low pressure: 29.176 inches (Sunday)

Average pressure: 29.586 inches

Weather Highlights:

-Some strong breezy conditions on Sunday

-Thursday morning there was some ice pellets mixed with rain for most of the morning. 

The week ahead:

-I don’t think we’ll see anything significant this week.

Potential wet snow mixed rain tonight?

I think there is a remote chance for a possible rain and snow mixed, or snow shower tonight.  Cold air is lightly flowing down from the north due to a weak low pressure in Oregon.  When these are stronger low pressures it typically becomes a snow maker.  I'm not sure how cold the air in B.C. is right now, it may not be cold enough after last weekends march of mild moist storms through the region.  However, I think a good chance is still there.  Temperatures dropped this afternoon from 41°F down to 37°F, still dropping.

Weekly Weather, Jan 1/8 - 1/14 2011.

Warmest and coldest days are based on average temperature of the entire day, starting at midnight.  Averages are based on the whole week.

Warmest Day: 50.4ºF (Friday)

Coldest Day: 31.7ºF (Tuesday the snowy night)

Wettest Day: 1.71 inches (Mostly snow melt on Wednesday)

Rainiest Day: 0.59 inches (Thursday)

Average Temperature: 39.0ºF

High Temperature: 53.4ºF

Low Temperature: 26.4ºF

Total Rainfall: 2.48 inches

High Humidity: 100%

Low Humidity: 31%

Average Humidity: 88%

High Pressure: 29.766 inches

Low Pressure: 29.146 inches

Average Pressure: 29.5 inches.

Here’s how we are doing temperature wise compared to this month last year:

Snow event, then rapid melting

N 194th ST from Corliss Ave N.  Photo by: Carl Dinse

Time line:      
      Snow started falling right about 7:15pm Tuesday night.  Heavier snow hit at around 9pm at which point about 1 inch had accumulated.  At 1am we had 4-5 inches of snow on the ground depending on the area and elevation.  The rain started to mix in at about 2:15am Wednesday Morning but it was off and on snow and rain until about 6am.  After 6am the temperature rose sharply and all precipitation turned to 100% rain.  It also got quite breezy this morning and afternoon.


Here's the weather graph for the duration of the snow event:

Snow Melting and warmer weather is here:
       As the snow melted and temperatures warmed, even though it stopped raining at about 9am the rain gauge was measuring rain for most of the day as the snow piled in the rain gauge melted down.  Including the snow melt off, we've recorded 1.37 inches of rain so far since midnight.  More rain is on the way and it's expected to be very wet.  Land and mud slides may be a risk once again.

Overall:
Total snow accumulation at the weather station at 2am was 4.25 inches.  It begin to melt off after that time.  No freezing rain occurred in Shoreline so we only had to deal with a slushy wet mess for the morning commute hours, no ice thankfully.

Snow Depths

I did a little drive around Shoreline while getting gas and stopping at top foods.  Snow depth at the Rec Center was 5 inches.   Here in the Northeast corner of Echo Lake Neighborhood it is 4 inches.  Temperatures have warmed to 32.0ºF however have held steady at 32.0ºF for the past 2 hours.  The Winter Weather Advisory has been extended to 7 AM by the national weather service.  I will have a storm total accumulation when the change over to rain occurs or when the snow stops, whichever comes first.

Winter weather advisory has been extended.

The winter weather advisory has now been extended to 5 am for the Seattle, Everett area.  1-3 inches still expected, locally higher amounts. 

I am making my own prediction for Shoreline to be about 4-6 inches.  I am closely watching the rate of the warmer air to guess when the snow might change to rain, or freezing rain.  Temperature right now is 30ºF and holding steady, dropped from 35ºF in about an hour when the snow started falling.  At the moment, I am predicting the snow to change over to rain at about 2-3am.   I think there is also a strong chance that the cold air will hold here in Shoreline later than that, possibly through day break tomorrow morning.  Easterly winds are still running strong right now to support the cold air flow.

If a surface low develops south of the state, or south of the city it could continue the cold air flow for a prolonged period of time.  Anything is possible right now as this storm is somewhat dis-organized now.

Winter Weather Advisory issued

WAZ001-505>510-514-515-120600- /O.CON.KSEW.WW.Y.0006.110112T0000Z-110112T1200Z/ SAN JUAN COUNTY-EAST PUGET SOUND LOWLANDS-WESTERN SKAGIT COUNTY- EVERETT AND VICINITY-SEATTLE/BREMERTON AREA-TACOMA AREA- ADMIRALTY INLET AREA-EASTERN STRAIT OF JUAN DE FUCA- WESTERN STRAIT OF JUAN DE FUCA- 1059 AM PST TUE JAN 11 2011

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 4 PM THIS AFTERNOON TO 4 AM PST WEDNESDAY FOR THE SAN JUAN ISLANDS...WESTERN SKAGIT COUNTY...ADMIRALTY INLET...EVERETT AND VICINITY...EAST PUGET SOUND LOWLANDS...SEATTLE BREMERTON AREA...TACOMA AREA AND STRAIT OF JUAN DE FUCA...
A WINTER WEATHER ADVISORY FOR THE SAN JUAN ISLANDS...WESTERN SKAGIT COUNTY...ADMIRALTY INLET...EVERETT AND VICINITY...EAST PUGET SOUND LOWLANDS...SEATTLE BREMERTON AREA...TACOMA AREA AND STRAIT OF JUAN DE FUCA REMAINS IN EFFECT FROM 4 PM THIS AFTERNOON TO 4 AM PST WEDNESDAY.
* ACCUMULATIONS...ONE TO THREE INCHES OF SNOW LIKELY. LOCALLY HEAVIER ACCUMULATIONS ARE POSSIBLE NEAR THE CASCADE FOOTHILLS.
* TIMING...SNOW WILL BEGIN LATE THIS AFTERNOON AND CHANGE TO RAIN AFTER MIDNIGHT.
* IMPACTS...EXPECT WINTER WEATHER TRAVEL CONDITIONS.
* MAJOR IMPACT...SNOW IS LIKELY TO START FALLING DURING THE AFTERNOON COMMUTE PERIOD. PEOPLE SHOULD SERIOUSLY CONSIDER FINISHING THEIR AFTERNOON COMMUTE EARLY TODAY IF AT ALL POSSIBLE.
* FREEZING RAIN...THERE IS A POSSIBILITY OF BRIEF FREEZING RAIN DURING THE CHANGE FROM SNOW TO RAIN. FREEZING RAIN IS EVEN WORSE FOR MOTORISTS THAN SNOW.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF SNOW...SLEET...OR FREEZING RAIN WILL CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR SLIPPERY ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE DRIVING.
&&
$$
WAZ513-120600- /O.CON.KSEW.WW.Y.0006.110112T0000Z-110112T2100Z/ OLYMPICS- 1059 AM PST TUE JAN 11 2011

WWW.WEATHER.GOV/SEATTLE

National Weather Service of Seattle has issued a Winter Storm Watch

The following is the winter storm watch from the national weather service.


WWUS46 KSEW 110319
WSWSEW

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE SEATTLE WA
719 PM PST MON JAN 10 2011

WAZ001-503>512-514>517-111330-
/O.EXB.KSEW.WS.A.0001.110111T2100Z-110112T1800Z/
SAN JUAN COUNTY-WESTERN WHATCOM COUNTY-SOUTHWEST INTERIOR-
EAST PUGET SOUND LOWLANDS-WESTERN SKAGIT COUNTY-
EVERETT AND VICINITY-SEATTLE/BREMERTON AREA-TACOMA AREA-
ADMIRALTY INLET AREA-HOOD CANAL AREA-LOWER CHEHALIS VALLEY AREA-
EASTERN STRAIT OF JUAN DE FUCA-WESTERN STRAIT OF JUAN DE FUCA-
NORTH COAST-CENTRAL COAST-
719 PM PST MON JAN 10 2011

...WINTER STORM WATCH IN EFFECT FROM TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING FOR THE LOWLAND AREAS OF WESTERN WASHINGTON...
THE NATIONAL WEATHER SERVICE IN SEATTLE HAS ISSUED A WINTER STORM WATCH FOR THE LOWLAND AREAS OF WESTERN WASHINGTON...WHICH IS IN EFFECT FROM TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING.
* ACCUMULATIONS...LATEST MODEL RUNS SHOW ONE TO THREE INCHES OF SNOW ARE POSSIBLE OVER THE SEATTLE METROPOLITAN AREA...THE CENTRAL COAST...AND THE SOUTHWEST INTERIOR TUESDAY EVENING. HEAVIER AMOUNTS...SIX TO NINE INCHES...ARE LIKELY ALONG HOOD CANAL. HEAVIER AMOUNTS ARE ALSO LIKELY IN THE NORTHWEST INTERIOR...THREE TO FIVE INCHES...AND THE STRAIT OF JUAN DE FUCA AREA...ONE TO FIVE INCHES WITH THE HEAVIER AMOUNTS OVER THE WEST PART. THE NORTH COAST COULD ALSO GET THREE TO FIVE INCHES.
* TIMING...SNOW WILL BEGIN ON THE COAST AND SOUTHWEST INTERIOR TUESDAY AFTERNOON AND CHANGE TO RAIN TUESDAY EVENING. SNOW WILL BEGIN IN THE SEATTLE AREA AND THE STRAIT OF JUAN DE FUCA AREA LATE TUESDAY AFTERNOON AND CHANGE TO RAIN AFTER MIDNIGHT. SNOW WILL BEGIN IN THE HOOD CANAL AREA AND THE NORTHWEST INTERIOR LATE TUESDAY AFTERNOON AND PERSIST INTO WEDNESDAY MORNING.
* IMPACTS...WINTER STORM AMOUNTS ARE FORECAST FOR THE HOOD CANAL AREA...THE NORTHWEST INTERIOR...THE WESTERN STRAIT AREA...AND THE NORTH COAST. TRAVEL WILL BE SIGNIFICANTLY IMPEDED IN THOSE AREAS. LESS SNOW...ONE TO THREE INCHES...IS FORECAST FOR OTHER AREAS INCLUDING THE SEATTLE METROPOLITAN AREA.
* MAJOR IMPACT...SNOW IS LIKELY TO START FALLING RIGHT DURING THE TUESDAY AFTERNOON COMMUTE PERIOD IN THE SEATTLE METROPOLITAN AREA. IF THIS STILL APPEARS TO BE LIKELY ON TUESDAY...PEOPLE SHOULD SERIOUSLY CONSIDER FINISHING THEIR AFTERNOON COMMUTE EARLY ON TUESDAY IF AT ALL POSSIBLE.
* FREEZING RAIN...THERE IS A POSSIBILITY OF FREEZING RAIN DURING THE CHANGE FROM SNOW TO RAIN. FREEZING RAIN IS EVEN WORSE FOR DRIVERS THAN SNOW.
* THIS DOES NOT APPEAR TO BE THE MAJOR PROLONGED SNOWFALL EVENT THAT MODELS WERE PREDICTING SEVERAL DAYS AGO. AMOUNTS ARE LESS AND THE SNOW WILL CHANGE TO RAIN OVER ALL AREAS BY WEDNESDAY AFTERNOON. HOWEVER EXPERIENCE SHOWS THAT EVEN LOWER AMOUNTS OF SNOW CAN CAUSE SIGNIFICANT PROBLEMS ON HIGHWAYS AND STREETS.
* UNCERTAINTY...AS WITH ALL LOWLAND SNOW EVENTS IN WESTERN WASHINGTON...THE LOCATION AND AMOUNT OF HEAVY SNOW IS HIGHLY UNCERTAIN. HOWEVER IT DOES SEEM VERY LIKELY THERE WILL BE AT LEAST SOME SNOW EVERYWHERE...AND CERTAIN LOCATIONS INCLUDING HOOD CANAL AND THE NORTHWEST INTERIOR WILL PROBABLY GET THE HIGHEST AMOUNTS.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A WINTER STORM WATCH MEANS CONDITIONS ARE FAVORABLE FOR SEVERE WINTER WEATHER.
&&
$$
WAZ513-518-519-111330- /O.CON.KSEW.WS.A.0001.110112T0200Z-110113T0000Z/ OLYMPICS-WEST SLOPES NORTHERN CASCADES AND PASSES- WEST SLOPES CENTRAL CASCADES AND PASSES- 719 PM PST MON JAN 10 2011

...WINTER STORM WATCH REMAINS IN EFFECT FROM TUESDAY EVENING THROUGH WEDNESDAY AFTERNOON FOR THE CASCADES AND OLYMPICS...
A WINTER STORM WATCH FOR THE CASCADES AND OLYMPICS REMAINS IN EFFECT FROM TUESDAY EVENING THROUGH WEDNESDAY AFTERNOON.
* ACCUMULATIONS...ONE TO TWO FEET OF NEW SNOW IS POSSIBLE TUESDAY EVENING THROUGH WEDNESDAY AFTERNOON. THE SNOW LEVEL WILL RISE TO AROUND 4000 FT ON WEDNESDAY BUT EASTERLY FLOW WILL KEEP PASS TEMPERATURES BELOW FREEZING. THERE IS THE POSSIBILITY OF FREEZING RAIN AT SNOQUALMIE PASS ON WEDNESDAY.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A WINTER STORM WATCH MEANS CONDITIONS ARE FAVORABLE FOR SEVERE WINTER WEATHER. IF YOU MUST TRAVEL IN THE WATCH AREA...CARRY AN EXTRA FLASHLIGHT...FOOD...WATER...AND BLANKETS IN CASE OF EMERGENCY.
&&
$$
WWW.WEATHER.GOV/SEATTLE

Winter weather to note for the day.

Throughout the day today we had snow showers, most of the accumulations from each shower was about a dusting to a trace, however with temperatures hovering just above the freezing mark most of the snow melted off between showers.

The national weather service has continued with their special weather statement regarding a snow storm Tuesday evening.  It is now expected to start snowing about 3-4 pm in the afternoon, just in time for the evening commute.  Expected accumulations right now are 1-4 inches.  The change to rain is currently expected to happen just after midnight, if the storm stays on current track.  They warn most commuters to start an early commute home if possible for tomorrow to avoid a traffic mess not unlike the one we had last November.

Special weather statement issued.

    A special weather statement has been issued by the National Weather Service of Seattle at 3:52 pm.  The statement includes the cities of Shoreline and Lake Forest Park.

…Lowland snow possible beginning Tuesday night…

   Moisture from an expected Pacific frontal system is expected to spread into Western Washington Tuesday night.  The air mass will initially be cold enough for precipitation to begin as snow.  At least 2-4 inches could accumulate before turning over to rain Wednesday morning.  However most computer models are inconsistent and it’s very possible the storm surface low could track further south, which would generate much greater snow fall accumulations. 

I will continue to watch for any watches or warnings and further weather statements and or changes in the forecast.  Be prepared for extreme winter weather, possible power outages as wind may be associated with the surface low depending on its tracking.  Make sure all outdoor water fixtures are still winterized and make sure you have at least a  3 day food and water supply.  These types of storms are very difficult to predict, and can be very surprising to even the most experienced meteorologist.

Puget Sound Convergence Zone moving over Shoreline - Gold Bar

The Puget Sound Convergence zone has now moved over Gold Bar and Shoreline and is starting to intensify on radar.  Temperature is also starting to drop, indicating a chance of rain turning to snow, or mixing with snow.  Depending on how long it lasts, may bring a possibility of some local accumulation in Shoreline, I have no doubt that it is already snowing in Gold Bar however.

La Nino Winter's compared.

Average daily temperature comparison from the mild 2008/2009 La Nino winter vs. our current 2010/2011 La Nino winter.  I have so far plotted from October 1st through December 31st.  Click on the graph for the original size.

December 2010 Weather, how does it compare to 2009?

Here's a review of December's average daily temperatures and rainfall.

This graph show's December's average daily temperature, daily high temperature and daily low temperature:

This graph represents the daily rain fall for December 2010:

And finally this graph compares daily average temperatures from December 2009, compared to December 2010.

Weather statement from the National Weather Service

At 7:07 pm the National Weather Service issued a Winter Weather Advisory.

"
URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE SEATTLE WA
707 PM PST SAT JAN 8 2011

...WINTER WEATHER ADVISORY FOR EVERETT AND VICINITY AND THE EAST PUGET SOUND LOWLANDS...
WAZ505-507-091315- /O.NEW.KSEW.WW.Y.0004.110109T0307Z-110109T1800Z/ EAST PUGET SOUND LOWLANDS-EVERETT AND VICINITY- 707 PM PST SAT JAN 8 2011

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 10 AM PST SUNDAY FOR THE EVERETT AND VICINITY AND THE EAST PUGET SOUND LOWLANDS...
THE NATIONAL WEATHER SERVICE IN SEATTLE HAS ISSUED A WINTER WEATHER ADVISORY FOR EVERETT AND VICINITY AND THE EAST PUGET SOUND LOWLANDS FOR SNOW...WHICH IS IN EFFECT UNTIL 10 AM PST SUNDAY.
* SOME AFFECTED LOCATIONS INCLUDE THE NORTHERN PART OF WESTERN SNOHOMISH COUNTY...AND HIGHER TERRAIN IN THE EAST PUGET SOUND LOWLANDS. IF CURRENT TRENDS CONTINUE...SNOW IS LIKELY TO BE CONFINED TO SNOHOMISH COUNTY AND EASTERN KING COUNTY.
* ACCUMULATIONS...ONE TO THREE INCHES OF SNOW ARE POSSIBLE IN SPOTS. HOWEVER...NOT EVERYWHERE WILL SEE SNOW...AND SOME AREAS WILL GET A MIX OF RAIN AND SNOW. A CONVERGENCE ZONE IS APPARENT ON THE RADAR IN NORTHWEST SNOHOMISH COUNTY. PRECIPITATION IN THIS ZONE IS DRIFTING SOUTHEAST. WSDOT CAMERAS SHOW SNOW ALONG I-5 NORTH OF ARLINGTON. OTHER SPOTS ARE LIKELY TO GET SOME SNOW LATER TONIGHT...INCLUDING EVERETT.
* TIMING...SNOW WILL FALL OFF AND ON THROUGH THE NIGHT...THEN TAPER SUNDAY MORNING. THE ADVISORY ENDS AT 10 AM SUNDAY.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF SNOW...SLEET...OR FREEZING RAIN WILL CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR SLIPPERY ROADS AND LIMITED VISIBILITIES...AND USE CAUTION WHILE DRIVING.
&&
$$
WWW.WEATHER.GOV/SEATTLE
"

Shoreline has no accumulations at the moment, the ground is wet and it is partly cloudy outside.