Winter Storm Watch for Seattle and all of western WA

[AnthonyC]

You can clearly she the rainshadow between Everett and Olympia. Looks like the cold front is right off our coast...that's what is kicking up the southerly winds. It doesn't get interesting until that cold front passes through Western Washington. Currently 33 F with cloudy skies. But compared to last night, it feels like a heat wave!! Dewpoint is hovering between 34-35 F.

[R-Dub]

Just talked to my friend in Lynden, he is reporting 34 degrees with snow and sleet falling. Temp here keeps wobbling between 32.5, and 33.0 degrees. 500FT elevation and snow cover must be keeping my temps down a tad, might be under a bubble of cold air yet also.

[cloud9]

34*F here in Tulalip, nothing melting yet.

[R-Dub]

Did you get much accumulation this evening Cloud 9? How are the roads down there at Tulalip?
Here is my latest obs.......

1/11/05 LK Goodwin WA
7:41:54 PM CURRENT
Cloudy
Temperature (ºF) 33.0
Humidity (%) 84.7
Wind (mph) SE 1.7
Daily Rain (") 0.00
Pressure ("Hg) 29.93
Dew Point: 30.1 ºF
Snow Depth 1.5"

[andycottle]

Cloudy skies here with temp at 35 and DP of 29 here at 7:51pm. Wind was out of the SE just a moment ago. -- Andy

[R-Dub]

I have to drive down to Everett for a 8:45AM Dr appt. That may just put me in the thick of it! I don't mind driving in it, its the idiots that don't have a clue driving in the snow that is nerve racking!

Temp still holding at 33.0 here, dewpoint 29.8 degrees.

[TT-SEA]

39 degrees now... and continues to rise rapidly.

South winds at 18 mph.

Pretty depressing.

Should be all rain now for everyone until front passes and PSCZ forms. With warm air above the surface... even 33 degrees should produce rain now.

[R-Dub]

Since my work is frozen (golf course) and not thawing out anytime soon, I may have to take a trip over to my mom's place on Moses Lake. They are expecting a low of -13 degrees by Thursday night. I have never experienced anything near that cold, so it would be kind of cool

[TT-SEA]

Gentle light rain falling here now and 38 degrees.

[andrewr]

I've also got a gentle, light rain with 35.8F.

[R-Dub]

Temp up to 33.7 degrees, dewpoint 31.0
Nothing falling at the moment.

[R-Dub]

AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 845 PM PST TUE JAN 11 2005

.SYNOPSIS...A WARM FRONT ALONG THE COAST WILL MOVE THROUGH THE AREA BY MIDNIGHT. A COLD FRONT NORTH OF VANCOUVER ISLAND WILL SWEEP SOUTHEAST THROUGH THE AREA WEDNESDAY MORNING. SURFACE HIGH PRESSURE WILL BUILD OVER BRITISH COLUMBIA ON THURSDAY...BRINGING A STEADY FLOW OF COOL AND DRY CANADIAN AIR INTO THE REGION. A WEATHER SYSTEM WILL MOVE BY TO THE SOUTH OVER THE WEEKEND. &&

.DISCUSSION...POSITIVE TILT LONG WAVE RIDGING PERSISTS FROM THE ALASKAN PENINSULA SE TO 40N/140W WHILE A POLAR VORTEX SITS OVER THE NW TERRITORIES N OF ALBERTA. THE OFFSHORE RIDGE WILL SLOWLY DRIFT E OVER THE GULF OF ALASKA AND BE CENTERED NEAR 52N/140W BY LATE FRI WHILE SOUTHERN STREAM ENERGY GRADUALLY UNDERCUTS THE RIDGE AND HEADS TOWARD OREGON DURING THE WEEKEND. IN THE MEANTIME THE POLAR VORTEX IS EXPECTED TO MOVE CYCLONICALLY AROUND HUDSON BAY THEN TO NRN QUEBEC AS THE OFFSHORE RIDGE PROGRESSES E ACROSS WA BY EARLY NEXT WEEK. MODELS ARE GENERALLY CONSISTENT WITH THE PROGRESSION...BUT I WOULD NOT BE SURPRISED IF THE TRANSITION TAKES LONGER BASED ON PERSISTENT TROPICAL CONVECTION CENTERED AT 130-150E. THE NET EFFECT FOR WA WILL BE BELOW NORMAL TEMPERATURES AND PRECIPITATION FOR THE NEXT SEVERAL DAYS...UNLESS SOUTHERN STREAM ENERGY COMES FARTHER NORTH THIS WEEKEND PER THE ECMWF. IN THE SHORT TERM A WARM FRONT SITS FROM THE CENTRAL STRAIT OF JUAN DE FUCA WSW TO DESTRUCTION ISLAND THEN SE TO JUST E OF KHQM AT 03Z. THIS FRONT WILL MOVE NE THROUGH THE FORECAST AREA THIS EVENING WITH TEMPERATURES WARMING ABOUT 5 DEG F ABOVE THEIR CURRENT VALUES 10 PM TO MIDNIGHT TIME FRAME. ANY FLURRY ACTIVITY AS REPORTED BY A SPOTTER IN MARYSVILLE AT 6 PM WILL BE BRIEF AND WILL TURN TO LIGHT RAIN. STRONG WESTERLY FLOW ALOFT WILL PUT THE INTERIOR LOWLANDS IN A RAIN SHADOW THRU EARLY WED MORNING WITH ANY DEVELOPING PRECIPITATION BEING CONFINED TO THE MOUNTAINS. THEN AS A COLD FRONT NOW JUST N OF VANCOUVER ISLAND PUSHES SE INTO OUR AREA DURING THE MORNING HOURS...PUGET SOUND CONVERGENCE WILL DEVELOP N OF KPAE THEN SLIDE SLOWLY S INTO SRN SNOHOMISH N KING COUNTIES AFTN. THE 00Z 12KM ETA MODEL KEEPS THE CONVERGENCE ZONE GOING THROUGH EARLY THU MORNING. AS TEMPERATURES ALOFT COOL WED AND WED NIGHT EXPECT PRECIPITATION TO BE IN THE FORM OF -SHSN MOST AREAS N AND E OF SEATTLE WED AFTN AND WED NIGHT ESPECIALLY AS CONVECTION DROPS SNOW LEVELS. SOME AREAS E OF I-5/I-405 SUCH AS MALTBY... CLEARVIEW...AND DUVALL COULD SEE 1-3 INCHES OF SNOW WED OR WED NIGHT. EXPECT THE FOOTHILLS OF THE CASCADES TO SEE UP TO 4 INCHES WED AND POSSIBLY MORE WED NIGHT AS THE CONVERGENCE ZONE PERSISTS. THE CASCADES WILL SEE HEAVY SNOW SPREAD FROM N TO S EARLY WED. CURRENT WARNINGS FOR THE FOOTHILLS AND THE CASCADES MAY NEED TO BE EXTENDED INTO WED NIGHT. BUT FASTER GFS COUNTERS THAT IDEA. WILL NEED TO EVALUATE ALL 00Z GUIDANCE BEFORE MAKING ANY CHANGES TO CURRENT REASONABLE LOOKING FORECAST. THE EVENING SHIFT IS EVALUATING PROJECTED WIND SPEEDS DOWN THE STRAITS OF GEORGIA EARLY WED AND ITS IMPACT ON THE DEVELOPMENT OF A POTENTIAL SWELL TRAIN THAT WOULD HIT WESTERN WHATCOM COUNTY...IE SANDY POINT...AROUND THE TIME OF HIGH TIDE ABOUT 7 AM. IF GALES DEVELOP A BIT LATER PER THE NEW ETA...MAJOR FLOODING WILL NOT OCCUR AND WE WILL BE ABLE TO GO TO A MINOR TIDAL OVERFLOW FOR THE ENTIRE WATCH AREA. ETA ALSO DELAYS GALES IN ADMIRALTY INLET UNTIL WELL AFTER HIGH TIDE WED MORNING...AT THE EARLIEST. GFS REMAINS FASTER. WILL ATTEMPT TO RESOLVE ISSUES AND ISSUE AN UPDATE BY 10PM. ALBRECHT

[R-Dub]

Last update for the night, i'm going to bed!

1/11/05 LK Goodwin WA
8:42:33 PM CURRENT
Cloudy
Temperature (ºF) 33.9
Humidity (%) 84.6
Wind (mph) SE 1.8
Daily Rain (") 0.00
Pressure ("Hg) 29.92
Dew Point: 31.0 ºF
Snow Depth 1.5"

[AnthonyC]

Interesting NWS discussion, although I wish it were more specific. Latest GFS and ETA models are in fairly good agreement...850 mb heights on the ETA are -16C and -12C on the GFS. 500 mb thicknesses are 508 on the ETA, 518 on the GFS. That's pretty good agreement. This pattern could stay around for awhile as an amplified ridge continues to sit at 150W. Although the GFS is more progressive, the European models make the transition alot slower and not as extreme. Remember, the GFS models have a hard time with pattern changes...ie: this past Xmas. Sharp trough in the East, ridge in the West. GFS advertised a big pattern change beginning right after Xmas...instead it was a slow, gradual change that didn't fully emerge until December 31 and on. One interesting note...latest European models bring a southern branch system through central Oregon this weekend. With modified arctic air in place and moisture coming in from the south...well, you know what that means. Right now, it's the only model that indicates this solution, but the European model has handled medium-range forecasting very well this winter. If latest forecasts are correct, this pattern could continue through the beginning of next week. If the GFS is correct, the pattern will completely shift by Saturday of this week. We'll have to wait and see. I'm still interested in this possible high wind event through the Strait of Juan Defuca...I'll have to check back in at 10pm when NWS has another analysis on it.

Anthony

[TT-SEA]

O.K... that discussion pretty much ends the hope for snow tonight!!

Even tomorrow I think most places will have light rain or nothing at all.

W13 - I would say you are going to be missed completely by snow until maybe tomorrow night and then just a dusting if you are extemely lucky.

I would say even North Bend will basically be rain for the duration of the event.

[W13]

W13 -here is the forecast for your zip code...


http://www.wrh.noaa.gov/total_forecast/index.php?zone=waz007&county=wac033&wfo=sew&dgtl=1&lat=47.408422&lon=-122.19573


No Heavy Snow Warning. But you may get lucky!!

That's not where I live though. That is for downtown Kent, which is right at sea level. My zip code is 98031, so you punch that in and it says that I have a Heavy Snow Warning.

[TT-SEA]

The latest ETA based MM5 shows absolutely no snow within 25 miles of Puget Sound for the entire event.

Sorry R-Dub and W13... it shows nothing at all for your locations.

In fact the only place that gets snow is from about Woodinville east to North Bend tomorrow morning. I am not sure I even believe that.

Anthony was right... this is basically a non-event for most of the lowlands.

[TT-SEA]

I went to the Seattle NWS site and typed in 98031 in the zip code.

[W13]

Well, we will just have to see what happens. Hopefully I will get at least a little bit of snow.

[TT-SEA]

A couple observations before bed...

1) The convergence zone forms Wednesday morning and is quickly centered on the I-90 corridor. Then it slips south in the middle of the afternoon and COULD bring snow as far west as Auburn and Kent. Amazingly the ETA based MM5 shows about 10 inches of snow tomorrow in just six hours between 9 a.m. and 3 p.m. in Snoqualmie and North Bend. I refuse to believe this but that would be incredible. One other note... a secondary convergence zone forms tomorrow afternoon from about Mount Vernon to Concrete and slides south towards Everett before disappearing. This is forecasted to be much weaker than the original PSCZ but still could bring 1-3 inches to places like Arlington and Marysville (R-Dub could be in on this one).

2) The GFS has gone back to a warmer pattern for the weekend and into next week. Now we have the ECMWF in total agreement. In fact... one week from now we should be experiencing warm rain originating from the tropics with 500mb heights above 5640 and snow levels above 5000 feet.

We will see what happens tomorrow. Convergence zones are very difficult to predict!! Just 2 degrees could mean the difference between 10 inches of snow at my house and nothing but rain.