Pacific Northwest Weather

[R-Dub]

AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 400 PM PST SAT JAN 15 2005
.SYNOPSIS...A WARM FRONT WILL MOVE NORTH THROUGH WESTERN WASHINGTON THIS TONIGHT...BRINGING A MIX OF RAIN...SLEET...SNOW AND LOCAL FREEZING RAIN. THE FRONT WILL ALSO MARK THE END OF THE SPELL OF COLD WEATHER THAT HAS BEEN WITH US FOR SEVERAL WEEKS. NEXT WEEK WILL BE WET AND MILD...WITH STRONG SOUTHWEST FLOW ALOFT DIRECTING A SERIES OF PACIFIC FRONTAL SYSTEMS THROUGH THE REGION. &&

.DISCUSSION...WHATTA MESS! PRECIPITATION AHEAD OF THE APPROACHING WARM FRONT HAS GONE FROM FREEZING RAIN AND SLEET TO RAIN AND SLEET TO SLEET AND SNOW...AND I`M SURE THERE IS LOCAL FREEZING RAIN STILL AROUND. AT LEAST MOST SURFACES SEEM TO BE WET ENOUGH TO PREVENT GLAZE ACCUMULATION. SLEET IS VERY RARE FOR WESTERN WASHINGTON BY THE WAY. TEMPERATURES HAVE COOLED BACK TO THE LOWER 30S THIS AFTERNOON AS HEAVIER PRECIPITATION HAS ALLOWED A LITTLE EVAPORATIVE COOLING EFFECT IN THE LEFTOVER DRY AIR. THIS HAS INTRODUCED SNOW INTO THE CURRENT MIX OF RAIN AND SLEET. THIS SHOULD CONTINUE UNTIL THE WARM FRONT OVER THE CENTRAL OREGON COAST SWINGS UP ACROSS THE AREA AROUND MIDNIGHT. EXPECT THE PRECIP TO GO OVER TO ALL RAIN AND TAPER OFF WITH AND BEHIND THE WARM FRONT. THE EXCEPTION IS WHATCOM COUNTY WHICH HAD DEEPER COLDER AND DRIER AIR IN PLACE. SNOW WILL BE MORE PREDOMINANT THERE WITH THE CHANGE OVER TO RAIN LATE TONIGHT. HAVE GONE WITH WINTER WEATHER ADVISORIES COVERING ALL OF THE INTERIOR OF WESTERN WASHINGTON PAST MIDNIGHT WITH A WINTERY MIX OF PRECIP...WHATCOM COUNTY UNTIL 6 AM. ACARS SOUNDINGS FROM KSEA SHOWED THE FREEZING LEVEL UP TO AROUND 6000 FEET EARLY THIS AFTERNOON...BUT THE WARM AIR BULGE BELOW THAT HAS WEAKENED SOME DUE TO EVAPORATIVE COOLING ALOFT. WARM AIR ADVECTION WITH THE WARM FRONT SHOULD FINALLY WIN OVER LATER TONIGHT. IR SATELLITE IMAGERY SUPPORTS MODELS AND SHOWS WHAT`S IN STORE FOR THE AREA THROUGH MONDAY. WARM MOIST WSW FLOW ALOFT PREDOMINATES OVER THE NE PACIFIC. THE NEXT SHORT-WAVE TROUGH IS JUST EAST OF 40N/140W AND WILL SWING UP ACROSS THE AREA SUNDAY AFTERNOON. THIS FEATURE ISN`T VERY WELL ORGANIZED BUT SHOULD CERTAINLY STIMULATE SOME RAIN IN THE LEFTOVER MOIST ENVIRONMENT BEHIND THE WARM FRONT. FURTHER UPSTREAM IS A DISORGANIZED MASS OF CLOUDS NEAR AND W OF 150W. THIS IS WHAT THE MODELS TURN INTO THE LEADING SYSTEM OF A SERIES OF WARM MOIST SYSTEMS THAT WILL IMPACT WESTERN WASHINGTON THROUGH NEXT WEEK. HAVE BOOSTED MAX AND MIN TEMPS FROM MONDAY ON TO VALUES CLOSER TO MRF MOS...BUT DIDN`T GO WHOLE HOG IN ORDER TO MAINTAIN INTER-OFFICE COORDINATION. MODELS GO WITH QUITE HIGH FREEZING LEVELS NEXT WEEK...BUT AGAIN DIDN`T GO AS HIGH AS WHAT LATEST GFS ADVERTISED. KAM && .AVIATION...WARM FRONT WILL MOVE SOUTH TO NORTH THROUGH WRN WASHINGTON THIS EVENING. BECMG WDSPRD MVFR. MIXED PCPN WITH RAIN...FREEZING RAIN...SLEET...AND SNOW ALL OF WRN WA EXC COAST. AT KSEA...LIGHT SLEET/ICE ACCUMULATIONS POSSIBLE UNTIL ARND 07Z...THEN PCPN BECMG ALL RAIN. STRONG SW FLOW ALF 30-40 KT AND LIGHT E LOW LVL FLOW COULD RESULT IN SOME TRAFFIC COMPRESSION BELOW 5000 FT AGL UNTIL 07Z. DM &&

[R-Dub]

Just got the handy dandy tape measure out, and we are up to 1" so far. It is snowing and blowing!!!

I posted a couple more pics from earlier today over on the yahoo group if anyone wants to take a look. LK Goodwin is about 70% frozen over with snow on top of the ice.

1/15/05 LK Goodwin WA
4:29:12 PM CURRENT
Moderate Blowing Snow
Temperature (ºF) 27.9
Humidity (%) 97.6
Wind (mph) ESE 10.9
Daily Rain (") 0.00
Pressure ("Hg) 30.33
Dew Point: 27.0 ºF
Snow Depth 1"

[TT-SEA]

Snow slowed down for about 2 minutes and then has really picked up again as the next band has just reached us.

This reminds me of scenes from the movie "Fargo".

Just snowing and blowing.

[skipnfamily]

Just turned to heavy snow over the last half hour with more coming.. Its been more sleet here than snow until now..

When should we see the change over to rain???

Currently 30 here...

[TT-SEA]

Web cams show just rain and/or freezing rain in Auburn and Kent.

No snow anywhere south of Everett. Except east of Issaquah obviously.

Strange.

[R-Dub]

Sounds like after midnight will be the turn over.

[TT-SEA]

Andy... are you out there??

It looks like just freezing rain in Woodinville as well.

[cloud9]

Snow stopped here, waiting for the next round

[W13]

Web cams show just rain and/or freezing rain in Auburn and Kent.

No snow anywhere south of Everett. Except east of Issaquah obviously.

Strange.

Leading edge of the heavier precip is just now hitting us with some moderate freezing rain. Shouldn't this be all snow as our temperature is 28 F with a Dew Point of 28 F as well. Hopefully it changes over to snow like the Ice Pellets did earlier.

[R-Dub]

It is intense here right now! I can hardly see out to the road now with it snowing so hard. This is awesome!!!!!

[TT-SEA]

W13 - not there... the cold air is much more shallow in a line south of Everett curving down to west of North Bend and Enumclaw.

Basically from Seattle to Portland it is shallow cold air and therefore just rain despite the cold ground temperature.

Snow coming down harder than ever here now with this second band. Bigger flakes and really impressive.

[AnthonyC]

We still have freezing rain. My neighbor just called saying her daughter got in a car accident on the Mukilteo Speedway. I guess the roads are miserable. I pray once this heavier batch of precip makes it to Mukilteo, that this freezing rain turns to snow. Lights have been flickering for the past hour. I have a strange feeling we're gonna lose power tonight. Looks like the precip will finally transition to rain once that warm front makes it through Puget Sound...right now that looks to be around midnight. And TT-SEA, what's your elevation? Isn't it over 1000 feet? That's no fair!!! The rest of us are at sea level.

Currently 27 F, dewpoint 30 F.

[R-Dub]

I am half way to TT being at 500FT! Just took another pic of what is going on right now here, didn't turn out great with it being dark, but it does show the snow. I'll post it on Yahoo group.

[W13]

W13 - not there... the cold air is much more shallow in a line south of Everett curving down to west of North Bend and Enumclaw.

Basically from Seattle to Portland it is shallow cold air and therefore just rain despite the cold ground temperature.

Snow coming down harder than ever here now with this second band. Bigger flakes and really impressive.

So no change over to snow then, for the East Hill of Kent ... just miles away from Enumclaw ..

[TT-SEA]

I am at just under 1000 feet. But that should work against me in this situation. I am closer to the warm air aloft. Not a problem yet with near white-out conditions!!

Also... about 1 hour ago... I drove the 3 miles to North Bend (at 446 feet) and it is snowing like crazy there. All the way to the valley floor on this side of town.

Roads are an absolute mess.

[cloud9]

Like I said before, nothing is impossible with God

[TT-SEA]

The cold air dome must be thicker nearest to the Cascades like here in North Bend.

Surprising advantage here despite stong east winds that usually keep us dry.

Obviously the cold air is "masking the mountains"

There is no downslope disadvantage in this situation... evidenced by the heavy snow falling outside my window!!

[TT-SEA]

Amazingly the temperature is STILL falling... 26.8 at my house.

Remember it was 34 degrees here just after 1 p.m.

Dewpoint is rising now and that makes the snowflakes bigger and heavier.

[TT-SEA]

O.K... I am headed out for a "snow walk" with the family.

My wife and I are going to walk down our street pulling the kids in a sled.

Must enjoy this surprise snowstorm while it lasts!!!

[AnthonyC]

Believe it or not, the freezing rain has turned to PLAIN OL' RAIN!!! The current temp is still 28 F, but the warmer air aloft has won the battle. Too bad...I hoped this latest batch of precip would create enough evaporative cooling to turn everything to snow. But I guess not.