Pacific Northwest Weather

[andycottle]

Short Term Forecast

SHORT TERM FORECAST
NATIONAL WEATHER SERVICE SEATTLE WA
1155 PM PST FRI FEB 4 2005

WAZ006-007-051000-
EVERETT AND VICINITY-SEATTLE METROPOLITAN AREA-
1155 PM PST FRI FEB 4 2005

.NOW...AN ACTIVE PUGET SOUND CONVERGENCE ZONE ALONG THE KING
SNOHOMISH COUNTY LINE WILL PRODUCE BRIEF HEAVY RAIN AND HAIL AS WELL
AS SOME LIGHTNING IN THE NEXT TWO HOURS. THE CONVERGENCE ZONE IS
MOVING EAST AND WILL REACH THE CASCADES AROUND 2 AM SATURDAY.

$$
FELTON
WEATHER.GOV/SEATTLE

Looks like maybe anthother of T-storms for me..! -- Andy

[R-Dub]

Well we have had off and on ice pellets and wet snow for over an hour now! I woke up to the ice pellets hitting the roof, and my window. Nothing on the ground though...........


2/5/05 LK Goodwin WA
7:04:59 AM CURRENT
Ice Pellets/Wet Snow Showers
Temperature (ºF) 37.9
Humidity (%) 88.9
Wind (mph) W 0.0
Daily Rain (") 0.00
Pressure ("Hg) 30.16
Dew Point: 34.9 ºF

[R-Dub]

You can see the real thin convergance zone right over my head on the radar.......... At least as of 7:10AM

http://radar.wrh.noaa.gov/radar/loop/DS ... katx.shtml

[R-Dub]

Snipit from NWS Seattle...................
I could be at the perfect spot being at 500FT to see some snow on Sunday. Reading the discussion though, doesn't look like they, or the models have a good handle on the situation, still bares watching!!!

AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 300 AM PST FRI FEB 4 2005

H850 TEMPS COOL...RUNNING ABOUT -5C WITH 1000-500 MB THICKNESSES ARND 5280M. WHILE THE LOW LEVEL GRADIENTS REMAIN OFFSHORE...THE FLOW ABOVE THE BOUNDARY LAYER BECOMES S/SWLY. THE GFS IMPLIES SOME DRY DOWNSLOPING OFF THE CASCADES WITH LOWER QPF AMOUNTS PGTSND EWD...HOWEVER THE ETA12 CROSS SECTIONS IMPLY THIS DOES NOT DEVELOP WITH STRONGER SLY FLOW TO DOMINATE. THE ETA REMAINS THE PREFERRED MODEL AT THIS TIME...WITH GENEROUS QPF AMOUNTS FOR THE LOW LANDS...POSSIBLY IN THE .50 TO .75 INCH RANGE. STRONG DIFFLUENCE/DIVERGENCE ALOFT AND VERTICAL MOTIONS ENHANCED BY A STRONG JET AND PVA INTO THE LOW CENTER SUGGEST SNOW LEVELS COULD ARTIFICIALLY LOWER AT TIMES...ESPECIALLY IF THE LOW SETTLES DIRECTLY OVER WRN WA LIKE THE ETA SHOWS. FOR NOW...HAVE KEPT THE MAIN SNOW LEVEL AROUND 1000 FEET. WOULD NOT BE SURPRISED IF SOME WET SNOW MIXES IN AT TIMES TO THE LOWLANDS...BUT NEAR SFC TEMPS TOO WARM TO SUPPORT AN ALL SNOW SCENARIO. MERCER &&

[AnthonyC]

Coldest morning in over three weeks...currently 33 F with partly cloudy conditions. There's a little frost on the ground, but generally everything is wet. As for last night, what a show!!! I went to bed fairly early because I wasn't feeling well, and I was woken up around midnight to thunder!!! It was LOUD!!! Very LOUD!!! I rain downstairs and once again in the east direction, bolts of lightning were flashing through the sky. It lasted for about 20 minutes before the PSCZ continued to shift east. That PSCZ is one interesting weather phenomena.

As for tonight and Sunday morning, things still look very interesting. As of now, things still look like an all-rain event but at least there will be plenty of moisture around. But, there are many dynamics that could come together and create a snow event, particularly for the cascade foothills and Hood Canal. 1-4 inches is NOT out of the question. Though, places near the foothills may experience a dry, east wind which my prohobit precip from hitting the ground. NWS keeps a general snow level at 1000 feet...but with heavier showers and convective cooling, snow levels could easily fall to 500 feet or lower. And once the low moves east Sunday afternoon/night, that wrap-around moisture might meet with some of the coldest air and end as some wet snow across parts of Western Washington. Definitely not a slam-dunk, but each model run and NWS discussion leans toward the idea.

Anthony

Currently 34 F with partly cloudy conditions...BRRRRR!!!

[TT-SEA]

Yeah... it looks wetter now. The hills could be white tomorrow.

Nice to see pics from Snoqualmie Pass this morning as the PSCZ finally made it down to them. In fact Mount Si and the ridge behind our house are white. First time in a month. It looks NORMAL again!!! But still above freezing and should stay that way for the lowlands even if some slush comes tomorrow.

Shaping up to be a nice scenario... we really need precipitation in the lowlands and snow in the mountains. We get both.

[R-Dub]

Finally some snow in the mountains again!!!!!!!!!!

http://wsdot.wa.gov/traffic/default.aspx?cam=1132

http://wsdot.wa.gov/traffic/default.aspx?cam=1100

http://wsdot.wa.gov/traffic/default.aspx?cam=1138

[R-Dub]

WINTERSTORM WATCH has been issued for the Kitsap, and Hood canal area.
Now this is a discussion ...........................

I really like this line........ "THE ETA12 ALSO INDICATES THAT HILLS EVEN IN THE SNOHOMISH/N KING COUNTY AREA COULD ALSO SEE WET SN SUN MORNING WITH QPF HIGH ENOUGH...LOW LVL GRADIENTS NELY...AND ISOTHERMAL 0C "

AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 835 AM PST FRI FEB 4 2005

.SYNOPSIS...WASHINGTON WILL REMAIN BETWEEN WEATHER SYSTEMS TODAY WITH JUST A FEW SHOWERS AROUND THE AREA. THE AIR MASS IS COOL ENOUGH THAT SHOWERS TODAY WILL CONTAIN SMALL HAIL. LOW PRESSURE DEVELOPING IN THE GULF OF ALASKA WILL AFFECT WASHINGTON LATE TONIGHT AND SUNDAY. THIS SYSTEM WILL BRING RAIN TO THE LOW LANDS AND SNOW ABOVE AROUND 1000 FEET. THE AIRMASS MAY COOL ENOUGH FOR WET SNOW NEAR HOOD CANAL AND OVER THE HILLS AROUND PUGET SOUND SUNDAY MORNING. THE LOW WILL MOVE SOUTHEAST ON MONDAY...WITH A TREND TOWARDS DRY AND MILD CONDITIONS BY MID WEEK AS A HIGH PRESSURE RIDGE BUILDS OVER THE AREA. &&

.DISCUSSION...AS ONSHORE FLOW AND A PUGET SOUND CONVERGENCE ZONE...PRODUCING SMALL HAIL AT TIMES IN PORTIONS OF THE LOWLANDS...WINDS DOWN LATER THIS MORNING...EYES WILL FOCUS ON A DEVELOPING LOW PRES SYSTEM NOW SEEN POORLY ORGANIZED AROUND 50N/140W. THIS ENERGETIC LOW IS MOVING INTO A DIGGING UPPER LOW MOVING FROM THE NORTHERN GULF OF ALASKA SE TOWARD WRN WA LATE SUN. THE TRACK AND STRENGTH OF THIS LOW WILL BE IMPORTANT FOR DETERMINING AMOUNT OF SNOW IN THE OLYMPICS AND SNOW LEVELS IN THE PUGET SOUND LOWLANDS...PARTICULARLY OVER THE KITSAP PENINSULA AND AROUND HOOD CANAL LATE TONIGHT THROUGH SUN. A WEAK RIDGE OF HIGH PRES ALOFT IN THE NORTHERN STREAM OF A SPLIT FLOW PATTERN DEVELOPS OVER THE AREA MON AS THE LOW DEPARTS TO THE SOUTHEAST AND ANOTHER LOW FORMS IN THE SOUTHERN STREAM AND HEADS TOWARD SRN OREGON OR NRN CA. THE COMBINATION OF OFFSHORE FLOW AND WEAK SPLITTING SYSTEMS WITH MOST ENERGY HEADED TO OUR SOUTH RESULTS IN TEMPERATURES MODERATING AND MAINLY OCCASIONAL MID/HI CLOUDS AT TIMES. SPLITTING SYSTEMS MOVING THROUGH THE AREA GIVE A BETTER CHANCE OF RAIN FOR NEXT FRI AND SAT. CONFIDENCE IN THE DETAILS...PARTICULARLY AFTER TUE...IS NOT HIGH AS THE MOVE TOWARD A MORE SPLIT PATTERN CAUSES PROBLEMS WITH MODEL CONTINUITY AND CONSISTENCY. .TODAY...SHOWERS WITH A CONVERGENCE ZONE EXTENDING SE FROM VANCOUVER ISLAND INTO ARLINGTON AND SE SNOHOMISH COUNTY IS GIVING ENOUGH HAIL IN PLACES TO COVER THE GROUND. ALSO SEE THE PUGET SOUND CONVERGENCE ZONE FROM W OF PORT TOWNSEND SEWD APPEARING TO GET INVIGORATED EARLY THIS MORNING. WILL ISSUE A QUICK UPDATE SOON TO COVER THE SMALL HAIL/GRAUPEL THIS MORNING. SHOWERS SHOULD TAPER OFF THIS AFTN AS ONSHORE FLOW RELAXES IN ADVANCE OF THE NEXT INCOMING SYSTEM. .TONIGHT AND SUNDAY...WATER VAPOR AND IR SAT IMAGERY INDICATES WHAT LOOKS LIKE VIGOROUS LOW LEVEL CYCLOGENESIS OCCURRING NEAR 47N/141W AT 15Z. THIS IS TO THE SOUTH OF WHERE THE MODEL SIMULATIONS SHOW A DEVELOPING LOW CENTER. UPPER LEVEL SUPPORT IS A BIT TO THE NORTH OF THE LOW LEVEL CENTER...SO MODELS MAY NOT BE TOO FAR OFF. NONETHELESS EXPECT THIS 1005 MB LOW TO DEEPEN TO 990-995 MB AS IT APPROACHES THE N OR CENTRAL WA COAST SUN MORNING. THIS WOULD BE 5-10 MB DEEPER THEN MODELS FORECAST. THE LOW MATURES OVER THE COASTAL WATERS OR ON THE COAST BY MIDDAY SUN THEN TRACKS SWD INTO NW OREGON SUN EVENING AS IT BEGINS FILLING PER ETA 12 KM GUIDANCE. THE GFS GUIDANCE IS NOT AS DEEP WITH THE LOW AND MAYBE SLIGHTLY FARTHER E WITH THE TRACK...THOUGH NOT SIGNIFICANTLY DIFFERENT. MODEL QPF IS HIGH OVER THE OLYMPICS WITH 1.5 INCH 21 HR TOTALS ALONG THE S AND SE SLOPES. TROUBLING THING IS THAT QPF IS ALSO QUITE HIGH OVER THE KITSAP PENINSULA AND HOOD CANAL AREA. ETA 1000-850 THICKNESSES ARE 1295 M WHILE GFS IS 1305 M. CLOSE ENOUGH THAT I WILL ISSUE A WINTER STORM WATCH FOR LATE TONIGHT AND SUN FOR BOTH THE OLYMPICS AND THE KITSAP HOOD CANAL AREA. WILL UPGRADE TO A WARNING THIS AFTERNOON IF 18Z GUIDANCE IS ON TRACK AND WILL SCALE IT DOWN IF IT APPEARS THAT THE LOW WILL TRACK A LITTLE FARTHER OFFSHORE OR CONDITIONS WON`T BE COLD ENOUGH. THE ETA12 ALSO INDICATES THAT HILLS EVEN IN THE SNOHOMISH/N KING COUNTY AREA COULD ALSO SEE WET SN SUN MORNING WITH QPF HIGH ENOUGH...LOW LVL GRADIENTS NELY...AND ISOTHERMAL 0C TEMPERATURES FROM 925MB TO NEAR THE SURFACE. LESS CONFIDENT IN THIS VERIFYING AT THIS TIME. .SUNDAY NIGHT...THE SYSTEM PULLS AWAY TO THE SOUTH AND EAST DECREASING SHOWERS AND GIVING PARTIAL CLEARING. .MONDAY ON...NO CHANGES AT THIS TIME. ALBRECHT &&

[R-Dub]

Also it looks like I may see more hail/Ice pellets today.........

.TODAY...SHOWERS WITH A CONVERGENCE ZONE EXTENDING SE FROM VANCOUVER ISLAND INTO ARLINGTON AND SE SNOHOMISH COUNTY IS GIVING ENOUGH HAIL IN PLACES TO COVER THE GROUND. ALSO SEE THE PUGET SOUND CONVERGENCE ZONE FROM W OF PORT TOWNSEND SEWD APPEARING TO GET INVIGORATED EARLY THIS MORNING. WILL ISSUE A QUICK UPDATE SOON TO COVER THE SMALL HAIL/GRAUPEL THIS MORNING.

[TT-SEA]

Beautiful morning here with bright sunshine and the temperature climbing fast... now up to 41 degrees. Sun shining on the snow-covered mountains here looks like a postcard.

You can tell that we have entered spring because sunshine is easier to come by now. In December it would have been dark and cold in this pattern. But now the sun seems to make appearance even with a trough overhead.

This is definitely not arctic air!!

[R-Dub]

To think just a few short yrs ago this state had the world record for snowfall (MT. Baker) Here is a article I dug up...................

SEATTLE, Feb. 28, 1999 - In one of the snowiest regions on Earth, it's been snowing - A LOT. Maybe enough at Mount Rainier to top the record year when skiers could peer down the chimney of the three-story Paradise Inn. Mount Baker already has gotten nearly 70 feet.

There are
A front end loader clears snow from a mid-February avalanche on Hurricane Ridge Road in Washington's Olympic National Park (AP).
a number of theories as to why the Northwest has been socked by an extended series of storms this winter: La Nina, the unusual cooling of water in the Pacific; global warming; a return to the wetter and colder winters the region had in the 1950s through the mid-'70s.

Or, ''It could be just a random event,'' said Mark Moore, director of the Northwest Weather Avalanche Center.

At lower elevations, the unusually dismal winter has brought rain - and more rain.

As of Thursday, Seattle had endured a record 87 days of rain since Nov. 1, and more rain fell this weekend. Forks, an Olympic Peninsula town that's one of the rainiest burgs in America, had 61 inches of rain - more than 5 feet - in that period.

The incessant snowfall, an average of 10 inches a day in some places, has created one of the most dangerous avalanche seasons in decades, said Moore. So far this year, one person has been killed and two are missing and believed dead.

Snoqualmie and Stevens passes, the main routes across the Cascade Range, have been intermittently closed as crews battled heavy snow and avalanches. Ski areas along those routes have had to close because of too much of a good thing.

Dangerous though the mountains may be, they also are spectacular.

''It's just been beyond beautiful,'' said Maria Gillett, a staffer at Mount Rainier National Park.

''I was born and raised at this ski area, and I've had the best days of my entire life up here this year,'' said Amy Howat, marketing manager at the Mount Baker ski area in northwest Washington.

Since Nov. 20, Mount Baker has had a record 833 inches of snowfall - nearly 70 feet.

Last week, the ski area shut down for two days after snow rose above the chairlift seats, and Howat, whose parents run the ski area, says even the natives are starting to get edgy.

''Boy, seeing the sun only once or twice in three months just doesn't get it,'' she said.

At Hurricane Ridge in Olympic National Park, 30-foot snowdrifts have buried the visitors lodge. For more than a week, crews couldn't even reach the lodge because of avalanches along its 17-mile road.

Officials can't even tell if the park has had record snowfall, said spokeswoman Barb Maynes.

''We have a snow-measuring stake - it's 21 feet tall - but it's been buried for the last five or six days,'' she said.

A small ski area at Hurricane Ridge has
Two snow plows work in concert in attempt to clear Hurricane Ridge Road in Washington's Olympic National Park in mid-February (AP).
been closed since late January. Crews tried to reopen one run there a week ago, Maynes said, but the 40-foot-tall towers for the ski lift reached only chest-high above the snow.

At Mount Rainier National Park, Paradise Lodge has received 756 inches of snow this winter, 200 inches above average, said the park's chief ranger, John Krambrink.

If heavy snow continues into the spring - Rainier often gets storms as late as July - it could top the 1,122 inches, or 93 1/2 feet of snow Paradise received in the winter of 1971-72 - the world record for any inhabited weather station.

''I was here in the regional office at that time,'' Krambrink said. ''The three-story Paradise Inn, just the upper roof crest and part of the chimney were sticking out, and that's it. And we skied across the roof crest, my wife and I.

''We're wondering whether we will get to do that again.''

[R-Dub]

Another great article...........

http://depts.washington.edu/nwst/articl ... _knows.pdf

Also I did a little checking, and as people know Feb, March can be wild months, with dramatic weather changes by the hour.

Example........
On Febuary 22, 1976 it was 75 degrees in Everett
On Febuary 27, 1976 it was 36 degrees for a high and snow, that lasted through the second of March.

The last few days of Jan 1989 highs in the 50's
First part of Feb, Highs in the upper teens/Low twentys, Lows in the single digits.
This is just one of many examples!

Don't let the sun fool you.

[TT-SEA]

Well... the debate will be settled soon.

Lets lay out our cards. Thats the only way we will know who is right.

TT's forecast (Sea-Tac):

Thursday - Mostly Cloudy Hi-54 Lo-42
Friday - Rain developing Hi-47 Lo-40
Saturday - Showers Hi-44 Lo-37
Sunday - Showers Hi-42 Lo-35
Monday - Showers / Sun Breaks Hi-42 Lo-30
Tuesday - Partly Cloudy Hi-48 Lo-32
Wednesday - Partly Cloudy Hi-50 Low-36
Thursday - Partly Cloudy Hi-54 Lo-38
Friday - Mostly Sunny Hi-59 Lo-40

So far... I have been pretty close. The high at Sea-Tac yesterday was 50 degrees (warmer than I thought) and the rain came in the moring. The NWS is forecasting mid 40's at Sea-Tac today and Sunday so I might have forecasted a little too cold on those days. I should be good through Thursday but my Friday forecast looks wrong now as a splitting system should come through that day with showers (highs in the low 50's.) One day earlier than I thought.

All in all... not too bad.

[R-Dub]

Don't forget TT, that NWS hasn't updated there forecasts yet.
They are still calling for rain and highs in the 40's on Sunday in the Hood canal area, but NWS just issued a winterstorm watch for them. I think they will trend down the temps, so you maybe right on with your origainal forecast, or even be a little warm.

[R-Dub]

WINTER STORM WATCH

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE SEATTLE WA
911 AM PST SAT FEB 5 2005

.A DEEPENING LOW PRESSURE SYSTEM WILL MOVE TO THE WASHINGTON COAST
EARLY SUNDAY MORNING THEN DROP SOUTH INTO NORTHWESTERN OREGON SUNDAY
EVENING. THE COMBINATION OF A LOW SNOW LEVEL AND HIGH PRECIPITATION
AMOUNTS WILL LIKELY GIVE HEAVY SNOWFALL AMOUNTS TO THE OLYMPICS. IT
MAY ALSO PRODUCE A WET HEAVY SNOWFALL OVER THE LOWLANDS ON THE KITSAP
PENINSULA AND NEAR HOOD CANAL. SNOWFALL AMOUNTS AND SNOW LEVELS WILL
DEPEND ON THE EXACT TRACK AND STRENGTH OF THE LOW.

THIS WINTER STORM WATCH MEANS THAT HEAVY SNOW IN THE WATCH AREA IS
LIKELY...BUT NOT CERTAIN OR IMMINENT. A HEAVY SNOW WARNING WILL BE
ISSUED OVER ALL OR PORTIONS OF THE WATCH AREA IF CONDITIONS DEVELOP
AS EXPECTED



Yet here is there not yet updated forecast for the same area.........

Issued: February 05, 2005 05:26:37 PST (WAZ010)

Today: Mostly cloudy. Chance of showers. Highs in the lower 40s. Southwest wind 10 to 15 mph.

Tonight: Rain likely...then rain after midnight. Lows in the mid 30s. South wind around 10 mph increasing to 15 to 20 mph after midnight.

Sunday: Rain. Highs in the lower 40s. South wind 10 to 15 mph in the morning becoming light.

Sunday night: Showers likely. Lows in the lower 30s. Northeast wind around 10 mph.

[R-Dub]

How many times have I seen it where suddenly snow is forecasted for hoodcanal area, and hills in Snohomish/King counties, and it turns into a widespread event........MANY times. Don't let your guard down just yet. That is all I will say

[AnthonyC]

I'm still skeptical with this coming storm. Dynamics are present, but it would take a miracle for all factors to come together. One big thing missing from the equation is arctic air. We have a cooler airmass currently over the Pacific Northwest, but it's definitely not cold for early February. For any lowland snow, that current low in the Gulf of Alaska must interact with that batch of moisture off the Vancouver Island coast. If that occurs, the surface low must basically "bomb" and move inland across the WA/OR border. If that happened, it can briefly pull colder air from Western Canada and create evaporative cooling...in a sense "fake" arctic air...for a short period of time. Like I said, alot of dynamics must come together to bring any lowland snow. As of now, the best places look to be the Hood Canal and the higher Cascade foothills. But still something to watch.

Anthony

[TT-SEA]

Anthony and R-Dub... good points.

No arctic air... but the surface low could surprise us depending on the track. Truly a spring storm.

[snow_wizzard]

Well...I think it's time for both myself and TT to admit we were wrong. The lowland snow, which is very likely for some areas, would make me right about the snow. TT repeatedly said there would be no snow below 1000 feet. On the other hand...the cold will not set in quite as good as I had hoped. I never said we would have Arctic air this soon, but on Sunday. Even though we will get some continental air drawn in by the low tonight and tomorrow, it will not be all that cold. There is a strong chance that many areas will see highs in the mid to upper 30s tomorrow, due to heavy precip coming down in combination with evaporative cooling. There could still be a night or two where the lows could dip into the mid 20s, in the outlying areas. Still...not what some of the model runs had promised.

Another big issue is how the models continue to trend away from the ridge next week. At this point it looks like mostly zonal flow for the end of the week. Quite a change form the highly blocked pattern witnessed so far this winter. It is highly unusual for the weather to have a complete regime shift right in the middle of the winter, but it will probably happen this winter. To go from blocked and split to wide open at this point is intriguing. This could spell a huge recovery for the mountain snowpack. This aint spring yet folks!

As for the snow in lowlands tonight and tomorrow...there are a thousand possible scenarios. The best bets for snow are...the Hood Canal area, parts of the NW interior (if the GFS is correct), and the central foothill areas. Offshore gradients combined with abundant precip should create significant wet bulb effect cooling. I remember a low tracked something like this a few years ago and brought snow down to 500 feet with 850mb temps of about minus 2C...tonight they will be -5. It is still possible this could be a widespread snow event with at least a dusting for the entire central Puget Sound area, above 200 feet. It will be very hard for areas at sea level to get snow with this, except for the Hood Canal / Kitsap Pen area.

[AnthonyC]

I find it pretty amazing that not one place in the entire country will experience an arctic outbreak for at least the next two weeks. It is the beginning of February...prime time for a major arctic outbreak. Overall, this winter has been above normal temperature wise for the entire country. We haven't had a "severe" arctic outbreak...I wouldn't call that cold snap in the East a major arctic outbreak. Looking at some of the weather tapes, it seems the entire country was under an arctic blast when snow was mentioned in the Pacific Northwest. But this year, the arctic outbreaks haven't made it very far south and their duration have been very short lived. Is this from global warming?

Anthony