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What's this another blog entry! Two in one day, what's the world coming too? Anyway since everybody is doing a 2007 look back, here's my version. Drum roll please....The 2007 weather review.
A couple of statisticsI left off the graphic above, the coldest high temperature. 32 degrees on January 13th. The wettest day happened just this month. December 2nd we had 1.65" of rain. And even more noteworthy, Christmas Day snow! The first time measureable snow fall in the Rose City on Christmas day in 70 years!
Right now the Cascade Mountains of Oregon are a skiers dream. In the last week over 3 feet of snow has fallen in the mountains. Mt. Hood ski resorts are reporting reporting well over a 100 inch base. What's even better the type of snow, this is not the usual "Cascade Concrete" most Oregon skiers are used to. It's a light fluffy powder. Skiing the pow-pow is like skiing through flour.
Each one of those snow flakes means dollars to mountain resorts and businesses. And trust me after this weekend mountain resorts got a lot of money,some of it was mine.
Was there anybody left in Portland over the weekend? I joined the migration over the weekend and skied Mt Hood Meadow. I snapped a picture of the lift lines.
Even though the line were long nobody complained. Everybody knew they were skiing snow more suited for Utah or Colorado. Most folks I talked with had one goal in mind, make as many runs as possible. Snow like this comes maybe once every 5 or 6 years in the Cascades.
If you're hitting the slope for New Years, remember to ski in bounds. In the distance I could hear the thud of dynamite sticks and cannon fire.
Sking out of bounds with all that new snow is down right dangerous! Avalanche dangers on most of the steeper slopes remains high.
Happy New Years
Dave
Unless you live above 500 to 700 ft, this snow forecast was a big fat bust. As I said in last night's blog, I was not real impressed with the potential for an all-out valley white-out. The computer guidance up to last night was pretty much saying snow, but a couple things needed to happen:
We needed really heavy precipitation rates! When that happens, melting snow cools the air and lowers the snow level. I've seen it happen here, but its rare, and difficult to forecast. We only needed cool a layer of air about 500 to 1,000 ft thick.
We needed a source of cold air! The east wind eventually picked up a bit in east Multnomah County, but the temperatures in and east of the Gorge were just too warm. We also had too much south wind.
If the low level air had been dry we would've had a better chance of seeing snow reach the valley floor because of evaporative cooling. Like the melting I described above, evaporation cools the air, even more effeciently than melting. But the air mass was saturated so there was no substantial evaporation to cool the air.
There was some decent snowfall in Clark County, and elevations above 500 ft.
Ridgefield, WA (100 ft) 3" Wow!
La Center, WA (650 ft) 6"
Clark County, WA (1400 ft) 7"
NW Portland (1200 ft) 4"
Cascade Locks 4"
So that's that one. I'm sure we'll have a few more chances of valley snow before spring.
Matt Zaffino
KGW Chief Meteorologist
This isn't the perfect situation for widespread valley snow, and the closer we get to Thursday morning the less impressed I am with the potential for heavy valley snow. The problem, as I see it, is the wind direction. Too much south wind, not enoough east or north wind. Yes, the pre-existing air mass is cold, Hillsboro has already been as low as 28°. But we can warm up rapidly when the south wind aloft gets going. I use the term "warm" a bit loosely here, I just mean warm enough so we get rain. Another wildcard is the precipitation rates. If it comes down really hard, there can be enough colling with the falling snow to lower the snow level and overcome any south wind warming. Bottom line is, south wind snow events are rare. Unless we get a good shot of offshore (east) winds, I think this is going to be more of a snow event for elevations just above the valley floor, with maybe an inch in the valley before it changes to rain.
Stay tuned!
Matt Zaffino
KGW Chief Meteorologist
So here we are, 9:30 on the night before Christmas. Not a creature is stirring - except for the Christmas storm that is getting closer and closer to the Northwest! But will that storm bring a white Christmas to Portland?
The latest computer model updates have recently come in, and they are largely unchanged - which means my forecast of rain, and only rain, in Portland for tomorrow afternoon still looks pretty reliable. Of course, above 1,000 feet, we're still talking snow - and it will accumulate! Up to 4 inches of snow may fall in the highest West Hills locales by mid-day Wednesday.
There is always that outside chance that the snow level will be lower than 1,000 feet. But with each successive computer-model run coming in unchanged - and still indicating just rain for the valley floor - the chance of a huge shift is getting smaller and smaller. There will probably be some snow mixing in with the rain showers by Wednesday. But steady and accumulating snow on the valley floor is looking increasingly unlikely with this system.
Merry Christmas!
Joe
Working in television has many perks and benefits - but it also comes with some negatives. One of those negatives is the wacky schedule! =) But there's one day that you may be surprised to learn that I don't mind working, and that day is Christmas Eve.
On Christmas Eve, I have the pleasure of tracking Santa. This may seem odd - after all, why does a 27-year old guy enjoy tracking Santa? Ever since I started working in TV I have pretty much always worked Christmas Eve evening. And on my first year working it - and tracking Santa - I recalled what it was like when I was a kid...when I used to watch the local TV weatherguy track Santa. I remembered how excited I used to get, watching...and waiting...to see where Santa was, and when he would arrive in my town.
That first year I tracked Santa, I realized that I was now spreading a special kind of Christmas joy to countless children who - like I had 15 years earlier - couldn't wait to find out when Santa would be arriving.
And - since I get to have this pleasure, a pleasure that can only be had on Christmas Eve - I actually consider it to be an honor of sorts to work on December 24.
If you have some little ones that just can't wait for my report - and want to know where Santa is right now - click here. =)
Merry Christmas!
Joe
Just a quick update for all of you blog readers out there...
Yesterday I blogged about the difficulty of predicting snow in the Northwest. As of today, it still looks like parts of Portland could see some snow on Christmas! Late on Christmas Eve, rain will begin in downtown Portland - but above 1,000 feet, snow will be falling - and it will be accumulating. After midnight on Christmas Day, as we head into the 26th, the snow level will start dropping lower than 1,000 feet. In fact, a mixture of rain and snow showers can be expected down at the valley floor by the morning of the 26th. There could be some slushy accumulation - but most of the accumulations will be above 1,000 feet. Up there, there could be five inches of snow on the ground by Wednesday afternoon!
I'll keep you posted here on the blog, and in our newscasts on NewsChannel 8.
Happy Holidays!
Joe
So on tonight's newscasts I explained that some valley snow is possible by late in the day on Christmas. I also said that it's still up in the air - that the snow level could be anywhere between the valley floor and 1,000 feet. Why don't I know exactly what's going to happen? Well - that's a pretty complicated question!
Forecasting, in general, is very complicated. One part of most meteorologists' forecasts is advanced computer models. But those computer models often make mistakes. They make mistakes because the data they ingest is often inaccurate. Additionally, the data is typically incomplete. And, the computer models themselves typically don't have the atmosphere modeled completely accurately.
The bottom line - meteorology is more of an art than a science! =)
But creating that art - and having a forecast be accurate - becomes much easier as the day in question gets closer and closer. Take, for example, Christmas Day. Right now - three days away - it's tough to say what's going to happen. It could be snowing in Portland...or it could be raining in Portland...or it could be sleeting in Portland! But as we get closer and closer to Christmas Day, the forecast will become much more focused, and much more reliable. That's the nature of these computer models - and the forecasts we base them on.
So - only time will tell if Santa has some snow in his bag! =) I'll keep you posted!
Joe
Now that winter solstice has passed, most folks expect the days to get longer. The sun should begin to set a little later and rise a little earlier each day. But if you look at at a sunrise-sunset table, you'll find this is only half true until early January. In Portland, the "crossover" date, which I'll explain later, comes on January 5th in 2008. Until then, yes, our sunset is happening later, but sunrise also continues to get later! What's up with that?
The ominous sounding Equation of Time is responsible for the asymmetry in sun rise and set times.
Two factors determine sunrise and sunset time: the tilt of the earth's axis relative to it's orbit around the sun, and the fact that said orbit is not a circle but an ellipse. The elliptical orbit means the earth has to travel faster in it's orbit when it's closest to the sun, which occurs in early January. It's kind of like how a skater spins faster when she or he pulls their arms close in to their body.
But back to the sun. Around the solstices, the angle of the sun (caused by earth's tilted rotational axis) is changing very little day by day. But the earth's position in its orbit around the sun is changing a lot. So this factor dominates in determining the change in sunrise and set.
Why? We have to consider something called the Solar Day. This is the amount of time it takes for the sun to go from one spot in the sky back to that exact same spot the next day. And guess what? It's MORE than 24 hours around the solstices! In fact the time of the solar day varies throughout the year. The 24-hour clock we use is an average over the course of the year, and occasionally has to be adjusted by adding a "leap second".
But let's not make a complex discussion more complicated. Back to sunrise and sunset times. Because the solar day is longer than 24 hours, it pushes the perceived sunrise and sunset times later, starting before solstice! In Portland this year, our sunsets started getting later on December 15. This is the beginning "crossover date", which is the day when the length-of-solar-day portion of the equation of time dominates the tilt-of-the-earth's-axis portion. The ending crossover date is January 5th in 2008, when the tilt of the earth's axis portion of the Equation Of Time begins to dominate the tricky little solar day portion and time progresses the way we all expect it to.
So between December 15 and the solstice, the solar day-dominated equation of time works with later sunrises but against earlier sunsets. Between the solstice and January 5th in 2008, the solar day-dominated equation of time works with the expected later sunsets, but against earlier sunrises, making the sunrises later too, until the tilt of the earth's axis component of the equation of time begins to dominate.
Phew! It's a complicated little system.. this whole earth-sun thing. And it works the same way for summer solstice, but it's not as pronounced, because the earth is then farthest from the sun and moving slower (skater's arms held wide) so the length of the solar day, while longer than 24 hours, isn't as long as in December.
Attention Weather Geeks
If you want to meet fellow weather geeks in the Portland area, here's your chance:
What: Fun meeting of weather blog folks and Oregon Chapter of the AMS members of all ages and a trip over the the National Weather Service Office in PDX.
When: Saturday, Dec 29th @ 12 noon. Meet at the Stark Street Pizza Company located at 9234 SE Stark Street. Take the Stark St exit off of I-205 (near Rockey Butte). Click here for a map and directions.
After pizza, around 2pm, the weather posse heads for The National Weather Service office in NE PDX for a fun tour of the facilities up there.
Merry Solstice and Happy Holidays to all,
Matt Zaffino
KGW Chief Meteorologist
mzaffino@kgw.com
So here it is Wednesday morning and I'm chained to camera five doing cutins while I watch and report about the snow falling in the Cascades. I'm green with envy for those who are able to get some time in on the slope today.
Not to pour any salt in the wound Amy Troy, just came by the weather center to check on snow conditions. Amy, has been dubbed our snow bunny today. She's been dispatched up to Mt. Hood to report on travel and ski conditions. Amy's a big skier, when I told her about the snow coming over the next few days she said "Epic" conditions on the hill. Then she muttered something about picking up her skis on the way up to Mt Hood. You don't suppose she plans on making a few runs during her lunch hour?
Timberline Lodge and Mt Hood Meadow both report 9" of new snow overnight. Both resorts reported snow totals about 50% of average last weekend. With all the new snow coming this week and weekend snow totals could easily reach 100 to 110% of average! Yes we're going to see that much snow!
Extended forecasts call for a brief lull in the precipitation Friday, Then another be storm arrives an brings more rain to the valley and snow in the mountains. Christmas eve will be fairly soggy in Portland. Christmas day I think we'll see another break with mostly cloudy skies and showery conditions.
For those of you wondering about the chance of a White Christmas in Portland, here are the facts. Over the past 75 years there is a 60% chance of preciptitation in the Rose City on Christmas day. However there is less than a 1% chance that the preciptitation will be snow. Sorry...
Dave Salesky
Get set everybody it's going to be a very, very active week in the weather. A lot of people will be on the go later this week. Many of you will be taking to the roads, rails and sky for Christmas vacation. With several storms headed for the region over the next few days, deteriorating weather might slow down a lot of travelers-especially if you're driving over any mountain passes.
I'm forecasting three storms will reach the Oregon & Washington coasts by weeks end. Each system will bring lots of rain, wind and mountain snow. None of the storms will be as bad as last months wind storm, but each has the potentual to cause problems. For most the biggest issue will be driving over the Cascade and Siskiyou mountain passes. This weekend we'll be measuring new snow in feet, not inches!
By Thursday cold air will arrive and drive snow levels briefly fall as low as 1000 feet. We won't see any sticking snow in here in Portland, but rain snow mix may fall on windshields. Snow levels will climb above 2000 feet Friday but remain below pass level through next week.
Dave Salesky
My ski season got off to a well-fed and scenic start last weekend at the Five-Mile Fire Lookout Tower in the Mt Hood National Forest.
I spent an hour or so out in the crisp cold night making pictures of the lookout tower. This 30 second exposure is one of my favorites. I've skied into fire lookout towers more times than I can remember, but I'm always struck by the stark and stately beauty of these structures against the backdrop of winter. The horizontal line of light on the right is an airplane on final approach to PDX. The orange glow on the left is the lights of Portland. You can see another light-line, angling off from the vertical at the top of the shot. This is either a high-flying airplane or a satellite, but it's cool because I didn't notice it until I was home looking at my pictures.
The Five-Mile Lookout sits on a 30-foot tower and has views of Mt Hood, Mt Adams and Mt Rainier and of course a sweeping view to the east.
Xena mostly ran and I skied in to the tower in the awesome late afternoon light to meet our good friends Terry and Bill. My pack in the background is a lot heavier than Xena's!
Xena carries her food and ski-jore (future blog subject) gear, along with a couple adult beverages in her dogpack. Once it's on her she doesn't even notice it. Hey the girl's gotta carry her own weight! Not literally of course, she only has a few pounds in there.
We got to the tower in time to catch some nice Mt Adams alpenglow. That's Mt Rainier on the left.
Terry and Bill are great back-country cooks. But this is not really that. The lookout has a propane oven and stove, so it's not exactly primitive. And since the early season snowpack is shallow, the ski in was short. So we brought A LOT of supplies!
How about a fondue and fresh crab feast?
I brought the fondue cheese and bread, Terry and Bill hauled in the fresh crab. Yummy!
After scarfing scraps and her dog food, Xena thinks she just might settle in on the bed for a nap.
But she slept on the floor near me. The wood-burning stove was doing a great job of heating up the place, so she occasionally crashed by the door for some heat relief.
In the morning she did a good job of scouring the left-over congealed fondue cheese out of my pot.
And she was all over it when Bill dropped an egg on the cabin floor.
The ski out was a little short for Xena, she would have preferred to keep going!
If you're interested in learning more about Forest Service lookouts available for public use, you can make reservations and find out more at
http://www.recreation.gov
Matt Zaffino
KGW Chief Meteorologist
Cold weather has become pretty common around here! Today the high temperatures in Portland didn't get out of the 30s. And this past Sunday, highs didn't get out of the 30s, either. In fact, it was cold enough for a little light snow. Not quite as much as in this picture, but still, it was something. =)
A shot from Corvallis in November, 2006
So where is all this cold air coming from? Numerous storms have been dropping down from the north, and dragging that cold air down along with them. And it's probably part of a larger pattern. With La Nina in place, more unseasonbly cold weather can be expected throughout the winter months.
Will we have a white Christmas? Historically, there is less than a 25% chance that there will be some snow on the ground on Christmas day. But with unseasonbly cold weather expected...that probability may be increasing this year. Guess we'll have to wait and see! =)
Joe
The storm pictured below is developing rapidly Sunday night and will cause more potentially damaging winds over the Northwest. Ahead of this 3rd storm, winds gusted to 113 mph just after 10 pm Sunday night at Cape Blanco on the southern Oregon Coast. The storm will continue to strengthen... we call this "deepening" in meteorology because the pressure gets lower as the storm gets stronger... until Monday morning when it begins to weaken, or fill.
But it's still a very dangerous storm and will likely be stronger than the Sunday morning storm that caused the wind gusts listed below.
Offshore buoys measure swells for us. The giant waves will also increase as this 3rd storm works on the ocean's surface.
Both of these storms formed from moisture that originated in the tropics, from two former typhoons. Even though Monday's storm will be weakening as it makes landfall farther away from Oregon than Sunday's storm, it's stronger to begin with and the wind field ahead of it is very large. That means this is a long duration wind event (hence the giant swells) with gusts at least as strong as the Sunday morning winds. And this last in this series of storms brings more monsoon-like rains to the the Northwest. Already several inches have fallen in the valleys. Rain totals will push three inches in the valleys and eight inches in the mountains. There are a number of flood warnings up for area rivers.
Be careful out there!
Matt Zaffino
KGW Chief Meteorologist
Wow. I can't remember the last time we had such an incredible array of weather issues around the Northwest. Let's start with the snow. Portland didn't see much because as the storm developed off the Washington Coast, it induced too much of a south wind. This warms the lowest elevations enough to turn the precipitation to liquid. This is always a concern when forecasting a storm that develops to the north of Portland. We had enough cold air in place for sea level snow, in fact there was snow at the beach early Saturday morning. But the transition to a south wind happened fast enough to squelch our opportunity for accumulating snow in the city. Not the case at my house, at 1200 ft:
Matt's House Saturday 430 pm. 1200 ft. 33º, Winds SW 23 G 39 mph
The Cascades are another matter of course when it comes to snow. A dangerous matter, in fact. Our early season snowpack is becomging increasingly unsafe. We have light, low density snow that is being loaded with increasingly heavy wet snow. This is a classic recipe for avalanches. But it's not just heavy snow on top of light snow. Three to eight inches of RAIN is expected to fall Sunday night and Monday on top of two to three FEET of new snow that falls before the snow level climbs to 7,000 ft Sunday night. Avalanche Watches and Warnings blanket the Cascades.
But the main event coming up will be the wind. A strong Pacific storm will develop and move into the Coast. Below is a computer forecast map valid for 1 pm Sunday.
The map shows a strong low making landfall on the south Washington coast. Potentially damaging south winds will follow the storm up the coast. If the storm continues to strengthen as it makes landfall, winds could be damaging even in the valleys. A second storm will follow this one Monday afternoon. It will be a stronger storm but make landfall farther north. The two storms will generate huge swells that may reach 45 feet off the Oregon coast!
The second storm has prompted the National Weather Service in Portland to issue the first Hurricane Force Wind Warning for the Northwest. It's not that we've never seen winds like this before, this is just a new class of wind warning for a non-tropical storm that has hurricane force winds. Sustained winds will reach 70 to 80 mph with gusts of 100 mph expected late Sunday and Monday.
This storm may take a track similar to a damaging wind storm that moved up the Coast in October 1967. Weather fanatic Steve Pierce of Vancouver sent me these archived weather maps from that storm:
There are some major differences between the 1967 event and what is likely to happen Monday, including the upper air pattern:
But between Hurricane Force Wind Warnings, Winter Storm Warnings, Avalanche Warnings and High Surf Advisories, the next two storms are likely to become case studies we look back on to judge future storms.
Matt Zaffino
Chief Meteorologist
KGW TV
May 2008
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