Dry Start To April; Make Up Time Next 7 Days

April 16, 2014

11pm Wednesday…

April has been quite dry so far, with less than 1″ rain falling in the past two weeks:


But it looks like that will change tomorrow, and again next week with a few wet weather systems moving through our area.  You can see from the chart below that as of mid-April we are about halfway between the wettest and driest time of the year in any average year; April is one of the 6 driest months…typically.

A nice cold front moves through the region Thursday afternoon, giving us a rainy and breezy day.  Beyond that the Easter Weekend is looking like a mix of wet and dry, with the rain likely arriving sometime Saturday midday or afternoon and then disappearing around daybreak Easter Morning.  Those of you headed to sunrise services outside will PROBABLY stay dry.  The rest of the day looks dry as well.  If so, it’ll be our 3rd dry Easter.  Remember last year?


It was incredible; both days of that weekend were 77 degrees and mostly sunny!  No such weather this year, but once again at least it appears dry.  Next week looks showery and cool to me; we have cool upper level troughs either sitting over the area or swinging through most of the time.  You can see the below average 850mb temps on the 12z ECMWF ensemble chart:


The ensemble average temp drops below average next Monday and stays there for the following week or so.  Interesting that a few members try to warm us up with some ridging NEXT weekend, but just a few.

So…get ready for showers and chilly temps next week!

Chief Meteorologist Mark Nelsen

Lunar Eclipse Tonight

April 14, 2014

5:30pm Monday…

It’s a total lunar eclipse tonight:  First “chunk” starts disappearing out of the moon at 10:59pm, then progressively gets “eaten” up until the entire moon goes nearly black for a little over an hour starting at 12:08pm.  Some have been calling it a “blood moon”, but it’s only expected to be a yellowish-orange due to the lack of dust in the earth’s atmosphere right now.


Here’s the problem, we’ll have a lot of clouds arriving about that time so we may or may not actually see it here west of the Cascades.  For MOST OF US, I think there will be breaks in the cloud cover; at least enough to see it part of the time.  Most likely the clouds will be packing up against the Cascade foothills as we head towards midnight, so those areas on the east side of the Willamette Valley and in the foothills have a smaller chance of seeing the eclipse.  The best chance overall is east of the Cascades, or east of Cascade Locks in the Gorge.  Take a look at our RPM forecast for 1am and you get the idea:


Chief Meteorologist Mark Nelsen

Beautiful April Weather Continues

April 10, 2014

10pm Thursday…

Another sunny and warm day today…66 here in Portland for the official high today.  Today was our 5th day in the 60s (or 70s), and it appears we have at least 4 more.  Many years we don’t see a warm and dry stretch that long in the month of April.  Take a look at the sunset this evening!


Photo by Michael Trofimov.  One more picture came in today from Gene Blick, showing a nearly snow-free Lost Lake basin:


As I’ve mentioned a bunch of times during the late winter and early spring, we’ve had unusually low snowpack below about 4,000′.  Luckily the northern Oregon ski areas had enough snow in February and again in later March to prolong the ski season a bit.  Both Mt. Hood Skibowl and Hoodoo Ski Area have their final weekend coming up; both will be closed for the season after Sunday.   Mt. Ashland was never able to open this season for the first time in its history.  Of course higher up on Mt. Bachelor and Mt. Hood the end of the ski season comes later.  Interest sure wanes at the ski areas in April, especially when we have such terrific weather in the lowlands.  I know it really annoys the ski area operators since they always have more snow on the ground in April and May than early on in November when just about everyone tries to get up on the slopes.  Then, this time of year (in a normal year) there is plenty of snow but interest totally drops off.  I have the feeling the reason is that in November/December it’s usually wet and always chilly outside, so why not head up to the snow and enjoy it?  But we have limited warm weather and sunshine around here in the lowlands so when it finally shows up in spring we want to do all the things we couldn’t do in the winter.  Like bicycling, running, hiking, golfing, gardening etc…  Maybe it’s really just the opposite of November; there is pent-up demand to get outside and do things in the lowlands this time of year so snowplay in the mountains seems so…winterlike.

Okay, enough about that.  Let’s move on to the forecast.

No big changes the next 4 days as upper level ridging builds along the coast and then shifts inland Sunday.  When that happens Sunday, we’ll see a “thermal trough” develop along the coastline with easterly wind from the Cascades all the way to the beaches.  That means one very warm day…probably into the 70s out there too!


Of course we’ll be much warmer here in the valleys as well.  I think MOS temperatures (derived from model information) are too cool with high temps right around 70 degrees.   Just as in the winter, I think they are allowing too much cool air down into Eastern Washington and Oregon.  My April temperature chart shows an 850mb temperature around +9 (models agree on this) with strong easterly flow should give us a high temperature between 74-78 degrees.  Up until the 00z GFS, models have been showing a big marine push Monday afternoon as an upper level trough approaches the Northwest.  The 00z GFS splits that trough, prolonging the warm weather and possibly giving us temperatures closer to 80 Monday.  It IS the GFS, so I ignored it and went with the ECMWF for making my 7 Day forecast.

Beyond that, cooler and wetter weather comes back, although I don’t see an unusually cold and wet pattern.  Take a look at the 12z ECMWF ensemble chart, showing temperatures at about 5,000′ over Oregon over the next 10 days:


Notice the long period of near average temperatures after the warm period Sunday-Monday.

Enjoy the sunshine this weekend!  I plan to clean up the last of the ice storm mess (flames!) in my yard from early March, take a long bike ride, and soak in some rays.

Chief Meteorologist Mark Nelsen


75 Degrees Monday! Mild Weather For The Week Ahead

April 7, 2014

We didn’t hit the record, but the high of 75 degrees in Portland today was the warmest since September 19th!


Quite an achievement considering we started with low clouds/fog in some areas this morning and no easterly wind surfacing in the metro area.  There was a light east wind in the Gorge the first half of the day with gusts around 30 mph in the Corbett area.  A big help was the warmer than expected 850mb temp; it was +11.8 degrees over Salem at 5pm.  That easily pushed us into the mid 70s.  In past cases, that same temperature with easterly flow has given us a high temp between 78-82 degrees in April, so it could be even warmer!  Take a look at the maximum temperature each of the last 9 years in the month of April here in Portland:


Last year we didn’t see 70s until later in the month, when we had a 4 day stretch.

Tomorrow will be a little cooler, but still very warm.  A weak cold front sweeps across the region tomorrow night, giving us a quick shot of rain.  I expect less than .20″ here in Portland.

Then we get weak ridging through this upcoming weekend.  The ECMWF had a chilly trough swinging by just to our east on Saturday, so it was cooler Friday and Saturday.  I ignored that since its ensemble members didn’t support that idea.  Either solution is dry, so it appears we have very little rain in the next 7 days.

Enjoy the mild and mainly dry weather the next few days!  Our 7 day forecast is real pleasant for early-mid April:

7 Day

Models show temperatures near or maybe a little above average in the next 10-15 days.  I sure don’t see a long cool/wet period;  more likely just typical warm, then cooler weather periods.  You can see this on the 850mb temp chart from the 12z ECMWF and the new 00z GFS:





Chief Meteorologist Mark Nelsen


3.3 Magnitude Earthquake Jolts the Portland Metro Area

April 6, 2014



Did you feel it?  The USGS is reporting a 3.3 magnitude earthquake hit 5 miles NW of Sherwood tonight at 8:33 PM.

At a depth of 12.9 miles, it was a pretty shallow quake, which is probably why so many people in the area felt it.  According to a PSU geologist we spoke with tonight, there’s a major fault line that runs from Newberg to Sherwood to Tualatin, but this quake didn’t hit on that fault line.  In this area, we get earthquakes this size once every couple of years, on average.

If you and your house got a good jolt, and you’re thinking, “Wow, that was scary!” here is some perspective… the earthquake that hit Chile on April 1, 2014 was nearly 100,000 times stronger than the quake that hit Oregon tonight.

An earthquake this small usually doesn’t cause any damage, but it’s a good reminder for all of us to be prepared.

Here’s a look at some of the recent big quakes to hit the Pacific Northwest.




Portland Weather Anchor Change: Bruce Sussman is Out

April 4, 2014

The Portland TV rumor machine has been in overdrive the past 3 days.  That’s because for the first time in about 5 years there is a change in the Chief Meteorologist job at one of the 4 stations.  It doesn’t have anything to do with me or FOX12, but anyone who reads this blog is interested in weather.  And if you’re interested in weather you probably also have an interest in who is presenting weather nightly on local TV.

Here’s the latest:

1.  Bruce Sussman over at KOIN has been let go.  Or you can choose your own wording such as “fired” or “contract not renewed” based on whether you are a viewer, owner of a tv station, etc…

2.  His last day was Thursday and last broadcast was 11pm.  I noticed the wording of his last forecast update yesterday was telling:   “If this forecast (sun next week) holds…don’t expect to see me on the news…I’ll be out playing with the kids!  Thanks so much for getting your news from the KOIN weather team. I’ve always appreciated you doing that.    Bruce Sussman – Chief Meteorologist”.   His bio is already gone from their website.

3.  Rumor also says Kristen VanDyke, a forecaster from station KRQE in Albuquerque, is coming to take that job soon.  You can see her here:  http://krqe.com/2014/04/03/kristens-thursday-morning-forecast-11/

Bruce is a good friend and it’s very disappointing to see him losing his position of course.  Although we do all know in this business that the end can come at any time, especially at a station that has problems.

KOIN has been struggling for years with numerous management changes, changing owners, and poor ratings.  Still, from a purely meteorological point of view, it’s never good to swap out a forecaster with almost 20 years of local forecasting experience with someone from out of the area.  Of course only half of what we do is weather forecasting and the rest is TV, so it’s a balancing act for TV stations.

The last time we saw a dramatic change like this was back in 2009 when Dave Salesky jumped from KGW over to KATU, bumping Rod Hill from KATU to…KGW.  Apparently in this town most of us just move from station to station.

Good luck Bruce, I’m sure you’ll do just fine wherever you land!

Chief Meteorologist Mark Nelsen




Light Rain, Then Warmer Weather Still on Tap

April 3, 2014

It was a gloomy end to Thursday with light rain at times from around 2pm onward here in the Portland metro area.    Still, it was nice to have some dry weather this morning, at least dry enough to get outside and do some yard cleanup in my case.  I sure noticed that spring has sprung even higher up where I live with trilliums just starting to appear in the woods, they look like this:  trillium The weather pattern has been quite dull and boring this week.  One weak system came through our area today and then several weak waves of moisture (clouds and rain) will move through a developing upper-level ridge Saturday and Sunday.  The weekend probably won’t be a total washout, in fact Sunday may be mainly dry SOUTH of the Portland area as the ridge pushes the light rain farther north. What about Monday and beyond?  Models are still pushing upper level heights up around 570-576dm at 500mb, a very nice setup in April and May for 70 degree temperatures.  850mb temperatures make it to around 10-12 degrees celsius (ECMWF) both Monday and Tuesday.  Even the cooler 8 degree temps on the GFS produce temps in the lower 70s Monday and Tuesday. Now it appears that a trough will pass by to the north on Wednesday, cooling us down and possibly some showers push south into NW Oregon too.  However, the generally higher than normal upper-level heights seem to stick around for a few more days.  Here’s a very confusing, yet interesting chart from WeatherBell.  They provide (for a fee) access to lots of extra model information and they have some really interesting presentations of model data. KPDX_2014040312_maxx_240 Everyone got that?  I think the forecast is VERY clear from this chart.  Just kidding, but stay with me, it actually makes sense if I annotate it a bit: New Scene   What you are seeing is maximum temperature forecast for each 12 hour period in Portland.  The last 11 runs of the ECMWF model are stacked from newest on the bottom to oldest on the top.  So the bottom row is the CURRENT forecast from the ECMWF.  Notice it shows a high around 70 Monday and 67 Tuesday, then 62 Wednesday.  If you go up one line, but stay in the same column, that’s the same time period but one model run back in time.  A lineup like this allows a forecaster (or you) to see how the last 11 runs of the model have trended for any one date.  In this case you can see the high temp forecast for Monday has been very consistent.  You can also see the Tuesday forecast high has trended down the past few days as the ECMWF has gradually weakened the ridging for next week.  Maybe most interesting is that for several days the ECMWF was showing high temps around 80 degrees next Wednesday and Thursday.  Instead we now have a trough “crashing the ridge” on Wednesday, thus a much cooler temperature forecast.  A chart like this is extremely helpful; one can digest many different model runs with just a glance.  The minimum temperature chart (not shown) is just as useful for tracking how models are doing with approaching cold weather in the winter too.

This is definitely not a TV graphic…don’t you agree?

BIG PICTURE:  3 more days of cool and wet, then warmer & drier than average next week.  Are you a gardener like me?  Next week will be our first multi-day dry period in over two weeks…time to get some outside work done! Chief Meteorologist Mark Nelsen