Cooler Today, Much Cooler at the Coast

May 15, 2014

11pm Thursday…



Quite a bit cooler today with temps only in the lower 80s around the metro area, although that was STILL 15 degrees above average!

But we’re cooling quickly this evening with temps already mainly in the 55-65 degree range in the metro area.  Cooler marine air is coming up the Columbia River and also moving in through gaps in the Coast Range.  Speaking of that, check out the temperature change from highs yesterday to the 5pm temperatures today!


This continues tomorrow so high temps should drop about 10 degrees = unusually warm weather is over.

That said, after cool showers this weekend it appears we have another warmer period starting on Tuesday.  You can see that in the ECMWF meteogram from this morning’s run:


Chief Meteorologist Mark Nelsen

3 Record Highs Today

May 14, 2014

10:30pm Wednesday…

Today was the warmest May day in 6 years here in Portland…the first time we’ve been to 90 in May during that time as well.


It was hot and 3 records (that I’m aware of) were set today.  But at least this time of year the heat doesn’t stick around as long as it does in July.  In just 3 days we’ll be back in the 60s.  You might even briefly turn on the heat either Sunday or Monday mornings too, depending on your tolerance of cooler weather.  Okay, maybe that’s a bit dramatic, but possible.

We get a marine push along the coastline tomorrow for much cooler temps, then that cooler air surges inland for 10 degrees or more cooling Friday.

A cool upper-level trough moves overhead Saturday through Monday giving us showers at times, the it appears we go back to more mild (not hot) weather next week.  Of course Memorial Day weekend is just around the corner, but it’s still a bit too far away to know how the weather is looking.

Chief Meteorologist Mark Nelsen


4pm…91 In Portland; A May Scorcher

May 14, 2014

Glad we didn’t weenie out and go with 88 or 89 today in Portland!  We have hit at least 91; that is the 3:53pm temp at PDX.  Most likely it’ll rise 1 or 2 more degrees so our forecast high of 91 will be slightly on the cool side.  These temps are the highs SO FAR as of 4pm…


How unusual is this?  We have hit a record for the day, the old record is 88 degrees set this day in 2012.  Also it’s the warmest May day in 6 years!  Sometimes we go through several Mays without hitting 90.

Even weirder is the forecast screwup at the coastline today.  The onshore wind didn’t arrive until early-mid afternoon at most locations, which means temps skyrocketed until that time.  That means we’ve had two episodes in early-mid May with temperatures in the 80s or even lower 90s at the beaches.

It appears Cannon Beach and Tillamook both hit or exceeded 90 degrees.

Final high temps will be out within the hour.

Chief Meteorologist Mark Nelsen


Warmest So Far Wednesday: 90 Likely in Portland

May 13, 2014

11pm Tuesday…

Okay, I’ll admit it.  A little warmer than I’d like (for May) late this afternoon/evening.  We hit the mid 80s in most of the metro area today, buoyed by the offshore wind flow.  Even most of the coastline was between 75-80 degrees.


We didn’t hit the record, which is 92 degrees.  But tomorrow’s 88 degree record is definitely at risk.  I am forecasting a high of 91 tomorrow; in reality I wouldn’t be surprised if it was as low as 88 or as high as 93.  It should be in that range with cloudless skies, offshore flow, and an 850mb temp between 18-19 degrees celsius over Salem.  That means in the open atmosphere, the temperature around 5,000′ should be around 66-67 degrees.  We’ll see how that plays out tomorrow.  Today it was +15.6 degrees over Salem around 5pm.  The soundings are taken twice a day by balloon…old style!

So assuming we hit 90 tomorrow, how rare is that in May?  Well we haven’t done it for the past 5 Mays, although we have hit 88-89 at times:


The last time was during a heat wave in 2008.

Temperatures will cool dramatically Friday through Monday.  In fact you can see the below average temperatures up at 5,000′ (850mb) on the ensemble chart from the 12z ECMWF.  You may also notice one other thing; temperatures go back above average after next Monday.  It appears mild weather is going to stick around through most of the 2nd half of the month.


The new 00z GFS chart is similar, showing the 2nd half of May looking more like mid June:


So I’m planting my tomatoes and squash…looks like a good chance they can get settled in with the mild weather and handle a (hopefully) brief cool spell in June.  Around 2010-2011 I couldn’t do that until around the 4th of July!

Chief Meteorologist Mark Nelsen



A Warm Week

May 12, 2014

11:00pm Monday…

This is another nice week with temperatures more like July than mid-May.  Interesting that we had a warm-hot week, then a cool/wet week last week, and now back to another warm spell.  I don’t see any extreme heat with temps above 90 degrees for several days, but we’ll be quite close to 90 for one day…Wednesday.

We hit 78 in Portland today; quite a change from the low-mid 40s this morning!


we’ll see another 10-12 degrees warming over the next two days.  Then cooling Thursday-Saturday.   The warming is once again brought to us courtesy a strong upper-level ridge developing along the West Coast.  Take a look at the Wednesday afternoon GFS forecast:


585dm heights are real impressive in mid May.  In fact, I figure anytime 500mb. heights are 570 or above the weather is pretty decent in May and June.

Today we saw the east wind make it all the way to the beaches and it surfaced in the Portland metro area too.  The temperature sure took a jump from 11am-noon (the chart above) as the east wind kicked in…66 to 73 in that one hour.    That may happen again tomorrow and possibly Wednesday as slightly weaker easterly flow continues.    That combined with forecast 850mb temps of +18 over Salem on both the GFS and ECMWF should push us to right around 90 degrees.  2 weeks ago we hit 89 with an 850mb temp of +19 under similar offshore flow conditions.  So that’s why I went for 90 since it’s two weeks farther into the season (2 weeks closer to summer).

After that we get weak onshore flow Thursday afternoon, then an upper-level low just in time for…THE WEEKEND.  I heard some complaints about that here at work, but I reminded folks that we had some really nice weekends in January, and I think again in March.  Or was it April?  One of the latter two occurred, so quite your whining.  At least that’s what I told my co-workers.

Longer term, there is some hint that we warm up again in the days leading up to the Memorial Day Weekend.  Here’s the 12z ECMWF ensemble chart:


and the brand new 00z GFS ensemble chart:


IF we get to 90 on Wednesday, this is how that will line up with other “First 90 Degree Days” in the past 6 years.


Remember those two cool summers in 2011 and 2012?  Those really were strange years.

Chief Meteorologist Mark Nelsen

2014 National Climate Assessment: A Few Thoughts

May 9, 2014


I received 2 emails about Global Warming (or Climate Change) this week, which appear to have been sent to lots of TV meteorologists at one time (a “form” email).  The 2nd one went something like this:

Dear Local Meteorologists;

The American Meteorological Society (AMS) has affirmed the conclusions of the overwhelming majority of the scientific community, that climate change is happening, that humans are the cause, and that increased global temperatures are already having a profound impact on our weather system. (Read the AMS’ Information Statement On Climate here.)  In other words, the debate about climate change is over.
Viewers trust and rely on weather reporters for accurate information about weather and climate. As global warming increasingly changes the weather and places our communities at risk, talking about Global warming is a journalistic responsibility. 

Please consider these facts while conducting future weather news forecasts


Of course what prompted those emails was the release of the 2014 National Climate Assessment on Tuesday.  I considered doing a blog post on the Pacific Northwest portion of the assessment.  I put it off for a few days since it was going to be a big pain.  But then UW Professor Cliff Mass saved the day!  He did a posting on his blog Thursday, doing all the work for me.  I strongly suggest you take a look at it here:


His main points:

1. SO FAR, there has only been very slight warming in the Pacific Northwest, with most of that occurring more than 60 years ago.

2. There have been no significant changes in our precipitation, at least statistically significant changes.

3. Snowpack has declined around 20% in the Cascades in the past 80-100 years and it’s possibly not even related to global warming.

4. Our location right up against the Eastern Pacific Ocean means that there have been very few changes in our climate here SO FAR due to the moderating effects of all that water.

5. In the future, assuming the globe does warm dramatically as models show, we can expect less mountain snowpack and heavier rains/flooding events.


Basically we haven’t seen many changes here SO FAR.  THAT would be why I rarely (or never) talk about Global Warming on the air.  What would I say?  By the way the wording “Climate Change” drives me nuts.  It’s all started by a warming globe (thus GLOBAL WARMING) and that can cause a changing climate.

Considering all the other issues humanity is facing, I think a slowly changing climate over the next 60-80 years isn’t at the top of the list.  And I hate to be negative, but it’s obvious that we won’t be slowing down our CO2 output anytime soon.   Take a look at this graph from the Seattle Times:


Anything we do here to cut our emissions will be dwarfed by massive increases in the developing world.  We’ve made our choices and now we’ll see what happens in the next 30, 50, or 100 years.

By the way, for 7 years I’ve had a web page with a few more of my opinions on the subject…it’s here:

Chief Meteorologist Mark Nelsen





A Soaker Today, but Summer Preview 2.0 Ahead

May 8, 2014

10:45pm Thursday…

What a gray and wet day, with the biggest downpours this evening.  For some reason it decided to really pour while I was making a “donut run” for the kids; what a good father, willing to risk TV makeup and wet hair just for the kiddos.  At least I think so.

Here are the rain totals as of 10pm…


Colder air moving in aloft tomorrow along with sunbreaks points to hail and possible thundershowers tomorrow.  Take a look at the WRF-GFS depiction of CAPE (Convective Available Potential Energy) for tomorrow afternoon.


When you see numbers above 300 or so west of the Cascades that’s always good.  Up around 800 or more is “big time” thunderstorms for us.  “Big Time” in this case means more than one flash every 5 minutes of course…

So tomorrow (Friday) should be an active weather day as a cold pool of air in the upper atmosphere passes overhead.  It’ll be shifting to our south quickly on Saturday, thus a much better day with just partly cloudy skies and a few sprinkles or a shower.

Beginning Sunday, an upper-level ridge builds over the West Coast for the 2nd time this month.  That means another period of much warmer than normal temps and abundant sunshine.  Basically another preview of summer for a few days.

How warm is it going to get?  The 12z GFS and 12z ECMWF were in excellent agreement; here are their ensemble charts:

tseries_850t_000-360_Portland tseries_850t_000-384_Portland

Both show 850mb temps around +10 over us by Monday afternoon, and +15 to +18 for Wednesday and Thursday afternoons.  Low level flow turns offshore Tuesday and Wednesday, with flatter flow (depending on the model) Thursday.  Pretty good agreement on these models and most of their ensembles, so I went for some mid-upper 80s in the 7 Day forecast.

The 00z GFS has come in significantly cooler, although still very nice, the middle of next week.  Even the ensembles are a little cooler so if the ECMWF follows suit we’ll need to lower our 7 day forecast temps by 5 degrees or so.  Here is the fresh 00z chart:

tseries_850t_000-384_Portland (1)

We’re definitely headed for a dry period, check out the 12z ECMWF meteogram showing no rain after Saturday afternoon for the following 8+ days:


So enjoy the rain because we’re headed back into a dry pattern for a while.

By the way, last night I showed this hail graphic on the 10pm newscast:


I was curious how large hail has been in our viewing area in the past.  I do clearly remember the July 9, 1995 supercell thunderstorm event in north-central Oregon.  Once in a great while we have seen quarter size hail west of the Cascades, but the main action happens east of the Cascades. Almost every summer we hear of golf ball size hail at least once somewhere over there.  But it’s been 16 years (1998) since larger sizes have been documented as you see in the graphic.

Chief Meteorologist Mark Nelsen