Crazy Coastal Heat Today

April 17, 2016

10pm Sunday…

80s at every single weather station along the north/central Oregon coast today…plus a few spots touched 90.  That is incredible for April.

In fact it appears Florence’s high of 91 was only a little below the hottest places in California today.


Crazy stuff, here in the valleys we stopped in the low to mid 80s.  With a slightly warmer atmosphere tomorrow, a warmer start, and a little less wind, we should see mid-upper 80s in the valleys Monday.

The models have gradually been holding  the weak offshore flow more into Tuesday so our temperature forecasts have gradually been rising.  As a result, mid-upper 80s will still around Tuesday as well.

Beyond that, more typical warm-ish April weather Wednesday-Friday, then back to cooler/showery for at least a few days.

As of this evening, April 2016 is the warmest on record in Portland, it’ll be interesting if we hold onto that record over the next 12 days.

Chief Meteorologist Mark Nelsen

Hot at The Beaches!

April 17, 2016

4pm Sunday…

Just got into work and saw these temps…wow!


The east wind is doing the trick. Most of the metro area is in the lower 80s, but the strong wind areas from PDX to Troutdale are a few notches cooler.  A bit less wind tomorrow and warmer atmosphere means well into the 80s.  We should set 3 records for today, Monday, & Tuesday as high pressure and offshore flow holds through most of Tuesday

Here’s the view at 4pm from our Chinook Winds camera…you don’t see that temperature out there very often!


More later this evening when I get a chance to delve into maps/models a bit more

Chief Meteorologist Mark Nelsen

Big Soaking Today & Record Highs Sunday

April 14, 2016

9pm Thursday…

Today was a cold one, at least by recent standards.  Actually I think today was a long overdue cold and showery spring day!  Take a look at the rain totals since midnight:


And the 24 hour totals on the eastside show we’ve seen a real nice soaking:


That’s about it for rain now as we head into another unusually warm (hot?) pattern for a few days.


Strong high pressure builds over the Pacific Northwest Saturday and Sunday, giving us our 3rd consecutive mild and dry weekend.

How warm this time around?  

We’re forecasting temperatures very similar to the record-setting weather we just saw 7 days ago:


You might be wondering how we arrive at a forecast that seems to be warmer than other forecasts (as of Thursday evening)?  Our reasoning (both Liana & I negotiated the numbers!):

  1. 850mb temps reach +17 to +18 deg C. over Salem late Sunday and early Monday; exactly what was forecast last time around (it ended up hitting +20).
  2. Solid sun Sunday and Monday
  3. Easterly flow (3-5 millibars gradient through the Gorge) all day Sunday and most of Monday too.  Gradients go flat late Monday, but no onshore flow
  4. 9 days farther into the spring = slightly more heat from the sun and slightly easier to break overnight inversions
  5. Last time around PDX & East Metro high temps were kept down slightly by the very strong east wind.  That gradient should not be nearly as strong this time around so I expect these locations to be more similar to the other locations that were in the 87-90 degree range last time.

7 Day

There you go, that’s the plan.  The possible thunderstorms on Tuesday or Wednesday are a huge question mark.  It depends on the orientation of an upper-low as it swings north and knocks down the ridge early next week.

By the way, records are 79/80/80 for Sunday/Monday/Tuesday at PDX.  I’m quite confident we’ll bust two of those records, but Tuesday is a huge guess depending on timing of a big marine push coming behind the warm weather.  We HAVE seen 5 80+ days in one April (2004) but it has only happened once.  Otherwise we’ve never seen more than 3 80+ days.

One more thing, before you attribute THIS APRIL (and this April only) to warming springtime temps, that’s definitely not the case.  Yes, our summer and early fall temps have definitely been getting warmer.  But until the last few years we were seeing lots of chilly April temps.  Look at the 90 year chart and you’ll see we’ve seen warmer periods than cooler periods.  Interesting that spring, unlike other seasons around here, has not been consistently warming eh?


Chief Meteorologist Mark Nelsen


A Soaking, Then Record Warm Temps Again

April 12, 2016

10pm Tuesday…

A nice cold front passed through the metro area this evening dropping temperatures about 10 degrees in just an hour or so.  It hasn’t exactly been a big soaker so far, but considering a lot of us just planted some veggies, any rain is good.  I expect more showers tomorrow and Thursday but unfortunately a huge soaking is out of the question.  Check out the paltry totals from our evening RPM model run:


Could April actually end up with below normal rain?  We haven’t seen a drier than normal month since November, but we still have almost 3 weeks of the month to go…plenty of time for rain!

We have another highly anomalous warm period coming up.  It appears we’re headed for record-setting warm temperatures early next week.  This with our average monthly temperature running 5-7 degrees above average!

A strong ridge and split in the jet stream flow will return over the weekend and be held in place by an upper-level low approaching California.  This is the pattern I would have expected to see more of back in our El Nino winter.   Take a look at the GFS ensemble surface temperature anomaly over the next 2+ weeks.


WAY above normal Saturday-early next week, then a little closer to normal after that time through the last week of April.   The ECMWF ensembles show a long period of dry weather after our few days of showers:


The blue is the operational model run we all look at and the green is the ensemble average.  Very dry for mid/late April.

Here’s what I find far more interesting; this 2nd highly anomalous “heat wave” coming didn’t even show up on ensemble/model forecasts a week ago!  Not even a hint.  Clearly they are having trouble with this split flow and/or lows diving towards California.  Take a look at the ECMWF ensemble chart from ONE WEEK AGO showing the end of the first “heatwave” and then near normal conditions through the following 10 days:


The TODAY is where we are right now (12th).  Now look at what is forecast from this morning’s run laid on top of last week’s run:


The new/current forecast now has the big ridge where there was no hint a week ago.  Interesting eh?

So how warm this time around?  We know that it’ll be 9-12 days farther into spring thus a slightly higher sun angle.  850mb temp forecasts keep rising too.  Check out the last 3.5 days of GFS run 850mb temps, latest run is the bottom line:


Note the +16 to +17…that’s exactly what the ECMWF is showing for both Sunday and Monday, and now the latest GFS run (not shown above) is right in line too.  We get offshore/easterly wind at least on Sunday, we’ll see about Monday.  Offshore flow at +16 has produced high temperatures around 83-86 degrees in Portland in mid-April.  Of course very few data points this high up.  Regardless, I’m feeling pretty confident that we would beat both Sunday and Monday’s record highs of 78 & 80 degrees.  Stay tuned.  I’m even more confident that we’ll have a 3rd consecutive dry and mild April weekend…crazy.

This is good news for your lawn mowing of course.  If you forgot to tell your son to mow before leaving for work Sunday (me), you can do it either late Friday or for sure over the weekend.


Chief Meteorologist Mark Nelsen

First “Marine Cloud Forecast Bust” of 2016

April 10, 2016

7pm Sunday…

It may have been only the first, but there will be more of these busts between now and September!

Last night we forecast the marine clouds to thicken again, be solid in the morning, then break up in the afternoon.  That KIND OF happened, except at a FAR slower pace than expected.  Take a look at the visible satellite image this morning:

Sat11amAt 11am low clouds filled all areas west of the Cascades below about 3,000′.  To find sunshine you needed to go up into the Cascade passes, or east of Cascade Locks in the Gorge.  By the way, that’s why I’ve said it before and I’ll say it again:  I consider Hood River to have almost a perfect climate in our area.  Marine clouds don’t EVER get east of about Wyeth, yet the cooling west wind in summer means Hood River/White Salmon areas aren’t really any warmer than Portland.  You get constant sunshine in the warm season but without the Eastern Oregon heat (like at The Dalles).  Plus, annual snowfall is around 2 feet or so…dependable winter snowfall (most years).

Okay, by 3pm the low clouds had still only cleared WEST of I-5:


Still cool/gloomy/overcast for 1/2 of the metro area at mid-afternoon.  Finally at 5pm most of us were seeing sunshine:


but those far east metro spots were STILL socked in (Sandy/Estacada/Colton).

Even the best models have trouble dealing with marine cloud burnoff time.  Check out the 1.33 km WRF-GFS total cloud product…


clear all the way to the coastline by 2pm!  I don’t think so.  High temperatures seemed chilly today, but they were finally “Normal”.


This evening the clouds have actually thickened over the west slopes of the Cascades…this view was clear an hour ago from our Skibowl Cam:


Moving on…

Tomorrow doesn’t look much different so I lowered the forecast high into the lower 60s.

Starting Tuesday, we’ll see some upper-level troughing nearby through Thursday, or possibly Friday.  As a result we finally get some rain after a very dry week; nice since a lot of us may have just planted a few veggies.  I planted onions and potatoes and I’m too lazy to water them, so I hope we get close to an inch at least.  Models imply we’ll get less than that in the western valleys this week.

Enjoy the cool showers because models are in decent agreement that the 2nd half of April will see mainly above normal temps.  Check out the GEFS (GFS ensembles) surface temperature deviation from normal for the next 2 weeks:


Models have been trying to push up some sort of ridging over us next weekend (that first spike), then after that we are generally a bit warmer than normal.  The ECMWF is similar with the 850mb temps although the warm spike is more dramatic next weekend


So…to summarize, it appears this could end up being ANOTHER warm month.  We’ve been warm now for over 2 years with no “cold months”.  When will it change?  I don’t know of course.  Theoretically a La Nina winter coming up (may or may not happen) could end the warm streak.  For now, sea surface temperatures remain well above normal across the far Eastern Pacific.


If that doesn’t change in the next month or two, we can get used to more of those warmer than normal nights and weaker than normal marine pushes as we’ve seen the past two warm seasons.

Seem like a pretty long blog post for a weekend?  It’s because I’m working this Sunday evening as part of an adjusted work schedule.  Same evening shows, but Sunday-Thursday instead of Monday-Friday.  Better for family life (my school district does 4 day weeks, Fridays off) plus more of you watch 10pm newscasts on Sunday night vs. Friday PM anyway = more Mark exposure on bigger nights!  It’s not too unusual at FOX network stations because they have much higher ratings on Sunday nights than Friday.  I’ve heard in Seattle the “weekday” crew at KCPQ works the same Sunday-Thursday schedule.

Chief Meteorologist Mark Nelsen


Final Numbers: A Scorcher For Early April

April 7, 2016

PDX hit 85 today, setting several records:


As you can see it was quite a weather event for early April.  Just about every weather station in our area set a record high.  Here are a few more from the Portland NWS:


The only official airport locations close to us that hit 90 were Kelso and Roseburg.

That coastal forecast is always extremely tricky…a 50 degree body of water is within a mile or two of most of those locations.  As soon as the east wind dies and/or wind switches to a westerly direction the temperature takes a nosedive.  It didn’t happen today until after the noon hour thus the real warm temperatures.

Here in the valley temperatures spiked dramatically compared to yesterday.  The highs were somewhere between the very warm WRF-GFS and coolish MOS and model surface temps.  Good to remember in early April 10 years from now when it happens again…

Tomorrow will still be fantastic, but significantly cooler.  We lose the easterly wind, see a gusty northwest wind kick in during the afternoon (onshore flow) and the atmosphere overhead cools a bit as well.  That should keep high temperatures in the 70s for just about all of us west of the Cascades.

The “Heat” Is On Today

April 7, 2016

9am Thursday…

We’re all set for a historic day temperature-wise in the region.

A record warm airmass is overhead.  When the morning weather balloon went up over Salem this morning (it’s done twice a day), at the 850mb level (about 5,000′), the temp was 68 degF.  It’s never been that warm until the first week of May as you can see by the dot on the chart.  The squiggly red line shows each day’s warmest temperature ever recorded at that height. 


East wind is very strong, with 7 millibars easterly gradient between The Dalles and Portland this morning.  Actually a bit stronger than I would like to see.  If it were to gust 20-30 mph at PDX all afternoon that could hold the temperature down lower than the 86 I forecast last night.  We’ll see.  Regardless, it’s spreading across the metro area as the warm air above begins to surface and the overnight cool air ponded in the valleys warms.  That means a dramatic jump in temperatures between now and 11am.

Corbett, in the wind all night, stayed in the 60s; this in a place that has an average HIGH this time of year in the mid-upper 50s.  Tropical by April standards.  Eagle Creek RAWS between Sandy and Barton suddenly jumped to 74 at 9am! Several 70 degree temps at 9am in Damascus area too already as warming surfaces…crazy for April!  Sunset Transit Center at 217/26 has jumped to 69 as well in that exposed east wind spot.

There are a few locations in the Cascades and/or foothills that have already at 9am reached or exceeded yesterday’s highs…with 8 hours of heating to go!  Ariel near Lake Merwin and Brush Creek (2400′) near Eugene are both 75 degrees.

So I think we’re all set for 80s this afternoon.  Enjoy the record warm temperatures, at least the wind and dry air should keep it from feeling real “hot”.

Chief Meteorologist Mark Nelsen