April 2021 Pacific Northwest Weather Obs

[iFred]

Looking forward to an active month. Graupel, hail, thunderstorms, cold nights.

[TigerWoodsLibido]

Finished March with a respectable -1.4F departure but we were -3.5" for precip...approaching -12" for the water year on top of a -17" from last water year...I mean....fuckk

If we don't get much of anything before going into the blast furnace then I'm concerned for the metro area. We are going to be a tinderbox.

[snow_wizard]

Started the month off with a chilly 35.  It appears more frosty nights lie ahead.

[snow_wizard]

7 hours ago, TigerWoodsLibido said:

Finished March with a respectable -1.4F departure but we were -3.5" for precip...approaching -12" for the water year on top of a -17" from last water year...I mean....fuckk

If we don't get much of anything before going into the blast furnace then I'm concerned for the metro area. We are going to be a tinderbox.

I just can't believe how dry it's been down there.  Up here we haven't gotten close to being too dry.  There is still reasonable hope this will be a cool summer though.

I ended up with a -1.3 on the temps and -2.37 on precip.

[hawkstwelve]

Got down to 34 last night after a 69/27 spread yesterday.

[snow_wizard]

14 minutes ago, hawkstwelve said:

Got down to 34 last night after a 69/27 spread yesterday.

We can get some pretty big diurnal spreads here.  Temperature wise this is a good microclimate.  I'm impressed you made 27 yesterday.  I only pulled off a 30, and then a high 63.  Your added elevation may give you lower dew points and potential for greater diurnal range.  I also had a SW breeze yesterday which may have moderated the max.

[Jesse]

Low of 41 here. Up to 46 now with some sun.

[TT-SEA]

 Beautiful day... sunny with a little east wind.  

Later next week is looking really nice on the 12Z GFS.    A little rain on Sunday (of course) and then Tuesday/Wednesday.    But today and tomorrow also looked wet earlier this week and that did not happen.

[snow_wizard]

Yet another situation next week where a very complex pattern evolution could give us anything from a torch to well below normal temps.  In recent weeks the cold outcomes have won out most of the time in these cases.

[snow_wizard]

4 minutes ago, TT-SEA said:

 Beautiful day... sunny with a little east wind.  

Later next week is looking really nice on the 12Z GFS.    A little rain on Sunday (of course) and then Tuesday/Wednesday.    But today and tomorrow also looked wet earlier this week and that did not happen.

Right now my money is on the colder EPS later next week.  I only say that because of recent precedent.

[Jesse]

1 minute ago, snow_wizard said:

Yet another situation next week where a very complex pattern evolution could give us anything from a torch to well below normal temps.  In recent weeks the cold outcomes have won out most of the time in these cases.

The EPS looked quite cool later next week.

[TT-SEA]

7 minutes ago, snow_wizard said:

Yet another situation next week where a very complex pattern evolution could give us anything from a torch to well below normal temps.  In recent weeks the cold outcomes have won out most of the time in these cases.

Yeah... we have been in a cycle in which the colder scenarios win out in the end overall.   But we have also had periods trend warmer and drier too... like the period from today through Saturday which a week ago looked cold and wet on most runs.

[snow_wizard]

35 minutes ago, Jesse said:

Low of 41 here. Up to 46 now with some sun.

I notice NW OR was way milder last night.  Did you have heavy cloud down there?  Of course OLM pulled off yet another freeze.

[Jesse]

31 minutes ago, snow_wizard said:

I notice NW OR was way milder last night.  Did you have heavy cloud over there?  Of course OLM pulled off yet another freeze.

There was an easterly breeze here until late. The same east winds that gave the immediate Portland area the warmest temps in the region yesterday. There was some high cloud cover that moved in late as well. Although wind/mixing was probably the biggest factor. HIO (which tends to be more sheltered from easterlies) fell into the mid-30s overnight.

[snow_wizard]

Looks like Sunday night will be another rapid clear out behind the cold front.  That quick clearing is why we have seen so many cold nights.  These are true sharp cold fronts we have been getting.

[snow_wizard]

It appears this new GFS model has a tendency to dump too much energy southwestward under offshore blocks.  Obviously that ends up torching us.

[Deweydog]

Lovely morning. No joke!

[TacomaWaWx]

Not so chilly low of 40 this morning. Nice filtered sunshine this morning. 

[TacomaWaWx]

Next few days look pretty dry on last nights euro run...gets wetter by the end though. Don’t think we will see a April 2020 repeat of no rain for 3 weeks. 

[Jesse]

Looks like PDX ended up with a -1.0F anomaly on the dot for March.

[Phil]

55 minutes ago, TT-SEA said:

Yeah... we have been in a cycle in which the colder scenarios win out in the end overall.   But we have also had periods trend warmer and drier too... like the period from today through Saturday which a week ago looked cold and wet on most runs.

Usually the scenarios that “win out” are those most aligned with the background state. Which in this case is decidedly La Niña.

Won’t happen all the time, and there’s likely to be two distinct periods of warmth this month, but on the edges, the La Niña like pattern will probably overperform guidance.

[snow_wizard]

The GEM is chilly for next week.  Looks petty dry though.

[snow_wizard]

25 minutes ago, TacomaWaWx said:

Next few days look pretty dry on last nights euro run...gets wetter by the end though. Don’t think we will see a April 2020 repeat of no rain for 3 weeks. 

40 is probably still about normal for you this late.  Now it appears we have several opportunities for more frost over the next 10 days.  Few if any nights look above normal.

[snow_wizard]

26 minutes ago, Jesse said:

Looks like PDX ended up with a -1.0F anomaly on the dot for March.

Now let's see if we can keep the streak going with a cold April.

[bainbridgekid]

2 hours ago, hawkstwelve said:

Got down to 34 last night after a 69/27 spread yesterday.

A 42 degree diurnal spread is very impressive. That's about as big a daily swing as we ever get around here.

[The Blob]

Today looks beautiful, to bad I'm too sleep deprived to go out and enjoy it

[snow_wizard]

The moisture has really washed out with this cold front.  The models actually show a decent period with clear skies tonight.  850s look to bottom out round -3 so there is still some chilly air with it.

[snow_wizard]

10 minutes ago, bainbridgekid said:

A 42 degree diurnal spread is very impressive. That's about as big a daily swing as we ever get around here.

That is a good one alright.  45 to 50 is probably the biggest you will ever see, and that would be years like 1951 which were ridiculous in that regard.  The EPSL away from Puget Sound can do petty good sometimes.

[TT-SEA]

Up to 60 now after a low of 42... beautiful start to April. 

[TT-SEA]

12Z ECMWF shows a deep trough moving in by day 8... we will see if it holds.      If you go back 6 days... the current period through Saturday looked almost exactly the same as what it is showing on day 8 on the 12Z run.

[snow_wizard]

The ECMWF shows a very deep trough late next week.  The GEM and ECMWF are both 100% out of phase with the GFS.  The GFS upgrade appears to be a flop IMO.

[TT-SEA]

23 minutes ago, snow_wizard said:

The ECMWF shows a very deep trough late next week.  The GEM and ECMWF are both 100% out of phase with the GFS.  The GFS upgrade appears to be a flop IMO.

So you are assuming the ECMWF is accurate and the GFS is totally wrong... but the reality will likely be a compromise.    That is what happened with this current period when looking back at the model runs a week ago.     Its too early to say the GFS is a flop.   

[TT-SEA]

Not saying it will happen again... but here is an example illustrating how the ECMWF did not cut off enough energy.   I have been noticing that the cut off bias seems to have switched from the ECMWF to the GFS now.    

Top image is day 8 from the 12Z ECMWF run last Friday... and the bottom image is how that same day looks on the 12Z run this morning.   It actually did not cut off enough energy to the southwest.  

 

[GHweatherChris]

Surprised it dropped down to 35 this morning here.

[TacomaWaWx]

Up to 55 now. 

[SilverFallsAndrew]

We got down to 37 last night. A bit warmer than previous nights. 

[SilverFallsAndrew]

Looks like SLE ended up with a -2.4 departure for March. Coldest average March minimum at Salem since 1985... Thought SnowWiz would like that nugget. 

[SilverFallsAndrew]

Just noticed, the average low at Silver Falls in January was the warmest all-time... Not really a surprise. Average low in March was the coldest in 23 years though, about 7F colder than the average January low (37.6 vs. 30.5).

[snow_wizard]

I would call the last few days of the ECMW insanely cold.  Highs and lows both way below normal.

[Phil]

Clown range EPS control run looks freakin’ awesome.

 

[snow_wizard]

48 minutes ago, TT-SEA said:

So you are assuming the ECMWF is accurate and the GFS is totally wrong... but the reality will likely be a compromise.    That is what happened with this current period when looking back at the model runs a week ago.     Its too early to say the GFS is a flop.   

True.  I will be interested to see how it plays out.

[snow_wizard]

1 minute ago, Phil said:

Clown range EPS control run looks freakin’ awesome.

 

No doubt the Euro models are freeking cold right now.  The op is about as cold as it gets in April.

[snow_wizard]

9 minutes ago, SilverFallsAndrew said:

Looks like SLE ended up with a -2.4 departure for March. Coldest average March minimum at Salem since 1985... Thought SnowWiz would like that nugget. 

Yup.

[TacomaWaWx]

3 minutes ago, snow_wizard said:

I would call the last few days of the ECMW insanely cold.  Highs and lows both way below normal.

looks like this run has some high temps in the mid 40s and lows in the mid 30s for western WA at the end. 

[snow_wizard]

7 minutes ago, SilverFallsAndrew said:

Just noticed, the average low at Silver Falls in January was the warmest all-time... Not really a surprise. Average low in March was the coldest in 23 years though, about 7F colder than the average January low (37.6 vs. 30.5).

January has to come around eventually.

[Phil]

Will be interesting to see how the background/low frequency state battles the coming MJO wave.

If it overperforms relative to MJO climatology, in theory, that could be interpreted as a good sign for the warm season.

[snow_wizard]

Just now, TacomaWaWx said:

looks like this run has some high temps in the mid 40s and lows in the mid 30s for western WA at the end. 

Even low 30s in a lot of places.  You know we are in a cold regime when we get clear nights during the troughing.

[Phil]

It’s actually snowing here now.

Ma’ nature must be in the April fools spirit.

[snow_wizard]

The cold nights just keep rolling in the Euro.  Shows some upper 20s Sunday night and lots of frost Monday night as well.  Tonight and tomorrow night both go well below 40 in many places.

[SilverFallsAndrew]

7th driest March on record at PDX.