April 2017 Observations and Model Discussion for the Pacific Northwest

[stuffradio]

I'm currently sitting at 5.05" of rain this month.

[SilverFallsAndrew]

It also sounds like April has been much wetter further north.

[ShawniganLake]

Well, the top 06z GFS-based analogs are 1993 and 1964. I'm not saying I expect a "repeat" verbatim of either, but the persistence of some of the cool summer years is occurring for a reason, and that reason appears to be linked to the +SIOD/cool IO and warm EPAC regime. Lots of extended-jet/low wavenumber patterns in that setup.

 

In particular, the 1993 analog has shown up every day for the last 4+ weeks:

 

http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/gifs/500hgt_comp_06gfs814.gif

I see 2004 on there twice. Hmmm!

[SilverFallsAndrew]

2.48" of rain here so far this month. Right around average.

[TT-SEA]

Awesome new satellite... 

 

http://weather.cod.edu/satrad/exper/?parms=northwest-02-48-0

 

[Kayla]

Awesome new satellite... 

 

http://weather.cod.edu/satrad/exper/?parms=northwest-02-48-0

 

 

Amazing, thanks for the link! 

[TT-SEA]

Amazing, thanks for the link! 

 

And it appears to update every 5 minutes.   

[wx_statman]

Good information. Things could change obviously, but if current models are to be believed we could break the record. As it stands now, third place is basically a lock.

 

I'm really conflicted about Sunday now. On the one hand I'm ready for a nice spring day, but on the other hand that 67 on Mark Nelsen's forecast would leave us in 2nd place. 

[Kayla]

And it appears to update every 5 minutes.   

 

The clarity GOES-16 has is spectacular. 

 

I'm interested to see when or if this will be implemented into our global models and the benefit we may see from this added resolution.

[wx_statman]

One word.... solar

 

If it were so simple...

[Jesse]

I'm really conflicted about Sunday now. On the one hand I'm ready for a nice spring day, but on the other hand that 67 on Mark Nelsen's forecast would leave us in 2nd place.

Sunday is a tough call. With a chilly start it will all be dependent upon how fast cloud cover moves in. Mark's forecast is probably a little on the warm side, hedging on them holding off longer.

 

Even if we do manage to rise above 64, second place is still pretty impressive considering we haven't even come close in 60 years.

[wx_statman]

Sunday is a tough call. With a chilly start it will all be dependent upon how fast cloud cover moves in. Mark's forecast is probably a little on the warm side, hedging on them holding off longer.

 

Even if we do manage to rise above 64, second place is still pretty impressive considering we haven't even come close in 60 years.

 

I don't like the trend though. We've gone from 62 to 67 over the last couple days. That said, a "miracle" ala last Wednesday could always be in the works. That's the only reason we're having this conversation right now...

[Jesse]

I don't like the trend though. We've gone from 62 to 67 over the last couple days. That said, a "miracle" ala last Wednesday could always be in the works. That's the only reason we're having this conversation right now...

Models have fluctuated more than Mark's 7-day. He will usually go warm in a situation like this. I'm guessing the 62 was put in by the weekend person.

[TT-SEA]

Models have fluctuated more than Mark's 7-day. He will usually go warm in a situation like this. I'm guessing the 62 was put in by the weekend person.

12Z GFS looks even better than the 00Z run.

[wx_statman]

Models have fluctuated more than Mark's 7-day. He will usually go warm in a situation like this. I'm guessing the 62 was put in by the weekend person.

 

I'll trust you on that. Being a climo guy, I don't usually look at models. 

[Jesse]

I'll trust you on that. Being a climo guy, I don't usually look at models.

There has been a trend towards keeping Sunday drier in recent days. But it is still a sort of flimsy looking setup for 65+ warmth. Albeit still our best shot this year so far.

[Front Ranger]

It also sounds like April has been much wetter further north.

April has been quite wet for south Portland metro north. Though drier in the north Sound.

 

[Kayla]

Models have fluctuated more than Mark's 7-day. He will usually go warm in a situation like this. I'm guessing the 62 was put in by the weekend person.

 

Mark always weighs his forecast heavily (as he should) on the Euro. 00z says 67 on Sunday. I'd say at this point it's a pretty good forecast and not a warm bias forecast at all. 

 

Even the EPS says 65.

[BLI snowman]

Models have fluctuated more than Mark's 7-day. He will usually go warm in a situation like this. I'm guessing the 62 was put in by the weekend person.

 

Basically no model support for a

[Jesse]

Basically no model support for a

Still not as warm as the 71 on 4/1. The ultimate April Fool's present!

[BLI snowman]

Still not as warm as the 71 on 4/1. The ultimate April Fool's present!

 

 

Jessecast: It rained a few weeks ago so 65+ on a sunny mid April day sounds kinds sketchy.

[Jesse]

Jessecast: It rained a few weeks ago so 65+ on a sunny mid April day sounds kinds sketchy.

I said it looks like our best shot this year so far.

[IbrChris]

Awesome new satellite... 

 

http://weather.cod.edu/satrad/exper/?parms=northwest-02-48-0

 

Great find! Been looking for a dedicated page for real-time GOES-16 imagery

[TT-SEA]

Great find! Been looking for a dedicated page for real-time GOES-16 imagery

 

Cliff Mass actually wrote about it recently...

 

http://cliffmass.blogspot.com/2017/04/new-goes-weather-satellite-imagery.html

[TT-SEA]

12Z GFS is quite dry for most of the run... certainly better than we have been seeing recently.   

 

Not totally dry of course... but lots of dry days.  

[TT-SEA]

12Z WRF is not too crazy for Sunday... low to mid 60s up here it appears.

 

[TT-SEA]

Actually looks like places to the south have a better shot at a sunny day on Sunday... there is no massive shield of clouds moving up from the south like on previous runs.

 

 

[IbrChris]

Cliff Mass actually wrote about it recently...

 

http://cliffmass.blogspot.com/2017/04/new-goes-weather-satellite-imagery.html

If you wanna see something cool select Southwest then after seeing the visible image go to mid-level WV (water vapor) for same region. Notice all the mtn waves over the Great Basin (esp E Nevada) that visible and IR don't pick up because they don't reach saturation at the crest of the wave (no cloud formed). I think this is the first time we've had the resolution to show these individual micro-scale features on a satellite image (when they aren't denoted by clouds).

 

 

[stuffradio]

12Z GFS is quite dry for most of the run... certainly better than we have been seeing recently.   

 

Not totally dry of course... but lots of dry days.  

Except Easter Monday, 12Z GFS is wet almost every day up here. I only need less than an inch to reach average for this month.

[TT-SEA]

Except Easter Monday, 12Z GFS is wet almost every day up here. I only need less than an inch to reach average for this month.

 

Easter Sunday is nice up there as well.   

 

And even Saturday looks decent...

 

[stuffradio]

Easter Sunday is nice up there as well.   

 

And even Saturday looks decent...

 

There's precip every day except on Monday and the 21st.

 

http://models.weatherbell.com/gfs/2017041312/station/CYXX_2017041312_tx_240.png

[TT-SEA]

There's precip every day except on Monday and the 21st.

 

http://models.weatherbell.com/gfs/2017041312/station/CYXX_2017041312_tx_240.png

 

 

The models show absolutely no rain up there for Sunday.   

 

http://www.tropicaltidbits.com/analysis/models/gfs/2017041312/gfs_mslp_pcpn_frzn_us_14.png

[Phil]

Big Hudson Bay Vortex/low wavenumber pattern advertised on nearly all guidance, aided by the cool IO/+SIOD. Keeps N/NE Canada in the freezer and reduces the poleward transfer of mass and heat via the WHEM conduits.

 

Makes it easy for the NH to shed heat and consolidate tropical convection equatorward.

[IbrChris]

Big Hudson Bay Vortex/low wavenumber pattern advertised on nearly all guidance, aided by the cool IO/+SIOD. Keeps N/NE Canada in the freezer and reduces the poleward transfer of mass and heat via the WHEM conduits.

 

Makes it easy for the NH to shed heat and consolidate tropical convection equatorward.

Sounds like a good primary pattern for a +PNA and finally some west-oriented warmth.

[TT-SEA]

Sounds like a good primary pattern for a +PNA and finally some west-oriented warmth.

 

 

Something has to eventually change... this pattern has been ridiculously persistent for us.   

[Phil]

Sounds like a good primary pattern for a +PNA and finally some west-oriented warmth.

Yeah, I agree. At least for a few weeks.

 

I think I mentioned earlier that I'm leaning towards a progression into a warmer pattern over the next few weeks via a W/SW retrogression of the GOA trough following the east-Asian mountain torque backcycle. Should help retract the NPAC jet for awhile, then maybe a return to troughing as the anticyclone retrogrades NW in early/mid May?

[Jesse]

Sounds like a good primary pattern for a +PNA and finally some west-oriented warmth.

#wishcast

[IbrChris]

Yeah, I agree. At least for a few weeks.

 

I think I mentioned earlier that I'm leaning towards a progression into a warmer pattern over the next few weeks via a W/SW retrogression of the GOA trough following the east-Asian mountain torque backcycle. Should help retract the NPAC jet for awhile, then maybe a return to troughing as the anticyclone retrogrades NW in early/mid May?

Yeah any ridging this time of the year is pretty transient...transient meaning generally no more than 3-5 days.

[IbrChris]

#wishcast

Not asking for much...just a couple days in the 70s in April. Of course some folks would prefer we not see 70 until July.

[IbrChris]

Potential for storms again over the next 2-3 hours or so along the I-5 corridor at least from OLM to EUG as another negative-tilt shortwave swings through the region. Getting some sunbreaks similar to yesterday and although the boundary layer is a bit cooler vs yesterday mid-level temps are also cooler (500 mb cold pool overhead) which is allowing for slightly greater instability vs yesterday.