February 2017 Observations and Model Discussion for the Pacific Northwest

[VancouverIslandSouth]

The 0z ECMWF is looking better than the GFS already. Still staying strong with the northern shortwave and weak with the cutoff low to the south. The Friday low is also a bit weaker but closer to the coast. This has quite a nice look to it:

 

http://www.tropicaltidbits.com/analysis/models/ecmwf/2017022200/ecmwf_z500_mslp_namer_5.png

[VancouverIslandSouth]

Overall it looks like a decent 0z ECMWF, flirting with a few shots at snow this weekend then perhaps a chance at a more significant snowfall the following weekend.

[HighlandExperience]

Overall it looks like a decent 0z ECMWF, flirting with a few shots at snow this weekend then perhaps a chance at a more significant snowfall the following weekend.

Wxbell snow maps for fun?

[ShawniganLake]

Wxbell snow maps for fun?

[Jbolin]

Nice upper level low to our NW on Friday. 925's look good too but moisture will be the ?

[Perturbed Member]

Friday-Saturday is looking pretty interesting for the PDX  area. NAM and last 2 GFS runs bring the low a bit closer to us as it sinks south. 

 

1-3 inches seems reasonably well supported by models. Still a marginal setup but could be a nice little event.

 

http://maps1.pivotalweather.com/maps/models/gfs/2017022212/072/sn10_acc.us_nw.png

[VancouverIslandSouth]

The GFS is caving to the ECMWF on Sunday. The latest run shows a robust low coming down the coast on Sunday, which would give a lot of places a good shot at accumulating snow. The Friday low now seems well agreed upon as well and should at least produce scattered flurries.

 

http://www.tropicaltidbits.com/analysis/models/gfs/2017022212/gfs_mslp_pcpn_frzn_nwus_17.png

[MR.SNOWMIZER]

i like the 4 inches for kitsap

[Phil]

Man, the IO domain is ridiculously cold right now. There are no years in the satellite ere that have the coldest tropical SST anomalies located in the E-IO domain.

 

Have to go back to the 1950s and 1960s.

[Jesse]

Man, the IO domain is ridiculously cold right now. There are no years in the satellite ere that have the coldest tropical SST anomalies located in the E-IO domain.

 

Have to go back to the 1950s and 1960s.

 

What implications does this have on spring/El Nino prospects?

[ShawniganLake]

Dropped down to 27F here this morning.

 

The GFS has sure trended away from anything good next week.

[SilverFallsAndrew]

Dropped down to 27F here this morning.

 

The GFS has sure trended away from anything good next week.

 

Yeah it really has. Disappointing, but unsurprising. Some run of the mill chilly unsettled weather for the next week and then much warmer. We could be looking at some mid-60s by the 2nd week of March if the GFS were to verify. Going to be down in N. California the 2nd weekend of March, hope it dries out a bit down there by then. 

[Phil]

What implications does this have on spring/El Nino prospects?

Strange. The La Niña modiki Walker Cell regime always keeps troughing in the west during the warm season, however, it usually corresponds to a warmer IO, which plays a huge role in that.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/EA164109-4D22-4090-9A66-1C5BD47E9657_zps8beyetnk.jpeg

 

Right now, we have the warm SSTs/convection in the EPAC/left domain of WHEM, which is classic of Niña modoki, however, we also have the frigid E-IO domain, which is an opposing signal to that. This is a destructive interference regime, so *unless* we can somehow sustain a very high tropical wavenumber for months on end (very unlikely), one of these will win out, and the other will be disintegrated.

[jakeinthevalley]

Another .8" yesterday from 7am to 7pm.  14.3" for the month.

[SilverFallsAndrew]

Another .8" yesterday from 7am to 7pm. 14.3" for the month.

SLE needs 0.22" to break the month record. I think they can get it done. Pretty impressive record if they do it, much more so than PDX. 1996 was more anomalously wet the further south you went and SLE has about a 50 year longer period of record.

[Phil]

Basically, either the unified wave/ENSO attempt fails/is aborted (examples of which include 2011 and 2012), or a dominant signal emerges and we transition into a +ENSO wave state (examples of which include 2002 and 1986).

[Phil]

Also, this QBO state is just absurd. Not even a hint of a downwelling easterly in there. The precursory SAO in the mesosphere is already back-cycling, so I doubt we see the easterly in the upper sigmas until at least mid-summer.

 

However this turns out, it's obvious that something has happened to the QBO. It just isn't functioning properly anymore. Scientists worldwide are scratching their heads over this. We've followed the QBO since the 1950s, and nothing like this has ever been observed.

[SilverFallsAndrew]

Interesting to see the 12z ensembles. The 06z ensemble was actually pretty chilly still, slightly better than the 00z actually. 

[Jesse]

Strange. The La Niña modiki Walker Cell regime always keeps troughing in the west during the warm season, however, it usually corresponds to a warmer IO, which plays a huge role in that.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/EA164109-4D22-4090-9A66-1C5BD47E9657_zps8beyetnk.jpeg

 

Right now, we have the warm SSTs/convection in the EPAC/left domain of WHEM, which is classic of Niña modoki, however, we also have the frigid E-IO domain, which is an opposing signal to that. This is a destructive interference regime, so *unless* we can somehow sustain a very high tropical wavenumber for months on end (very unlikely), one of these will win out, and the other will be disintegrated.

I understand maybe 5% of this.

[MossMan]

Strange. The La Niña modiki Walker Cell regime always keeps troughing in the west during the warm season, however, it usually corresponds to a warmer IO, which plays a huge role in that.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/EA164109-4D22-4090-9A66-1C5BD47E9657_zps8beyetnk.jpeg

 

Right now, we have the warm SSTs/convection in the EPAC/left domain of WHEM, which is classic of Niña modoki, however, we also have the frigid E-IO domain, which is an opposing signal to that. This is a destructive interference regime, so *unless* we can somehow sustain a very high tropical wavenumber for months on end (very unlikely), one of these will win out, and the other will be disintegrated.

The WHAM is back!!!!

[Jesse]

Yeah it really has. Disappointing, but unsurprising. Some run of the mill chilly unsettled weather for the next week and then much warmer. We could be looking at some mid-60s by the 2nd week of March if the GFS were to verify. Going to be down in N. California the 2nd weekend of March, hope it dries out a bit down there by then.

The GFS ensembles have a ton of spread in the mid-long range, and the Euro and GEM have consistently looked better.

 

Hard telling what will happen a week from now, let alone the second week of March.

[Phil]

Note how this winter has been dominated by a westward propagating rossby wave regime, focused over the mid-latitude WHEM domain (or as we say, retrogression ). Meanwhile, the NATL/Eurasian wave state has been stable.

 

Here's a hovmoller of the 500mb height anomalies. Note the map on the bottom of the image for the domain in question, which includes the PNW/NPAC.

 

I drew this up very quickly, so it's not perfect.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/70BCBA3D-C72A-4831-88DA-51B41105529E_zps5lew7bx7.jpg

[jakeinthevalley]

SLE needs 0.22" to break the month record. I think they can get it done. Pretty impressive record if they do it, much more so than PDX. 1996 was more anomalously wet the further south you went and SLE has about a 50 year longer period of record.

Only 28 days this year. 1996 had 29 days, but I haven't looked to see if that extra day had any precip at SLE

[Phil]

Note how this winter has been dominated by a westward propagating rossby wave regime, focused over the mid-latitude WHEM domain (or as we say, retrogression ). Meanwhile, the NATL/Eurasian wave state has been stable.

 

Here's a hovmoller of the 500mb height anomalies. Note the map on the bottom of the image for the domain in question, which includes the PNW/NPAC.

 

I drew this up very quickly, so it's not perfect.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/70BCBA3D-C72A-4831-88DA-51B41105529E_zps5lew7bx7.jpg

This type of system state arises through a harmoneous resonance between the tropical convection and EAMT/NAMT exchange ratios. I call it a pendulum cycle, because that's basically what it is, and it's most common in weak ENSO states where you have the intraseasonal forcing trying to break away from the ENSO background state, while said background state keeps pulling it back each time it tries to escape its phase space.

 

Eventually you develop a resonant exchange of sorts with the mid-latitude wavetrains, where the frictional and gravity wave drag torques out of Eurasia and North America alter mass/momentum flux gradients over space/time to back-resonate with the convection, such that the intraseasonal break-aways and mid-latitude influence (torques) become synchronized.

 

This system state often persists until it overamplifies and self destructs (waves amplify enough to corrupt PV/NAM, which hence is no longer the "springboard" maintaining structural coherence of says regime).

[HighlandExperience]

[Deweydog]

The GFS ensembles have a ton of spread in the mid-long range, and the Euro and GEM have consistently looked better.

 

Hard telling what will happen a week from now, let alone the second week of March.

#bringbacktheLOLemoticon

[ShawniganLake]

[Phil]

Kinda OT, but still interesting to note. After receiving a whopping 10 feet of snow in one week, many lake effect cities on the Tug Hill plateau are on pace to break all-time snowfall records, should the modeled pattern progression verify. The waters are still toasty, and some very cold air will consolidating in Canada. Given how warm this winter has been, it would be quite the feat to pull off a record.

[jakeinthevalley]

Showers getting ready to pop around McMinnville.  Might be a fun afternoon if the convection is deep enough.

[Brennan]

IMG_0571.PNG

That's about the pattern the models were projecting about a week before we got blasted here in early February....  

[ShawniganLake]

That's about the pattern the models were projecting about a week before we got blasted here in early February....

[MossMan]

Snowing here at my work.

[MossMan]

IMG_0475.PNG

Should I start prepping my jetski and boat for summer?

[ShawniganLake]

Should I start prepping my jetski and boat for summer?

I guess not. That was what the euro was showing 10 days before the February snowstorm. Check the date stamped on the map.

[MossMan]

I guess not. That was what the euro was showing 10 days before the February snowstorm. Check the date stamped on the map.

Oh my...yep. 

[MossMan]

Moderate snow now here. 

[Chewbacca Defense]

I understand maybe 5% of this.

 

 

That's 4.99999% more than I understand!  

[MossMan]

Moderate snow now here. 

And now its done. 

[SilverFallsAndrew]

Sun is warm today. Had to roll the windows down and turn on the AC

[Timmy]

And now its done.

Great story bro