September 2016 Observations and Model Discussion for the Pacific Northwest

[snow_wizard]

00z ensembles are certainly much improved.

 

If the height anomalies over the North Pacific can remain the same they have been through October our chances for a great winter will be pretty high.  So far the warm autumn in NW forecasts have been proven wrong.

[Phil]

New 00z Canadian & ensembles are also improved, deeper western trough and sharper/stronger ridge into Alaska. That ridge amplifying poleward instead of flattening south of the Aleutians seems to be the difference maker.

 

I think the operational GooFuS was a blip.

[Jesse]

If the height anomalies over the North Pacific can remain the same they have been through October our chances for a great winter will be pretty high.  So far the warm autumn in NW forecasts have been proven wrong.

 

Indeed. The prospects for a fairly cool September are looking good. I don't think any major forecasting outlet or long range model (Euro weeklies, CFS, etc) predicted that.

[snow_wizard]

Things look to remain rather unchanged in the tropics so it should remain troughy here overall.  No doubt ENSO SST's will react to this amazing run of trade winds pretty soon.

 

 

[snow_wizard]

Pretty big change on the CFS ENSO forecast the past week or so.

 

[SilverFallsAndrew]

SLE picked up 0.44" in an hour this evening with the t-storm. 

[Phil]

The 12z ECMWF ensembles are also emphatically shooting for a prolonged trade wind surge. I think the Niña deniers on the eastern forums are in trouble.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/EE3986E2-62AB-4727-BC59-DF39F4382948_zpsv9tb5dqi.jpg

[Deweydog]

Pretty big change on the CFS ENSO forecast the past week or so.

 

http://www.cpc.ncep.noaa.gov/products/CFSv2/imagesInd3/nino34Mon.gif

That one lil' guy gets awfully cold next June.

[snow_wizard]

The 12z ECMWF ensembles are also emphatically shooting for a prolonged trade wind surge. I think the Niña deniers on the eastern forums are in trouble.

 

 

Even more dramatic than the GFS.

[Phil]

Dr. No is out to 96hrs. Can already see differences over Asia, though it was already gunning for the stronger sharper NPAC ridge.

[Jesse]

Tonight could break the 49 barrier at PDX.

[snow_wizard]

That one lil' guy gets awfully cold next June.

 

Such a cutie!

[snow_wizard]

Tonight could break the 49 barrier at PDX.

 

SEA did manage to do that yesterday.  Today's 52 was absurd.

[Phil]

Even more dramatic than the GFS.

Can really see that low-frequency Niña Walker Cell having consolidated over the last few months.

 

Now, if we could just shift everything ~25 degrees eastward, so the convergent maximum sits around 150E. That'd just be perfection..1978/79 on -PNA 'roids.

[Jesse]

SEA did manage to do that yesterday. Today's 52 was absurd.

PDX has been down to 49 a few times this month, but hasn't fallen any lower just yet.

[stuffradio]

I just want to see Joe B have his winter forecast bust for the PNW being warmer than normal and less snow than normal.

[Phil]

00z ECMWF completely does away with the Midwest ULL, instead goes with a trough split. Resulting changes to be determined.

[Jesse]

00z ECMWF completely does away with the Midwest ULL, instead goes with a trough split. Resulting changes to be determined.

I would guess a more progressive, full latitude trough for us that doesn't cut off as much as advertised on the 12z.

[Phil]

I would guess a more progressive, full latitude trough for us that doesn't cut off as much as advertised on the 12z.

Yeah, it's definitely more progressive over the US, though it's also somewhat flatter with the NPAC ridge, which helps widen the downstream ridge over the Intermountain West.

 

Might be a wash in the short term.

[ShawniganLake]

The euro is looking kinda yucky. Similar to 12z.

[Phil]

Meh, next. Offshore ridge is too flat, given its latitude, for much of a downstream push. Also has that stronger polar vortex, so most of the jet energy is consolidated northward.

[BLI snowman]

SLE picked up 0.44" in an hour this evening with the t-storm. 

 

Meanwhile going on over three months without a storm up here. Been a super lame year for convection, even by our barely there standards.

[snow_wizard]

The ECMWF actually isn't that bad.  The NPI is very high almost the entire time.  Definitely better looking at the surface than the upper levels.  You also have the fact it could easily turn out much bette than progged at the 500mb level with a few minor adjustments.

[Phil]

The ECMWF actually isn't that bad. The NPI is very high almost the entire time. Definitely better looking at the surface than the upper levels. You also have the fact it could easily turn out much bette than progged at the 500mb level with a few minor adjustments.

Eh, note the 500mb snake out of Asia. That's a classic precursor to a +NAM and/or +EPO.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/D7137ED3-DBC5-44C9-9246-44354A6419F4_zpsiualirpp.gif

[TT-SEA]

Looks like SEA is on pace to finish up September very much like last year.   Cool and wet the first week of the month... then generally dry and near normal the rest of the month.     

 

September 2015 was -0.8 at SEA and so far this September is -0.7 with the rest of the month probably averaging close to normal.

 

August of 2015 and 2016 were the same as well at +2.6

 

The more things change... the more they stay the same.  

[TT-SEA]

00Z ECMWF looks great on the surface maps for the next 10 days (only exception is Friday).

 

9 out of 10 days that are fairly sunny and pleasant.

 

Interestingly... it shows upper 50s to barely touching 60 on Friday for both PDX and SEA with a perfectly timed front for cool anomaly lovers.

[Jesse]

Euro ensembles continue to look way different than the operational. The trough is directly over us from mid week onward on the ensemble.

 

06z GFS looks that way too, with very good ensemble support.

[TT-SEA]

ECMWF ensemble control run shows one transient trough later next week followed by a return to ridging. I like the control run in general because its not so blended after day 6. Sometimes its very different than the operational run which is informative as well. When its really different then you know the operational will be changing significantly.

[Jesse]

Tonight could break the 49 barrier at PDX.

47!

[Front Ranger]

Indeed. The prospects for a fairly cool September are looking good. I don't think any major forecasting outlet or long range model (Euro weeklies, CFS, etc) predicted that.

 

I think it's been proven repeatedly that long range models like the Euro weeklies like to stick to what's been working. In other words, they overvalue persistence. At least, they value it too long. That's probably why the weeklies have been so bad in recent months.

 

The CFS, of course, has no logical explanation.

[Front Ranger]

Looks like the 5th low in the 30s this month at OLM this morning.

 

Speaking of OLM, they now have a -1.4 anomaly on the month, twice SEA's. The two were running neck and neck through the first 10 days, but as usual, SEA has pulled away on the warm side of things.

 

A lot of places will probably finish this September cooler than last.

[Front Ranger]

The 12z ECMWF ensembles are also emphatically shooting for a prolonged trade wind surge. I think the Niña deniers on the eastern forums are in trouble.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/EE3986E2-62AB-4727-BC59-DF39F4382948_zpsv9tb5dqi.jpg

 

Powering into October! Certainly fits Nina climo.

[Jesse]

Looks like the 5th low in the 30s this month at OLM this morning.

 

Speaking of OLM, they now have a -1.4 anomaly on the month, twice SEA's. The two were running neck and neck through the first 10 days, but as usual, SEA has pulled away on the warm side of things.

 

A lot of places will probably finish this September cooler than last.

 

Easily. PDX is sitting at -2 as of today. At this point Sunday-Tuesday look like the only real positive anomaly days the rest of the month.

[Phil]

Interesting fact: Through 9/22, the Atlantic has generated the lowest ACE of any year except 1963 (Niño/-QBO). Given that we're in a Niña/+QBO (reduction in equatorward convective integral over Pacific relative to Atlantic), this is quite confounding. Possibly to the point where I'm going to factor Atlantic ACE into my winter analogs.

 

Also, for the first time on record (since 1856), we've observed back to back years (2015 & 2016) without any hurricanes from 9/1 to 9/22.

 

Seems we've entered an inactive era in the Atlantic. A significant shift in the Atlantic Hadley Cell looks to be the culprit..it occurred abruptly and simultaneously w/ the NPAC Hadley/Walker regime change of January 2013. Starting to look as if that month was the marker of a climate shift.

[Phil]

Powering into October! Certainly fits Nina climo.

Yup, powered by a convective burst over 120E, which is (as you noted) a classic Niña hallmark. Would still like to (eventually) get the convection closer to 150E, allowing for a more ideal NPAC configuration for the West. It's okay for this time of year, however.

[Phil]

Spatially speaking, the dominant trough was located in the West over the last 90 days, reflecting the Niña/-AAM background.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/46B8FC56-E60D-468D-BC48-A5E6FE9E8480_zpsfle3mysk.jpg

[Timmy Supercell]

Between 2:30am to 3:00am there was heavy rain in Klamath (heaviest since the May storm). It was noisy even with the window closed. No t'storms here but yesterday evening it looked like there was going to be some convection. Just some cells along the I-5 area in SW Oregon.

 

Looks like the season for lowland storms is beginning, while mine is ending.

I heard from a bunch of people on Facebook yesterday that it was quite active up in NW OR.

[Phil]

(Credit: Michael Ventrice/WSI).

 

"Atmospheric ENSO index" (basically, convective/circulatory tendencies derived relative to ENSO climatology) is dropping into negative (Niña) territory for the first time in over 2yrs:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/3072345F-5632-4A01-878A-93918DA629AC_zpsdksyqnay.jpg

[ShawniganLake]

The 12z ECMWF ensembles are also emphatically shooting for a prolonged trade wind surge. I think the Niña deniers on the eastern forums are in trouble.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/EE3986E2-62AB-4727-BC59-DF39F4382948_zpsv9tb5dqi.jpg

hopefully they actually do something this time.

 

http://www.tropicaltidbits.com/analysis/ocean/nino34.png

[TT-SEA]

hopefully they actually do something this time.

 

http://www.tropicaltidbits.com/analysis/ocean/nino34.png

 

 

No kidding... a couple weeks ago all the hype was about the strongest trade wind burst in history and the ENSO regions warmed anyways.