October 2016 Observations and Model Discussion for the Pacific Northwest

[Perturbed Member]

Yeah, the newest edition of the 00z NAM definitely trended towards the EURO. Now it's the GFS and GEMs turn. Positive steps in the right direction.

 

Yep, I think the NAM might be validating the idea that the other models have been too quick to deepen the low before it gets close to us hence the northward track. Going to be very interesting watching the other runs tonight.

 

Here is the MM5 NAM

[TT-SEA]

As shown... the NAM would be pretty quiet for the Seattle area.   

 

Storm moves right overhead and weakens.     

 

But these storms ALWAYS end up north of what is shown even the day before... and that would be fairly destructive for the Seattle area.

[Tundra]

Yep, I think the NAM might be validating the idea that the other models have been too quick to deepen the low before it gets close to us hence the northward track. Going to be very interesting watching the other runs tonight.

 

Here is the MM5 NAM

Yup, good points. It's going to be fun sorting out the small details run by run. I'm not going to get much sleep the next few days!

[Phil]

The biggy has been the persistent GOA ridge since mid June. The fact it is slated to return yet again later in the month is extremely encouraging. The persistent SE US ridge is also a very good sign. There are many other favorable things going on also.

The GOA ridge and SE ridge can be summarized within a single function, technically speaking, but the nature of the wavenumber response to various stimuli seems to change seasonally.

 

Running correlations on both entities (GOA ridge & SE Ridge), there's a decent correlation w/ the GOA state in S/O/N and that of D/J/F. As for the SE ridge, there's very little cross seasonal correlation, which suggests to me that off-domain transference could be in play, regarding the NATL state.

[Perturbed Member]

Yup, good points. It's going to be fun sorting out the small details run by run. I'm not going to get much sleep the next few days!

It's probably the same for all of us . Once the weather gets exciting everyone comes out of the woodwork and is addicted. I swear model riding has to be worse than crack.

[TT-SEA]

So many times lows have come in too far north... and north of what the models showed... and ruined snow chances.    

 

Then of course we are all disgusted with the idea of a windstorm.  

 

Whatever the models show Friday... it will be north of that based on history.  

[Phil]

It's probably the same for all of us . Once the weather gets exciting everyone comes out of the woodwork and is addicted. I swear model riding has to be worse than crack.

It's an unhealthy addiction, too. Last winter, I went a week without getting more than 3hrs of sleep a night tracking that blizzard.

 

Sandy was even worse. I think I pulled two consecutive all nighters.

[Phil]

Speaking of windstorms, Nicole might impact Bermuda as a Cat4 tomorrow. Yikes.

[Kayla]

Looks like the GFS is sticking to its guns... But continues to trend ever so slightly further south.

[Jbolin]

That's easier said than done. I think you're taking quite a few liberties here... The odds of this system mimicking the effects seen from Freda are really, really low given that there's only one model showing that solution, and that model's ensembles have continued to trend toward the NAM/GFS/GGEM solution.

 

Ummm no they don't, in fact the opposite could be said 

[Gradient Keeper]

00z GFS this run was actually the closest to the ECMWF yet for a dangerous wind storm on Saturday evening/night. Post tropical Songda was handled nearly identical to the ECMWF from 160 to 140 W weakening it to just a strong wave briefly. The issue here is the low developed exploding a tad sooner near 135 W, thus it curved north a bit sooner. This is a common solution we see and it's why we often "dodge the bullet" of a big, destructive wind storm. Bares watching.

[Deweydog]

WRF puts a 50kt bullseye over the north valley tomorrow evening.  At this point probabilities are decent tomorrow night's system will be the strongest of the set for this neck of the woods.

[Gradient Keeper]

00z GEM/CMC has heavily trended towards the dangerous ECMWF

 

 

http://www.tropicaltidbits.com/analysis/models/gem/2016101300/gem_mslp_wind_nwus_12.png

 

http://www.tropicaltidbits.com/analysis/models/gem/2016101300/gem_mslp_wind_nwus_13.png

[seattleweatherguy]

00z GEM/CMC has heavily trended towards the dangerous ECMWF

 

At face value, what does this mean for seattle and what for medford or as sister is headed there.

 

http://www.tropicaltidbits.com/analysis/models/gem/2016101300/gem_mslp_wind_nwus_12.png

 

http://www.tropicaltidbits.com/analysis/models/gem/2016101300/gem_mslp_wind_nwus_13.png

[Phil]

Love seeing that IO subsidence dominate the ensemble averages in the extended range. Tight, contracted Niña cell boosts WHEM wavenumber and correlates to -EPO/-NAM during D/J/F.

 

GEFS/CMC Ensembles:

 

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2016101218/gfs-ens_chi200_global_33.png

 

http://www.tropicaltidbits.com/analysis/models/gem-ens/2016101212/gem-ens_chi200_global_33.png

[Perturbed Member]

Mark Nelsen posted an update, looks like he is pretty sure Saturday won't be anything like the 1962 storm. All eyes on the ECMWF. 

[MossMan]

00z GEM/CMC has heavily trended towards the dangerous ECMWF

 

 

http://www.tropicaltidbits.com/analysis/models/gem/2016101300/gem_mslp_wind_nwus_12.png

 

http://www.tropicaltidbits.com/analysis/models/gem/2016101300/gem_mslp_wind_nwus_13.png

Going to be fun to track and experience!!

[snow_wizard]

Speaking of windstorms, Nicole might impact Bermuda as a Cat4 tomorrow. Yikes.

 

It is amazing to note that initially before Nicole even became a tropical depression it wasn't expected to develop at all.  Once it did develop it was expected to be  quick flash in the pan.  Now it has evolved into a long lasting monster.

[Tundra]

00z GEM/CMC has heavily trended towards the dangerous ECMWF

 

 

http://www.tropicaltidbits.com/analysis/models/gem/2016101300/gem_mslp_wind_nwus_12.png

 

http://www.tropicaltidbits.com/analysis/models/gem/2016101300/gem_mslp_wind_nwus_13.png

Going to be fun to track and experience!!

The Sou'wester strengthens as it races up the Oregon coastline before weakening. This run has a lot of similarities to the Columbus Day Storm 54 years ago today!

[Deweydog]

Man, the Canadian has been awful lately.

[snow_wizard]

The thing with both the storm tomorrow night and the one on Saturday is the surface gradients are progged to maintain a bit of an easterly component which usually mitigates winds for the Seattle area.  The new WRF does show rather high winds for Seattle proper tomorrow night though.  It's hard to know how this will play out exactly since the jet doesn't dig quite as deeply off the coast as it does with many of our big windstorms.  Tough call.

[snow_wizard]

The Sou'wester strengthens as it races up the Oregon coastline before weakening. This run has a lot of similarities to the Columbus Day Storm 54 years ago today!

 

The trajectory is different though.

[snow_wizard]

Man, the Canadian has been awful lately.

 

Do you think something looks wrong with tonight's run?

[Deweydog]

Do you think something looks wrong with tonight's run?

Nothing in particular, it's just been an outlier way more often than not for several weeks now.

[Tundra]

The trajectory is different though.

 

Yeah I'm hoping it doesn't curve northward until it's closer to the coastline. Small details will make all the difference.

[snow_wizard]

Absolutely gorgeous GOA / Aleutian ridge for week two.  It's almost alien to me to actually get what I was hoping for!

[stuffradio]

Man, the Canadian has been awful lately.

Sorry, I'll try and smarten up.

[Tundra]

Mark Nelsen posted an update, looks like he is pretty sure Saturday won't be anything like the 1962 storm. All eyes on the ECMWF.

For tomorrow he's calling for South gusts 40 to 50 mph for PDX Metro. Pretty decent winds if it verifies. Yeah time for the EURO!

[Phil]

Absolutely gorgeous GOA / Aleutian ridge for week two. It's almost alien to me to actually get what I was hoping for!

I'd like that GOA ridge farther poleward (which I suspect will happen eventually, within the next 6 weeks). Flat Aleutian ridges are dangerous to play with.

[Phil]

Yeah I'm hoping it doesn't curve northward until it's closer to the coastline. Small details will make all the difference.

A deeper low during the earlier stages will occlude faster. A weaker low during the earlier stages will begin that process later.

[TT-SEA]

The thing with both the storm tomorrow night and the one on Saturday is the surface gradients are progged to maintain a bit of an easterly component which usually mitigates winds for the Seattle area.  The new WRF does show rather high winds for Seattle proper tomorrow night though.  It's hard to know how this will play out exactly since the jet doesn't dig quite as deeply off the coast as it does with many of our big windstorms.  Tough call.

 

 

Just normal windy for both of us on the 00Z WRF with the system tomorrow night and Saturday night.

[snow_wizard]

I'd like that GOA ridge farther poleward (which I suspect will happen eventually, within the next 6 weeks). Flat Aleutian ridges are dangerous to play with.

 

It's still a nice looking ridge.

[ShawniganLake]

Moderate rain here as the outer bands of Songda begin to rotate in. A very untropical like 45F though.

[snow_wizard]

I was just looking at the analogs to the 18z GFS.  Some pretty orgasmic winters / seasons in the mix.  I expect the 0z ones will be similar.

[snow_wizard]

Moderate rain here as the outer bands of Songda begin to rotate in. A very untropical like 45F though.

 

I think Songda is still way out in the Pacific.

[Tundra]

A deeper low during the earlier stages will occlude faster. A weaker low during the earlier stages will begin that process later.

Yeah I know that, the EURO has been slower with the development of the low. I think the GFS is being too aggressive with how fast it develops in its initial stages.

[Gradient Keeper]

Post tropical Songda update
Wow. Check this out. What will become Saturday's mega low now located near 172 E approaching the date line is absolutely racing east along 40 N and perhaps as fast as I can ever recall any system moving on a satellite loop. As I have mentioned so many other times, it is neat that we can now watch this in real-time and not have to just rely on the models.

IR Loop http://www.atmos.washington.edu/~ovens/wxloop.cgi?ir_common+12

http://www.atmos.washington.edu/images/sat_common/201610130430_ir.gif

 

[Phil]

I was just looking at the analogs to the 18z GFS. Some pretty orgasmic winters / seasons in the mix. I expect the 0z ones will be similar.

00z analogs are out. Some epic ones in there, but several losers in there also. Hinges on the latitude of the NPAC ridge.

 

http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/gifs/500hgt_comp_00gfs814.gif

[snow_wizard]

Just for reference, I thought it might be instructive to post a surface plot of the Columbus Day 1962 storm near its peak intensity:

 

 

Do you have the map showing how it tracked after that?  The WRF shows it being a classic sucker storm.  If it were to track inland over southern Vancouver Island and then track east from there Seattle could be walloped.  For it to get really windy here with a storm like this the center has to get more straight north of us.

[VancouverIslandSouth]

Things sure flipped quickly today. The sky was still almost entirely clear with dry air around 1pm, we're now getting a dose of moderate rains. Telltale calm before the storm I suppose, these transitions don't normally happen this quickly, it takes quite a bit of energy to break through a cool dry airmass. The TPW maps are lighting up tonight. Tomorrow nights' storm is going to deliver some mega rainfall totals, probably more than Saturday's storm albeit with weaker winds.

 

http://tropic.ssec.wisc.edu/real-time/mimic-tpw/epac/anim/latest72hrs.gif