December 2014 Observations for the Pacific Northwest

[Guest Winterdog]

You're betting on the worst model?

I'm saying I just can't go full in on this thing when the GFS is showing -7C 850's for a couple days then a big warm-up. The GFS shows no snowfall and seasonably cool temps for a short period. I hope that model has out-served it's usefulness but it's still a major player as a forecasting tool for the NWS and to minimize it is short-sided IMO.

[Jesse]

http://www.nco.ncep.noaa.gov/pmb/changes/

 

Looks like 14 January. That must be why the MeteoStar site is going pay-only on the 15th.

Ah, I see. Thanks for the info.

 

I was still under the impression that was all happening this week.

[Jesse]

The fact it looks exactly like the ECMWF much of the time is proof enough for me.

It would stand to reason that the parallel is the superior model even though it hasn't officially usurped its predecessor yet.

[snow_wizard]

I'm saying I just can't go full in on this thing when the GFS is showing -7C 850's for a couple days then a big warm-up. The GFS shows no snowfall and seasonably cool temps for a short period. I hope that model has out-served it's usefulness but it's still a major player as a forecasting tool for the NWS and to minimize it is short-sided IMO.

 

Even the operational GFS would bring below normal temps for a few days.

[ShawniganLake]

The fact it looks exactly like the ECMWF much of the time is proof enough for me.

Has this been an ongoing theme, or are we just jumping on its bandwagon because it's showing what we want to see.

 

Weren't the other models playing catchup with the gfs last week with the windstorm. Seems sensible to be pretty cautiously optimistic at this point.

[Snow]

Has this been an ongoing theme, or are we just jumping on its bandwagon because it's showing what we want to see.

 

Weren't the other models playing catchup with the gfs last week with the windstorm. Seems sensible to be pretty cautiously optimistic at this point.

The Upgraded GFS did a better job at the strength and path of the Sou'wester than the regular GFS.

[Guest Winterdog]

It would stand to reason that the parallel is the superior model even though it hasn't officially usurped its predecessor yet.

I agree if all things were equal but there was some talk earlier in this thread about someone hearing that the new GFS has long-range problems. I don't know but there could be some bugs to be worked out with this thing. The old GFS couldn't have degraded, so I would think we are looking at the same reliability as always from thatmodel. I definitely want to go with the new model but as long as that old GFS is being contrary I will be suspicious.

[ShawniganLake]

The Upgraded GFS did a better job at the strength and path of the Sou'wester than the regular GFS.

Well then I'm sold. Throw the old one in the trash. It's gonna cold and snow Christmas through New Years.

[jaya]

Maybe...the Pacific controls quite a bit. In this case, the storm in the East was quite a bit different by day 7 on the 0z GFS (compared to 18z), and yet the end result was essentially the same because the offshore ridging wasn't able to phase together and hold off the southern jet.

 

The operational GFS is run at rather low resolution. The parallel is high res throughout.  But...higher res doesn't mean better all the time.  The operational GFS has been performing well of late.

[jaya]

The operational GFS is run at rather low resolution. The parallel is high res throughout.  But...higher res doesn't mean better all the time.  The operational GFS has been performing well of late.

In the extended that is.

[snow_wizard]

Has this been an ongoing theme, or are we just jumping on its bandwagon because it's showing what we want to see.

 

Weren't the other models playing catchup with the gfs last week with the windstorm. Seems sensible to be pretty cautiously optimistic at this point.

 

The biggest reason I disregard the GFS now is because the GFS based MJO forecast is much different than the ECMWF MJO forecast and the ECMWF has pwned the GFS on MJO forecasts this season.  No contest.  The ECMWF based forecast is showing an MJO wave that should deliver the goods quite nicely.

[snow_wizard]

The operational GFS is run at rather low resolution. The parallel is high res throughout.  But...higher res doesn't mean better all the time.  The operational GFS has been performing well of late.

 

It has done terrible on the cold waves.  I distinctly remember it showed the late November Arctic outbreak being no more than a chilly shortwave when it was only a week out.  It's very hard to ignore the fact the ECMWF ensemble means have been quite out of phase with the GFS operational runs as of late.  The GFS has lost its way on this event.

[Bedonbye]

this site is making me laugh. did you consider the PCA TOC, SOL,PVC how About the KONI LOW which is west in the Pacific. read my post no snow for the lowlands of western WA. this winter. DO NOT BUY A SKI PASS UNLESS YOU LIKE ROCKS

[Alex_Snakes]

Special. Wind. Maps.

[snow_wizard]

I do want to make the point I don't totally agree with Phil on the evolution we're going to see.  I think our chances are higher of scoring something big in the week two and week three periods (7 to 20 days) than they are of scoring as we get deeper into January.  I'm not convinced we will have another chance of scoring a favorable set up after the sequence that is showing up on the models now. 

[whitechristmas]

this site is making me laugh. did you consider the PCA TOC, SOL,PVC how About the KONI LOW which is west in the Pacific. read my post no snow for the lowlands of western WA. this winter. DO NOT BUY A SKI PASS UNLESS YOU LIKE ROCKS

 

Yes, the "KONI LOW" has been mentioned in previous comments and has been considered.

[Deweydog]

this site is making me laugh. did you consider the PCA TOC, SOL,PVC how About the KONI LOW which is west in the Pacific. read my post no snow for the lowlands of western WA. this winter. DO NOT BUY A SKI PASS UNLESS YOU LIKE ROCKS

I believe it's the KUNI LOW brought to you by Kuni BMW of Portland.

[IbrChris]

Well if you get off on reloading arctic blasts you might want to find a sock before indulging in the 00z GFS-PARA. This brings up a question: How accurate is the GFS-PARA (ie GFS-Parallel)? Truth is we don't have much idea yet aside from some "from the hip" stuff like: "It handled that last storm really well yadda yadda..." 

Too unscientific, stopped listening. We just don't have the verification stats to say one way or the other whether the GFS-PARA is even equal to the GFS in accuracy let alone more accurate. We really won't know until we've had an opportunity to see how it performs over multiple seasons...preferably a couple winters and a couple summers. For now it's anecdotal if we're talking overall accuracy...sure we know the GFS outperformed the Euro on the strong windstorm we recently had but that means nothing w.r.t. the GFS-PARA and the possible arctic blast in the medium range.

Just my two cents.

[Gradient Keeper]

Well if you get off on reloading arctic blasts you might want to find a sock before indulging in the 00z GFS-PARA. This brings up a question: How accurate is the GFS-PARA (ie GFS-Parallel)? Truth is we don't have much idea yet aside from some "from the hip" stuff like: "It handled that last storm really well yadda yadda..." 

 

Too unscientific, stopped listening. We just don't have the verification stats to say one way or the other whether the GFS-PARA is even equal to the GFS in accuracy let alone more accurate. We really won't know until we've had an opportunity to see how it performs over multiple seasons...preferably a couple winters and a couple summers. For now it's anecdotal if we're talking overall accuracy...sure we know the GFS outperformed the Euro on the strong windstorm we recently had but that means nothing w.r.t. the GFS-PARA and the possible arctic blast in the medium range.

 

Just my two cents.

It seems after day 5 the Parallel nearly mirrors the ECMWF, where as the regular GFS is worlds apart.

[Deweydog]

10 years ago right now we probably would be pretty much clueless to any upcoming pattern changes. Sounds delightful.

[TT-SEA]

It seems after day 5 the Parallel nearly mirrors the ECMWF, where as the regular GFS is worlds apart.

 

 

Wait... now I can't worship my precious ECMWF any longer?   Silly me saying it is the far superior model for the last 3 years.  Now everyone wants to toss out the GFS without any fanfare?   We should throw a going-away party. 

 

The ECMWF detailed precip maps are so far beyond anything the MM5 can manage.   I hope the MM5 models sync up seamlessly with the new GFS and maybe they will start to be worth something in the challenging situations.

[Phil]

Is there any/ enough data to show the new gfs had superiority over the older one.

Verification suggests it's about the same, actually. Thing that bugs me is they didn't touch the convective/cumulus parameterization(s), which is a major problem for the GFS.

[IbrChris]

The most important piece is actually the bombogenesis event in the East..that's the pattern changer..the breaker associated with that is what bends the flow upstream..weaker breaker = more zonal AAM propagation = cold sliding east of the Rockies..

 

The GFS loves to flatten these things out, so it might be in error..can't wait until this model is gone for good..

Well...not to be a party pooper but I rather see this as a classic case of downstream development. Look where we're coming from: massive continent-sized sprawling ridge over virtually the entire northern tier and Canada for the last 7-10 days (I lost count after I stopped looking at model runs for about a week...also corresponding to vacation). 939 mb low off Kamchatka seems to be the forcing mechanism...with an amplifying ridge downstream (which becomes a quasi-Rex block due to the Kona low that is actually about 1000 miles NE of the Hawaiian Islands but I digress). In turn we see amplification downstream of that over the western and central US in the form of an initial ULL which drops into the western US around Christmas and depending on which model you buy into either digs into the SW as a secondary ULL/PV lobe settles over the eastern US, or as a singular entity traverses the midcon into the eastern US during the latter 6-10 and early 11-15 (GFS ensemble mean sol...keeping the action east of Rockies). Euro ensembles have backed off the earlier, colder Euro Op sol as well as the heavenly (for cold addicts) GFS-PARA sols. However, Euro Weeklies seem to support the notion of a very robust Bering/W Alaska block even into the 11-15/week 2. That may be an artifact of similar IC for those Euro runs and the Monday Euro Weeklies...I'm guessing the model eq are mostly identical given both are ECMWF products.

 

I think a clear trend toward a weaker, more brief event is evident [edit: in the PNW]...the trend in ensemble cluster solutions is unmistakable. Assuming the block over Baffin Island/Davis Strait (stronger than Alaska "block") we will see a sharply negative NAO coupled with the AO, east will score big. While a coast-to-coast event is possible in the 6-10 it is likely to be Rockies east or even Plains east in the 11-15. So I'm not buying the Euro Op and GFS-PARA sols personally...much too optimistic IMO.

[TT-SEA]

Verification suggests it's about the same, actually. Thing that bugs me is they didn't touch the convective/cumulus parameterization(s), which is a major problem for the GFS.

 

 

Crap.    Scratch my last comment.

[Front Ranger]

Day 7 of Euro.

 

 

[TT-SEA]

Well...not to be a party pooper but I rather see this as a classic case of downstream development. Look where we're coming from: massive continent-sized sprawling ridge over virtually the entire northern tier and Canada for the last 7-10 days (I lost count after I stopped looking at model runs for about a week...also corresponding to vacation). 939 mb low off Kamchatka seems to be the forcing mechanism...with an amplifying ridge downstream (which becomes a quasi-Rex block due to the Kona low that is actually about 1000 miles NE of the Hawaiian Islands but I digress). In turn we see amplification downstream of that over the western and central US in the form of an initial ULL which drops into the western US around Christmas and depending on which model you buy into either digs into the SW as a secondary ULL/PV lobe settles over the eastern US, or as a singular entity traverses the midcon into the eastern US during the latter 6-10 and early 11-15 (GFS ensemble mean sol...keeping the action east of Rockies). Euro ensembles have backed off the earlier, colder Euro Op sol as well as the heavenly (for cold addicts) GFS-PARA sols. However, Euro Weeklies seem to support the notion of a very robust Bering/W Alaska block even into the 11-15/week 2. That may be an artifact of similar IC for those Euro runs and the Monday Euro Weeklies...I'm guessing the model eq are mostly identical given both are ECMWF products.

 

I think a clear trend toward a weaker, more brief event is evident...the trend in ensemble cluster solutions is unmistakable. Assuming the block over Baffin Island/Davis Strait (stronger than Alaska "block") we will see a sharply negative NAO coupled with the AO, east will score big. While a coast-to-coast event is possible in the 6-10 it is likely to be Rockies east or even Plains east in the 11-15. So I'm not buying the Euro Op and GFS-PARA sols personally...much too optimistic IMO.

 

 

And another big downer of a post.  

[TT-SEA]

Day 7 of Euro.

 

euro.png

 

Seems way faster... cold air way south by Christmas Eve.

[Snow]

Day 7 of Euro.

 

euro.png

Excellent!

[IbrChris]

Verification suggests it's about the same, actually. Thing that bugs me is they didn't touch the convective/cumulus parameterization(s), which is a major problem for the GFS.

I'd like to see this verf data on GFS-PARA vs GFS...haven't found it when searching.

[snow_wizard]

Nice improvement in the GFS ensemble tonight particularly in the 10 to 12 day period.  A lot more cold members and some that are very favorable a for a big snow event for somewhere in the western lowlands.

[Front Ranger]

And another big downer of a post.  

 

Pretty much opposite of what he was saying 48 hours ago.

 

Lots of opinions and model solutions flying around. 100% chance this will continue in the 1-5 day range, and very likely beyond.

[bainbridgekid]

Day 7 of Euro.

 

euro.png

Certainly a healthy looking block. Looks much more like the Parallel GFS than the operational in that frame.

 

I wish the Northern part of the block wasn't pushing as far East though. Seems like that would fight a reload.

[snow_wizard]

Day 7 of Euro.

 

euro.png

 

Looks much colder than the 12z at day 7 and even a tad colder than the 12z at day 8.  At least a tad lower heights.

[Front Ranger]

Seems way faster... cold air way south by Christmas Eve.

 

It's faster with the initial trough dropping down into the West, but not quite as cold day 7-8 as 12z. For the PNW, at least.

 

Here's day 8. 850s are only around -4C for the western lowlands here.

 

 

 

[wx_statman]

I wonder what the GFS-parallel would be showing at this point in 1968.

[Guest Winterdog]

It looks like the Euro blinks at 192.

[snow_wizard]

Well...not to be a party pooper but I rather see this as a classic case of downstream development. Look where we're coming from: massive continent-sized sprawling ridge over virtually the entire northern tier and Canada for the last 7-10 days (I lost count after I stopped looking at model runs for about a week...also corresponding to vacation). 939 mb low off Kamchatka seems to be the forcing mechanism...with an amplifying ridge downstream (which becomes a quasi-Rex block due to the Kona low that is actually about 1000 miles NE of the Hawaiian Islands but I digress). In turn we see amplification downstream of that over the western and central US in the form of an initial ULL which drops into the western US around Christmas and depending on which model you buy into either digs into the SW as a secondary ULL/PV lobe settles over the eastern US, or as a singular entity traverses the midcon into the eastern US during the latter 6-10 and early 11-15 (GFS ensemble mean sol...keeping the action east of Rockies). Euro ensembles have backed off the earlier, colder Euro Op sol as well as the heavenly (for cold addicts) GFS-PARA sols. However, Euro Weeklies seem to support the notion of a very robust Bering/W Alaska block even into the 11-15/week 2. That may be an artifact of similar IC for those Euro runs and the Monday Euro Weeklies...I'm guessing the model eq are mostly identical given both are ECMWF products.

 

I think a clear trend toward a weaker, more brief event is evident [edit: in the PNW]...the trend in ensemble cluster solutions is unmistakable. Assuming the block over Baffin Island/Davis Strait (stronger than Alaska "block") we will see a sharply negative NAO coupled with the AO, east will score big. While a coast-to-coast event is possible in the 6-10 it is likely to be Rockies east or even Plains east in the 11-15. So I'm not buying the Euro Op and GFS-PARA sols personally...much too optimistic IMO.

 

We'll see.  A strong negative PNA can force the action into the West even with very low AO and very low NAO.  See Jan 1969.

[IbrChris]

Pretty much opposite of what he was saying 48 hours ago.

 

Lots of opinions and model solutions flying around. 100% chance this will continue in the 1-5 day range, and very likely beyond.

Well a +NAO would certainly help...as would a SE US ridge. I'm not saying we don't get chilly briefly but support for a reloading behemoth stretching well into early January...I'm just not seeing it at least not for the west. A couple days ago our trusty Euro ensemble suite was leaning toward a blast out west in the 11-15, GFS parked a ridge near the west coast. Euro ensembles have steadily gravitated in that direction which is at least in part due to the -NAO and propensity for arctic air to dive down east of the Rockies into the trough over the eastern 1/2 of the country, esp as we enter the 11-15. I for one would love to see tonight's GFS-PARA become reality but am not going to ignore the ongoing shift in the Euro ensembles. 

[snow_wizard]

It's faster with the initial trough dropping down into the West, but not quite as cold day 7-8 as 12z. For the PNW, at least.

 

Here's day 8. 850s are only around -4C for the western lowlands here.

 

 

day8.png

 

You can sure see that reinforcement starting to drop down though.

[Phil]

Well...not to be a party pooper but I rather see this as a classic case of downstream development. Look where we're coming from: massive continent-sized sprawling ridge over virtually the entire northern tier and Canada for the last 7-10 days (I lost count after I stopped looking at model runs for about a week...also corresponding to vacation). 939 mb low off Kamchatka seems to be the forcing mechanism...with an amplifying ridge downstream (which becomes a quasi-Rex block due to the Kona low that is actually about 1000 miles NE of the Hawaiian Islands but I digress). In turn we see amplification downstream of that over the western and central US in the form of an initial ULL which drops into the western US around Christmas and depending on which model you buy into either digs into the SW as a secondary ULL/PV lobe settles over the eastern US, or as a singular entity traverses the midcon into the eastern US during the latter 6-10 and early 11-15 (GFS ensemble mean sol...keeping the action east of Rockies). Euro ensembles have backed off the earlier, colder Euro Op sol as well as the heavenly (for cold addicts) GFS-PARA sols. However, Euro Weeklies seem to support the notion of a very robust Bering/W Alaska block even into the 11-15/week 2. That may be an artifact of similar IC for those Euro runs and the Monday Euro Weeklies...I'm guessing the model eq are mostly identical given both are ECMWF products.

 

I think a clear trend toward a weaker, more brief event is evident...the trend in ensemble cluster solutions is unmistakable. Assuming the block over Baffin Island/Davis Strait (stronger than Alaska "block") we will see a sharply negative NAO coupled with the AO, east will score big. While a coast-to-coast event is possible in the 6-10 it is likely to be Rockies east or even Plains east in the 11-15. So I'm not buying the Euro Op and GFS-PARA sols personally...much too optimistic IMO.

I agree that the initial forcing mechanism for the downstream amplification is the cyclogenesis in the NPAC, however, a lot of what occurs over the Midwest/East (as far as bombogenesis/WB is concerned) related to the orientation of the STJ and the timing of phasing between the southern shortwave and the northern vort, as I'm sure you agree. I guess one could argue that in of itself is also somewhat determined by the happenings upstream, however, the wave breaking event that results will determine a lot for the West. Downstream blocking (like we saw in 1968-69/1978-79) appears to be vital with low heights south of the Aleutians. Without it, I don't think the west will see much for a little while longer.