Jump to content
  • Member Statistics

    17,606
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

Medium/Long Range Discussion


tombo82685

Recommended Posts

Its that time of the year where the medium to long range has even more significance as we approach winter and potential cold/winter storms.

After this weekend and next weeks cold snap, that should carry on into the following weekend. It looks like we should start to see a warm up towards mid month. we are currently in a negative mtn torque wave right now we should correlate in a week to week and a half of warmer conditions. This is supported by the mjo which is in phase 6 right now, a colder phase for the east coast. In the longer range it shows signs of coming out of the COD and traversing phases 8-1 which are warm phases this time of the year in a week or two. Their are also signs the severely negative epo right now works its way towards positive towards mid month and after combined with a -pna looks like some warmwer weather may prevail after this cold shot. wild card as usualy is the nao, signs though from the mtn torque show it looks to be in a positive phase once into mid month after we come out of this negative phase...You can also see it on the 8-10 day forecast on e wall for the gfs and euro. You can see how the nao is decently positive, the slug of a -epo is replaced by by a vortex in the bering sea area. You can see once the cold wave pushes off the east coast a a pacific flow sets up. Which is supported by the negative mtn torque which corrisponds to zonal flow.we shall see. The gfs is different in some regards as it connects the siberian ridge with the -epo while develops almost a split flow with a cutoff in the sw. You can though start to see the ridge breaking down as the flow off the pacific looks to become dominant....Would love to hear other thoughts and some good discussion...

test8.gif

compare.we.png

ECMF_phase_51m_small.gif

gltaum.90day.gif

Link to comment
Share on other sites

  • Replies 1k
  • Created
  • Last Reply

Good write-up. Would agree a warmer trend may occur in about 10 days or so. Personal view not NWS/CPC.

Its that time of the year where the medium to long range has even more significance as we approach winter and potential cold/winter storms.

After this weekend and next weeks cold snap, that should carry on into the following weekend. It looks like we should start to see a warm up towards mid month. we are currently in a negative mtn torque wave right now we should correlate in a week to week and a half of warmer conditions. This is supported by the mjo which is in phase 6 right now, a colder phase for the east coast. In the longer range it shows signs of coming out of the COD and traversing phases 8-1 which are warm phases this time of the year in a week or two. Their are also signs the severely negative epo right now works its way towards positive towards mid month and after combined with a -pna looks like some warmwer weather may prevail after this cold shot. wild card as usualy is the nao, signs though from the mtn torque show it looks to be in a positive phase once into mid month after we come out of this negative phase...You can also see it on the 8-10 day forecast on e wall for the gfs and euro. You can see how the nao is decently positive, the slug of a -epo is replaced by by a vortex in the bering sea area. You can see once the cold wave pushes off the east coast a a pacific flow sets up. Which is supported by the negative mtn torque which corrisponds to zonal flow.we shall see. The gfs is different in some regards as it connects the siberian ridge with the -epo while develops almost a split flow with a cutoff in the sw. You can though start to see the ridge breaking down as the flow off the pacific looks to become dominant....Would love to hear other thoughts and some good discussion...

test8.gif

compare.we.png

ECMF_phase_51m_small.gif

gltaum.90day.gif

Link to comment
Share on other sites

Tombo, aren't you going to post the gfs map that has all of Canada and 40 of the 48 conus states snow covered? :whistle:

BTW Nice write-up, still not sure about the 2nd half because of some non-factor (COD) mjo outlooks.

yea the weatherbell one will have snow reaching the gulf coast ina week or two

Link to comment
Share on other sites

I still think we get a period after oct 15 of abv normal temps. With the brief spike of the mtn torque into negative territory, should argue for some zonal flow for a week. Also, the mjo forecasts shows an emergence in phase 8, which is normal to slightly warmer than normal. A month ago that would of been a warmer look, but since we are nearing the winter time months that phase starts to take on a colder look compared to aug-sept. Also, i would very weary of the -nao prospects which are showing up in the teleconnects. Is it a -nao yes, but its not one that really hleps us. The center of the warmer hgts shown here

test8.gif

are centered to far northeast for our liking. This is a solid east based -nao which is to far north.

Link to comment
Share on other sites

I still think we get a period after oct 15 of abv normal temps. With the brief spike of the mtn torque into negative territory, should argue for some zonal flow for a week. Also, the mjo forecasts shows an emergence in phase 8, which is normal to slightly warmer than normal. A month ago that would of been a warmer look, but since we are nearing the winter time months that phase starts to take on a colder look compared to aug-sept. Also, i would very weary of the -nao prospects which are showing up in the teleconnects. Is it a -nao yes, but its not one that really hleps us. The center of the warmer hgts shown here

test8.gif

are centered to far northeast for our liking. This is a solid east based -nao which is to far north.

Tombo,

Since at one time one of the nao winter outlook ideas was to flip the October sign for the winter and at the same time the warmer the October, the warmer the winter, both thoughts would seem in conflict. In reality probably because of wavelength, a negative nao in October may or may not have as much impact as a negative nao would in January.

Link to comment
Share on other sites

Tombo,

Since at one time one of the nao winter outlook ideas was to flip the October sign for the winter and at the same time the warmer the October, the warmer the winter, both thoughts would seem in conflict. In reality probably because of wavelength, a negative nao in October may or may not have as much impact as a negative nao would in January.

Yea, i was solely saying that about the -nao because a -nao now would translate to colder temperatures for us which would help your cold october analogs.

Link to comment
Share on other sites

the 12z euro is what u want to see during the winter, beautiful blocking, west based -nao, developpment of a -epo. Cold pool trapped underneath the blocking. Though that could lead to a suppressive pattern

12zeuro500mbHGHTNH240.gif

Yea, with that lower heigh anomalies over British Columbia, it would be a cold, zonal flow with no amplification out west.

Link to comment
Share on other sites

Wow, haven't looked at the MJO lately, but its on PED(s) and in phase conflict with the cold that the op GFS has late in its run. On the other hand, those tropical systems would make sense given the outlook.

From what I could tell, P8 and P1 in October seemed to correlate with a warmer east. and especially southeast...probably because of shorter wavelengths this time of year. I'm always careful about MJO stuff in the Fall because I'm not sure how useful the correlations are, but on the other hand...it's a rather strong wave as modeled. I'll admit it is a little surprising that it wouldn't be cooler in the east given what we normally think of in the winter with p8 and p1. Not what you expect at first, but maybe Autumn wavelengths are at play.

Link to comment
Share on other sites

question for the mets or whoever can answer this. In mtn torque, a positive mtn torque represents meridonal flow (using the himlayian one). Does that always dictate a trof on our side of the country? Since meridonal flow is highly amplified trofs and or ridges. Could you have a pos mtn torque and a big trof in the west and ridge here? Or is their a different mtn torque that western states use? Or do you just use the rocky mtn torque, which if positive usually hints at some blockiness to backup the forecast?

Link to comment
Share on other sites

From what I could tell, P8 and P1 in October seemed to correlate with a warmer east. and especially southeast...probably because of shorter wavelengths this time of year. I'm always careful about MJO stuff in the Fall because I'm not sure how useful the correlations are, but on the other hand...it's a rather strong wave as modeled. I'll admit it is a little surprising that it wouldn't be cooler in the east given what we normally think of in the winter with p8 and p1. Not what you expect at first, but maybe Autumn wavelengths are at play.

That would be my thought also. The CPC confidence levels are higher for phase 1 than 8, especially in your area (best in the south overall). Meanwhile the cfs weeklies are warm through the rest of the month and the naefs week 2 is a flip of the MJO confidence levels, warmest for you,.less farther to the southwest. Given that its a phase 8/1 hugger and all of the above, I wouldn't be terribly confident saying the op GFS is off its rocker just yet.

Link to comment
Share on other sites

question for the mets or whoever can answer this. In mtn torque, a positive mtn torque represents meridonal flow (using the himlayian one). Does that always dictate a trof on our side of the country? Since meridonal flow is highly amplified trofs and or ridges. Could you have a pos mtn torque and a big trof in the west and ridge here? Or is their a different mtn torque that western states use? Or do you just use the rocky mtn torque, which if positive usually hints at some blockiness to backup the forecast?

Tombo,

I don't think it can, but this is honestly a guess on my part, I don't know if shorter wavelengths come into play with it also.

Link to comment
Share on other sites

Tombo,

I don't think it can, but this is honestly a guess on my part, I don't know if shorter wavelengths come into play with it also.

That was going to be my guess as well, but that's all it is, since I'm fairly certain I know less about mountain torque than you do.

Link to comment
Share on other sites

I think second half of october warm idea should verify decently. I don't see a long lived cold shot til late october beginning of november. Going off the models it looks like a good cold shot is going to come into the west coast late next weekend or the following week that will slowly work its way eastward. This is supported pretty good by the mjo phase 1 for next week, which is cold west and central, warm east. Then it works its way into phase 2 which is a cold phase for us. Their definitely looks to be a cold shot coming south with a solid -epo developing -ao developing.

Link to comment
Share on other sites

The cold should start in the west with the -pna despite the -nao. Once that pna switches to positive around the end of next week we should see an infiltration of cold air working east by halloween or just after

Pretty confident about Halloween week averaging cooler than normal around us. A couple of players as you have stated are coming into place.

First full week of November EC's MJO outlook is better for sustained cold. GFS doesn't look as promising rolling it forward and we look like we are entering a down cycle to the torquing for now.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Guest
This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...