Jump to content

Carvers Gap

Members
 View Profile  See their activity

  • Posts

    15,664

  • Joined

  • Last visited

 Content Type 

Everything posted by Carvers Gap

  1. Carvers Gap
    Preliminary thoughts on December. AN(maybe one torch week in weeks 2-3) weeks 1-3...transition of seasonal or cold by week 4. SSW and -NAO(how long does it last) are big wild cards.
  2. Carvers Gap
    12z GEFS continues to portray the western trough establishing itself early next week. Not sure I buy that yet....but it is growing more consistent with this feature. Pretty steady evolution of a flip of its original output over the past 5-6 model runs. IMHO, I think the current cold pattern has just about run its course. Only way we can dodge a big warm-up is if the NAO can go negative and mute what is an MJO that is trending into a tour of the warm phases(maybe at a decent amplitude at that). The other wild card is the SSW. This very well maybe a run-up pattern to that as described in my post yesterday. If that occurs, later December/early January would likely have some strong cold anomalies somewhere over NA...good luck guessing where! Not great signs for December at this point, especially with the GEFS moving the pattern flip to within seven days.
  3. Carvers Gap
    The 0z Euro continues to show fairly strong warming at 10mb at high latitudes. Have to think that is playing some part in the flip-flopping of modeling. It has in the past. Also means the PV is really gonna get bumped around.
  4. Carvers Gap
    Some definite trends(all though not super consistent at this point...about 2/3 of the time) in placing the trough out West on most global modeling ensembles at 0z. Those trends on modeling began last week. I don't think they are set in stone yet, but frequency of AN heights(in the East) on modeling in the LR is increasing. On the 0z GEFS the Aleutian low begins to disappear though the block over Greenland is there. I do hold out hope for a full latitude trough over NA. But honestly, looks like models are trying to decide if the trough stays in the West...or rolls eastward. Seems like the lean is West. Tough to find many Decembers that are cool with this SST set-up. So, if it does get cold in December and stay cold...pulling a bit of a needle out of a haystack.
  5. Carvers Gap
    18z GEFS has returned to form. Pretty chilly run.
  6. Carvers Gap
    @jaxjagman, can you see the day 8-10 10mb/30mb/50mb temps on your site? Those layers look pretty warm to me. What do you think?
  7. Carvers Gap
    Good graph there... would be interesting to see where it is in a couple of weeks. The 12z Euro and GFS have some pretty strong warming between days 8-10 at 10mb, 30mb, and 50mb. If the Euro/GFS combo is right, PV is going to take a decent beating - no idea if it results in a PV split. Also, with the MJO flirting with phases 3-5, that does correlate to a pretty good jostling of the PV at all levels of the atmosphere. Going to be fairly interesting. I prefer for the PV to be weak...those SSWs are not always money. That said, looks like some things are being set into motion which will rough it up pretty good.
  8. Carvers Gap
    Good find. I hadn't read anything in detail, but I saw that it was mentioned. If you get a time, let me know. Hopefully, they will leave the video up. Even better, maybe she will give us some current SSW snippets.
  9. Carvers Gap
    Pretty impressive cold to begin November at TRI. We are -7.2F through November 16th. Not a single day AN so far. That will change, but still impressive.
  10. Carvers Gap
    Amy Butler is my go to for SSW events(thanks to Jax for sharing about her expertise a while back). She had this to say last Thursday. Pretty interesting to see that big ridge along the EC at 500 sending a bunch of warm air northward in conjunction with potential polar vortex disturbance at the higher levels of the atmosphere. Probably going to be some tropospheric disturbance at the least.
  11. Carvers Gap
    So I went back and looked at the run-up to last year's PV split which occurred in early January I think. I also looked at the time around the Feb 2018 split. Here is the 500mb map from December 28, 2018. This occurred right before the SSW last winter and is referenced in the referenced post above. It is not in that post. I have had to clear my memory cache since then. But here is the actual reanalysis of that date.... Here is the 500mb pattern about a week after the SSW which occurred in mid-Feb of 2018.... Here is the GEFS at 258.... Here is the 12z EPS at 258 I wanted to show above that sometimes these big ridges that hook into Greenland block at 500mb seem to show up just before or just after a significant disruption of the stratospheric polar vortex higher-up in the atmosphere. Their duration is relatively short in natured(edit). I have been saving this in the back of my mind. We in the forum have kicked this around some, I think Jeff included. The big ridge along the EC has occurred just before or just after the last two strat splits. It tends to feed a ton of warm air at lower-mid levels of the atmosphere into the higher latitudes. Also, not sure I am a huge fan of the SSW. It doesn't always equate to cold here. This is just wx talk and not really so much about if it is going to get cold here...though the EPS would indicate as such. So, let's see if the PV doesn't get bumped around pretty good here in 10-20 days. (BTW...the 12z EPS is still a textbook -NAO evolution into an eastern trough. The EPS dumps that trough into the East and flattens it a bit into a nice, stormy pattern typical of a Greenland block.)
  12. Carvers Gap
    And here is last year's discussion...I will see if I can go find the pic in my files. When the SER or WAR hooks into a forming Greenland block..the PV (at the tropospheric and stratospheric level) has been split just after or during this event. So, let's see if this actually happens again. If it does, it would make three times this pattern of a mega-ridge(WAR/Greenland Block) presented itself and three times an SSW was occurring or about to occur.
  13. Carvers Gap
    Knew I had filed that away for a reason...plenty of discussion about the SER hooking up with the Greenland block around the time of an SSW in mid February of 2018.
  14. Carvers Gap
    Seeing some consternation on other sub-forums about the ridge around d10 that rolls through on the GEFS. That is definitely a break in continuity. Given the amount of change in the higher latitudes, not unsurprising. We have seen this pop up on run in the past on several runs - I was complaining about this look last week as a matter of fact. And this is my observation....this 500 setup has proceeded strat splits in the past. Yeah, it is not the stratosphere...but when the WAR hooks into a Greenland block better look out. All kinds of craziness bout to get unlocked if that holds into place for very long. That is a crap ton of heat getting unleashed into a block. Like winding up a top and then letting it loose. Maybe we should call that a Tasmanian Devil Ridge(TDR), cause what happens next is going to be significant (in terms of cold) and nearly random in terms of where it goes. I am going to go back and see if I can find a post on that WAR/Greenland Block ridge.
  15. Carvers Gap
    Still some pretty textbook NAO looks on both the GEFS and EPS. Ridge rolls through the East quickly and the trough deepens behind it. The block may actually mute warm MJO phases and also mute what would have been a very warm pattern as our source regions for cold are pretty much on empty - cold is in Asia. Hopefully the block lasts long enough for the MJO to rotate into colder phases. I think if this happens, colder air finds its way over the pole and into the East. Interesting LR pattern for sure. The GFS has some solutions yesterday where it appeared systems were beginning to feel the block and were partially suppressed. edit: There are systems in the 6z GFS already being forced south. edit: 0z Euro as well.
  16. Carvers Gap
    Look at the pattern at hour 72 of the 18z GEFS. Now, compare it to the pattern above in the first slide. What appeared to be a problem in modeling is just the first step in the -NAO process.
  17. Carvers Gap
    Fascinating look at the NAO. I encourage to find and read all three tweets about the evolution of a -NAO(500 and surface) and its antecedent pattern. Good stuff. Here is my favorite. Look at the patterns(be sure to read the labels and to click each pic...some have more photos than the Twitter thumbnail) and think about what the ensembles have been trying to work out for the end of the month. Looks very similar to many runs.
  18. Carvers Gap
    Pretty solid move to the GEFS over the past two runs by the EPS. Good to see. Not a frigid pattern, but pretty much seasonal to BN. If November has a good correlation to the winter base pattern...November needs to have cold and blocking.
  19. Carvers Gap
    The 0z EPS is much more in line with the GEFS now in the LR. The run-to-run change corrected much more to a trough in the East for d10-15. That was not a warm run! Really not much more to add...we will see if that holds. Models can and do flip in the LR...but the door is cracked for a cold "open" to December, especially if one believes the 6z GEFS.
  20. Carvers Gap
    Man...if the Weeklies had run from the 0z run....
  21. Carvers Gap
    Don't sweat the small stuff. Temp anomalies on the Euro Weeklies have had a severe warm bias for many months. The bias begins after week 2. They must have monkeyed with the algorithm. The 500 pattern doesn't look to bad to me until mid-late December which is after d28. The Weeklies have been pretty awful past week 3. Also, the Euro run from this morning was pretty awful. The Weeklies are only as good as the run they are derived from.All of that said...I do have a warm December as part of my ideas, so I probably can't complains. I don't think a warm December is a slam dunk though. The GEFS has done a much better job of recognizing cold patterns. It has flipped back cold for the past two runs. The EPS also has erroneously tried to warm the current pattern several times. I don't trust the GEFS, but the EPS has been equally bad if not worse. It seems like some sort of BN heights are going to establish for a short amount of time in the Southwest(a few days...maybe even a week or two). That said, the Euro also has a bias of not being able to get energy out of the SW - like ever. It just sits there. Need to keep an eye on the Greenland Block. If it forms...it won't go as quickly as forecasted IMHO. That said, HM has been banging the drum the Aleutian low is going to be a driver here. I think that has potential to be the most important driver early during winter. Keep in mind that the Weeklies completely missed the November cold pattern...almost a total whiff. The EPS has been playing catch-up for about four weeks. The only danger is that the GEFS is always cold....makes it tough to find the pattern change to warm if it occurs. My money for now is on the GEFS, though I never really discount the Euro - but it has really struggled to see much cold at all in NA.
  22. Carvers Gap
    Actually after reading through the MA forum...the EPS solution might be in doubt at this point. It has been pretty bad during the d10-15 range. The GEFS has had a bit of a hot hand. Need to watch the block over Greenland. If it develops...we might be in good shape. As Boone mentioned, the MJO might be causing some flip-flopping as well due to modeling trying to figure out how to handle the warm phases of the MJO while at the same time having to navigate early high-latitude blocking. Lastly, keep an eye on any weird, super-anomalous ridges over NA - especially the EC. They have been precursors to strat splits. I don't want one of those as they seem to have bad aim with cold air! LOL.
  23. Carvers Gap
    12z EPS buries the trough in the southwest. Might be real. Might not. That has been a trend on more than one model. Suffice it to say, the EPS has flipped in its d10-15. It may flip back, but that is a flip to a ridge in the East and a trough in the southwest. It backed up the overnight run, and dug in even more. Is it up to its old tricks? Not sure, but the GEFS has a similar look, just cooler in the SE. Not good trends, but still plenty of time to switch round.
  24. Carvers Gap
    Sorry...wasn't trying to correct you. It wasn't a response to yours, because I hadn't even read your previous post. I think your comments actually fit really well based on where the GEFS was previously. I was just trying to be humorous. My apologies that it read that way...it was just coincidence that my post seemed to correct yours. I often say, "Well, that was not a warm run!" Pretty much in that context. Just hyperbole.
  25. Carvers Gap
    12z GEFS is not warm...really at any point. As Bob Chill noted in the MA...really want to see this get into December. Great question, DB. Many of the wx models that we use were likely built post 1980. What would a truly blue northern winter look like on modeling? Probably a mess before and during. One area where the AI aspect of modeling has issues is with recognizing pattern changes. People catch those changes in modeling because they will see glitches in the LR modeling. It is what I actually look for. Hiccups can mean nothing or they can mean everything. Right now, the d10-15 ensemble runs are bouncing around in terms of putting the cold into the southwest or east or both. I suspect the high latitude blocking is wrecking havoc on consistency much like a big, cold high coming out of Canada would. Jeff said it earlier...not going to be an easy few months of professional or hobby forecasting.
×
×
  • Create New...