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Carvers Gap

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  1. Carvers Gap
    This run isn’t gone be denied one last shot. 1053 high crashing down into MT to end the run. After these crap d10 ensemble runs today, I raise my glass to a DGEX throwback run! Verifation score might take a hit. Someone post the snow map with the best snow algorithm! Full d16 map...nothing to lose, right!
  2. Carvers Gap
    These snow amd ice amounts are gonna be just silly. #happyhourridesagain
  3. Carvers Gap
    1054 high over MT at 300. Let’s see if future runs have that.
  4. Carvers Gap
    18z GFS showing what happens when the trough does not get hung up in a feedback loop like it did 12z. That is one potential option in a positively tilted trough. If the cold pushes, things could get interesting. Multiple ice storms across the SE post d10. I think what is happening is the cold(prob overmodeled) is pushing at the surface. We have seen this once before this winter and it did not verify. The 500 map trumped the surface map in reality. Still, that shows what can happen. Likely? Prob not.
  5. Carvers Gap
    12z EPS basically has the same look for an ensemble out to d10. Observable changes after that which are basically a variation of the same look from the past few days. After d10 the EPS digs the western piece of cold and really buries the trough in the West - which has been discussed as a possibility ad nauseam. So, the nice trend of cold being centered over MN at 300 is now centered over WY/UT. Massive AN heights in AK and GOA. All anomalous features over NA are much more amped than 0z. Still looks like two amps from d10-15 regarding where to put the cold. Eventually, the EPS tries to pull the cold back to HB at 318. But overall, the message of the EPS is, "You had better score in early Feb." By the end of the run strongly +NAO, +PAN, ++AO, retrograding(westward EP). If there is one slight hope, it is that the EPS is dragging its heels in the West, but I have my doubts with that. But since we know the models are not verifying well at d10-15 at times, I wouldn't lose sleep...it will change. @Holston_River_Rambler, any PV updates. We may need it after Feb 10. Interestingly, the Weeklies look to have nailed the MJO for the middle of Feb. Let's hope they are right about what comes after.
  6. Carvers Gap
    At 240, there is a near perfect negative til trough at 500 (vort maps are a nice look) as it is leaving Alabama. That is a big storm look. But it is at 240. If it is there in a few more runs, I will post a map. I assume most of you can find a site and give it a look anyway. If new, try Pivotal Weather or Tropical Tidbits for Euro maps.
  7. Carvers Gap
    12z Euro just ran. It is not too dissimilar to the GFS. The trough at 500 goes neg tilt late in the run. So who knows if that holds. Big difference is losing the pseudo -NAO mid-run. I say pseudo because it is only there due to the HB block being lifted out. That changed the configuration of the run and changed the config of the window for a storm. Again, I will say that we are hunting a window for a storm. Once it became obvious there was nothing to hold the cold in place, were are basically looking for a winter storm as the trough enters or leaves. Losing blocking up top causes problems with cold sources and with forcing troughs underneath. -NAOs matter when hunting EC storms but a 50/50 low(low holding just north of Maine) will do it. Something has to block the storm south. Anyway, overall synopsis is the trough digs into TX and holds slightly more than 0z. What that does is to allow it to do is sharpen the trough. Energy hits the bottom of the trough and there you go. If you want a lot of cold, that is probably not your run. If you want a trough that digs enough to force a (SECS) storm to track, that is your run. Of note, there is another piece of energy at 192 that could also work. So, it is similar to the GFS that a couple of pieces of energy start beneath us and work up.
  8. Carvers Gap
    BTW, the reason I am not buying that after d10 is not because it doesn't hit MBY, it's just the aforementioned progression looks really odd. Anyway, that 18z run at least gives us one possibility of maybe what is happening(excluding the trough digging to Guam) under the hood within ensembles that show the ridge dig west after d9 and then press eastward.
  9. Carvers Gap
    That ridge in the GOA is impressive impressive though d10+. Again, just an odd run at that point. Probably will stick a trough back in the East late in the run, but its progression is unlikely after 240 - which is not surprising given that we are talking about an operational at range. Sure enough big ice storm late in western areas of the forum. Again, not really buying much after d10, but interesting. That was probably five sentences too much, but there you go.
  10. Carvers Gap
    And then beginning at 240, the GFS digs a system at 500 from Idaho to off the coast of Southern California. West Coast version of a Miller B? I think there will a trough digging, at least initially out there, but that looks like a feedback issue.
  11. Carvers Gap
    Way out there...the setup on the 12z GFS at 200 is not terrible. It is the third of three waves that pass progressively more eastward between February 4th and 8th(5th through 8th in MBY). That system would likely not be fighting to overcome crazy warm temps. Looks like waves 2 and 3 are something I will watch for MBY. Areas in west TN and Arkansas would need to watch the first wave per the GFS. Right now, it cuts right over west TN. But if the trough speeds up, that could change. It sped up just a hair after several runs of slowing down.
  12. Carvers Gap
    Great question. I will start the discussion, but am certainly not the final say. I am no fan of La Nada. "Meh" is my word for those years. Some call this year a Modoki El Nino, but I think it will be classified officially as a La Nada. The problem this year is the Modoki is centered right over the top of the phase 6 MJO! LOL. Not good. I think that ENSO 4 region has caused havoc along with a record IOD. It(the phase 6 MJO region) is/has been a near constant area of convection and rain. I think what has caused modeling problems is the rest of the MJO has propagated normally while phase 6 just sits there and stews. It has trumped all other phases that have fired. Now, I do think modeling does much better when Nina or Nino locks in as the pattern is fairly consistent, especially during either winter or summer. Shoulder seasons are always a crapshoot. If you haven't already, search for TyphoonTip's discussion about the SST gradient in the Pacific. We really have not had a moderate Nina since January of 2012 though January of 2018 was close. Our last strong La Nina was January 2011. Interestingly some of those great winters around the 2010 timeframe occurred in between some moderate to strong La Ninas. I am a big fan of weak La Nina ENSO patterns. Like anything they don't always work out but they can be very cold at times. That said, I think the Super Nino of 15-16 really warmed the Pacific and has screwed up the temp gradient there. It is above normal. We really need a strong Nina to wipe that out. We haven't had one in nearly nine years. IMHO, until that temp gradient gets cooled...we get what we have had the past two winters which are analogs(based on ENSO) that don't work. Jeff talked about analog problems recently. To paraphrase Typhoon, he basically said that a weak Nino needs a stronger gradient/transition to cooler water. Right now most of the Pacific is warm, and the gradient between the warmer SST area and a cooler one is non-existent as much of it is AN. I think much of the reason for that is because we have not had a strong La Nina to cool the Pacific and reset the gradient. Now, strong La Ninas are usually warm winters here, but we might need to suffer through one of those winters in order to get a better gradient. Next winter's ENSO? Probably a good question for @jaxjagman. I have seen commentary for both a Nina and Nino. I have read some information that when we exit the solar min and get closer to the max that Super Ninos are possible - hopefully several years from that. I have also read that the winters just after a solar min have more blocking. I won't hold my breath, but we will see. Next winter's ENSO is a question mark for me. Looks like ENSO neutral is forecast through summer and into fall with slightly negative SSTs. If forced to make a summer forecast based on that alone - As the summer progresses we might have increasingly dry and increasingly AN temps. Might be a normal start and a hot August and September. https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf https://ggweather.com/enso/oni.htm
  13. Carvers Gap
    The EPO on the EPS yesterday was positive. Overnight, it flipped negative as evidenced by the pic below. To give you an idea at how much modeling is bouncing around. In the medium and LR, the EPO has reversed large portions of the EPO with reach run going back to Jan 26. Overnight it looked like this. Will it stay? No idea. This started occurring about the time we started talking about the PV splitting. The AO is strongly positive which I wonder if that will reverse given the nature and structure of the upcoming trough. One index we have not spoken about enough is the AO. It has been quite positive this winter and is forecast to remain strongly so. That said, observed AO readings are currently of of sync(below) what predicted values on the CPC site. Regarding the pattern after the 10th, let's keep an eye on the EPO trend as that seems to be the only thing available that can help us at times.
  14. Carvers Gap
    One thing to keep an eye on is the EPS trend weakening the area of BN heights that slides into the West after d10. For three straight runs it has displaced the stronger heights northeastward towards eastern Canada. That gives modeling a couple of options. It could be that modeling will bring back an eastern trough periodically or it could pull the cold up to the Hudson Bay. If it pulls up to the Hudson Bay, heights will likley build under the area of BN heights w periodic shots of cold pinwheeling into the SE and East. @Holston_River_Rambler, another thing to watch is if the TPV splits...modeling could flip on a dime if modeling thinks that is going to hold. Sometimes that flip is good(see 2018) and sometimes it is bad(see Jan 2019). In both cases modeling had pretty consistent looks and then bang...everything was upended within about two suites. If the SPV occurs in early Feb, not sure it can help us as the lag of effects into the troposphere would possibly not get here until mid-late Feb. That said, seems like the strat and troposphere are coupled right now. If it stays that way, the effects could be immediate. And then sometimes SPV splits don’t translate to the troposphere at all. I suspect an SPV split this time does translate down. A TPV split can work like an electrical breaker. Flip that switch and things on modeling often switch dramatically. So circling back, having the BN heights on the EPS building over the HB might be a hint at where one of those PVs ends up. Speculation on my part, but something I have noticed.
  15. Carvers Gap
    I actually still like the February 5-10 window. Here is the side-by-side comparison of the past two runs at 500. 0z was actually colder with the initial front on the 5th. And again, without a -NAO it is going to try to lift out. This is at 18z on February 5th. One positive is the trough and initial front sped up a bit and deepened quite a lot compared to the previous run. The run-to-run change at 2m was actually net colder on the Euro OP for d5-8 when compared to 0z. I would post the R2R maps of those days, but I think you can get the picture by looking at the comparison at 500 at 186. New run is on the left. For once, the overnight run during this time frame actually improved.
  16. Carvers Gap
    Well, sometimes the tropical polar vortex at the surface will split first and work its way into the stratosphere. And at other times, the stratosphere polar vortex will split first and work its way down which is top down. Both work, but the first one has a more immediate reaction. The top down changes can take 2-3 weeks(sometimes immediate thought) sometimes to impact the troposphere and sometimes an SPV doesn't affect the TPV at all. That is why I like that animation that you post. You can see where the split is occurring.
  17. Carvers Gap
    Looks like 2-3 are firing pretty well. I kind of agree with you that the phase four area is firing. You are likely going to be right on that.
  18. Carvers Gap
    Which means modeling is going to be all over the place if that occurs. Can you tell, Holston, if that is a "top down" split? Sometimes we can get immediate reactions from those and sometimes not. I know in the spring of 2018, it took about 2-3 weeks to really impact the troposphere if I remember correctly...Basically, what I am getting at is if the TPV is affected and when?
  19. Carvers Gap
    Whew, I should have kept looking at that data.
  20. Carvers Gap
    @John1122, thanks for that verification site. Man, I missed the first half of the TN basketball game working through that. LOL!!!
  21. Carvers Gap
    GEFS just reaffirms that modeling is really struggling with the LR. Beats down the SER like the EPS did. Man, it is cold at the surface. I can't possibly understand why it is said to have a cold bias. J/K. Man that is a lot of blue and purple on Tropical Tidbits.
  22. Carvers Gap
    With it being late in the season and it taking a beating...that PV is going to be ragged. Will be tough for it to reconsolidate. Holston, we want to be under the warm anomalies, right? I know that sounds counterintuitive, but I "think"(???) that it is colder under those warmer strat areas....
  23. Carvers Gap
    Seriously great site, @John1122. I could spend days there. This is line graph data from the same site. I would set forth the idea that four time periods are skewing normal model tendencies during the past 90 days(early Nov, mid Dec, early Jan and mid Jan). Looks like there is a big bust in December where models missed by 10-15 degrees and early and mid January where models busted by 7-10+ degrees during week one and two. Overall, January misses have skewed model tendencies...as we know January has not been a good month for modeling. I know the big bust in early January was where modeling was too cold. I am assuming the miss in December is also the same based on the idea that we have been head faked twice and Christmas being warm was a huge miss. For example, the December 13th 12-day forecast would actually verify on December 25th which we know was warm. I might assume Novembers model numbers were actually too warm as twelve days after October 30 were a period of severe cold. December and January were both well documented bad time frames for modeling as was early November when modeling completely missed the cold. What would be interesting is to see the rest of the year. Not sure how to dig those up. Interestingly the GFS ensemble was better than the Euro at spotting cold last November from the d12 range. It was nearly two degrees better than the EPS(albeit bad scores for both). As suspected, the GEFS spotted the cold snap in mid November. So overall, I would suggest normal model tendencies are skewed and potentially might misrepresent modeling as being "too cold" because of an anomalous two month warm period(December to January). So it is a tale of two contrasting biases. In early November(when the pattern changed to cold) the models were too warm. During December and January, modeling was too cold during near record warmth as modeling almost always has trouble with extremes. So, those maps above have two months of cold bias and one week of warm bias. So, makes sense they are skewed. So, I think we have to consider current model tendencies but be wary of using past performance as and indicator of future performance. For example, I think many assumed modeling in December(that predicted warmth) was possibly wrong, because its past performance had been too warm in early November. The warm December forecasts verified. It is possible that the same thing will happen in reverse where modeling busts high. Not saying that will happen, but the antecedent performance of November certainly did not continue into December. In other words, sometimes modeling mistakes can move from a cold bias to a warm bias vey quickly as occurred in November.
  24. Carvers Gap
    Good find. I wouldn't argue with many of those, but I think(am nearly certain) the EPS has a really strong warm bias from d10-15 and also for the Weeklies. It is usually significantly warmer at 2m than any of the American model output. Not sure how those are generated, but the 90d timestamps might be skewing those. I can say from personal experience, the EPS has a warm bias in d10-15. Maybe the miss earlier in January and over Canada last week is skewing those maps as the past 90 days of modeling have had some wicked busts where modeling verified much warmer than modeled d10-15. Additionally, I would think that modeling would have some sort of correlational coefficient rating based on where features verified on a map - I would be interested to see those as well.
  25. Carvers Gap
    It has been a fight all winter. I am looking for some cold pattern persistence! LOL.
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