Carvers Gap

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About Carvers Gap

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  • Four Letter Airport Code For Weather Obs (Such as KDCA)
    KTRI
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  • Location:
    Tri-Cities, TN

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  1. Whew, I should have kept looking at that data.
  2. @John1122, thanks for that verification site. Man, I missed the first half of the TN basketball game working through that. LOL!!!
  3. 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.
  4. 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....
  5. 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.
  6. 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.
  7. It has been a fight all winter. I am looking for some cold pattern persistence! LOL.
  8. The thing I am seeing today is a bigger presence by the EPO ridge and a deeper trough somewhere east of the Rockies after Feb 5th. I really have run with the premise that the trough does not hold. But if that trough were to old like the EPS is showing, that would allow for really cold air to enter into the US. Give me that pattern on the EPS and 2m temps take care of themselves. No idea if that type of extreme look would verify. If I remember correctly, the CFS and EURO had similar MJO trajectories this morning - for once. I like that look, but do I trust the CFSv2? LOL. Anyway, at this latitude there are about 100 ways to achieve worse pattern. Right now, I am just pointing out with modeling how things could lead to a decent window.
  9. Couple of images to explain my thinking regarding the EPS. 0z is on the right. 12z is on the left. The first image(figure 1) is hour 198 which is February 5 @ 18z. Notice the core of the colder air is further west vs being over Quebec. Notice that the cold north of Alaska is stronger. That stronger area of BN heights near Alaska likely weakens the downstream trough. Notice how at 0z they(the two areas of BN heights) are similar. JB likes to point out that there is only so much energy to go around. Again, I don't do 2m temps on the EPS as they are often very biased towards warm. I look at 850s. That said, the 2m temps later in the run are impressive. So, the trough at 500 is later by roughly 12-18 hours now that I have had time to dig into it. You can compare the two images. Instead of the cold digging with the feature in Quebec, it digs into the Plains and pushes eastward. Almost all modeling is bouncing back-and-forth between placing the lowest heights in the northern Plains or Quebec. You can see the difference. Figure 1 Figure 2 shows what I consider to be fairly important improvements. Notice the stronger heights at 330 are centered over Minnesota instead of Montana and Quebec. That might mean the EPS is just splitting the difference between the two cold pools OR it actually now sees the cold in the Plains. Either way, the result on this run is the positive axis of the trough being moved quite a bit further East. With the area of lowest heights centered in the northern Plains, the cold air presses further into the SE and nearly eliminates the influence of the SER in our forum area, even bringing BN heights into west TN, Arkansas, far western KY, and Missouri. That also means the storm track would theoretically slide eastward and run from Houston through TN to Massachusetts verbatim. In reality that front probably presses further east at the surface due to the cold being centered so close in the Plains relatively speaking. That is a cold pattern. Also note the ridging In Alaska along with the ridging building into the coastal areas of Pacific NA. Another difference is the lack of Atlantic ridging. That may very well have allowed the trough to be displaced eastward. But the biggest takeaway from LR(and really LR at that) is that the EPS takes a big bite out of the SER and centers the cold further East. Figure 2 Lastly, I thought I would compare the Weeklies to actually EPS stuff now that it is in range. This is the 7day 500 anomaly for February 4-11. Figure 3 is from the Euro Weeklies derived on January 20th. Figure 4 is the same time frame from the 12z EPS today which is a run eight days later. While not perfect, the cold and trough axis in the lower 48 is nearly the same place. Just showing that the Weeklies are doing fairly well right now in week 3. Also note that the actual trough is being modeled deeper on today's run. Figure 3 Figure 4
  10. In my book that is a split given where it began at hour 0. But I am comfortable with different terminology. So, instead of split I will use an Eastman term: process upset. Used in a sentence it would work something like this....The SPV at 50mb is experiencing a major process upset.
  11. @Holston_River_Ramblerlooks to me like that trough is going to lift out of the West fairly quickly. Have seen that trend on modeling. That is a textbook easterly QBO/solar min look. I actually am a fan of the PV being over the HB an pivoting down cold - and I may have that backwards but that is what sticks in my mind.
  12. That run of the 12z EPS will work. The cold is centered in the Plains and not the Rockies. The cold would push on that boundary. IF true, that taps the GOM with that look late. See how the boundary drags into the Gulf? Fairly strong improvement IMHO and the ridge is closer to the West coast. The SER has really been pushed toward the EC.
  13. At 288, more ridging into Alaska is evident. Core of the cold is over the Plains. Looks very much like a microcosm of November.
  14. The interesting development on the 12z EPS is that the trough is a bit slower to lift out and the storm track would be optimum around 228. Of note, the ridge in the eastern Pacific is closer to the coast and stronger at 288.
  15. Also, looks like the 12z Euro OP splits the SPV as well. I will let Holston unpack that.