jpeters3

Meteorologist
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Everything posted by jpeters3

  1. Check out the 18Z TLH sounding. Some pretty impressive 0-1 km and effective inflow layer SRH, but the numbers aren't quite as astronomical as some of the guidance this morning had predicted. Lacking a little bit in curvature within the lowest 1 km, which may be why these cells aren't becoming widespread tornado producers just yet. http://www.spc.noaa.gov/exper/soundings/17012218_OBS/
  2. Looks like the fired a massive OFB out to their west. Perhaps they were inundated by their own outflow?
  3. Right. 15 kts at the surface and 35 kts at 850 in a similar direction might give you the same shear magnitude as 5 kts at the surface and 25 kts at 850, with a lot of veering. 00 Soundings should come out soon. The sort of "best guess" of what a sounding might look like is typically one taken from the RAP analysis (though I'm starting to find out that these can be pretty bad too). College of dupage website has a good "point and click" interface with the RAP, so you can point to a location on a map at a given time and get a forecast sounding. If you want an approximately current sounding, find the most recently initialized RAP run and look at the forecast hour that corresponds to the current time.
  4. Mesoanalysis has 300-400 J/Kg effective SRH in that area, and 15-20 kt 0-1 km shear. Just goes to show that it's the shear that matters - not the actual wind magnitude at 850.
  5. I'm in Fort Collins too, and this one made me squirm a bit ;-)
  6. Result was actually kind of a surprise to me. I would have agreed with you prior to seeing the data.
  7. I'm currently doing a study on this, and you are incorrect. More often than not, tornado events that produce EF-1 or greater tornadoes during the spring last into the night. Edit: The question of whether chasing is very relevant after 03Z depends on who you are asking ;-)
  8. I generally agree with this - anywhere near, or slightly south of the boundary (and slightly south of the sounding I posted) is going to be prime. I do expect that some of the convection the model is blowing up north of this region is going to be elevated though. Might end up being elevated supercells with the very high low-level SRH, but elevated none the less.
  9. Shallow convection/clouds or warm front are sort of semantics. Shallow convection/clouds is common just north of a warm front. Regardless of what is causing the profile to look like this, the shallow statically stable layer shows up in pretty much every profile north of the KS/NE boarder, and has in several rounds of model runs. What the model shows as SBCIN is not based on the actual surface virtual temperature (you see, the lifted parcel path starts to the right of the surface virtual temperature in the sounding), so the actual SBCIN is probably higher than what is listed on there. You can easily get supercells within an environment like this, but it is very difficult to develop a tornado when surface parcels are convectively inhibited.
  10. I am still convinced that most of the profiles in southern NE are actually slightly north of the surface front, and any supercells that develop there will end up being elevated. Take a look at some profiles out of the high sigtor regions in S nebraska. They all look like this: http://climate.cod.edu/hanis/model/fsound/index.php?type=12|NAM|US|con|stp|36|*129,113*|ml|severe Shallow saturated stable layer.
  11. After looking at the 12Z NAM, I've got my eyes on the KS/NE boarder somewhere between Belleville and Phillipsburg KS. While the NAM goes crazy with sigtor in southern Nebraska, soundings from this area all show a shallow and very moist inversion, suggesting to me that they are north of the effective surface front and that surface parcels in this area will be somewhat convectively inhibited. I like the profiles I see in northern KS around 00Z.
  12. With all the focus on VBV here, I can't seem to find any peer reviewed articles that demonstrate its effect on supercell dynamics. Can someone point me to an article that addresses VBV? From what I gather from rather "hand-wavy" arguments, VBV implies that a supercell ingests the opposite sign of vorticity from its ambient environment at mid levels, which is detrimental to mesocyclone. The problem I have with this argument is that the primary "fuel source," or the effective inflow layer to a supercell is usually well below the layer where the back-veer portion of the profile is. So I'm not entirely convinced that the storm is ingesting the opposite-signed ambient horizontal vorticity at mid levels. I could be convinced that the changes to the storm-relative wind profile implied by VBV results in more precip falling within the storm's inflow region, and thus evaporative cooling contaminating the storms inflow and leading to outflow dominated storm modes. Any thoughts? I spend most of my time reading MCS papers, so I could have missed some recent articles that address this.
  13. You have me on this one. I should have stated 'To the best of our knowledge, Hurricane Patricia is the strongest tropical cyclone in the history of reliable observations'. My apologies for harping on you, and then turning around and making a statement like that.
  14. The assertions in this article are still speculative. You earlier saw with this storm how significantly ADT numbers can sometimes give poor estimations for observed winds. In this case, the observed winds were higher than ADT estimates; however, there is certainly an error margin on ADT, and 'concluding' that unobserved storms that had ADT numbers a few decimal points higher simply isn't good science.
  15. I wouldn't venture to conclude anything from unsubstantiated speculation. Also, the Dvorak estimates for this system were comparable to, or higher than any other numbers I am familiar with. Does anyone recall what the highest observed Dvorak numbers are?
  16. These are probably correct. Dean on the Yucatan in 2007 is another candidate (155 kt I believe).
  17. Just to alleviate any confusion: https://en.wikipedia.org/wiki/List_of_the_most_intense_tropical_cyclones
  18. Hurricane patricia IS the strongest tropical cyclone in history in terms of 1-min sustained winds. End of story. There is no 'sensationalizing' a TC that achieves a low central pressure of <=880 hPa and 200 mph 1 minute sustained winds for > 6 hours. This has never happened since reliable measurements have been taken. Don't try and under sensationalize this event.
  19. No, but I deff woke my girlfriend up like 3 times between 6 and 7am with overly excited and unsolicited updates :-)
  20. I rarely see the GFS initialize with the correct pressure (presumably due to resolution issues). Furthermore, a significant component of storm track and intensity is dictated by large scales... so don't throw in the towel on every run that doesn't get the exact pressure right.