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About KevinH

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    "Lemme 'splain something to you..."

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  • Four Letter Airport Code For Weather Obs (Such as KDCA)
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  • Location:
    Duluth, MN
  • Interests
    Photography, software development, case studies.
  1. A squall line NST which does F3 damage? I would classify that as highly unlikely. Much more common is a supercell embedded within a squall line. So in this case, I would tend to believe this would fit the "tornado over water" archetype rather than the NST "traditional waterspout" archetype. --Kevin
  2. Not as much as they once were. The environmental precursors that support non-supercell tornadoes are relatively well established (very steep, nearly dry adiabatic low-level lapse rates, strong ambient vertical vorticity, low 100 mb mixed-layer CIN, 0-3 km mixed-layer CAPE of 100 j*kg-1, and weak deep-layer shear). Abundance in one of those parameters may even compensate for deficiencies in others. The biggest challenge, at present, is the poor radar presentation of these circulations, which makes warning decisions extremely difficult, and reliance on spotter reports more crucial. As for minimal damage, no, not exactly. Non-supercell tornadoes have caused damage up to (E)F-2 intensity in the past. They are certainly a threat to life and property, even on the low-end of the scale. Remember, an EF-0 tornado has sufficient strength to take large branches out of trees. Injuries and fatalities occur each year with EF-0 and EF-1 tornadoes. (E)F-1 Fatalities, by year 2014 - 2 (to date) 2013 - 3 2012 - 2 2011 - 5, 1 EF-0 fatality 2010 - 4 2009 - 3 2008 - 4 2007 - 4 2006 - 8 2005 - 3 2004 - 5, 1 F-0 fatality 2003 - 3, 1 F-0 fatality 2002 - 6 2001 - 4, 1 F-0 fatality 2000 - 2 1999 - 6 15 year total: 64, 4 (E)F-0 fatalities --Kevin
  3. I apologize for the offense, none was intended. When I was "investigating" meteorology in high school I came across definition #2 in many sources, including Encyclopedia Brittinica (http://www.britannica.com/EBchecked/topic/637532/waterspout). Granted they were all older sources, ca 1970s. I don't know the origin of definition #1 but realize this is the most common usage. In everything I had read on the topic, it seemed non-supercell waterspouts and supercell tornadoes over water occupy a distinct hazard space. NST waterspouts would tend to occupy, almost exclusively, the low end (EF-0, EF-1) side of the curve, while supercell tornadoes can vary anywhere from EF-0 up to EF-5. The distinction isn't so important for marine interests, since each phenomena represents a threat to life and safety, but for land-based interests, where the feature may come on shore, the distinction is significant. Yes, I would advocate the use of "tornado" or "tornado over water" in SMWs. I'll have to check, but I believe our WarnGen templates already do this. There is no need to "officially" add new words to the lexicon in order to describe a phenomenon that already has a name, "tornado". Supercells produce tornadoes. They can occur over land or over water. This does not change the dynamic process that creates the feature, nor alter the damage potential of such a whirl. For marine users, I doubt any distinction is necessary. A whirl is a whirl. Both types represent a hazard to shipping and recreational interests. The response to each should be the same, seek safe harbor until the storm has passed. My point is that we do not need to create another term to represent something that already has a term. Call it a "tornado", call it a "tornado over water", it makes no difference to me. "Supercell waterspout" doesn't add any special meaning, especially considering a supercell could produce a tornado over water, associated with the mesocyclone, or a NST along the forward-flank or rear-flank gust front. Again, I apologize for the condescending language. It seems I was "too cute by half" to set the right tone. I do wish for this to be a serious discussion and have very strong feelings about the subject matter. --Kevin
  4. Please, pretty please, with sugar on top can we agree to not to do that? There's already name for "supercell waterspouts": tornado. There is absolutely no benefit for creating a new name for a phenomenon which already has a name. A supercell tornado over water is as much of a hazard to marine interests as it is to land-based interests. A "waterspout", however, is mainly a hazard to small craft. There are distinctly different processes responsible for the creation of each and it is possible, even easy, to distinguish between the two. I know the term "waterspout" has been genericised to apply to any tornado over water. As meteorologists, however, we should know better and realize the "hazard space" for each is not interchangeable. --Kevin.
  5. For software langugages, I will second MATLAB, Python, UNIX/LINUX shell scripting, FORTRAN, and anything GIS related. You might also consider Java since that is the underlying architecture of AWIPS2. All of these languages/skills have specific uses. FORTRAN is good for numerical weather prediction and some research applications. MATLAB is also used in research (formal and ad hoc). UNIX/LINUX is very important since most meteorological applications are designed on those systems, not much Mac/Windows at this time nor in the foreseeable future. Python has applications in nearly any field and is quite flexible, I've found. Also remember, no matter what language you study the important thing is to learn as much as you can. Software languages all do roughly the same thing, make it easier for a person to tell a computer what to do. If you learn one language really well, you can pick up other languages as needed and fairly quickly. The main differences are syntax. COMET/MetED is another great website with abundant training modules for a variety of skills. I would also suggest looking at resources from the NWS Warning Decision Training Branch (http://www.wdtb.noaa.gov). They have some excellent training courses available to partners and the public. If you complete training modules, keep a list of the completion dates and scores (where applicable) to include on your resume. Good luck! --Kevin
  6. There are two potential processes involved here, adiabatic (reversible) and diabatic (irreversible). "Heavy_wx" has already covered the diabatic process, so I won't duplicate his comment here. In the event the rising parcel does not generate precipitation, the cooling is completely reversible. Think of a somewhat dry airmass and a small hill. As the dry air is advected over the terrain feature, adiabatic cooling occurs. If we make the airmass sufficiently dry and the hill sufficiently short, such that the advected air does not produce clouds or precipitation, the parcels will warm on the descent side of the hill to their original thermodynamic values from the upwind side of the hill. --Kevin
  7. *This is just my opinion, I do not speak on behalf of my agency!* I can't help but think how useful a new 88D installation near the Bakken would be. Perhaps with the economic boom, increase in population, and number of man camps, there would be sufficient political support to purchase and install such a radar. It might be worth writing the governors of Montana and North Dakota, along with the congressional delegation, to see if support can be generated. --Kevin
  8. The answer to this question is simple...and complicated. First the simple. Technically a "tornado" is a "rotating column of air pendant from a cumuliform cloud and in contact with the ground". So most "landspout" tornadoes, nearly all "water spouts", and all "tornadoes" fall into that category. If there is rotation at cloud base and rotation at the ground, that's all you need. What is the difference between a waterspout and a tornado? There is some debate on this topic. Not all "waterspouts" are "tornadoes" and not all "tornadoes over water" are waterspouts. Waterspouts form from a different dynamic process than supercell tornadoes, and are similar to non-supercell processes. The reason there is so much information on waterspouts relates to how common they are in the Florida Keys and other areas along the Gulf of Mexico. That lead to a research program in the 70s (if my remembrance is correct) to study their formation. Waterspouts generally form in weak updrafts and are pendant to the puffy "fair weather" Cu common during the summer months. "Tornadoes over water" tend to be pendant from a supercell thunderstorm. Regarding the tornadoes in the video: First, they are NOT what any experienced person would call a "stovepipe"; Second, it's hard to make a definitive assessment from this video alone. I, however, am undaunted by the challenge and am not afraid to be wrong from time to time, so will make an attempt. Given the appearance of the storm and the weak, thready appearance of the funnels, they would seem to be a non-supercell tornado process, possibly a waterspout that wandered on shore. They are a (1) rotating column of air, (2) pendant from a cumuliform cloud, and (3) in contact with the ground. So they are "tornadoes" in either case. Hope this helps. --Kevin
  9. I apologize for arriving late to the party. If anyone wonders if TWC's winter storm names are anything more than a gimmick designed to boost ratings, simply reflect on the way they handled "Caesar". With blizzard warnings flying last Friday and Saturday, TWC was holding fast on withholding a name. Only when the storm appeared to bear down on Minneapolis/St. Paul, after the storm had been producing snow for hours on the Twin Cities Metro, did they decide to coronate "Caesar". In order to draw attention to the hazard and increase awareness, they would need to name the storms well before the mid-point of the storm. With this in mind, and their handling of the other Northern Plains blizzard from earlier this cool season, I'm convinced their naming scheme is solely an attempt to boost ratings and not designed to increase awareness, etc. Your mileage may vary. -- Kevin.