It’s been rough. \u00a0Most of the project scientists have been involved in field work where the focus is intercepting tornadoes. \u00a0Most haven’t really wrapped their heads around how to extract new knowledge from whatever that atmosphere offers up. \u00a0And the personal costs are high: missed classes, impacts on student learning, making up lectures, families back home, arranging and rearranging travel and accommodations daily, missions that start at 4 AM, and on and on.<\/p>\n
There are mission\u00a0days when we are pretty sure that there won’t be significant tornadoes even though the lead-up looked promising, and there are a few that do<\/em> seem to have significant tornado potential. \u00a0Last Wednesday was one of the latter. \u00a0There was an SPC moderate risk in northern AL, and a high risk further south. \u00a0The usual tornado forecast parameters were all in place. \u00a0But the activity in northern AL was benign. \u00a0The cumulonimbus clouds were fairly vigorous in the lower levels, but in the middle levels they became fuzzy and shredded. Mixing with\u00a0warm dry air appeared to be\u00a0evaporating them. \u00a0Anvils were never solid-looking, but were puffs of ice drifting away from the updraft. \u00a0Was there too much shear? \u00a0Too warm and dry aloft? \u00a0Not enough focus in the lower levels? Something wrong with the hodograph?<\/p>\n On radar, the echoes were strung out along\u00a0the strong upper level flow. \u00a0Those few echoes that had any longevity seemed to be moving into these bands of moistened air. \u00a0For the most part, the echoes were weak. \u00a0And another pathology that I have not seen before: \u00a0the echoes had the shape of cyclonically rotating supercells, but many appeared to have anticyclonic wind shear in the Doppler radar data. \u00a0The only storm in the domain to produce a research-worthy low-level vortex did not appear to be a supercell on radar, and was perhaps enhanced by terrain effects near Sand Mountain.<\/p>\n I’ve heard a different\u00a0explanation of this day’s “failure mode” from each meteorologist I’ve talked to. \u00a0This is all speculation (OK, OK… informed<\/em> speculation). \u00a0Once we dig into the rich set of soundings obtained by VORTEX-SE, and perhaps do some computer simulations of the overall setup as well as individual “storms”, we can move from speculation to some more solid information.<\/p>\n This is important. \u00a0As usual, I believe the forecasters in the NWS forecast offices and the SPC did just about as well as our current understanding allows. \u00a0Any forecaster (this blogger included) can look at an event in hindsight and “explain” how the forecast went wrong. \u00a0We can satisfy ourselves that our own comprehension of the situation was better than some other\u00a0forecaster’s. \u00a0And the risk here is that our self-confirmed (mis-)understanding of the event becomes the lens through which\u00a0we look at future events.<\/p>\n But we really have a lot to learn about severe weather forecasting. \u00a0We do know that when\u00a0a significant tornado occurs, it is\u00a0probably in an environment that features a certain mix of CAPE, deep shear, near-ground shear, etc. \u00a0Our climatologies show this. \u00a0We have sounding analysis tools based on this understanding. \u00a0But our climatologies also show us that when that certain mix of\u00a0conditions is\u00a0present, a large percentage of the time there will not<\/em> be significant tornadoes. \u00a0In other words, in these potent-looking environments, most of the time “something” will reduce tornado potential. \u00a0In the last 25-30 years we have learned a lot about the conditions present when significant tornadoes happen, but we have learned little about these “somethings” that usually get in the way of tornado production.<\/p>\n It could also be true that our most-used forecast parameters are not the most physically relevant, but instead are only reasonably well-correlated with some\u00a0yet-to-be-discovered pertinent parameters, so we may be able to improve forecasting by finding more reliable forecast parameters. \u00a0I was involved in some of the early research to identify the environmental conditions that are present when significant tornadoes occur. \u00a0And I look forward to the day when researchers can show how my early work was off the mark, and the old ideas can be discarded.<\/p>\n Over time, researchers will probably increase their focus on the “failure modes”, and we will learn to recognize the factors that reduce tornado risk. \u00a0This may be one of the bigger short-term contributions of VORTEX-SE. \u00a0We certainly have a rich palette of observed failure modes to study!<\/p>\n Erik<\/p>\n P.S. \u00a0The psychological and social aspects of this event, and VORTEX-SE in general, are worthy of a lot of blogging. \u00a0In many ways, they loom a lot larger than the meteorological aspects. \u00a0I hope I can convince some of my colleagues and VORTEX-SE researchers to share some of their insights and perceptions in this blog someday soon.<\/p>\n","protected":false},"excerpt":{"rendered":" STATUS: DOWN VORTEX-SE has been down for the last week. \u00a0This is a much-needed break for the researchers, and for me. \u00a0Right now, there are no hints of significant severe… <\/p>\n![\"\"](\"https:\/\/inside.nssl.noaa.gov\/vortexse\/wp-content\/uploads\/sites\/18\/2017\/04\/pic4-800x600.png\")
\u00a0 (looking south-southeast from the SWIRLL facility at U. Alabama-Huntsville)<\/p>\n