Weather: July 2008 Archives

I'm fortunate to work at an unnamed national severe weather forecasting center that serves as one of the last bastions of frequent manual map analysis in the nation. Twice a day, the mandatory level (925, 850, 700, 500 and 250 mb) upper air charts appear from printers on 11" x 17" paper for analysis in support of the core forecast mission. Surface maps are printed for analysis many times per day as forecasters take the time and interest to do so. When these analyses are done in a careful, detailed way, this is a very, very good thing; for it forces the mind to slow down and truly immerse in the observations, connecting them into a carefully constructed, multivariate conceptual model of that snapshot of our atmosphere.

Excellent analysis is time-consuming, and requires a good deal of both skill and practice. Unfortunately, especially in local offices, hand analysis is vanishing, partly because of increasing volumetric workload (and resulting loss of time) and partly from ignorance and laziness. I often feel that time pressure myself, and fear that the same fate may befall the national center(s) if we're not diligent and careful. The slow creep of forecast automation -- and of the related phenomenon of "meteorological cancer" (first noted in this 31 year old paper by Snellman) -- is on the move in some insidious ways. As I've pointed out here before, procedure is taking over forecasters' time at the expense of meteorology.

Sometimes it seems like those of us who bother to do detailed hand analysis are becoming an endangered species. It utterly baffles me why so many put so little value in it, and why the quality of many hand analyses is so poor -- with lines on the wrong side of data, closed highs or lows unlabeled, missed boundaries, unlabeled lines, time continuity jumps (e.g., a cold front oscillating backward from one map to the next) and other fundamental errors. Were I still a synoptic meteorology teaching assistant, I would assign grades of "D" or lower to 90% of the drawn maps I have seen, anywhere, in the last several years. I don't understand this inattention to excellence in hand analysis. Is it lack of exposure or training, time pressure, disinterest, inexperience or all of the above?

Acquiring the deepest possible grasp on the current state of atmosphere is absolutely essential to forming the conceptual models needed for consistently good forecasts, and also, for good forecasts of rare and extreme events that are most poorly handled by objective analyses and guidance. Throughout all the technological advances, this basic truth remains unaltered.

I engage both hand-drawn maps and objective analyses of all kinds on a daily basis, in considerable detail, and can assure you that the latter is a piss-poor substitute for the former, when excellence in hand analysis is made top priority. Now please understand that I wouldn't violate the Golden Rule by holding anyone else to a greater standard than myself; nor do I claim to be a more skilled analyst. The principle of (and need for) analytic excellence absolutely applies to me as much as anyone. I can (and do) go back and find inexcusable and shameful mistakes in my own analyses.

A missed max or min here or there, or a boundary not drawn under hurried circumstances, may not seem like much, but how does one know what "minor" feature is really unimportant until the event is over?

Superficial skimming of objective, computer-drawn analyses -- which often miss or misplace small but critical features -- is not the same as truly diving into the data, taking the time to thoroughly draw for and interpret it. If it comes to a choice between more hand analysis or more model output, I'm choosing the hand analysis. An informal (not yet published) experiment called Project Phoenix, managed by Pat McCarthy of Environment Canada's Prairie and Arctic Storm Prediction Centre, showed over several seasons that forecasters who looked at observational information only (including hand analyzed charts, as well as satellite, radar and other observed data) performed better at forecasting basic variables during day-1, and often into day-2, than those on regular, operational shifts looking at numerical models. Why would this be?

I don't advocate eschewing model guidance any more than I would dropping hand analyses. In the practical sense of operational forecasting, it would be dumb to ignore the most pertinent nuggets of prognostic information. I make intensive use of models in day-to-day forecasting, including an increasingly heavy reliance on clues provided by short-range ensemble forecasts (SREF). But when pressed for time, I'll sacrifice a deterministic model or two for more insight into the current state of things. After all, how can we consistently predict the future atmosphere without deepest possible understanding of the present atmosphere? Those who claim to have such understanding by ignoring manual diagnostics and looking at objective analyses instead have deluded themselves, amidst the intoxicating abundance of quick-n-ready digital diagnostics -- the choice drug of forecasting, so to speak. These forecasters are dooming themselves to a fate they probably deserve -- automation of their jobs -- but in the process, increasing that risk for the rest of us as well. Just remember: garbage in, garbage out. Without corroboration from reality, how does one know the computer drawn map is accurate?

Failing to do good hand analysis also is quite selfish. The subjective analyses are not just for the forecaster doing them; they are for the entire forecast team and shift successors, and are important to continuity of understanding of an evolving situation. Even if a forecaster doesn't "get much" from his own analysis (which is a surefire sign of a scientific and conceptual deficiency on his/her part), it has meaning to others, and as such, should be done and done thoroughly. Hence...

Understanding the current state of the atmosphere isn't a matter of personal choice; it's a matter of professional responsibility.

The solution for the troubled forecaster is simple: Get out those colored pencils and start drawing! To help get going, here are links to online, national upper air maps, ideal for hand analysis and optimized for 11 x 17 printer paper (but useable at smaller sizes):

12Z Plots with VAD and Profiler Winds (PDF format): 925 mb | 850 mb | 700 mb | 500 mb | 250 mb

The first step in making the best forecast that the science permits requires a thorough high quality diagnosis. Successful short range forecasts are more the result of good diagnosis than of prognosis.

- Len Snellman, 9 October 1991

Some colleagues and I have had a discussion about the merits and demerits of wind farms when storm observing, which also wandered into some concern over the impact of removing gigawatts of energy from the boundary layer. The latter is very nebulous, but photographically speaking, one thing is clear: One man's eyesore is another's photogenic desire. I've found the wind farms in some sky-scape settings to make great subjects or foregrounds (e.g., from SkyPix, Outflow Power and Solar Powered Wind Power), and fully intend to make use of them in the future as opportunity permits.

Some other storm observers have taken great shots using wind farms as foregrounds or silhouettes. Elke and I also took a bunch of mixed wind-farm pics (old style windmills in front of the giant new turbines) recently in Baca County CO, just W of US-287 (not while chasing). I'll post those links once we get the shots processed. [Still working on images from 2008 chase vacation...]

I'm in favor of more wind farms, which is fortunate since their numbers across the Great Plains are rising no matter what we think about them. They provide relatively clean energy and an economic boost to remote and downtrodden communities. In the process of learning more about the Roscoe wind farm shown in that last link, I came across this article from NPR online, which illustrates the point well.

Many of these areas have been beaten into submission economically and welcome both the income infusion and the opportunity to contribute some cleaner energy to the power stream than what's come out of the ground beneath. The expensive part, from various sources I've read, is providing the high-capacity transmission infrastructure to get this power from remote, windswept reaches of the Great Plains to somewhat nearby areas of high demand (e.g., the Metroplex, DEN, MKC, etc.).

Boone Pickens wants to set up essentially a nearly unbroken chain of wind farms from west Texas to the Canadian border. The guy's motives are questionable and his schemes often laced with more hyperbole than legitimacy. Still, whether it's by his doing or from an aggregated collection of lesser fat-cats, you can count on the same basic thing happening: numerous wind farms from west TX to the Dakotas within 10-15 years. The energy source exists, and as it becomes more economically feasible, will be exploited to the extent that environmental regulation, private landowners and market economics allow. And it's going to be a lot harder to regulate something as wholly subjective and purely judgmental as "sight pollution" versus measurable, tangible, physical emissions from fossil fuels.

Like other Great Plains enthusiasts, I would like to keep the wind farms out of some areas of special scenic meaning to me as well (e.g., Flint Hills, Badlands, Wichita Mountains, national grasslands). [Incidentally, a part of the power I'm using to post this comes from that OEC wind farm N of the Wichitas, near Meers OK. That sucker slices across the northern horizon every time I'm atop Mt. Scott.]

Compromises will be necessary between competing aesthetic/economic/societal interests if this is going to work at all. But if we as a civilization decide to keep either exhausting or checking off sources like wind, coal, nuclear, oil, solar, hydro, etc., from the list, for various reasons large and small, then we might as well let the roads crumble, close down our offices, and go back to a mixed hunter-gatherer/agrarian society, and storm chasing and all BLOGs are moot matters anyway. [I am, BTW, for vastly expanded nuclear energy production in this country as well. ]

As far as the kinetic energy removed by wind turbines from the boundary layer, this needs to be analyzed better to see what, if any, physical feedbacks there are among pressure/height gradients (wind origin), forcings aloft for related isallobaric fields in the lowest ~100 m where the energy is being extracted, and the response/restoration of said gradients to that energy extraction (if any). I'll hypothesize that it's a negligible gnat fart of an effect given the small aggregated cross sectional area of the blades compared to any vertical cross section of the entire boundary layer across the Plains, but let's find out if that's valid.

Does an array of turbines extracting a few gigawatts of energy alter del-p at the surface, or isallohypsic patterns aloft by upward propagating influences of boundary layer processes? How big of a butterfly is a wind farm in Texas relative to a tornado in Kansas? We do know one thing: Ultimately, wind energy is solar in origin, and the sun's output is independent of kinetic energy removal in the ~100 m layer above ground. Beyond that...who knows? It's a great area for research.