Defense Articles

It has also increased the number of so-called “moral waivers” to recruits with criminal pasts, even as the total number of recruits dropped slightly. The sharpest increase was in waivers issued for serious misdemeanors, which make up the bulk of all the Army’s moral waivers. These include aggravated assault, burglary, robbery and vehicular homicide. The number of waivers issued for felony convictions also increased, from 8 percent to 11 percent of the 8,129 moral waivers granted in 2006.

Waivers for less-serious crimes, including traffic offenses and drug use, have dropped or remained stable.

The Army enlisted 69,395 men and women last year.

While soldiers with criminal histories made up only 11.7 percent of the Army recruits in 2006, the spike in waivers raises concerns about whether the military is making too many exceptions to try to meet its recruitment demands in a time of war. Most felons, for example, are not permitted to carry firearms, and many criminals have at some point exhibited serious lapses in discipline and judgment, traits that are far from ideal on the battlefield.
The military automatically excludes people who have committed certain crimes. They include drug traffickers, recruits who have more than one felony on their record or people who have committed sexually violent crimes. A felony is defined as a crime that carries a sentence of a year or more in prison.

Bill Carr, the undersecretary of defense for military personnel policy, said the military granted waivers selectively and scrutinized a recruit’s full record, the nature of the crime, when it was committed, the degree of rehabilitation and references from teachers, employers, coaches and clergy members. In many cases, Carr said, the applicant may have committed the crime at a young age and then stayed out of trouble. To his knowledge, Carr said, recruits who are issued moral waivers are not tracked once inside the military.

“If the community backs them, we are willing to take a hard look,” Carr said, referring to the waiver process, which includes local, state and federal records checks.

The majority of moral waivers are for serious misdemeanors, most often committed by juveniles. As Douglas Smith, the public information officer for the Army’s recruiting command, said, “We understand that people make mistakes in their lives and they can overcome those mistakes.”

Fewer than 3 in 10 people between ages 17 and 24 are fully qualified to join the Army; that means they have a high school diploma, have met aptitude test score requirements and fitness levels and would not be barred for medical reasons, their sexual orientation or their criminal histories. The Defense Department has also expanded its applicant pool by accepting soldiers with criminal backgrounds and medical problems like asthma, high blood pressure and attention deficit disorder, situations that require waivers. Medical waivers have increased 4 percent, totaling 12,313 in 2006. Without waivers, the soldiers would have been barred from service.

In the last three years, the percentage of moral waivers for all new enlistments in the four branches combined have decreased by 3 percent, with spikes in the Army and Air Force. Since 2003, a total of 125,525 moral waivers have been issued. The Marine Corps issues far more moral waivers than the Army — 20,750 in 2006 — but only because it has a stricter policy on drug use. It requires waivers for one-time marijuana use while the other services do not. Rules on waivers vary according to service.

“The data is crystal clear; our Armed Forces are under incredible strain, and the only way that they can fill their recruiting quotas is by lowering their standards,” said Rep. Martin T. Meehan, D- Mass., the chairman of the House Armed Services Subcommittee on Investigations and Oversight. He has requested more detailed data from the Defense Department on the use of waivers.

“By lowering standards, we are endangering the rest of our armed forces and sending the wrong message to potential recruits across the country,” Meehan added. “Our men and women in uniform represent the best and brightest in American, and we need to keep it that way.”

The 7th Circuit Court of Appeals said the clock for the statute of limitations begins to run at the time of discovery of an alleged 4th Amendment violation and that a plaintiff must bring a charge against the officers within the proscribed period.
Andre Wallace was 15 in 1994 when Chicago police arrested him on a murder charge. He confessed during questioning, which he later claimed was coercive and violated the 4th Amendment.

At trial, Wallace testified that he killed John Handy in self-defense. Wallace was convicted and served eight years in prison before various challenges to police tactics resulted in the suppression of the confession and all other evidence and Wallace was released.

Wallace filed civil rights damages claims against the officers nine years after the alleged false arrest, but the 7th Circuit rejected the damages claim because the Illinois statute of limitations of two years had expired.

The Supreme Court agreed to review Wallace’s argument that the statute of limitations for a civil rights claim of false arrest should begin at the time that a prisoner is released rather man at the time of discovery of an alleged police violation.
The 2nd, 6th, 7th and 10th circuits have rendered subsequent opinions that Crawford is not retroactive. But the 9th Circuit found that Crawford represented a sharp turn in jurisprudence and should be applied retroactively to all cases in which hearsay evidence was admitted without the defendant being able to directly confront the witness.

Thirty-six states have filed amicus briefs against retroactivity.

The case before the court-like many cases of hearsay testimony-involves sexual assault of a child. Hearsay evidence is also popular in domestic violence prosecutions.

In Crawford, the Supreme Court set a higher standard for hearsay evidence, limiting its use in a criminal trial only if the person who made the out-of-court statement is unavailable to testify and the defendant had a prior opportunity to confront the witness about the hearsay evidence.

The states said Crawford had already had a profound impact on prosecutors and making the decision retroactive as Bockting seeks to do would further expand the number of cases that would have to be retried.

In Ayers v. Belmontes, 05-493, the high court will decide whether a jury must be directly told to consider a capital defendant’s potential for reform as a mitigating factor.

The 9th Circuit Court of Appeals decided that jury instructions don’t go far enough in allowing the introduction of mitigating factors to reduce the penalty against the defendant.

Fernando Belmontes, who had a juvenile and adult history of violent crime, entered a home for a burglary, found a young woman at home and bludgeoned her to death with an iron bar. Belmontes stole her stereo, sold it for $100 and bought beer.

At trial, the 9th Circuit ruled, that the jury didn’t take into consideration the mitigating factor that Belmontes had shown improvement during an earlier incarceration at the California Youth Authority.

The Supreme Court has been asked to decide whether juries should receive more specific instructions to include the possibility of future reform as a mitigating factor.

In U.S. v. Resendiz-Ponce, 05-998, the Supreme Court will decide whether an omission of an element of a criminal offense in an indictment is a 5th Amendment violation that invalidates the indictment.

Juan Resendiz-Ponce, a Mexican citizen, was indicted for attempting to illegally reenter the United States, but the indictment did not explicitly allege an overt act beyond submission of a false identification card at the border.

Without any other act than submitting a false ID, the 9th Circuit Court found the indictment invalid and reversed the conviction.

Resendiz-Ponce had earlier been deported for illegal entry. He returned and was convicted again of kidnapping his stepdaughter, whom he had impregnated, and ordered deported.

Despite his history, the 9th Circuit said the government made a fatal error in failing to identify an overt act of an illegal attempt to reenter the United States.

A machine gun is a fully-automatic mounted or portable firearm, usually designed to fire rifle cartridges in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute. The first machine guns were manually operated, for example, by turning a hand crank.

Operating Prinsiples:
There have been two main machine gun eras: the era of manual machine guns and the era of automatic machine guns. The technical development itself is marked by a series of developments of specific automatic features, as well as technical developments (such as linked ammunition). The era of manual multi-shot devices extends back hundreds of years (such as manual volley guns), but the development of manual and automatic machine guns takes place almost entirely in the latter half of the 1800s. Manual machine guns are manually-powered, e.g., a crank must be turned to power reloading and firing, as opposed to simply holding down a trigger, as with automatic machine guns. There are many other notable features, but this is one of the most significant to allowing higher rates of fire common to machine guns.

Manual machine guns, as well as manual volley guns, saw their first major use in the American Civil War. The Gatling gun and “coffee gun” both used manually-powered automatic loading, fed via a hopper filled with cartridges. The Gatling gun would be the major type of the late 19th century, though there were many other manual designs with varying degrees of use (e.g. the Nordenfelt machine gun). The first automatic machine gun was the recoil-operated Maxim gun, which used linked (belt) ammunition, as well as a single barrel and automatic loading. This concept of using bullet energy would also drive the development of nearly all other semi and fully automatic firearms of 20th century.

The two major operation systems of modern automatic machine guns are gas operation and recoil operation. As the name implies, the gas operated system uses the gas generated from the burning powder to cycle the action, whereas the recoil operated uses the recoil generated from the ejecting bullet. The first gas-operated machine gun was the Colt-Browning M1895.[2]

Another (minor) type is the externally-powered machine gun. Rather than human manual power or energy generated by the cartridge, an external source such as an electric motor is used. These types are now called by more specific names such as Minigun and Chaingun. They are common on fighting aircraft and ground vehicles, where the externally powered mechanism allows for automatic clearing of many failure conditions that would otherwise disable the firearm.

Any medium through which the music signal passes, whatever its form, can be regarded as a filter. However, we do not usually think of something as a filter unless it can modify the sound in some way. For example, speaker wire is not considered a filter, but the speaker is (unfortunately). The different vowel sounds in speech are produced primarily by changing the shape of the mouth cavity, which changes the resonances and hence the filtering characteristics of the vocal tract. The tone control circuit in an ordinary car radio is a filter, as are the bass, midrange, and treble boosts in a stereo preamplifier. Graphic equalizers, reverberators, echo devices, phase shifters, and speaker crossover networks are further examples of useful filters in audio. There are also examples of undesirable filtering, such as the uneven reinforcement of certain frequencies in a room with “bad acoustics.” A well-known signal processing wizard is said to have remarked, “When you think about it, everything is a filter.”

A digital filter is just a filter that operates on digital signals, such as sound represented inside a computer. It is a computation which takes one sequence of numbers (the input signal) and produces a new sequence of numbers (the filtered output signal). The filters mentioned in the previous paragraph are not digital only because they operate on signals that are not digital. It is important to realize that a digital filter can do anything that a real-world filter can do. That is, all the filters alluded to above can be simulated to an arbitrary degree of precision digitally. Thus, a digital filter is only a formula for going from one digital signal to another. It may exist as an equation on paper, as a small loop in a computer subroutine, or as a handful of integrated circuit chips properly interconnected.

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In addition, people who may be exposed to indoor air pollutants for the longest periods of time are often those most susceptible to the effects of indoor air pollution. Such groups include the young, the elderly, and the chronically ill, especially those suffering from respiratory or cardiovascular disease.”

Nowadays camcorders are used for more than just filming home movies. A large community of amateur videographers now film short clips to put on web sites such as ‘Google video’, ‘You Tube’ and their own personal sites. Some of these are purely for entertainment while others are for information purposes e.g. local history societies interview people for their memories of the locality.

The quality of modern camcorders and computer based editing systems combined can produce excellent visual results which are often let down by poor quality sound. The main reason for this is that the built-in video microphone is usually too far away from the people being filmed.

At the time of filming, our ears, eyes and brain work together to effectively suppress the reverberation and other unwanted sound sources in the room to allow us to hear what someone is saying, what we hear is different to what a microphone ‘hears’.

This is where external microphones are required, the closer a microphone can get to the subject, the quieter other unwanted sounds effectively become.

If at this stage you don’t have any external microphones then the best advice for getting good quality sound from the built in video microphone is to get your camera as close to your sound source as possible i.e. about 3 feet away, however you might still hear some camera motor noise. If you are taking videography seriously then it’s best to wear closed-back headphones so that you only hear what will be on the audio tracks.

Usually camcorders have a built in stereo electret microphone which can either be unplugged from its socket or there are external microphone sockets and some means of switching between them and the built in video microphones. An A/V socket is usually available for plugging in an external audio mixer.

It might be necessary to buy a ‘stereo plug to two mono sockets’ lead so that you can make full use of the two tracks that are available on most camcorders.

Presenter

If your presenter needs to be mobile then it would be best to buy or rent a radio microphone kit (make sure you get a kit that has a small battery powered receiver - not a large mains powered one), this allows a lapel microphone (usually omni pickup characteristics) or a plugged in handheld microphone (usually cardioid pickup) to be permanently close to the presenter’s mouth. The lapel microphone is usually worn on a tie, suit lapel or shirt, try to avoid placing it on a shirt collar since this picks up too much sound from the throat, which sounds un-natural.

If the presenter is always static and fairly close to the camera at all times then an electret ‘line microphone’ can be worn connected via an extension lead, which should be framed out of shot.

Ever wonder what goes into the making of your new gadget? Electronic circuits are composed of individual transistors formed with resistors and diodes on a piece of silicon. The individual components are commonly connected using aluminum “wires” on the chip’s surface. This process results in the formation of IC, or integrated circuits. These ICs contain millions or just several transistors. ICs are responsible for the creation of video games, computers, digital watches, and most of today’s high tech gadgets.

ICs are usually grouped in two: analog/linear and digital/logic. But most sophisticated ICs combine digital and analog functions in forming a chip. As examples, digital chips sometimes include an analog/linear voltage regulator, while some analog chips include built-in digital counter. Combining integrated circuits is usually done to improve performance or add new features to a product such as giving counters time delays which are usually possible only with timers. These chips come in numerous different packages. In the present, the most popular and usual kinds are varieties of the DIP (Dual In-line Package). Ceramics or plastics are the usual components of standard DIPs with pins ranging from four to 100. Metals are also used for making DIPs but most manufacturers opt to replace these with more cost-effective plastic DIPs.

Despite the popularity of combination ICs and DIPs, there are still demands for separate integrated circuits. Analog ICs’ output and input voltage levels vary greatly in a broad spectrum. But despite these variations, output voltages are still directly proportional to input voltages which form a line graph. This is why analog ICs are termed linear. There are different types of analog ICs but the most popular and common types include voltage regulators and operational amplifiers. Voltage regulators alter voltages applied to inputs into variable voltages. Standard voltage regulators have excess transistors for the chips to manage driving loads that need added power than a standard op-amp is capable of. Most of these voltage regulators have metal tabs or include metal packaging to aid in radiating excessive heat out of the chips. Special linear ICs that include op-amps, like phase-locked loops and audio amplifiers, are made for TV, radio, computers, and telephone communications. Operational amplifiers are often considered as the most useful and versatile. Although their designs are basically intended for doing mathematical operations, they also amplify differences in voltages and signals of the inputs.

Digital integrated circuits are composed of “gates” regardless of the complexity of designs. These gates function like switches that turn on and off. A digital IC contains several gates and an IC with two input gates is usually referred as a logic gate. Increase in inputs and gates increase the ability of an IC to perform logical operations. As a result, digital ICs are often used in information transfers and exchanges. ICs are just small components of average devices like computers. But these devices rely on the efficiency of these ICs to function.

The sport of NRA High Power Rifle is all about distance and it’s true in more ways than one. On a regulation or full-length course, we’ll fire four events at 200, 300 and 600 yards. We shoot from three positions: standing, sitting and prone. Each event needs a different rifle setup, but we can’t use but one rifle to go “across the course.” Compromises are unavoidable.

However! The preponderance of NRA High Power Rifle competition doesn’t take place at 2/3/6. It’s done all around this country on “reduced” courses, and the majority are 100-yard. A very good while ago NRA recognized the issue and established reduced course provisions. Not every shooting community could afford their folks a full-length course. In my area there is one a little more than two hours away and another closer to four. The rest are overnight trips. I’m lucky, compared to many. There are areas with no reasonable access to 600-yard ranges.
I’m not snobbish over reduced-course shooting. I enjoy it and it’s not easier, not at all. The targets are scaled proportionally to their big brothers. Reduced courses are good training because environmental conditions are effectively removed from the usual High Power equation. The shooter can focus on shooting. I also have a choice of reduced course matches most any weekend of the year within an hour of home.

Now comes the problem the rifle here solved. If my “local track” is 100-yard courses, why am I shooting a full-length course rifle on them? That’s sort of like using a jackhammer to drive tacks. And the tack-driving part suffers.
I used to just lighten the bullet and also shoot a lighter load for reduced-course shooting. I think those are wise things. There’s no need to shoot an 80-grain bullet at 2,800 feet per second at rock-chunking distance. Also, such combinations won’t usually work too well on target. Long bullets and fast twist barrels don’t often shoot really small groups up close. Lightweight bullets with fast-twist barrels may perform poorly, too.

Reduced course targets are small. Some days they seem very small. The 100-yard reduced “600-yard” target has a .75″ X-ring and 1.75″ 10-ring. Right, most rifles will group smaller than that, but then there’s wiggle factor. Shooting a 20-shot group under 2″ prone with iron sights takes a pretty good hold. I have heard way too many “cuzzins” say they can shoot a lot better than that at 100 yards. They (rarely) come out, but have yet (ever) to come back.

I’d had an idea for years to build a rifle just for these events, and I finally did it. This reduced-course rifle is my daily driver. Stood to reason it ought to be made up the best way it could be. My idea was not only to adjust obvious specs to maximize performance at short range, but also to take full advantage of the opportunities these changes presented for improving my relationship with the rifle. “Take full advantage” is such music to my ears. I can smell gold-plated plastic through 3′ of concrete.

I first picked a builder, and I chose Gary Eliseo. Gary is a High Master ranked NRA High Power Rifle shooter and a thoroughly competent machinist. These two criteria are the “rules” for a project such as this. Your gunsmith really needs to be a machinist–someone capable of producing parts and unafraid of metal removal. I know it’s not necessary for a builder to be a hard-holder to make a great gun, but in this project it was productive to be able to discuss solutions to some of the problems I wanted to work around. If a builder doesn’t understand what I’m telling him is a problem, he’s going to leave the solution to me or,–worse–not really understand what I want well enough to help me attain it. The customer is not always right, but he needs to be happy, and that’s the point.

I had a few main ideas we needed to make work. Since the rifle didn’t need a long barrel I wanted to use the weight loss to add and move weight where and when I wanted it. I envisioned the most fit-tunable AR-15 I could have. I am a big believer in making a rifle fit the shooter. My rear sight mounting would give me the head position I shoot best with. I wanted a rear sight with extra-fine graduations to help better center groups. I wanted it bristling with trickery if only for the whole tailgate thing. Oh, yeah, and I wanted it to shoot teeny, tiny groups. This last goes first.

Make It Shoot

I wanted the smallest groups I could get from an AR-15 at 100 yards. Being fully aware that an AR-15 is not a Benchrest rifle, I still wanted to borrow and apply what I could from “them” to get what I wanted. Notice the capital “B” meaning the sport, not the shooting platform. Their game is group size. Teensy, weensy group sizes. Those who use 22-caliber tend to shoot 52-grain bullets through a 1:14″ twist barrel. They also tend to choose a 22″ barrel. Well, me too then.

I chose a Krieger barrel for this rifle, and I choose Krieger barrels for all my rifles, when/if I can. I got a stainless steel 1:14″ twist, 4-groove. Krieger barrels are cut-rifled. There are pros and cons to any rifling process I won’t debate here, but one point is using a single-point cutter makes it possible to rifle a barrel after it’s been contoured, as was this barrel. When barrel diameter is altered on the outside, it also changes on the inside. AR-15 barrels by necessity have steps cut into them, and these are usually square-shouldered and significant.

Union forces invested in as many as 20 varieties of carbines with the Sharps breachloader being the dominant arm. The system, patented by Christian Sharps in the late 1840s, became standard military issue by 1855 with rifles and carbines spread across the continent. Ninety to 100,000 of the carbines were produced for use in the War of Secession. Simple, muzzleloading carbines played a prominent role and were the official Confederate cavalry arm at the beginning and toward the end of hostilities.

Carbine designs varied considerably ranging from muzzleloaders to metallic cartridge repeaters and included a number of intermediate systems already obsolescent at the beginning of the war. I obtained current replicas of two major types from Dixie Gunworks. The S.C. Robinson Carbine made by Pedersoli, is the Confederate version of the Sharps breachloader. The Richmond, Virginia, company produced about 5,000 of these to augment the Sharps captured or obtained by other means. My other sample arm is the Pietta-made Smith Carbine. Designed in the late 1850s, it ranked 4th among carbines used during the conflict.
This one has the usual high standard of fit, function and finish I have come to expect of Pedersoli Arms. Like the original, it weighs in at eight pounds. Overall length is 39″ with a barrel length of just less than 22″. It is the more recent of two such arms currently in stock at Dixie Gun Works.

The S.C. Robinson Carbine

This variation includes production changes to meet historic specifications acceptable to the North-South Skirmish Association. The original Sharps employed a sliding gas check in the chamber intended to recoil backward during firing and prevent gas from escaping the breach. In practice, the gas check did not work particularly well and just made the weapon harder to clean.

The Dixie/Pedersoli replica eliminates the gas check depending upon a breach plate loading closely against the chamber. As with the originals, some gas does escape the action during firing. It is not an important issue so long as the shooter has eye protection and is careful not to allow loose powder to accumulate in the bottom of the action. (A number of historic Sharps and Robinsons have splintered fore-ends due to accumulated powder in the lever recess being ignited by leakage from the breach.)

The breach mechanism is a lever-actuated sliding block accepting the traditional ammunition–bullet and powder enclosed in combustible linen or paper cartridge and ignited by musket cap. To fire the arm, the soldier placed the hammer at half cock, pulled the lever down to open the action. He then inserted the cartridge and closed the action to shear the back of the cartridge, capped the arm, and brought the hammer to full cock to fire.

The original Sharps came equipped with a spool mechanism to advance roll caps with each function of the hammer. The Confederate copies eliminated this in favor of the simple musket cap. The expected rate of fire was 10 shots per minute–three times that of the standard infantry rifled musket. The carbine was not dependent upon manufactured cartridges and could be loaded with loose bullet and powder. This was a very important feature given the realities of Civil War supply lines.

Sharpshooter

To attain the rank of “Sharp Shooter,” the Union soldier had to put 10 rounds into a 10″ circle at 200 yards from a rest and demonstrate the same accuracy offhand at half the distance. N/SSA shooters routinely shoot at hanging tiles so sized offhand at 100 yards. I found the S.C. Robinson very nicely balanced for offhand shooting and managed a 7″ cluster on a silhouette at 75 yards. The open, fixed sights are highly visible and regulated very well for this range. The load–80 grains of GOEX FFg and 395-grain .544″ bullet –churns out about the same energy as some of the currently popular 50-caliber hunting revolver rounds but recoil is unobjectionable.

I had used the Dixie Sharps Cartridge Kit to roll authentic looking combustible cartridges using white household glue to affix the bullets. The instructions with the cartridge kit presuppose loading the bullet separately and creating a powder-only cartridge tube. My gluing in bullets probably explains why some of the nitrated paper didn’t catch and remained smoldering in the barrel and chamber. To avoid explosion, I ran a patch through the barrel after each shot and avoided any attempt at rapid fire. I found I could fire a maximum of five rounds between cleanings before the action became hard to work. Wiping the breach mechanism with a solvent-moistened rag every couple of shots was sufficient to allow sustained shooting. A more seasoned Sharps Shooter using Pedersoli metallic cartridge cases would be able to achieve the specified 10 shots per minute.

Flying an aircraft through a hurricane is risky business, even if the plane is specially equipped for the job. In the hurricane’s eye, skies are clear and calm prevails, but in the ring of intense storms surrounding the eye–the eyewall–rain falls in thick sheets and winds gust to 300 kilometers per hour.

In 2005, despite those perils, the pilots of three “hurricane-hunter” planes flew repeated missions into the cores of the monster storms Katrina and Rita as well as the much tamer Ophelia. During the missions–collectively dubbed the Rainband and Intensity Change Experiment, or RAINEX–scientists” on board the instrument-laden aircraft collected unprecedented data on the structure, configuration, and interaction of clouds within the massive hurricanes. Probes dropped from the planes garnered additional information.
In one case, the aircraft were the first ever to encounter and directly observe a ring of intense thunderstorms just outside the storm’s eyewall. Such secondary eyewalls, which appear to have significant effects on hurricanes’ strengths, had often been detected by satellites and radar but had never been seen in the fine detail achieved during RAINEX.

Analyses of data from that encounter may enable researchers to identify the features within a hurricane that most affect the storm’s intensity. With that information in hand, meteorologists could do a far better job of forecasting wind speed and ocean surge as a storm approached land. Also, scientists say, the new techniques that RAINEX researchers employed on shore to coordinate hurricane hunters’ flights could transform how such missions are flown.
INQUIRING MINDS Whenever meteorologists announce a new tropical storm or hurricane, two questions immediately arise: Where’s the storm headed? and How strong will it be when it gets there?

“The first question is by far the easier of the two” says Hugh E. Willoughby, an atmospheric scientist at Florida International University in Miami. The path that a hurricane takes depends largely on prevailing weather patterns throughout the surrounding region, including factors such as the strength, configuration, and movement of high- and low-pressure areas. Recent improvements in forecasting hurricane paths stem primarily from enhancements in the computer models used to predict weather in general, he says.

Meteorologists gauge the accuracy of path predictions by their “track error”–a measure of how far off its predicted line a hurricane’s eye wanders, explains James Franklin, a forecaster at the National Hurricane Center in Miami. In the 1970s, the average track error in the 3-day forecasts for hurricanes and tropical storms was 700 km. So far this decade, 3-day forecasts have missed the mark only by 300 km on average, he notes.

Predictions of hurricane intensity haven’t improved nearly as much. In the past 2 decades, errors in the National Hurricane Center’s 2- and 3-day forecasts for wind speeds within hurricanes and tropical storms have dropped only a couple of kilometers per hour. That’s because computer models that aim to represent hurricanes must pack data points close together to accurately simulate the small-scale, rapidly evolving features that swirl around the core of a storm. If a computer model has weather-data points spaced no closer than 5 km apart, for example, the theoretical storms it portrays turn out to be “larger, weaker cartoons of their counterparts in nature,” says Willoughby.

“It’s critical for forecasters to get a hurricane’s track right, but it’s an even bigger challenge to predict the strength of its winds,” says Bradley F. Smull, a research meteorologist at the University of Washington in Seattle.

Accurate wind forecasts are vital for several reasons. As well as directly affecting how much dam age a storm inflicts on structures, wind speed dramatically influences the height of a hurricane’s storm surge, the mound of water its winds push ashore. However, hurricanes are notorious for their sudden, and sometimes severe, variations in intensity.

Some of the factors behind such changes are well understood, says Willoughby. For instance, three of the four hurricanes that struck the Gulf Coast in 2005–Dennis, Katrina, and Rita–intensified as they passed over the Gulf of Mexico’s Loop Current, whose warm waters provided a ready source of energy for the storms. Rita strengthened from category-1 status (wind speeds between 121 and 153 km/hr) to category-5 (sustained winds exceeding 250 km/hr) in less than a day.

Then there are murkier influences on storm intensity, such as the interactions between thunderstorms immediately surrounding a hurricane’s eye and those arranged in bands that, seen from space, lend hurricanes a pinwheel appearance. The dearth of information about such interactions led researchers to propose the 2005 RAINEX missions, which ended up differing from previous hurricane-hunter flights in several ways, says Robert A. Houze Jr., an atmospheric scientist at the University of Washington in Seattle.