Golf balls, tennis balls, baseballs, even softballs. It may sound like the clearance bin at a local sports store, but it’s actually one of the many forecasting difficulties in the Central Plains; namely Kansas. We’re talking about hail. It can shatter windows, dent vehicles, and turn a hopeful wheat crop into an insurance adjuster’s nightmare. If there ever were a place where life and property were so controlled by the acts of Mother Nature, it is here in the Sunflower State. Next to Oklahoma, Kansas has the most risk for large, damaging hail events. With the freezing level often found so low in the High Plains, hail does not have time to melt before finally reaching the ground during strong thunderstorms. Even in a mesoscale situation, the freezing level over Western Kansas maybe extremely different than that of Eastern Kansas. How, then, does a forecaster know when to forecast hail and what size of hail will fall? Moreover, what will the implications be from that hail storm? When a forecaster sits down to prepare the day’s forecast, many thoughts and questions will be in mind. It’s not as simple as saying “chance of hail today” in the forecast! For one, that would be included in almost every forecast from March through about September! Secondly, it would be like crying wolf: eventually no one would listen or care about hail…until it was too late. A good place to start with a hail forecast is the SPC’s website. Read where the slight or moderate risk zones are for severe weather; read what the SPC probabilities are for large/damaging hail and where. This should clue the forecaster in on where to concentrate their focus for the day’s hail potential. Next, move on to looking at the Skew-T sounding for the area. It may take looking at more than one or two soundings to come up with a good idea of hail probability. The next step would be to look at other data related to severe weather: CAPE, Cap, winds, etc. You may have a sounding that supports large hail, but the atmosphere may not be able to support hail development! Let’s say we have conditions that are favorable for smaller sized hail stones to fall (pea to quarter sized). The models and soundings all agree on this, the SPC has mentioned it as well. Does the forecaster make this the “lead element” in their forecast? Or is it just a side thought? This opens up a whole different aspect of hail forecasting: when does hail size matter? Pea size hail may be a serious problem to someone from the East or West coasts. However, pea size hail is an afterthought for many in the plains states. Pea size hail often does little, if any, damage to property or to crops. In some cases, penny size hail is even considered to be of little concern to the general public in this area of Kansas. A recent online survey done by KSNW-TV shows that most people (of those who took the survey) don’t even become concerned with hail until it reaches 1” or larger. Even a small percentage said they don’t care until it gets to be the size of a golf ball! This has lead to some people complaining about why & when thunderstorm warnings are issued based on hail. There are many reasons given for this, including one mentioned previously: crying wolf. It has been said, and the public has echoed, that there are far too many warnings issued in the state during the spring because too many storms meet the ¾” hail rule. In turn, it’s caused some to ignore warnings and even complain about the amount of TV coverage a warning generates. Because of all the complaints, a new rule adopted by local TV forecasters in Wichita (not by the NWS) is: Thunderstorm warnings are only to be broadcast when the hail is larger than 1”. It is believed hail of this size can do more damage to a home or to a crop, versus ¾” hail. On a given day or night where generally small size hail is expected, the forecasters mention it just briefly: “…good chance of showers and a few thunderstorm, and you may see a little small hail out this. Otherwise, cool with highs in the 60s…”. On the flip side, it is not totally uncommon to experience hail the size of tennis balls or even baseball often during the convection season! These storms do get more attention and are played up a little more than the smaller scale hail storms. Given the fact of such a large range of sizes, forecasters need to stay aware of changes in the atmosphere during the course of the day. This can make forecasting a big challenge. Dynamics may change from what the AM Meteorologist forecasted for this afternoon into the evening, to what the afternoon Meteorologist may be dealing with come 4, 5, 6 PM. At the same time, all forecasters have to be aware of when they are ALERTING the public and when they are SCARING the public. If the morning Met. were to go on-air and say “ I promise Grapefruit size hail this evening!”, and then the afternoon Met. forecasts only pea to marble size hail, that morning forecaster may become known as one who scares the viewers. There must be consistency and policy in place when it comes to interpreting model data and then forecasting hail events. However, there is one other large factor that must be considered when it comes to hail forecasting: wind. While ¾” hail may be small and considered insignificant by many locals in this area, ¾” hail being pushed by 60 or 70 mile per hour winds is a different story. Granted, it may not put large dents into a car or do much damage to the side of a barn, but hail that size and at that speed could easily break windows and injure people who may become caught outside in the storm. Likewise, golf ball to baseball size hail traveling at speeds of 70+ mph could do great harm to life and property. Therefore, it becomes even more important for the forecaster to know what kind of storm features he/she is dealing with. This all ultimately leads into a situation of what to do when hail is expected in Kansas. Currently, this is an on-going issue. While the “general public” may not care all that much about ¾” hail, a wheat farmer will probably be glued to a TV/radio/internet to find out when & where the ¾” hail will strike (and the wind speeds too). Their income, future, and even family hang in the balance of hail damage done to a crop. In relation, the domino effect kicks in and a bad year for wheat crops (or any crop for that matter) could mean higher prices for the “general public” in the months that follow a bad hail storm. TV forecasters, then, really toe the line -- not just in Wichita, but in many Plains States – because hail storms have become such a delicate situation. When do you break into TV programming? When does ¾” or even 1” hail become “important”? When does it not matter? How much coverage and urgency do you give to the particular storm? Cutting into a popular TV show could damage your reputation with the viewers who missed their show…not cutting into a show could also damage a forecaster’s image because they failed to alert the public to a damaging hail storm. Some of these issues have been cleared up thanks to “scrolling text” across the TV screen. But more problems arise with this method too. In the end, hail forecasting has and will seemingly continue to be a difficult challenge for TV forecasters in any of the Plains States. There simply is not a “cut & dry” method to forecast and alert the public on such a constantly evolving dynamic of Mother Nature’s wrath; especially when hail damage is taken as a matter of opinion. *It should be noted that all three major TV stations in Wichita (KSNW, KWCH, & KAKE) are responsible for forecasting the greater 2/3rds of Kansas: from sections of SW Nebraska, all the way down to the Oklahoma line; then East as far as the KS Turnpike and North to the Nebraska border. As you can see, this makes the concern of when to alert and where, such a big issue here. For more coverage details, visit: www.ksn.com/weather REFERENCES: Freeman, Dave (Chief Meteorologist KSN-TV): Personal interview. March 2008. KSNW Online Hail Survey. Conducted: summer 2007. Dave Freeman, KSNW-TV KSNW Website: www.ksn.com. Accessed: March/April 2008. Storm Prediction Center Website. www.spc.noaa.gov |