During winter weather forecasts, you often hear us say "it depends on the temperature" or "it depends on the track of the storm". For some, this might just sound like an excuse in case things do not pan out, but these minor changes can and do create significant differences in snowfall totals. As we saw last week, it took just a single degree to completely alter the snowfall totals.
Storm track is also a crucial component to snowfall, where even minor changes can make a huge difference. So, let's go through what are the different types of storm track which bring us our snow, why the specific path of the storm matters, and does a 20-mile shift really alter snowfall totals?
TYPES OF STORM TRACKS
Low-pressure systems don't follow one set course through the country, each one moves in a different path and at different speeds, no two low-pressure systems are alike. However, there are common patterns that do emerge in regard to snow events. In the United States, generally storms develop in 5 areas, all named after the origin of the low-pressure system.
Alberta Clipper - These storm systems originate in Alberta, Canada, and sweep quickly southeast through the northern US. Oftentimes, Alberta Clippers bring little in the way of snowfall to the region. This is because of its moisture source. Alberta clippers are unable to tap into the reservoir of Gulf of Mexico moisture to bring more snowfall, meaning it typically is a dry snow. Alberta Clippers often brings colder air in its wake, as it will this coming weekend.
Colorado Low - If you live in Omaha and want snow, this is the low-pressure system that will do it. Colorado Lows are named because they form off the Rocky Mountains in Colorado and move into the central US. They typically either move east into Kansas, a perfect recipe for heavy snow for Omaha. These low-pressure systems also move northeast into Nebraska, often responsible for the wicked blizzards seen in western Nebraska into the Dakotas. Colorado lows are also responsible for much of our severe weather in the spring.
Gulf Low - Oftentimes, Gulf Low's do not have a significant impact on Omaha. These systems develop off a temperature gradient along the Gulf coast, strengthening across the southeast. These lows often have plenty of moisture to work with and are responsible for snowfall events in the southeast. Rarely, these Gulf lows can cut further north into the Midwest. One famous example of a Gulf low impacting the Midwest was a significant blizzard on Halloween in 1991.
Nor'easter - Even if you do not live in the northeast US, chances are you have heard of a Nor'easter. These low-pressure systems strengthen off the east coast of the US and are responsible for bringing blizzards to places like New York City and Boston.
Panhandle Hook - These are the rarest types of storm tracks. These develop in the Panhandles of Texas and Oklahoma, and hook to the north through the midwest. These are also responsible for bringing Omaha significant snow. The Blizzard of 1975 was a hybrid example of this type of storm system, as it developed over the Oklahoma panhandle and swung through Iowa into Minnesota.
WHY DOES STORM TRACK MATTER
In the above examples, depending on what type of low-pressure system we see can determine our snowfall totals in a big way. An Alberta clipper will not give as much snowfall potential as a Colorado low will. But even then, very subtle changes in the track can make huge differences.
Let's take this hypothetical scenario with a Colorado low moving through northern Kansas into Iowa. In this scenario, Omaha will experience light snow. A band of heavy snow will set up from Columbus to Tekamah, and rain will fall to the south near Beatrice to Nebraska City.
If this storm track moves just 40 miles to the north, the same distance between Nebraska City and Omaha; or Lincoln to Fremont. Everything changes for the Omaha metro, what was once light snow now mostly falls as rain, Norfolk picks up on heavier snowfall, while Columbus misses the axis of heaviest snow.
Now let's take our original storm track just 40 miles to the south. Omaha now sits in the heaviest band of snowfall when it was just in the light band.
These changes happen with such minor differences in track, which can sometimes make snowfall forecasting so tricky. A slight deviation in storm track could mean completely different outcomes in regard to snowfall or even precipitation type. Sometimes, we do not know the exact track of the storm until the morning of, which is sometimes why snowfall forecasts vary from day to day. Snowfall forecasting is tricky, but it also helps you be prepared when a winter storm moves in.
