Sudden whiteout conditions with road icing along narrow corridors, motorists and air traffic are suddenly at risk. And if lake-effect snow is involved, rapid and heavy snow accumulation can close roads and paralyze cities. It’s a snow squall!
Are you using all the weather products that can help you forecast and track snow squalls? Accurate and timely forecast and monitoring information can help mitigate the impacts from squalls and may even make the difference between life and death. On 18 December 2019, a winter-weather system moved through central Pennsylvania, causing a series of snow squalls and life-threatening icing on highways and other thoroughfares.
In this lesson, we'll focus on this case and introduce some satellite products that can provide useful information about snow squall events.
Answer the four questions below. Use the arrows to navigate between them.
What are some of the particular forecasting challenges posed by snow squalls? (Choose all that apply.)
The correct answers are a, b, c.
Compared to their better-known warm-season cousins, squall lines and bow echoes for example, the conditions that lend themselves to wintertime snow squall events are more subtle. Therefore, monitoring the snow squall environment requires a more specialized set of forecast and observational tools that are tuned for the conditions supporting their development.
What are snow squalls’ warm-season analogue?
The correct answer is b.
There are many similarities between snow squalls and linear-oriented warm-season convection that includes squall lines and bow echoes. The more generic term for these types of convective systems is Quasi-Linear Convective System (QLCS). When you consider ingredients that are common to both the winter and summertime QCLS, such as the wind’s orientation to the line of convection or front, the instability out ahead of the line or front, and the different shear components, winter squalls are the cold season’s analogue to severe convection in the warmer months.
With those issues in mind, how do you currently prepare to identify and monitor snow squalls?
With the idealized conceptual model of a snow squall in mind, an approach utilizing a mix of tools can help to assess the environment and potential for snow squall activity, including numerical model guidance, conventional observations, radar and satellite products. For example, model output can help forecasters anticipate the dynamic, thermodynamic and synoptic environment typically seen with snow squalls hours or even days in advance. Closer to the event, surface and sounding observations will help validate what the models may be hinting at. And newer satellite capabilities from both GOES-R and JPSS play an increasing role by providing observations that are either unique or complementary to the existing observational toolkit.
Given what you know about existing satellite products and their use for forecasting and observing winter weather, what benefits do you think will come from incorporating the following products into your forecast process with events like this one?
The correct answers are shown above.
In this lesson, we’ll investigate the observing capabilities of these satellite products in relation to some of the analysis and forecasting challenges posed by events like the 18 December 2019 snow squall in central Pennsylvania.
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