At the time of writing, the picture for Baltimore is very pretty:
The picture for New York is not as pretty but still intriguing. We are having a bout of summer and hence the white space (no precipitation):
Interpreting this innovative chart is a tough task - this is a given with any innovative chart. Explaining the chart requires all the text on this page.
The difficulty of interpreting the SparkRadar chart is twofold.
Firstly, the axes are unnatural. Time runs vertically, defying the horizontal convention. Also, "now" - the most recent time depicted - is at the very bottom, which tempts readers to read bottom to top, meaning we are reading time running backwards into the past. In most charts, time run left to right from past to present (at least in the left-right-centric part of the world that I live in.)
Location has been reduced to one dimension. The labels "Distance Inside" and "Distance from Storm" confuse me - perhaps those who follow weather more closely can justify the labels. Conventionally, location is shown in two dimensions.
The second difficulty is created by the inclusion of irrelevant data (aka noise). The square grid prescribes a fixed box inside which all data are depicted. In the New York graphic, something is going on in the top right corner - far away in both time and space - how does it help the reader?
Now, contrast this chart to the more standard one, a map showing rain "clouds" moving through space.
(From Bing search result)
The standard one wins because it matches our intuition better.
Location is shown in two dimensions.
Distance from the city is shown on the map as scaled distance.
Time is shown as motion.
Speed is shown as speed of the motion. (In SparkRadar, speed is shown by the slope of imaginary lines.)
Severity is shown by density and color.
Nonetheless, a panel of the new charts make great data art.