So how will the radar do this? I will try and not get to technical. Basically a radar works by sending out horizontal pulses of microwaves (yes the same ones you cook with). The pulses hit rain, snow, or debris and are bounced back to the radar. It then produces an image we have all seen on tv, the greens, reds, and yellows representing rain and all that other jazz. Even the tv radars work like this. These types of radars are called "Conventional Radar" (See fig.1).
If you look at fig.2. Its an example of DP data showing the tornado debris signature from the Branson tornado. You will notice that Branson is surrounded by reds and yellows forming a sort of hole around the city. Thats the debris the radar pulses are bouncing off of producing that signature.
|fig.2 Branson Tornado|
Now there are some limitations to all this great technology of course.
I'm thinking of writing another post next week going a little bit deeper into each of the new products DP has to offer. Stay tuned for that!
While it will be easier to detect snow, it can still be difficult to determine on the radar without knowledge of the surrounding environment. There is still some work to be done, but from what I have seen so far, this is going to be a great upgrade. Fig. 3 is another DP example from the NWS office in New York.
|Fig. 3 Radar image of a mixed precipitation weather event in New York. Dual-Pol helps forecasters distinguish between rain, snow, hail, and other objects.|
|This is where important changes to the radar signal is made so that it can send out beams in the horizontal and vertical. This is located on the back side of the radar dish.|
Here are some helpful links. Click on the WDTB link to learn the technical ins and outs of DP radar. They also have a "Storm of the Month" series going on.
WDTB Dual-Polarization Radar Training:
The WSR-88D dual-polarization upgrade deployment began in September 2011. The Deployment Schedule is available, but it will likely change over time.