Hurricane's Blog: Why We Have StormRanger10, a Radar on Wheels | NBC 10 Philadelphia

Hurricane's Blog: Why We Have StormRanger10, a Radar on Wheels

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    NEWSLETTERS

    NBC10

    Why Have a 'Radar on Wheels?'

    Radars just aren’t close enough together in the existing fixed radar network. The map below shows all the National Weather Service radars across the country:

    Photo credit: NOAA

    The dots are small, but basically our area is "covered" by radars in Ft. Dix, New Jersey; Dover, Delaware; and State College, Pennsylvania. As I explained in a blog when StormRanger10 debuted, they are simply not close enough for equally good coverage across our area.

    The biggest radar "gap" in our area is clearly in Chester and Berks Counties. Places outside the yellow area on the map below have the worst coverage of fixed radars. I would call areas in yellow "marginal" for tornadoes, precise rain/snow lines, and small showers. The areas in green are covered the "best."

    If we want to get the best look at storms, especially in the areas with the poorest coverage up to now, we need to move the radar to the storms. That is what StormRanger10 does.

    Amazing Results From Small Storms

     On Friday, Sept. 9, the radar showed very little on it anywhere in our area. The conventional, fixed radars showed NOTHING in Bucks County and Mercer County. We had sent StormRanger10 to Quakertown, which happens to be southeast of Allentown-in the yellow area on the local coverage map. If any storms were going to develop, we expected them to form (or move to) within 30 miles of our selected site.

    Around 5:30pm, StormRanger10 suddenly saw a small but intense shower develop right near Easton, Pennsylvania -- yet, the fixed radar system still showed just light showers at the very same time!

    This wasn’t even happening in the main "gap" area, yet the difference was striking (and frankly, surprising). As the showers tracked southeast through Bucks County, we saw our most striking result yet. At 6:15, StormRanger10 showed an intense shower in Trenton, New Jersey, while the fixed radar didn’t show a drop of rain in all of Bucks or Mercer counties. So how could the fixed radars miss that heavy shower?

    Photo credit: NBC10

    The answer had to be that, by the time the Ft. Dix or State College radar beams got to the shower, the beam was too wide. The radar beam is very narrow at first, but the farther it gets from the radar, the wider it gets, and therefore can’t detect as much detail. In this case, they missed some very heavy rain.

    Meanwhile, StormRanger10 kept tracking the shower, which was still dumping heavy rain on a small area. And this all happened during our newscasts, so I was able to show the difference on TV-live.

    Test Results Even Better Than Expected

    As I stated earlier, it was surprising to capture a heavy shower without the fixed radars showing anything-in an area not even in the main radar "gap." We clearly expect future radar beams from the fixed radars to show:

    1. What looks like precipitation, but it’s really just moisture in mid-level clouds and is not reaching the ground (beam gets too high)
    2. The higher parts of rain and snow clouds-missing intensity near the ground
    3. Small and weak radar returns in some places where it is actually raining heavily (beam gets too wide)

    We’re excited to see what we find with future thunderstorms, floods, and winter storms. Remember, this is all new. StormRanger10 is the first of its’ kind for TV. And you’ll be able to see the discoveries right along with us by watching NBC10 and/or our APP. Extreme Weather: Polar Vortex Is BackExtreme Weather: Polar Vortex Is Back