K5MAR
Member
n5bew1 said:
Well, then if you aren't watching the OKC broadcast stations then, to quote that famous little old lady: "Where's The Beef!" :lol: :lol:
Mark S.
KFOR new radar
- Thread starter dbestfirefighter
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Well, then if you aren't watching the OKC broadcast stations then, to quote that famous little old lady: "Where's The Beef!" :lol: :lol:
Mark S.
I guess it never fails. You just can't go and talk some facts and figures about TV radar and NWS radar with someone that just happens to be affiliated with the news getting their panties all up in a bunch and taking what was being said out of context. It's just an extension of the weather wars. Look... this thread was about a new TV radar, and I decided to share some of my knowledge and experience (some 15 years worth) to help clear up some of the misconceptions that were being posted. Sorry to disappoint, but that was my only motive. Spouting invective on behalf of TV stations does not speak well for them nor does it increase their stature with me or anyone else...
Over the years, I've been inside both TV stations AND NWS stations during times of severe weather. dbest was right... the NWS's that I've been in have the ability to monitor the local news. I don't see what that has to do with this thread, though. This thread has nothing to do with NWS forecasters or how they build their forecasts. What I said has NOTHING to do with how NWS forecasters make their forecasts.
In the end, I'm not a gambling man, but I'll stand 100% behind what I said. Any REAL meteorologist on TV is using NWS radar data to make their forecasts. In fact, I would hope that any TV meteorologist who says something like "I want people to want to trust us with their lives when it comes to severe weather" would be smart enough to use NWS radar data to build their forecasts. Are you saying that the best TV mets don't? If they don't in OKC, then I am certainly justified that I don't watch them.
dbestfirefighter
Dozer
You must work for the FAA
2112 knows what he's talking about. I have been inside every single tv station in this market and used to be on air. When he said:
"The reason that the TV radar can complete a sweep in 30 seconds and the NWS radar can complete a sweep in 6 minutes (or 5 minutes if they really want to beat the crap out of the radar) is that the TV radar is not doing a volume scan... it scans at only one level."
I would like to add one thing to that. The NWS has a new scanning mode called "VCP 12" that completes a volume scan in 4 minutes. It does more low level elevations to detect circulations quicker. I'm told it will become the new standard, replacing VCP 21, the 5 minute scan pattern.
I'm curious, is this "lack of sampling time" you spoke of the reason the cells look elongated when the antenna turns fast? It almost sounds like it contradicted the "speed of light" comments but I figure the short sampling time means the computer processor just can't handle the amount of data coming in, or am I off base?
Don't fool yourselves folks.. the tv stations in Oklahoma City do care about saving lives. However they do a lot of things for the sake of ratings. You often see a "heavy thunderstorm" map up on the corner of the screen when the meteorologists know it'll never go severe. Nowdays, you will see the map up for cells of 30-35 dbz (moderate rain) with VILs of 15 (hail begins around 40-50 VIL usually, depending on the atmospheric situation). It wasn't this bad 10 years ago. They do it to get people to watch, which means more money in their pockets because higher viewership means they can sell the commercials for higher dollar amounts. It's all about who has the best helicopter and ground chaser tornado video today and how many people saw it. Otherwise, why bother with severe weather if you can't make money. One Oklahoma City meteorologist said it best, something to this effect: "Severe weather coverage should be so good, one could sit down and eat a bowl of popcorn and watch it like a movie."
"The reason that the TV radar can complete a sweep in 30 seconds and the NWS radar can complete a sweep in 6 minutes (or 5 minutes if they really want to beat the crap out of the radar) is that the TV radar is not doing a volume scan... it scans at only one level."
I would like to add one thing to that. The NWS has a new scanning mode called "VCP 12" that completes a volume scan in 4 minutes. It does more low level elevations to detect circulations quicker. I'm told it will become the new standard, replacing VCP 21, the 5 minute scan pattern.
I'm curious, is this "lack of sampling time" you spoke of the reason the cells look elongated when the antenna turns fast? It almost sounds like it contradicted the "speed of light" comments but I figure the short sampling time means the computer processor just can't handle the amount of data coming in, or am I off base?
Don't fool yourselves folks.. the tv stations in Oklahoma City do care about saving lives. However they do a lot of things for the sake of ratings. You often see a "heavy thunderstorm" map up on the corner of the screen when the meteorologists know it'll never go severe. Nowdays, you will see the map up for cells of 30-35 dbz (moderate rain) with VILs of 15 (hail begins around 40-50 VIL usually, depending on the atmospheric situation). It wasn't this bad 10 years ago. They do it to get people to watch, which means more money in their pockets because higher viewership means they can sell the commercials for higher dollar amounts. It's all about who has the best helicopter and ground chaser tornado video today and how many people saw it. Otherwise, why bother with severe weather if you can't make money. One Oklahoma City meteorologist said it best, something to this effect: "Severe weather coverage should be so good, one could sit down and eat a bowl of popcorn and watch it like a movie."
oklameatman
Member
Focus?
What happened to talking about radios and scanners?
What happened to talking about radios and scanners?
K5MAR
Member
Re: Focus?
Define "radio". After all, RADAR does stand for RAdio Detection And Ranging! :lol:
Mark S.
oklameatman said:
Define "radio". After all, RADAR does stand for RAdio Detection And Ranging! :lol:
Mark S.
WhatsnOKC said:
This is an effect of physics that is seen in all radars. First of all, keep in mind that the radar sends very short bursts of RF out as it completes a scan. The distance between each pulse sent is very small close to the radar however the distance between pulses/beams increases at a greater distance.
Think of slicing a pie. Start at the center of the pie and then go to the outside edge to make the first cut. Now go back to the center to start the second cut in order to make a slice. You have no choice but to angle the second cut so that the pie slice is triangular. For the next slice of pie, once again, you'll have to angle the cut in order to make a slice of the pie.
So how in does this apply to weather radar? Well, if you draw a circle on a piece of paper to represent the radar scope and then plot each pulse repetition you would see this pie slice effect. You will see that the distance between the beams becomes much greater from each other near the edge of the radar scope. Therefore the range bins are much larger. To compensate for this the radar will fill the entire range bin with the dBZ level that is measured in that beam. This will cause the storm to look elongated since it simply can’t resolve what is happening between the beams at that distance. It is a matter of physics and not whether the radar transmits four times the power of others like KFOR claims to their viewers. All radars are subject to the laws of physics and KFOR’s is not an exception.
To elaborate further on this… next time you see a squall line in western Oklahoma on a radar near Oklahoma City (whether is be KFOR’s new radar or another) notice how when the storms approach the radar site that they appear to break up. In many cases they are not, rather the radar is simply able to resolve the storms better because of smaller range bins and it will become apparent that the squall line is actually made up of smaller individual cells.
I agree with 2112. The National Weather Service’s WSR-88D is much more advanced in that it has several products and algorithms which other radar’s owned by television stations don’t. There are so many products available to NWS meteorologists that the majority of the public would not see by watching KFOR or another television station. These products, and interpolation of the available algorithmic data as well as the ability to see the vertical structure of a storm by taking advantage of the numerous tilts available on the WSR-88D, are vital in the warning decision making process.
In my opinion, the only advantage I see with KFOR’s new radar is it’s location. It is further west than other radars (including the WSR-88D Twin Lakes site). This provides for smaller range bins resulting in better resolution in those areas just a slight bit southwest of where we are used to seeing the best resolution.
Also, to address the comment about the television monitors in the National Weather Service in Norman… they are used during severe weather to view live images such as those from the news helicopters for further verification of what is being seen on radar. Many offices will use the television monitors to simulcast the display of a chosen AWIPS work station for better visibility around the office or to display a rotating sequence of products/images such as satellite imagery and SPC outlooks. They are not used to listen to “what the tv stations are saying about specific storms.”
Sorry for sliding slightly off the topic toward the end.
Randy – K4TVS
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