• What is WeatherTAP?
• Why should I buy a subscription to WeatherTAP when there is so much free weather data?
• Do I have to download any software?
• Can I try the service before I purchase it?
• Do you have archived information?
• Is there a way to avoid having to enter the username and password every time I visit the site?
• Can I repost WeatherTAP images on my web site?
• Where can I get technical or customer support?
• How do I change my password?
• How do I update my credit card?

What does a radar image tell me?
• How often are the radar images updated?
• What is "ground clutter"?
• Why do the mosaics look different than the local radar sites?
• How can I tell if the radar is in clear air mode or precip mode?
• What are the funny streaks on the radar mosaics that appear to move across the country in the mornings and evenings?
• Where can I learn more about radar?
• What is RadarLab? How do I access it?
• What is the Winter mosaic? How does it work?

• How often are conditions and forecasts updated?
• When I request a forecast by zip code why is a different city's current conditions shown?

 

WeatherTAP is a data service that provides web-based access to thousands of weather graphics and text-based weather products. WeatherTAP contains no advertising nor does it receive any government funding. Instead, the site is supported entirely by subscribers who pay a small subscription fee for access to a huge repository of constantly updated, real-time weather data.

There is no such thing as "free" weather data. There are other sites on the internet that are either supported by advertising or receive government funding. Many users find that the "free" sites meet their needs and are willing to live with annoying ads and limited availability during peak times. Other users, however, find that the quality of product, absence of ads, and certainty of availability, even during peak times, to be worth the modest subscription price. WeatherTAP presents big, bold, screen-filling graphics unencumbered by advertising, at lightning speeds. Since only subscribers can access the service, the number of users is constrained, limiting the maximum load placed on the servers and thus protecting the service from being overloaded, even during peak times such as hurricane landfalls. This means that in times of crisis, while others struggle to get data from ad-supported and government sites, WeatherTAP users enjoy fast response and peace of mind. In addition, the breadth and depth of data available on WeatherTAP far exceeds that of most other sites.

Although we make a free weather client available to subscribers ( WeatherTAP Studio ), this piece of software is NOT required to access WeatherTAP. All that is required is a web browser and internet access.

Absolutely. Just send your request for an evaluation to webmaster@tappublishing.com, or call 1-800-337-5263.

No. WeatherTAP primarily specializes in real-time data. We do not offer archived data to the public at this time.

Yes. You may activate the Automatic Login feature to enable you to bypass the login. This option is located in the "Service" drop-down menu.

It depends. You may NOT repost realtime imagery from WeatherTAP. However, you may post individual images to your site for educational or journalistic purpose subject to the following rules:

•Radar and satellite images may be re-posted or published, but absolutely no lightning images may be posted or published.

•All re-posted or published images must be at least 1 hour old.

•The WeatherTAP copyright message must be retained in the upper left-hand corner and the language "used with permission" and some language crediting WeatherTAP as the source of the image must be present.

•In the case of web re-posting, there needs to be a link to http://www.weathertap.com somewhere close to the image.

•You may manually re-post or publish images subject to the above restrictions for use as a visual aid to accompany an article or news event for which you are reporting. Automated and/or continuous manual re-posting of images is not acceptable.

First, visit the support page. You may also send support requests to webmaster@weathertap.com or call 1-800-337-5263 M-F, 7AM-4PM Central.

You can change your password by selecting My Account from the Services drop-down menu, then selecting the "Change Password" option.

You can change your credit card number by selecting My Account from the Services drop-down menu, then selecting the "Change Credit Card" option.

 

Radar works by transmitting radio energy into the atmosphere then "listening" for any energy which may be returned. Energy may be returned back the radar transmitter when it bounces off of water droplets present in the air. There are several types of radar images, but the most common one simply portrays the magnitude (or "reflectivity") of the energy reflected back to the transmitter. Higher levels of reflected energy is indicative of denser concentrations of water droplets which in turn is indicative of precipitation and severe weather. Therefore, it follows that radar images indicate, indirectly, areas of precipitation and severe weather.

Individual radar sites produce updated data sets every 4 to 10 minutes, depending on the exact scanning mode that the radar is set for. In general, if there is no significant precipitation within the radar's coverage area ("clear-air mode"), images are updated at 10 minute intervals. If there is precipitation within the area ("precip mode"), then images are updated every 4 to 6 minutes.

Radar mosaics, in general, are updated at 5 minute intervals.

Technically speaking, "ground clutter" is radar energy that is reflected from ground-based obstacles such as buildings, mountains, antenna toweres, etc. In actual practice many people apply the term "ground clutter" to any radar echo that originates from any source other than precipitation. This could includes aircraft, fog, insects, migrating birds, etc. Clutter echos are usually characterized by small points of reflected energy often distributed in seemingly random patterns. Ground clutter does NOT represent precipitation or convective activity.

Radar mosaics are images that are created by combining data from more than one radar site. This process is quite complicated as many radar sites overlap and several different reflectivity values may be available from different sites for a single geographic region. The mosaicing algorithm must intelligently decide which radar to "believe" when coverage areas overlap. In addition, de-cluttering algorithms and filtering techniques are applied to the mosaic data. The result is an image that is representative of the radar observations, but not necessarily identical to data from any single site.

The gray information bar that appears on the right-hand side of every local radar image will indicate whether the radar is currently in Clear Air or Precipitation mode. This indicator appears immediately to the right of the "MODE" label.

As the sun rises in the morning and sits in the evenings, it reaches a level on the horizon that coincides with the radar dish angle. The result is that twice per day each radar transmitter's dish receives direct sunlight. Solar energy contains many EMF wavelengths and will tend to register as reflected radar energy. The result is a "spike" which appears on the radar image, originating at the radar site and extending radially outward. The spike extends eastward from the site in the morning and westward from the site in the evening. The effect is only observed for a short time every morning and afternoon.

As the sun rises, the eastern-most radar sites will experience sun spikes first. The spikes will then move westard across the country as the sun rises. When viewed on national and regional mosaics, these spikes give the appearance of objects moving at high speed across the country from east to west. Some conspiracy-theory web sites have even used this phenomenon as "proof" of nefarious government activity. In fact, this is simply a naturally occuring phenomenon and is easily explainable.

A good place to start is the WeatherTAP Radar Tutorial. It contains links to other radar education resources as well.

RadarLab is a sophisticated web-based application that allows WeatherTAP users to better control the radar display. It includes options to allow users to add their own points on the radar image, filter radar data, turn on or off various overlays, and many other features not possible by simply viewing a static image. RadarLab can be accessed by clicking on the "RadarLab" button that appears at the bottom of every local radar page. Alternatively, you may choose the "RadarLab" option from the Radar drop-down menu, then choose a radar site that you'd like to view.

In the Winter months WeatherTAP makes available a "Winter" mosaic. The Winter mosaic is color-coded to distinguish rain, snow, and mixed precipitation. Unfortunately radar does not tell us what form the precipitation is in when it reaches the ground. Instead, the precipitation form is predicted based on computational models of the atmosphere initialized with actual measurements and observations. The Winter Mosaic product works by depicting the radar reflectivity using three different color scales depending on the form of precip (rain, snow, or mixed) as determined from the numerical model. This portrayal allows the user to quickly see the coverage, intensity, and likely form of precipitation reaching the surface.

 

The conditions are generally reported at the top of every hour. WeatherTAP makes them available on the site as soon as they come in, usually less than five minutes after the hour. If radical changes occur in the current conditions for a station before the next scheduled report, then new conditions will sometimes be reported. WeatherTAP always displays the latest reported conditions transmitted to us by the NWS. Forecasts are usually issued 2-4 times per day depending on the conditions. If a weather event occurs that leads to a radical change in a forecast, then a new one will be issued. As always, WeatherTAP always displays the latest issued forecast.

Zip codes are used by the US Post Office for mail delivery. They have nothing to do with weather, and forecasters do not issue forecasts for zip codes. Zip codes do, however, provide a way to approximate a geographic area. As such, WeatherTAP allows the user to enter a zip code as a means of retrieving forecasts and possibly observations as well. When the user enters a zip code, the WeatherTAP servers must examine a database of zipcodes and attempt to relate the area covered by the zip code to a forecast zone. In addtion, an attempt is made to locate the closest observation station. If a match is found, then the data is displayed to the user.

In the vast majority of cases, the forecast zone returned it very closely related to the zipcode entered. However, since zip code boundaries and forecast zone boundaries are not the same, it is possible that a forecast zone will be returned that is not the one intended. That may be due to the fact that a zipcode may span several forecast zones, or simply due to an error in our database that links zip codes to forecast zones.

Additionally, there are many forecast zones for which an observation station is not available. In such cases, WeatherTAP will attempt to locate the observation station closest to the forecast zone, but in fact the station may be located outside of the zone proper.