Noaa Full Loop (2024)

FAQs

What are the 7 frequencies for NOAA? ›

All NOAA Weather Radio stations broadcast on one of seven frequencies in the VHF Public Service band: 162.400 megahertz (MHz), 162.425 MHz, 162.450 MHz, 162.475 MHz, 162.500 MHz, 162.525 MHz, and 162.550 MHz.

Values of 50 dBZ or more normally are associated with heavy thunderstorms, perhaps with hail, but as with most other quantities, there are no reliable threshold values to confirm the presence of hail or severe weather in a given situation.

In clear air mode, images you see are updated every 10 minutes. In precipitation mode, images you see are updated every five or six minutes. The collection of radar data, repeated at regular time intervals, is referred to as a volume scan.

NEXRAD (Next Generation Radar) obtains weather information (precipitation and wind) based upon returned energy. The radar emits a burst of energy (green in the animated image).

NOAA Weather Radio (NWR), also known as NOAA Weather Radio All Hazards, is an automated 24-hour network of VHF FM weather radio stations in the United States that broadcast weather information directly from a nearby National Weather Service office.

Radio frequency communications for spacecraft are conducted between 30 MHz and 60 GHz. The lower frequency bands (up to S-band) are typically more mature for SmallSat use, however extensive use of these bands has led to crowding and challenges acquiring licensing.

VIP 1 (Level 1, 18-30 dBZ) - Light precipitation. VIP 2 (Level 2, 30-38 dBZ) - Light to moderate rain. VIP 3 (Level 3, 38-44 dBZ) - Moderate to heavy rain. VIP 4 (Level 4, 44-50 dBZ) - Heavy rain.

Generally speaking, reflectivity values lower than about 35 dBZ are light rain; values between 35 and 50 dBZ are moderate rain; and values above about 50 dBZ are heavy rain. Reflectivity values above about 55 dBZ are usually hail.

A wind direction of 'VR' indicates a variable wind direction during the hour. VR5 or VR10 indicate variable direction wind at 5 or 10 km/h. This is only for the hourly forecast. To learn more, visit: Public weather forecast bulletins: Hourly Forecasts. More about wind direction.

As a raindrop falls through the atmosphere, it can attract tens to hundreds of tiny aerosol particles to its surface before hitting the ground. The process by which droplets and aerosols attract is coagulation, a natural phenomenon that can act to clear the air of pollutants like soot, sulfates, and organic particles.

Is the air clearer after rain? ›

Bottom Line: Does Rain Reduce Air Pollution? Rain has a small impact of 0-30% on reducing particulate air pollution. Even the heaviest rains reduce PM2. 5 air pollution by less than 10%, whereas the winds that sometimes accompany rainstorms have much larger effects.

Clear air mode is used when no significant precipitation echoes are in the area, to examine very light precipitation or other particulates, and to detect subtle boundaries or fronts. Lower elevation angles are used since this is primarily where clear air targets such as dust, birds, and insects will be located.

On a weather radar map, a tornado is usually indicated by a smaller area of red surrounded by a larger area of green. However, modern radar systems can also indicate debris balls, a sign of a tornado on the ground.

Decibel relative to Z, or dBZ, is a logarithmic dimensionless technical unit used in radar, mostly in weather radar, to compare the equivalent reflectivity factor (Z) of a remote object (in mm⁶ per m³) to the return of a droplet of rain with a diameter of 1 mm (1 mm⁶ per m³).

If the radar were in precipitation mode, the amount of coverage would be limited to the baby blue areas. A negative dBZ means that the radar is detecting very small hydrometeors. As mentioned above, this is a great way for forecasters to detect very dry light snow or drizzle which have lower reflectivity values.

NOAA 18 and NOAA 19 weather satellites provide free accessible weather data continuously through Automatic Picture Transmission at 137.9125 MHz and 137.1000 MHz frequencies.

NOAA Weather Radio broadcasts the latest weather information on seven frequencies in the 162.40 to 162.55 MHz range and can be received up to 40 miles from the transmitter.

NOAA Weather Radio currently broadcasts from over 800 FM transmitters on seven frequencies in the VHF band, ranging from 162.400 to 162.550 megahertz (MHz) in fifty states, Puerto Rico, the Virgin Islands, Guam, and Saipan. These frequencies are outside the normal AM or FM broadcast bands.

The alert tone is transmitted over the NWR in which its listening area is affected by the warning or watch. The tone is sent at a level of 1050 Hz and will set off an alarm on those weather radio receivers that have a "tone alert" feature.