National Weather Service United States Department of Commerce

Heavy Rainfall Across South Texas and the Northeast; Thunderstorms in the Southern Appalachians and Rio Grande Valley

Widespread showers and thunderstorms producing heavy rain may bring flooding to South Texas and parts of the Northeast U.S. tonight into Friday morning. Scattered severe thunderstorms with damaging gusts and large hail are expected over parts of the southern Appalachians, and Rio Grande Valley of Texas into Friday morning. Read More >

Upper-air Observations Program

 

Map of North America showing current status of station

Upper-Air Operational Level Status as of 05/05/2025

 

The National Weather Service (NWS) Upper-air Observations Program is managed by the Office of Observations (OBS), which is part of NWS Headquarters located in Silver Spring, Maryland. Upper-air Program staff oversee the operation of 92 Radiosonde stations in North America and the Pacific Islands. While also supporting the operation of 10 stations in the Caribbean, a Cooperative Program known as the Cooperative Hurricane Upper Air Stations (CHUAS). Radiosondes provide upper-air data that are essential for weather forecasts, research, and historical climatology, and are launched twice daily at (00z and 12z), with additional SPECI releases supporting critical weather at 06z and 18z, or as needed.  OBS staff are also involved in the development, testing and implementation of new radiosonde ground systems, as well as any part of the balloon flight train that brings the radiosonde into the atmosphere.  This can include cotton twine, parachute, balloon and dereeler/unwinder.  In the event of any issues during flights, the Sterling Field Support Center Upper Air Help Desk was created to offer assistance 16 hours a day, seven days a week, to mitigate loss of data (https://www.weather.gov/soic/field_support).

 

Related Links


Fact Sheet - Information on radiosondes.

Network Maps - Maps showing station locations..

Special Studies  - NWS HQ radiosonde data studies.

Background - History of upper-air observations.

FAQ - Frequently Asked Questions.

NCEI - NOAA/National Centers for Environmental Information. Official source for archives of NWS upper air soundings.

NWSM 10-1402 Radiosonde Observations Handbook This manual provides procedures for upper air launch sites operationally using the AROS or MROS system.

Upper-air Sites Ground Equipment and Radiosonde Types

 

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