The National Oceanic and Atmospheric Administration's (NOAA) Acquisition and Grants Office, Eastern Acquisition Division-Kansas City intends to negotiate and award a purchase order, on a sole source basis, under authority of RFO FAR 6.103-1, with Vaisala for replacement radiosondes (p/n RS41-SGP) to be delivered to the National Logistics Support Center in Grandview, MO. The sole source determination is based on NOAA's Sole Source Justification. The Vaisala Line Replaceable Units (LRUs) are integrated components since the inception of Automatic Radiosonde Observing Systems (AROS) into the National Weather Service (NWS). Vaisala is the only manufacturer of these Line Replaceable Units. This order will help the AROS system maintain accurate barometric pressure readings for radiosonde weather balloon launches. Radiosondes are instruments on weather balloons that collect critical atmospheric variables, including temperature, humidity, pressure, and winds at various altitudes, which are essential for weather forecasts and weather models. This pre-solicitation notice is not a request for competitive proposals and no solicitation package is available. However, firms that believe they can fully meet the government's requirements may submit substantiating documentation or a request for additional information in writing to the (Contract Specialist) within 15 days after publication of this pre-solicitation notice. Such requests and documentation will be evaluated solely for the purpose of determining whether or not to conduct this procurement on a competitive basis. A determination by the government not to conduct a competitive procurement, based upon responses to this notice, is solely within the discretion of the government. Oral communications are not acceptable in response to this pre-solicitation notice.