18-01261_SOW_Amendment_1.docx

STATEMENT OF NEED

National Severe Storms Laboratory

NRMAG000-18-01261

1. Background and Purpose The Verification of the Origins of Rotation in Tornadoes EXperiment-Southeast (VORTEX-SE) is an ongoing research program to understand how environmental factors characteristic of the southeastern United States affect the formation, intensity, structure, and path of tornadoes in this region. The National Severe Storms Laboratory (NSSL) is the executing partner and lead organization in developing the research program to meet the VORTEX-SE objectives.

2. Scope and Objectives:

As part of the Meso18-19 Field Campaign of the VORTEX-SE experiment, NSSL will require atmospheric soundings from southeastern Texas. Soundings from College Station will be required at a six-hour intervals during ten special observing periods, each lasting 48 hours, between October 1 2018 and April 30 2019. The purpose of this sounding site is to fill a gap in a special NWS upper air observing network. The sounding data will be utilized in real-time NWS forecasting, as well as a variety of numerical forecasting experiments, both real-time and retrospective, as well as observational studies.

3. Product Specifications:

· Conduct soundings from two sites simultaneously at 0000, 0600, 1200, and 1800 UTC during ten separate 48-h periods between 1 November 2018 and 30 April 2019.

· Soundings must be launched within 10 km of College Station, TX.

· 48-h periods (nine soundings inclusive) will be determined by a project Planning Group. The contractor will be notified via telephone or email at least 24 in advance of the beginning of a 48-h active period.

· InterMet Systems sondes and related sounding expendables (balloons, dereelers, and chutes) will be provided by the National Severe Storms Laboratory (NSSL) if vendor is using InterMet Systems sounding receivers. The contractor must provide their own helium. Any unused sounding expendables at the end of the project must be returned to NSSL.

· Vendors are welcome to use another brand (must be equivalent to InterMet sondes and receivers) for the soundings, but the government will not be providing any sondes not compatible with InterMet receivers. All other sounding expendables (balloons, dereelers, and chutes) will still be available.

· All site selection and preparation activities for sounding launches are the responsibility of the contractor.

· Provide the soundings via electronic transmission immediately after sounding termination, to a collection point established by the VORTEX-SE Meso18-19 Planning Group. The format will either be a format produced by the InterMet receiver, or produced from InterMet output using conversion software provided by NSSL.

· Provide the soundings to the VORTEX-SE data archive by 1 September 2019.

4. Requested Delivery/Period of Performance:

The period of performance is 1 November 2018 - 1 September 2019. Delivery of soundings will be immediately after collection to a realtime collection point, and by 1 September 2019 to the VORTEX-SE permanent data archive.

5. Point(s) of Contact for this Action:

Alan Gerard, VORTEX-SE Program Manager NOAA/OAR/National Severe Storms Lab 120 David L Boren Blvd Norman, OK Phone: 405-325-6513

Technical point of contact:

Erik Rasmussen, VORTEX-SE Project Manager NOAA/OAR/National Severe Storms Lab/CIMMS 120 David L Boren Blvd.

Norman, OK 73072 E-mail: erik.rasmussen@noaa.gov