The purpose of this manuscript is to provide an update to the ATM-Weather Integration concept and diagram, along with an introduction to the related levels of weather integration into ATM systems. The initial discussions that led to the creation of the ATM-Weather Integration model took place in late 2009. Over the next six to nine months, as the concept itself was fleshed out, a diagram, the so-called “Catsup and Mustard Chart” (due to its bright red and yellow boxes), was created to accompany the text. The concept and diagram have been socialized in a variety of ways. They were included in V2.0 of the FAA ATM-Weather Integration plan, published in September, 2010, and a presentation centered on the diagram and one of the components of ATM-Weather Integration, Weather Translation, was delivered to the Aviation, Range and Aerospace Meteorology Second Special Symposium in Seattle in January, 2011. It has been discussed in other scientific and industry forums, including several hosted by the Collaborative Decision Making (CDM) community. Based on the range of conferences and meetings at which these ideas have surfaced, there would seem to be widespread acceptance of the overall concept. Over the last 12-15 months, a great deal of discussion has taken place on the topic of ATM-Weather Integration, and the concept itself has further clarified. However, no related changes or modifications have been made to the original diagram. This presentation highlights changes to the diagram that are under consideration, including the identification of specific inputs and outputs of each of the four ATM-Weather Integration areas: Weather Information, Weather Translation, Impact Conversion, and ATM Decision Support. Additional modifications may be made to the diagram to illustrate the need for real-time verification, as well as potential sources of required data. A discussion of the different levels of ATM-Weather Integration is covered including how to determine which ones are appropriate for individual programs. The presentation concludes with a review of areas of the concept needing further development, such as determining where translation will take place, whether there is a need for a translation Single Authoritative Source (SAS) and the difference between translated threshold events and NAS constraints.