Pushing the limits of our understanding of the Universe requires ever higher resolution observations across ever wider wavelength ranges. The current success of ALMA, one of the most demanded facilities worldwide, is a strong testament to this. Since the start of early science observations, the richness and diversity of the discoveries made possible by a combination of sensitivity and high spatial resolution, orders of magnitude greater than ever before, has enthralled the astronomical community. ALMA has offered astronomers the ability to  quantify how early planet forming structures are built (e.g. HL Tau and other ringed disks) and to detect previously unknown reservoirs of gas in high redshift galaxies, leading to a revised understanding of how everything from planets to galaxies form and grow.

The scientific goals of most major new facilities are highly complementary to those now being realised by ALMA. They include increasing our understanding of our local  planetary system and those around other stars, revealing what drives the physics of nearby galaxies, extending the redshift limit at which we understand the evolution of galaxies and ultimately revealing how structure is created in the Universe. The combination of high spatial resolution with spectroscopy drives these, and many other, fields forward. With this workshop, we aim to bring together researchers working with the leading facilities available today (ALMA) in order to plan for the next generation (JWST, ELT). Key to the motivation for this workshop is that astronomers must harness the high spatial resolution spectroscopic capabilities of each and every one of these facilities in a multi-wavelength approach in order to reach their scientific goals. We have therefore focussed the meeting around the technique, rather than a specific science area, in order to capture the combined scientific power. This meeting will bring together leading researchers from different astrophysical areas and with expertise in all of these telescopes to plan the programmes we need to answer the most important outstanding astronomical questions debated today.

A workshop in 2019 is very timely for developing the synergies between these observatories, something that has not been done before in a joint workshop. ALMA is reaching operational maturity, providing the scientific backdrop for our future plans.   It is now expected that the call for open time proposals for JWST will be issued approximately one year before the 2021 launch, in the first few months of 2020. A meeting in summer 2019 is perfectly timed to re-invigorate the thinking in the JWST community for cycle 1 science.  Proposals for JWST Early Release Science have already been selected and so there will be well-developed detailed science plans to present that will further stimulate discussion. The ELT instrumentation programme is well underway with the three first instruments (MICADO+MAORY AO system, METIS, HARMONI) finalising their preliminary designs  and two new instruments moving from conceptual design to definition of the scientific requirements prior to starting their preliminary design (MOSAIC and HIRES).