Nowcasting and the Working Group on Nowcasting Research

Paul Joe, Tom Keenan, Jim Wilson, Jenny Sun, Steve Goodman, Augusto Pereira, Alan Seed, Peter Li, Thomas Haiden,
Marianne Koenig and Jian Jie Wang

Nowcasting are tactical predictions that, in current operational practice, are "calls to action" and designed to save lives.
Nowcasts are about knowing what the current situation is and what it will be in the near future. So, it is highly dependent
on an timely analysis of high temporal and high spatial observations, either manually or automatically. Extrapolation techniques
have been traditionally been employed to extend this diagnosis or analysis of the current observations into the near future.
Improvements to extrapolation are rich areas of research. In current operational practice, nowcasts are synonymous with
convective weather and severe weather warning and therefore for the specific weather elements of heavy rains, strong winds,
hail and lightning. Extending nowcasting beyond convective severe weather, the focus has been on precipitation as it is the
most significant impact variable in terms of economic and societal benefits. Recently, progress towards the nowcast of other
weather elements have be made. Implicit in nowcasts is that the predictions are highly accurate and precise (temporally and
spatially) requiring a higher spatial density of observations with much more frequent reporting times.

Only a handful of National Hydro-Meteorological Services provide warning services and they have often been associated
with radar technology. The mandate of the Working Group on Nowcasting Research is to promote, advance and transfer
nowcasting technology for the benefit of WMO members. This have been accomplished through focussed workshops,
symposia, training, Forecast Demonstration and Research Development (FDP) and Developing Country Demonstration
Projects (RDP). The FDP and RDP's have played significant role in advancing the science as they form an enticing target
with a very firm deadline for participants to adapt, develop and verify their systems in a friendly and collaborative fashion.
Many WMO members do not have the resources to invest, nor support, nor maintain highly technological systems. Aid and
support by countries with advanced technologies, coupled with the development of simpler nowcast systems are needed
for the safety and security of all WMO members. These may include satellite and lightning.