Sanders and Gyakum (1980) credit Tor Bergeron for first characterizing cyclones that deepen at a rate of at least 1 mb/hr for 24 hrs as rapidly deepening. Today, we use the term explosively deepening, which perhaps derives from Fred and John's use of "Bomb" in their article.
Some historical background is needed to put Sanders and Gyakum (1980) in perspective. Today we are all products of the Internet age in which live satellite and high resolution (0.5 degree or better) global analyses with variational satellite radiance assimilation stream to us 24/7. In 1980, operational Geostationary satellite imagery was barely a decade old and the highest resolution model run by the National Meteorological Center (today's National Centers for Environmental Prediction) was the Limited Fine-mesh Model (LFM), which had horizontal grid spacings of 127 or 190.5 km depending on generation (Silberberg and Bosart 1982).
The LFM was the primary model used for forecasting when I started in college and we had various nicknames for it, the most family friendly being "Lousy Freaking Model." Although cutting edge at the time, the LFM was indeed bad by today's standards. A 72-hour forecast today has more skill than a 36-hour forecast in 1980.
Sanders and Gyakum (1980) includes several important findings that helped guide extratropical cyclone research in the 1980s and 1990s:
- Explosively deepening cyclones are primarily (but not exclusively) maritime phenomenon.
- Explosive deepening occurs preferentially in regions of strong SST gradients, such as along the Gulf Stream and Kiroshiro Current.
- Quasigeostrophic dynamics cannot explain the rapid pressure falls.
- Current NWP models poorly forecast these events.
Subsequent field programs (GALE and ERICA) examined the dynamics and evolution of marine cyclones, while a third, STORM-FEST examined continental systems. Research spawned from these field programs illustrated the importance of air-sea interactions for preconditioning the atmosphere and subsequent condensational heating for explosive deepening.
In the 1980s some thought that explosively deepening cyclones were poorly forecast because the NWP models were missing a piece of key physics. Instead, they were missing sufficient resolution to capture key non-linear dynamical processes, although advances in modeling and data assimilation have certainly contributed some to improved extratropical cyclone forecasts over the past three decades.
Today, events like Snowmaggedon are forecast days in advance. Of course, we still have work to do in the Intermountain West...