Monday, October 29, 2012

A Remarkable Forecast

It remains to be seen how good and useful forecasts of Sandy and her impacts will be as she comes ashore, but for anyone who is old enough to recall how difficult it was during the youthful days of numerical weather prediction to even predict the formation of an east coast cyclone, let alone the track in a complex situation like this one, the forecasts thus far have been quite remarkable.

Imagine if you will a situation where we have all of today's forecast tools, including satellites, but no numerical weather prediction systems produce a forecast.  My guess is that very few people would have anticipated several days in advance that Sandy would make a quick left turn and head to New Jersey, as she is presently doing.

Note in particular in the loop below the amplification of the upper-level ridge south of Greenland, which is playing a critical role in steering Sandy to the west.  Such an amplification, which is likely related to a predecessor cyclogenesis event over central Canada (see early in the loop) and strong heating within a precipitation region that extends over the eastern US and Canada, would be very difficult to anticipate without numerical model guidance.

As we discussed on Saturday, there was some uncertainty several days ago with regards to the specifics of Sandy's track, especially where she would make landfall, but with a lead time of a few days, the left hand bend was anticipated by most ensemble members.  

Time will tell if the details of the forecast during landfall will prove good and useful.  As a meteorologist, you want to see your profession do well, but admittedly, it would be better if Sandy proves less damaging than advertised.

1 comment:

  1. From my personal perspective (feel free to disagree): I have to reiterate that the ECMWF has given an amazingly consistent and accurate forecast, while the GFS has not (not that it's bad, but it's not the best), and this is consistent with many other weather events. Furthermore, this gap between the ECMWF and GFS seems to be growing. At a recent modeling conference in Boulder, it was clear that developers of European models (e.g., ECMWF, UKMO, COSMO) were very engaged in the research community and were pushing the bounds of promising new modeling ideas by incorporating high resolution modeling, new research experiments, and new observations into global NWP. I don't recall seeing much presented from NCEP model development at this conference. Reading through NCEP's strategic plan, I'm struck by the outrageous number of goals for a 5-year period (most of them not focused on improving models). When you try to do too much, you don't do anything well, and I think it would be best if NCEP took a step back and re-evaluated what is most important to their existence.