As aircraft operations in PACJET-2001 wind down today and tomorrow, and the operations
center is closed, it is clear that we have accomplished much of what we set out to do, and that we
will be better prepared for a possible PACJET-2002 next year. It is also important to note that
several key components of PACJET (
enhanced GOES winds,
PACJET-RUC model runs,
etc...) will remain active through March 2001 (see summary below). It has been both,
successful, challenging, and ultimately effective, to have invested much energy in making the
data and experiment available via the web where these remaining experimental components can
be found and where updates on future meetings, etc..., will be posted.
In a broad sense we have accomplished one of our greatest goals, that of bringing research
and operations together to address west coast storm prediction. The linkages and the synergy
were evident in many ways, from the fact that operational forecasters participated fully in the
experiment, to the fact that science objectives relating to the physics of air-sea interaction, coastal
orographic rain, and blocking were addressed.
One of the major outcomes already in hand is the demonstration of the potential for new
observations, models, and physical understanding to make a difference in real-time operational
weather prediction on the west coast. This includes examples from our
third flight where the P-3
reports of strong convection offshore of San Francisco led directly to the issuance of a Severe
Thunderstorm Watch for the Bay Area, to the improvement in numerical model initial conditions
yesterday's storm in the NE Pacific where dropsondes from the G-IV led to a 10 mb
improvement in the analysis of the strength of a major cyclone. In addition to these successes,
were examples where the data had marginal impact, examples that we can learn from for the
future. Clearly the experiment demonstrated the value of addressing the direct forecaster use of
data, i.e., a "forecaster-in-the-loop" strategy that feeds new data to people who issue forecasts,
and it also demonstrated potential to improve model guidance that is critical to forecasting.
From a purely scientific perspective it is apparent that many of our science goals will be met,
and that the analysis of the data gathered and of model performance will pay dividends in the
years to come. Some of the many preliminary impressions of success in this area include
evidence that the "warm rain" found in CALJET data occurred much less frequently in this non-El Niño year, and that the P-3 microphysics data confirmed that ice was not present in the one
case where we saw the same warm rain signature this year. Initial impressions of the air
chemistry data suggest that air pollution is drawn out from the Central Valley of California to the
coast and that this can act as a source for cool air trapped against the coast in cases of blocking.
Observations were made of air-sea interaction farther into the warm sector than were done in
CALJET, and, as expected, they include the potentially critical zone where the moisture fluxes
may be enhanced by large differences in sea surface temperatures and dew-point temperatures.
Several objectives relating to satellite validation/calibration now also have the critical and rare
oceanic and coastal data needed to begin analysis.
Finally, it is our team of talented people who make the technology work and who have made
the experiment a success. To all involved, please accept my heartfelt congratulations and
appreciation for you hard work, perseverance, and creativity (and for whatever you may have
done to help bring the storms we needed this winter)!
Sincerely, Marty Ralph, PACJET Chief Scientist, NOAA/Environmental Technology Lab.
Note: By mid April fully operating NOAA/ETL 915 MHz radar/RASS/met sites will be located