OVERVIEW
OF THE 1999 WINTER STORM RECONNAISSANCE PROGRAM
In January - February 1999, there will be winter reconnaissance dropsonde missions carried out over the
northeast Pacific, releasing dropsondes to improve initial conditions for short- and medium-range
numerical weather forecasts. The plan for the reconnaissance missions is based on the positive
experience accumulated during the FASTEX, NORPEX and CALJET field programs over the past two
years, regarding the use of adaptive observations.

The time and location of the dropsonde missions will be selected adaptively in order to minimize the error
in selected forecasts associated with possibly large societal impact and large forecast uncertainty. The
weather events for which forecasts are to be improved through enhanced initial conditions provided by the
dropsonde data will be selected by the Hydrometeorological Prediction Center of NCEP, after
consultations with NWS field offices and other NCEP service centers.  The sensitive areas where extra
data can reduce most the expected forecast error for the selected weather events at a given forecast lead
time will be determined by the Environmental Modeling Center of NCEP, collaborating with PSU and MIT
scientists.

The plans call for ten flights with USAF Reserve C-130 planes out of Anchorage, Alaska, and
approximately nine flights with the NOAA G-Vl aircraft, operated by NOAA AOC, out of Honolulu, Hawaii.
The first and last possible flight days for the C-130s are January 12, and February 11, while those for the
G-Vl are January 15 and February 14, respectively. The dropsonde data will be transmitted through
regular channels (GTS) in real time.