IOP 2, 29-30 Nov 2001

IOP 2: 29-30 November 2001

Time Period of IOP

1200 UTC 29 Nov-0000 UTC 30 Nov 

Overview of IOP

 The major storm of 28-29 November was followed the next day by a much less intense short wave trough, which passed over the radar area between 0900 UTC 29 November and 2100 UTC 30 November 2001. At 500 mb, this weak short wave moved rapidly from the west northwest from a longitude of 150oW at 1200 UTC 29 November (Fig. 1a) to 135oW by 0000 UTC 30 November (Fig. 1b). It was over the Oregon-Washington area at 1200 UTC 30 November (Fig. 1c). The trough was evident at 850 mb at 135oW at 0000 UTC 30 November (Fig. 2a), and by 1200 UTC it was affecting Oregon with southwesterly winds and weak warm advection (Fig. 2b). The region of clouds associated with the trough was just off the Oregon coast at 2100 UTC 29 November (Fig. 3a). The S-Pol radar at 2200 UTC showed scattered small convective cells (Fig. 4a). The region of clouds was over western Oregon at 0300 UTC 30 November (Fig. 3b). The coldest cloud tops formed a patchy pattern. At 0900 UTC 30 November, the last of these patches of cold cloud top was approaching the radar area from the west (Fig. 3c).  It was quite convective in character and just preceded the leading edge of the warm-frontal clouds of the next short wave. From 0600-0900 UTC the S-band profiler showed the echo lowering to the surface as the trough approached (Fig. 5a), and then from 0900-1200 it showed rather shallow and discontinuous convective cells (Fig. 5b). By 1500 GMT the echo on the S-band profiler had become deeper and more continuous (Fig. 5c). This echo area was located over the S-Pol area at 1500 UTC (Fig. 4b), and it continued to be located over the S-band until about 1630 UTC (Fig. 5d).

Convair-580 Summary

   No flight

P-3 Summary

No flight


S-Pol Radar Summary

The S-Pol radar was run continuously in the same mode of operation for the entire length of the field project.


Summary of Mobile Upstream Sonde Launches


Launch times at: Orleans, OR, Lat: 44.5500, Lon: -123.1500, Elev: 69 m

1625 UTC 29 Nov

1914 UTC 29 Nov


Summary of Leeside Sonde Launches


Launch times at: Black Butte Ranch, OR (a.k.a. ISS-3), Lat: 44.379, Lon: -121.679, Elev: 1027 m

1515 UTC 29 Nov

1700 UTC 29 Nov

1850 UTC 29 Nov

2055 UTC 29 Nov

2300 UTC 29 Nov


Summary of NWS Sonde Launches from Salem (SLE)


Launch times:

1200 UTC 29 Nov (standard)

1500 UTC 29 Nov (special)

1800 UTC 29 Nov (special)

2100 UTC 29 Nov (special)

0000 UTC 30 Nov (standard)


Summary of Snow Crystal Ground Measurements


Measurement times:Every 15 minutes from

1500 UTC 29 Nov-2215 UTC 29 Nov (at Santiam Pass, Corbett, and Tombstone Sno Park)