Daily Summary for 30 November 2006

A strong frontal system stretching from the Great Lakes to the Gulf Coast moved into the region, bounded on the north and south ends by strong surface lows over Hudson Bay and northeast Texas. This system produced severe weather over the southern U.S. and a mixed-bag of heavy rain, sleet, snow, wind and bitter cold temperatures on it's northern end. The front passed over CARE around 6:00 LT, but did not pass over Ottawa until ~ 15:00 LT. Both places experienced several hours of rain. Frontal weather is not ideal for CLEX, but it is certainly good for C3VP.

The flight was targeting the front along the Peterborough CloudSat overpass. The Convair 580 flew a successful C3VP satellite overpass mission today in rain clouds. There were no additional hours added on for CLEX primarily because the cloud field was an obvious wide spread rain event associated with an approaching synoptic front.

There were some mixed-phase zones within the complex cloud field which was typically deep and raining but occassionally layered. The lidar could not function within the deep cloud and was not turned on. The Convair 580 experienced steady icing at various temperatures during the flight between -10 °C and -26 °C. The Convair was at about 23,000 ft at CloudSat overpass time. The icing conditions were typically associated with deep cloud and rain below. The icing may have caused some instrument problems as will be discussed further below.

Another complicating factor for a CLEX mission today was the lack of a spare seat on board the Convair-580 for a CLEX scientist. An extra NRC technician was flown to deal with some critical computer data issues, effectively bumping our spot. During the flight, the problem was further diagnosed and a potential solution was crafted. We don't expect that the extra technician will be needed again. More seats should be available tomorrow for 1 or 2 CLEX scientists.

Instrument Status/Issues:

1. The 2D-S probe has developed some new problems after being repaired for a separate problem. It is down for now.

2. There was a problem with the 2D-C early associated with excess water that did not clear. This was likely an isolated 2D-C outage. For this mission, the DMT CIP was working and provided coverage for the needed size range.

3. HVPS was experiencing periodic outages requiring power cycle.

4. One of two Nevzorov probes did not function properly, possibly due to icing. More diagnosis is required.

Despite a few outages, all size ranges for cloud and precipitation particles were covered by instruments and they are available for next ops.

Below is a GOES visible image and the CloudSat swath during the flight courtesy NRL.