ALL COORDINATES ARE IN LAT-LON
ALL LATITUDES ARE FROM WEST OF GREENICH
ALL TIMES ARE YYMMDDHHMM IN UTC TIME

DATE AND TIME OF REQUEST:   9901111800

DATE AND TIME OF TAKE-OFF:   Around 9901121900

COORDINATES OF TURNING POINTS ON FLIGHT: Use North Pacific Track #16
Anchorage
45N  166W
40N  164W  Control time: 9901130000  (no later than: 9901130600)
40N 157W
48N 152W
Anchorage

DESIRED LEVEL OF DROPSONDE RELEASE: Highest level possible

TOTAL NUMBER OF DROPSONDES REQUESTED:  Approximately 20

COORDINATES OF DROPSONDES:
At each turning point, plus, on average, one every half hour between turning points. If a sonde fails, please try to replace it immediately. The sensitive area is south of 47N; the frequency of sondes here could be increased to 20-25 mins (and decreased elsewhere, if necessary).

COMMENTS: We may request a flight centered around 00Z 98011500.

BACKGROUND INFORMATION

NATURE OF UNCERTAIN SYSTEM:  Low pressure waves reaching the Washington, then the Oregon and Northern California coast, causing 2-3 inches of precipitation in the coastal areas.

TIME OF UNCERTAIN SYSTEM:  990114120000

LOCATION OF UNCERTAIN SYSTEM: 47.5N 125W

FLIGHT PLAN BASED ON SENSITIVITY RESULTS FROM:
Ensemble Transform technique, using NCEP ensemble from 99011100
(time window: 99011300-9901141200)

COMMENTS: The most sensitive area is further S of the requested track (centered around 35N 165W). The sensitivity chart can be seen at:
http://sgi62.wwb.noaa.gov:8080/ens/target/targetedobs.html