Flight Number: 970223H1 Page 1 of
Date: February 23, 1997 Aircraft ID: 42RF Scientist: Jorgensen
Event Log
Time Approx. Location Event & Comments
(UTC) (Lat, Lon, trk,
hd, gs, p, pa, ra)
10:35:19 Shannon Engine Start
10:40:21 Shannon Block out
10:47:58 SNN Take off
10:52:32 This is flight 12, IOP18, on Low 44 a P-3 only
mission including dropsondes to su
11:07:22 53.492 -10.406 radar system up nd running. Some bands evident on
505.7 5491 the LF 300-400 km to the west
11:23:21 apparently 27 sondes are on board-will use the
extra 7 for backups initially and will deploy a few
extra ones in the bent back region
11:24:37 54.344 -11.984 entering the airspace reservation box-turn to trk
339.9 346.6 150 north to pt. 1
505.8 5489 5163
11:42:09 55.841 -12.000 climbing from 18k ft to 20k ft for first drop ETA
13 minutes
11:49:01 LF looks a little noisy-probably due to retracting
the radome for the climb
11:55:55 57.017 -11.996 at pt. #1 - sonde #1 away-making outside turn to
358.5 2.6 164 trk to pt. 2
465.9 6092 5679
11:56:42 LF radome extended-picture looks much better
11:57:16 sonde #1 looks good
12:00:26 trk 235 in cloud-no echoes on TA
12:03:40 56.829 -12.362 sonde #1 clear - good drop
232.0 235.9 120
465.9 6091 5676
12:15:41 56.357 -13.459 sonde #2 away-beginning to see weak echo on the
227.8 232.2 113 TA-LF shows bands of precip (cold front) now 100 km
465.9 6091 5661 ahead
12:22:22 56.110 -14.035 drop #2 clear good drop-TA now shous extensive
224.6 229.5 113 stratiform precip-echo extends to about our altitude
466.0 6091 5649
12:25:20 55.992 -14.289 drop #3 away at the buoy-moderate stratiform
221.6 227.6 117 precip-bright band near the sfc
466.0 6090 5642
12:33:10 drop #3 clear - good drop
12:33:28 55.646 -14.991 radar system froze up-restarted
220.0 229.9 120
466.1 6089 5615
12:35:20 55.566 -15.163 sonde #4 away-starting perl #1 in moderate
223.2 233.0 120 stratiform precip
465.9 6091 5612
12:39:08 end of perl #1-concective cells on TA to the
left-convergence pattern at low levels on Vr
12:42:47 sonde #4 clear - good drop
12:48:18 55.224 -15.848 sonde #5 away - appears to be good-winds 173/95 knts
214.1 229.0 114
466.2 6087 5567
12:50:37 55.131 -16.034 broke out into the clear-blue skies
212.9 228.4 111 above-stratiform dect 500 ft below us
466.1 6089 5553
12:55:28 sonde #5 cleaar-good drop
12:59:52 54.761 -16.715 Relataive Humidity down to 9%
215.1 225.7 109
466.1 6089 5504
13:01:12 54.707 -16.811 going thourgh a field of small convective cells on
216.0 226.1 111 the TA radar. The cloud deck below is now a broken
465.9 6092 5499 field of cu
13:23:59 53.753 -18.545 convective storm to the left of track-overshooting
230.1 226.2 115 top on a large anvil-winds have now come araound to
466.1 6089 5462 240/58 as we track south of the low center
13:31:03 53.455 -19.064 at pt. 2-sonde #6 away-looks good-turning to trk to
231.0 225.0 118 pt. 3-climbing to 22k ft
466.0 6091 5472
13:37:50 53.698 -19.637 at 22k ft-at the very top of the altostratus cloud
294.9 297.4 126 deck
427.5 6713
13:45:09 53.916 -20.389 LF radar going down to check on the high apparent
294.0 296.2 117 noise level in the reflectivity
427.6 6712 6052
13:47:19 53.978 -20.599 stratiform precip now appearling gelow us on the TA
294.0 297.0 115
427.5 6712 6051
13:55:17 LF back up
14:06:38 54.499 -22.511 at pt. 3-sonde #7 away-good drop- turn to trk to
300.6 295.6 121 pt. 4-climb to 23k ft
427.6 6710 6061
14:10:05 LF still having problems with noise
14:10:21 54.725 -22.412 at 23k ft-stratiform echo increasing as we go north
16.3 24.9 134
408.6 7034 6355
14:14:41 54.994 -22.263 passing just to the right of a pretty good
2.3 12.4 124 convective storm
408.8 7032 6342
14:15:11 sonde #7 clear-good drop
14:21:24 55.460 -22.085 start perl #2 in heavy stratioform precip below
350.0 356.8 131
408.6 7034 6334
14:28:02 end perl #2 - precip decreasing again-can see sea
sfc-low center 200 km ahead is marked by absence of
sea return, indicative of calm seas
14:31:11 55.873 -21.866 winds now have dropped off to 320/25 knots as we
8.6 12.6 142 get closer to the low center
408.7 7034 6325
14:43:22 56.783 -21.416 winds just shifted from 320 to 125 so we're at the
16.4 14.1 149 low center
408.8 7032 6321
14:45:22 56.933 -21.339 sonde #8 away near the low center
25.4 19.1 151
409.1 7025 6318
14:48:09 sonde #8 failed readying another
14:50:02 57.291 -21.107 sonde #9 away-looks like good launch-we're north of
25.1 16.7 150 the low center winds now 112/38-only light precip
407.9 7047 6349 indicated by the TA
14:54:58 57.667 -20.953 in cloud again
24.7 16.8 144
408.4 7038 6356
14:56:09 57.755 -20.902 passing to the left of a pretty good convective cell
25.7 17.1 147
408.7 7034 6355
15:00:21 58.072 -20.709 sonde #10 away-looks like good drop-stratiform
24.8 18.3 148 precip increasing below our altitude
408.7 7034 6370
15:10:08 sonde #10 cleared 955 mb sfc press
15:15:19 59.252 -20.066 sonde #11 away-moderate stratiform precip-winds
26.7 19.7 155 126/31 knts
408.6 7035 6424
15:22:41 59.844 -19.677 winds beginning to drop off as we approach the coll
20.5 16.2 159 north of the low center
408.6 7034 6440
15:23:51 sonde #11 cleared-good drop
15:26:28 60.164 -19.495 at pt. 4-sonde #12 away-turn to trk to pt. 5- climb
20.5 16.2 166 to 24k ft
408.7 7034 6447
15:34:45 sonde #12 cleared-good drop
15:39:06 59.993 -21.398 stratiform precip increasing as we go west
248.6 252.5 161
392.6 7318 6697
15:50:23 59.993 -21.398 sonde #13 away in light stratiformprecip below
248.6 252.5 161
392.6 7318 6697
15:57:55 59.495 -24.476 precip tops coming down on TA-sun is coming out too
247.1 250.2 159
392.6 7317 6673
15:58:30 drop #13 clear-good drop
16:11:26 from the sonde data on the pass through the center
it appears that the low is about 60 nm north of the
forecasted position. Will shift pt. 6 to 58N, 20W
16:14:13 58.997 -27.026 at pt. 5-sonde #14 away-good drop in no
245.3 250.2 163 precip-climb to 25k ft
392.5 7319 6664
16:23:16 sonde #14 clear-good drop
16:25:21 58.869 -25.690 sonde #15 away-very light precip on TA
105.7 103.2 144
375.6 7628 6961
16:32:05 58.717 -24.733 winds finally coming more northerly as we move to
101.6 103.4 139 the center now 073/27 knts
375.7 7626 6960
16:35:19 58.665 -24.277 sonce #16 away in moderate precip-sonde #15
100.8 102.1 140 clear-good drop
375.7 7626 6958
16:37:20 58.635 -23.994 start perl #3 in moderate precip below-clear skies
108.2 108.1 141 above
375.7 7627 6958
16:40:50 end perl #3
16:44:02 sonde #16 cleared-good sonde
16:50:19 58.441 -22.686 sonde #17 away-apparently a bad drop
104.5 108.3 143
375.7 7626 6941
16:52:34 58.387 -22.369 sonde #18 away-good so far-precip has weakened
104.8 108.1 142 considerably-only very low level echo on TA below 2
375.7 7625 6937 km AGL
17:00:19 58.238 -21.271 sonde #19 away in no precip-sonde #18 clear-good
103.5 106.9 145 drop
375.6 7628 6920
17:08:30 sonde #19 clear-good drop
17:09:19 58.011 -19.961 at modified pt 6-sonde #20 away-climb to 26k
108.3 106.2 145 ft-apparently near the low cneter as winds dropped
375.5 7629 6893 below 10 knts
17:12:30 57.838 -20.121 at 26k ft- light stratiform precip below
225.3 226.9 157
358.7 7948 7195
17:26:29 56.989 -21.670 sonde #21 away in no precip on TA-winds have
228.2 224.7 162 shifted to northwesterly
358.6 7950 7208
17:36:28 56.372 -22.749 sonde #22 away in no precip
230.3 223.7 152
358.7 7947 7234
17:45:17 sonde #22 clear-good drop
17:47:42 55.713 -23.862 sonde #23 away
225.5 221.2 148
358.7 7947 7256
17:55:42 sonde #23 cleared-good drop
17:59:19 55.032 -24.943 at pt. 7-sonde #24 away in clear skies all the way
226.7 218.0 147 to the sfc
358.7 7948 7275
18:08:14 sonde #24 cleared-good drop
18:25:35 54.483 -20.779 shutting down the TA transmitter to preserve the
101.9 100.6 182 magnetron lifetim as there are no echoes likely on
358.8 7946 7274 return
18:50:22 53.898 -16.736 sonde #25 away-beginning slow descent to 25k ft for
107.9 106.0 191 approach to SNN
358.8 7946 7276
19:25:08 radar system secured
19:51:02 land
19:57:22 block in