Flight Number: 970122H1 Page 1 of
Date: January 22 1997 Aircraft ID: 42 Scientist: Jorgensen
Event Log
Time Approx. Location Event & Comments
(UTC) (Lat, Lon)
8:55:49 Shannon Engine Start, Electra block out a minute ago
9:00:49 52.695 -8.926 Block out
9:09:51 Shannon take off
9:12:56 radar system not up yet
9:15:09 52.684 -9.326 METMAN calling 404.9 mHz good freq for N49 drop
9:18:58 All aircraft look good for timing of first run
9:38:05 52.605 -11.815 Begin descent to point 1
9:42:21 52.580 -12.275 at 5kft
9:47:13 52.617 -12.765 just past point 1 right on time - no precip evident on
this leg
9:52:52 52.699 -13.350 light echo on TA mostly below our altitude
9:59:32 308D running about 9 min behind we'll show down 5
knots or so
10:00:42 52.794 -14.170 a little bumpy winds have shifted to southerly front?
10:08:39 METMAN's mid point time for leg 2 1134
10:12:32 52.937 -15.410 sfc press esitmate 1010 mb
10:14:21 52.959 -15.603 north south band of precip 5 mi ahead
10:20:13 53.026 -16.229 going through anonther weak N-S band of precip
10:25:48 308D estimates pt 2 at 1053, about 6 min slow
10:43:41 will do perl at end of leg (pt.2) and at pt. 3 to
allow 308D to catch up a bit, METMAN will deley about
6 minutes also to get synced up
10:46:17 53.270 -19.034 at pt 2 performing perl
10:50:15 53.212 -19.066 start run to point 3, trk 186
10:59:23 52.571 -19.224 convective cell 5 miles to left, 38 dBZ max
11:00:47 52.474 -19.250 patchy whitecaps on sea below
11:06:32 52.075 -19.335 at point 3 enter right hand perl
11:10:58 contact with N49RF
11:11:59 52.083 -19.361 start leg 2
11:13:06 more precip cells on this leg mostly small cells max
relfectivity to 35-38 dBZ. More turbulence too. ETA
to end point 1214
11:19:09 51.990 -18.631 convective cell 7 km to the right - sfc press 1015 mb
T=-5
11:20:53 METMAN dropsonde problems
11:25:44 49RF will drop at 51 30N, 18 00W
11:28:08 51.904 -17.704 more convection to the left
11:43:28 308D estimate to pt 4 1218 Z our estimate is 1215
11:48:25 METMAN breaking off to return to Lyneham because of
broken dropsonde system
12:01:39 308D cutting off leg at 13 30W to save some time,
we're going to go to 13 30W before turning too
12:05:13 51.476 -13.836 entering frontal zone convective cells plus some
stratiform precip
12:08:18 51.435 -13.495 end of leg at new point 4, turn to track S
12:17:03 new point 5 50 12 13 53W
12:17:25 50.893 -13.664 front well defined on LF
12:27:35 50.893 -13.664 front has several bands oriented 030 to the direction
of the front -
12:28:33 50.230 -13.875 end of leg, enter three perls to allow 308D to catch up
12:35:12 Will only go to 17 10 or so before cutting off leg
12:39:39 50.266 -13.771 end of 3rd perl trk 290 to new point 6 near 17 10 (leg
cut nearly in half to same Electra some time)
12:46:45 50.289 -14.439 stratiform precip
12:53:49 front has orientation more like 030 rather than 010,
many waves on the front with scales about 10 nm -
light stratiform precip
12:56:19 50.384 -15.322 wind shift to easterly - frontal boundary? or
pre-frontal squall sfc press 1009 mb
13:00:52 50.420 -15.764 wind shift to northerly - real front
13:12:46 308D gives 1319 Z as its turn point, we are estimating
1315
13:15:08 50.550 -17.151 end of leg turn to track 190 to new point 7
13:25:21 308D estimates new point 7 at 1337, we'll be at new
point 7 at 1335. Perform 1 perl (in stratiform precip
anyway) at that location
13:31:36 49.512 -17.584 Heavier stratiform precip. More turbulent too.
13:33:47 49.369 -17.643 end of leg at new point 7. Executing perl to the left
13:40:26 49.341 -17.048 end of perl roll out to trk 100 toward pt 8
13:43:10 49.346 -16.788 extensive stratiform precip
13:47:06 ETA to pt 8 1424 Z
ETA for Electra at their point 8 1421Z
13:50:49 49.205 -16.671 winds southerly, throught front? Chaotic radar
structure, east-west bands are evident ~35 dBZ max.
13:55:10 49.154 -16.263 perl to the right
13:58:51 49.151 -16.172 end of perl return to base track of 100
14:14:01 48.986 -14.775 winds 180/8 knots ahead of the front
14:19:28 radar data system crashed - rebooting
14:22:23 Electra at pt. 8, returning to SNN
14:25:22 48.833 -13.753 end of leg turn to tract to pt 9 at 47 36 14 9.6 about
a 20 min run
14:41:33 Roger received a polar orbit sat photo and reports
that the "comma" head was south of the cold front.
14:46:30 47.625 -14.157 End of leg at point 9, in clear, turn to trk 280 back
through system
15:01:32 47.796 -15.473 Cold front at this latitude is oriented SSE to NNE
with an extension to the NNE
15:07:10 47.862 -15.974 perl to the right just ahead of the frontal band
15:09:54 end of perl returning to 280 track through the fontal
band which is ~ 30 nm ahead
15:17:07 47.945 -16.644 in the frontal band
15:20:04 47.980 -16.926 begin perl behing band, mostly stratiform precip here
15:23:08 end of perl, resume base course
15:32:31 48.082 -17.816 Interesting "comma" head structure on LF
15:35:07 48.104 -18.058 perl to the right near the dry slot zone
15:38:19 end of perel, resume base course
15:50:06 48.231 -19.211 perl in light stratiform precip
15:50:58 GPS nav system is showing bad positions
15:53:05 end of perl, return to base course
15:55:20 48.234 -19.429 in clear air with sunshine, broken upper cloud deck
few whitecaps on sea sfc below
16:02:28 48.315 -20.090 at point 10, turn to track to the buoy
16:04:11 GPS went out about 1414 UTC, navigation via INE since
then
16:27:26 49.116 -18.345 Going through light stratiform precip with a few
embedded convective cells
16:37:16 49.431 -17.609 perl in heavy stratiform precip
16:41:10 end of perl, resume original track
16:50:22 49.754 -16.869 start of perl in heavy stratiform precip, bright band
clearly evident
16:53:35 end of perl, resume course to the buoy
17:00:23 49.977 -16.342 perl in heavy stratiform precip.
17:04:51 end of perl
17:13:10 50.281 -15.559 start of perl in moderate stratiform precip
17:16:23 end of perl, resume base course
17:21:34 50.449 -15.105 winds have turned back to southwesterlies
17:39:08 51.036 -13.557 over buoy, and of run and climb out for return to SNN
17:50:32 51.445 -12.484 LF echoes 50-100 nm north of track
18:29:13 52.645 -8.991 Land
18:38:21 52.643 -8.989 Block In