Flight Number: 970217H1 Page 1 of
Date: February 17, 1997 Aircraft ID: 42RF Scientist: Jorgensen
Event Log
Time Approx. Location Event & Comments
(UTC) (Lat, Lon)
3:06:47 Shannon Engine Start
Shannon This is IOP16, Flight 10, on Low 39a. Pattern will
be systematic survey of expected cyclone
development in the east-central part of the MSA.
C-130 and P-3 will participate in this mission.
3:10:03 Block Out
3:20:42 Take off
3:23:33 52.733 -8.594 light precip on take off and climb out
3:38:34 52.272 -10.123 radar system up and recording
3:43:06 52.163 -10.421 flying above a shallow stratiform precip deck echo
tops to 10k ft bright band well marked
3:54:42 METMAN59 reports ETA to pt. 1 0514 Z
3:57:26 51.784 -11.439 lots of needles, bullets, and rods on the PMS 2-DC
probe 1-2 mm in length
4:05:06 51.563 -11.971 precip intensity picking up a bit-well defined
bright band now
4:05:36 51.548 -12.008 begin descent to 5k ft
4:07:35 51.492 -12.154 GPS system is not working too well - probably the
antenna again-using INE2 as the primary nav system
tonight
4:09:03 51.454 -12.258 at 5k ft temps about 3C
4:25:34 51.016 -13.327 over the buoy-turn to track to pt. 1
4:31:14 51.297 -13.536 perl #1 to the left in moderate stratiform precip
4:34:09 end of perl #1 resume track to pt. 1
4:42:59 51.792 -13.780 sfc pressure has been falling as we move north -
was about 995 now it is 992
4:51:22 52.255 -14.081 entering a region of heavier stratiform precip
4:54:26 52.429 -14.194 sfc pressure now 988 mb
4:56:49 52.568 -14.285 going through a short east-west oriented band about
60 nm south of pt. 1
5:03:25 METMAN reports that the Ops Center suggests moving
the pattern 40 nm to the south-will subtract
one-half degree from all turn point latitudes-first
point will now become 53.0N 14.9W
5:08:16 52.996 -14.860 at net pt. 1 starting leg 1
5:10:25 53.107 -14.949 precip decreasing in intensity as we move NNW
5:23:30 METMAN estimates o607 UTC for end point of this run
- same as us
5:24:02 53.871 -15.545 sfc pressure now 980 mb-still in light precip
5:27:27 54.065 -15.687 LF shows a blob of precip about 120 nm due west of
here-near 54N 20W-about where Tim's storm track
said it would be
5:38:29 54.707 -16.187 no echo on TA at present
5:46:27 55.161 -16.549 stratiform precip increasing again-sfc press now
975 mb winds 242/40
5:47:56 55.248 -16.624 turbulence has picked up-must be flying near the
tops of small convective cells which are showing up
on the TA radar
6:05:54 56.272 -17.463 at pt. 2 end of leg 1
6:11:18 56.162 -17.891 sfc press continues to decline, temps too, now
T=-3.2C
6:16:58 56.014 -18.358 at pt. 3, start of leg 2-head for pt. 4
6:22:35 55.776 -17.935 upper cloud deck on TA, slopes down toward the south
6:29:14 55.473 -17.378 entering heavier stratiform precip now
6:31:46 55.361 -17.173 radar system froze up
6:32:31 radar system back up again
6:39:27 55.030 -16.559 heavy stratiform precip now-LF shows east-west
oriented band of precip extending to about 60 nm
ahead-we're apparently just on its eastern edge
6:52:22 54.471 -15.563 start perl #2 in heavy stratiform precip
6:53:22 METMAN suggests moving all points another 30 miles
farther south to capture frontal wave a bit better
6:55:19 end of perl #2 resume track to original pt. 4, then
will track 30 miles farther south
7:01:46 54.183 -15.058 very heavy precip now-bright band in excess of 30
dBZ
7:06:43 54.003 -14.642 start perl #3 in heavy precip
7:09:02 end perl #3-resuming track to original pt. 4 53.4
-13.8. Will then track south to new point 4 at
52.9 -13.8
7:13:58 53.755 -14.355 wind speeds and temps have jumped as we went
through the band-precip now weakening
7:23:59 53.263 -13.816 past the old pt. 4, now tracking 180 to get to new
pt. 4 end of leg 2
7:30:38 52.909 -13.817 at new pt. 4 - tracking to new pt. 5 at 52.6 14.7
7:35:10 precip zone of front is over 100 nm wide-now
oriented from NE to SW
7:43:12 52.607 -14.662 at new pt. 5 start of leg 3- turn to track 347
through frontal zone at 1500 ft to mark the
location of the sfc postion of the wind shift and
temp discontinuity
7:46:28 52.786 -14.797 at 1500 ft now entering precip zone
8:04:37 53.865 -15.559 pretty turbulent down here at 1500 ft - temps still
9C so we're on the warm side
8:11:33 54.277 -15.870 narrow ribbon of enhanced echo on LF 20 miles ahead
- narrow cold frontal rainband?
8:21:25 54.852 -16.327 through the rainband - the temps have dropped a bit
and the winds subsided some
8:23:26 54.967 -16.418 another band of precip 19 nm ahead
8:24:05 55.007 -16.456 winds have subsided to 11 knots and temps down to
5.5C
8:27:10 55.181 -16.594 perl #4 while we climb to 5000 ft bright-band to 35
dBZ
8:30:24 end of perl at 5k ft-resume trk to new pt. 6
8:37:08 55.627 -16.923 precip weakening as we move north
8:42:49 55.967 -17.186 at pt. 6 end of leg 3
8:54:32 55.583 -18.162 at pt 7 doing a couple of perls #5-6 while METMAN
catches up
8:58:17 55.555 -18.089 start of leg 4 trk 133 to pt. 8 ETA 0954 Z
9:11:54 54.988 -16.977 somewhat more turbulent-top of front?
9:15:06 54.849 -16.696 begin perl #7 in moderate precip
9:18:14 54.856 -16.633 end perl #7 resume 128 track
9:23:14 54.621 -16.212 going passed a line of convective cells most
intense reflectivities on LF to date >45
9:26:30 54.468 -15.960 that line was the narrow cold frontal
rainband-temps have come up to 2.5C and winds now
233/70 knots.
9:32:14 54.205 -15.542 begin perl #8 in moderate precip near a convective
cell on nose radar
9:35:06 end of perl #8 resume 130 track
9:45:10 53.788 -14.698 start of perl #9 in moderate stratiform precip
9:48:42 end of perl #9 resume track
10:00:22 53.234 -13.880 winds now 238/70 knots
10:04:48 53.021 -13.537 at pt. 8 end of leg 4
10:19:11 52.710 -14.364 at pt. 9 begin leg 5
10:21:29 light stratiform precip along this track so far
10:31:51 53.430 -14.895 precip mass has move to our NE
10:32:35 53.473 -14.924 passing through line of convective cells -
apparently not the cold frontal rainband which is
still about 40 km ahead
10:40:39 53.959 -15.279 going through the narrow cold frontal rainband -
pretty intense reflectivity cores >50 dBZ
10:46:07 54.287 -15.512 begin perl #10 in stratiform region north of narrow
cold frontal rainband
10:49:30 end perl #10 resume track to pt 10
10:51:43 54.428 -15.595 getting out of precip
11:02:34 55.042 -16.072 going through a narrow line of very shallow
convective cells-pretty turbulent yet the echo tops
do not reach our level
11:06:19 55.257 -16.241 at modified pt. 10 - end of leg 5-pt. 10 and 11
where cut off by 40 miles or so to save time and
get back to SNN on time
11:07:33 55.252 -16.352 slanted precip contours on TA velocity display from
south to north
11:11:55 55.143 -16.721 at pt. 11 start of leg 6
11:12:47 55.096 -16.723 in moderately deep precip no bright band though
11:25:56 54.482 -15.540 field of small convective cells below-anvil above
11:43:18 54.482 -15.540 passing through a small comvective line
11:44:21 apparently we passed west of the narrow cold
frontal rainband
11:49:06 53.405 -13.674 pretty turbulent-will try to climb a 2k ft to 7k ft
to avoid the tops of these cold air convective cells
11:55:12 53.117 -13.225 at pt. 12, end of leg 6, turn for SNN and climb to
9k ft
12:07:50 52.964 -11.549 still in fairly good stratiform rain bright band
well marked below
12:09:36 52.953 -11.288 winds 95 knots-about a 65 knot tailwind
12:26:32 52.884 -8.835 radar recording suspended on final to Shannon
12:36:11 Land
12:41:14 Block In