IFEX daily log
Thursday, September 8, 2005
N43RF was tasked for another overnight flight, with fix responsibilities, at 09, 12,
and 15 UTC. There would be a rotating figure-4 pattern flown at 5000 ft altitude. NHC
sondes would be dropped at the turn points, the center, and at the flight-level radius of
maximum winds. These sondes, in addition to the radar observations, would provide data
for the Frequent Monitoring experiment, which would again be piggy-backed onto this
tasked mission. The tail radar would be flown in F/AST mode for all legs except the
outbound west leg, where it would be run in continuous mode.
Satellite imagery from before the time of takeoff (Fig. 98) show that outflow was
significantly inhibited on the southeast side of the storm. This indicates southeasterly
shear, which was confirmed by a CIMSS shear analysis valid at the same time (Fig. 99).
A visible image taken several hours later (Fig. 100) shows distinct banding features
wrapping from the west around to the north side of the storm, with some convective
elements also forming on the south side of the circulation center. The presence of
growing deep convection is also supported by a radar image from Melbourne (Fig. 101),
which shows a clear eye in the reflectivity field and a solid patch of deep convection on
the south side of the eyewall. The banding feature seen in the visible image is also clear
in the radar image, wrapping from south of the center around to the west and then north
of the storm. The rain on the downwind (south) side of the band is primarily solid
stratiform, while moving upwind (around the west to the north) of the band the band
consists of more individual convective elements.
During the flight the storm deepened from the previous mission to a minimum
pressure of 987 hPa, with maximum surface winds of 50-55 kt. This is the fourth mission
in two days for this storm, making it a great frequent-monitoring case. N43RF obtained
F/AST data in all quadrants, and we were able to produce Doppler analyses during the
flight and transmit them to the ground. One leg was in continuous mode for vertical
incidence, and the cloud physics worked well. All in all it was a very successful mission.
As in the previous day, N42RF had a tasked mission during, this time with a
takeoff time at 0130 UTC on Friday. For this mission there was also the NOAA Frequent
Monitoring and Ocean Winds experiments piggy-backed onto it. As in the previous day,
the plan called for a figure-4 pattern to be flown, this time at 5000 ft.
Figure 98. GOES-East infrared image valid 0345 UTC September 8 2005.
Figure 99. CIMSS 850-200 hPa shear analysis (contours, kt) valid 03 UTC September 8
Figure 100. GOES-East visible image valid 1245 UTC September 8 2005.
Figure 101.Melbourne WSR-88D reflectivity (shaded, dBZ) valid 1330 UTC September
HRD Field Program director
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