Friday, September 2, 2005 Today there were no flights planned for any of the P-3掇. Keesler AFB, home of the Air Force 53rd Reconnaissance Squadron, was seriously damaged by Hurricane Katrina. In consideration of the personal needs of the 53rd personnel and because their aircraft have been diverted to flying humanitarian missions as their top priority, the two AOC P-3掇 have been designated as primary for reconnaissance tasking. This means that the NOAA P-3掇 will be tasked for invest and reconnaissance missions in developing systems near the coast. For more mature hurricanes, the Air Force C-130掇 will be available. In the tropics, T.D. #14 is still present, though has shown little signs of strengthening. Convection is still displaced to the northwest (Fig. 74). There is some moderate southeasterly shear (Fig. 75) and dry air over this system, preventing much development from occurring. The low-level steering flow (Fig. 76) indicates that T.D. #14 will move toward the north-northwest around 50 W, where it may enter a more favorable environment for development. Following this motion, T.D. #14 would be out of range for any IFEX or RAINEX objectives. Figure 74. GOES-East Visible image valid 1115 UTC September 2. Figure 75. CIMSS-derived 850-200 hPa wind shear (shading, kt) valid 09 UTC September 3. Figure 76. CIMSS-derived layer-average 700-850 hPa winds (kt) valid 09 UTC September 3. Saturday, September 3, 2005 The Tropics are still relatively quiet for areas in range of P-3 flights. An infrared satellite image from Saturday morning (Fig. 77) shows a well-organized system that was T.D.#14 and has developed into Tropical Storm Maria. The storm is under a narrow band of relatively low shear (Fig. 78), and thus has the potential to continue to develop. It is forecasted to track toward the north-northwest (Fig. 79), out of range of any possible operations. Elsewhere, a line of convection is evident off the southeast Florida coast extending to a point north of the Greater Antilles. This convection is associated with a broad upper-level trough and surface front that has extended off the U.S. East Coast, as indicated by water vapor imagery (Fig. 80). A flare-up of convection on the southeast edge of this trough has a midlevel circulation associated with it, while the southwest edge of the trough, associated with the southern extent of the surface front, is often an area favorable for tropical cyclogenesis. Global models indicate one or possibly two systems developing in this region over the next several days (Fig. 81). If the western system does develop, it likely would be tasked by NHC for SFMR or fix-responsibility missions. It is also possible that some coordinated RAINEX flights could be flown, if the system developed into a strong tropical storm. Elsewhere, the tropical Atlantic is relatively quiet. Figure 77. GOES-East Infrared valid 1315 UTC September 3. Figure 78. CIMSS-derived 850-200 hPa shear (kt) valid 09 UTC September 3. Figure 79. Track guidance for Tropical Storm Maria valid 12 UTC September 3, 2005. Figure 80. GOES-East Water Vapor image valid 1315 UTC September 3, 2005. Figure 81. Plot of detection of vortices in various global models for model runs initialized at 00 UTC 3 September 2005. Sunday, September 4, 2005 There are now two primary areas of interest for possible IFEX operations. They are both off the Florida coast, related to the area of convection associated with the upper- level trough and surface front that is now positioned off the U.S. East Coast. An infrared image from the morning (Fig. 82) shows a concentrated area of deep convection located around 67 W and another fairly organized area of convection just off the Florida southeast coast. Some global models (Fig. 83) are now indicating the development of a vortex off the coast of Miami within 24-36 h, while the GFS also indicates another system developing around 30 N 65 W within several days. Should either of these systems develop, the low-level steering flow (Fig. 84) shows weak flow, indicating slow movement to any system that develops. Tropical Storm Maria has now intensified to Hurricane Maria. It is out far east, though, and is continuing to move generally northward and north-northwestward. It is not a target for possible operations. Elsewhere, the Tropics are generally quiet. Figure 82. GOES-East Infrared image valid 1315 UTC September 4. Figure 83. Plot of detection of vortices in various global models for model runs initialized at 00 UTC 4 September. Figure 84. CIMSS-derived layer-average 700-850 hPa winds (kt) valid 09 UTC September 4 Monday, September 5, 2005 One of the two systems of interest, the one off the southeast Florida coast, shows widespread areas of deep convection but little organization (Fig. 85). Vertical shear (Fig. 86) is moderate over the system itself, but it increases to strong southwesterly shear north of the system. This shear is largely due to the presence of strong low-level northeasterly flow (Fig. 87) associated with a strong anticyclone behind the surface front off the U.S. East Coast. The low-level flow also indicates the possibility of the system, if it develops, moving over Florida and into the Gulf of Mexico. Track guidance (Fig. 88) indicates this possibility. NHC has tasked a NOAA P-3, N42RF, to investigate this system, scheduled to arrive in the storm around 18 UTC Tuesday September 6. This could serve as an excellent opportunity for a frequent-monitoring mission, especially if N43RF were tasked for overnight missions and the associated 12-h staggering. However, the pattern for N42RF calls for an altitude of 1500 ft. While this is optimal for finding a low-level circulation center at flight-level, it is impractical to drop sondes from this altitude, since it is too close to the surface. One factor making this a more appealing candidate for a research tag-along is that RAINEX is interested in flying with N42RF. The purpose of this coordinated flight would be to document the evolution of the deep convection and its interaction with the larger-scale vortex. In this sense the proposed coordination would be very similar to the Convective Burst Module of the Tropical Cyclogenesis Experiment, one of the other experiments in the 2005 HRD Hurricane Field Program. For this reason it was decided that a research component would be piggy-backed onto the tasked mission the following day. The other system of interest, further east along 65 W, also has widespread deep convection (Fig. 89). For this system the convection is more concentrated, suggesting better organization. Because of this improved organized this system was named Tropical Depression #15. Track guidance for this system (Fig. 90) indicates that it will likely track toward the northwest or north, well-removed from any possible targeting. Figure 85. GOES-East Infrared image valid 1315 UTC September 5, 2005. Figure 86. CIMSS-derived 850-200 hPa vertical shear (shaded, kt) valid 09 UTC September 5, 2005. Figure 87. CIMSS-derived 700-850 hPa layer averaged flow (shaded, kt) valid 09 UTC September 5, 2005. Figure 88. Track guidance for system off Florida coast valid 06 UTC September 5, 2005. Figure 89. GOES-East Infrared image valid 1215 UTC September 5, 2005. Figure 90. Track guidance for system north of Bahamas (eventual T.D. #15) valid 06 UTC September 5, 2005. Tuesday, September 06, 2005 The system off the Florida coast has become much better organized today, with concentrated deep convection (Fig. 91). Because of this improved organization, the system was named Tropical Depression #16. The large-scale vertical shear (Fig. 92) is moderate and southerly, reflecting upper-level southerly flow around an anticyclone centered over T.D. #15. Most of the track guidance now takes the system generally northward along the Florida coast (Fig. 93). Some of the dynamical models, such as NOGAPS, suggest a slow motion, keeping T.D. #16 off the Florida coast even after 4-5 days. The tasked mission for N42RF into T.D. #16 was scheduled to take off at ???? UTC. There would also be the NOAA Frequent-Monitoring experiment and the NOAA Ocean Winds experiment piggy-backed onto the tasked mission. The plan called for the NRL P-3 to also be in the system while N42RF was out there. The NRL P-3 would target a burst of convection, either circumnavigating the convective system as in the Convective Burst Module of the Tropical Cyclogenesis Experiment or running back and forth across one side of the convective burst. The actual flight pattern flown was similar to that planned (Fig. 94), providing good radar coverage for the first sampling in the Frequent Monitoring experiment. Elsewhere in the Tropics, T.D. #15 has become Tropical Storm Nate. Nate has wrapped convection around the center and is looking healthier this morning. Nate is underneath an upper-level anticyclone (cf. Fig. 92) and is expected to continue to intensify, but it is not a factor for operations. Figure 91. GOES-East Infrared image valid 0245 UTC September 7, 2005. Figure 92. CIMSS-derived 850-200 hPa vertical shear (contour, kt) valid 00 UTC September 2005. Figure 93. Track guidance for T.D. #16 valid 06 UTC September 6, 2005. Figure 94. Track of N42RF and NRL P-3 for flight 050906H1. Wednesday, September 7, 2005 N43RF was tasked for a flight into T.D. #16, with fix responsibilities of 06, 09, and 12 UTC. Takeoff time would be at 0430 UTC on September 7. Since the original plan called for this pattern to be flown at 5000 ft, it was decided to piggyback a research mission onto this tasked mission. Because of the near 12-h staggering between missions, and the tasking of N42RF and N43RF on the following days, this would make an excellent 12-h Frequent Monitoring Experiment. The mission involving N43RF consisted of a rotating figure-4 pattern, with the initial point 105 nm northwest of the center. The first two passes would be flown at 1500 ft, and then the plane would climb to 5000 ft for the final pass. Sondes would be dropped only from 5000 ft, at the turn points and the midpoints of that radial leg. The tail radar would be run in F/AST mode for most of the pattern, except for the second half of the first inbound leg, when it was run in continuous mode. The system was getting better organized while N43RF was in there. The pressure dropped to 1003 hPa during the flight, it was hence upgraded to Tropical Storm Ophelia. Banding was evident of the north, east, and southeast sides of the storm. The center was still located south of the convection, but it may be repositioning itself further north. N43RF was able to fly some of a frequent-monitoring experiment. Because much of the pattern was flown at 1500 ft, there were no drops, but there was radar coverage, at least on the north side of the storm where there were scatterers. The aircraft did climb to 5000 ft and drops sondes south, at the midpoint, north, and on the final downwind leg. There was also some limited vertical incidence data, and cloud physics data. Tropical Storm Ophelia has slowly organized overnight. Satellite imagery indicates a broad shield of cold cloud tops (Fig. 95) with outflow inhibited to the south, indicative of some southerly shear impacting the system. A radar image from the Melbourne radar (Fig. 96) shows the shield of convection extending fairly far north. A band is also evident onshore in northern Florida. Track guidance for Ophelia (Fig. 97) shows a wide spread. Some dynamical models (e.g., the Canadian global model) take Ophelia out to sea, while other dynamical models, such as the GFDL, bring the system over land and into the Gulf of Mexico. Such a wide spread is indicative of considerable uncertainty. Both NOAA P-3掇 are still tasked for fix/SFMR missions into Ophelia, separated by 12-h frequency. The N42RF tasked mission will also have 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. The NRL P-3 would not accompany N42RF this time, however. Figure 95. GOES-East infrared image valid 1115 UTC September 7 2005. Figure 96. Melbourne WSR-88D reflectivity (shaded, dBZ) valid 1147 UTC September 7 2005. Figure 97. Track guidance valid 06 UTC September 7 2005. 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 2005. Figure 100. GOES-East visible image valid 1245 UTC September 8 2005. Figure 101.Melbourne WSR-88D reflectivity (shaded, dBZ) valid 1330 UTC September 8 2005. Friday, September 9, 2005 Ophelia continues to linger off the east coast of Florida. Infrared satellite imagery (Fig. 102) shows that Ophelia is not experiencing as much shear as the previous day, but it is continuing to experience some southeasterly shear. This shear is confirmed by the CIMSS shear analysis product (Fig. 103). The eye of the storm is visible from Jacksonville radar (Fig. 104), which also shows a band of strong rain on the west side of the storm wrapping around to the southwest side. Figure 102. GOES-East infrared image valid 1830 UTC September 9, 2005. N43RF had a tasked mission today, with fix responsibilities at 12, 15, and 18 UTC. There is also a requirement for a figure-4 pattern to be flown at 5000 ft, with leg lengths of 105 nm. GPS sondes would be dropped for NHC at the center and at the RMW, while RAINEX sondes would be dropped at the turn points. At the end of the fix responsibility, N43RF would climb to 10,000 ft and begin a coordinated pattern with the NRL P-3 for a RAINEX rainband module. There was a possible band to target around the north and west side of the storm, as evident from the radar image (cf. Fig. 104). The actual pattern flown was similar to that planned (Fig. 105). The system was experiencing shear, and the pressure was lower than before, but the winds were not much higher. In between the second and third fix, N43RF flow along a rainband on the west and northwest side of the storm. N43RF flew two downwind and two upwind legs (Fig. Figure 103. CIMSS-derived 850-200 hPa vertical shear (shaded, kt) valid 09 UTC September 9, 2005. Figure 104. Reflectivity (shaded, dBZ) from Jacksonville WSR-88D valid 1845 UTC September 9, 2005. Figure 105. Tracks of N42RF and NRL P-3 for flight 050909I1. 106). It was outside the band, while the NRL P-3 was inside the band. After the third fix, N43RF set up for an upwind leg along the principal rain band on the west side. The aircraft tried to come back on the inner edge to follow down to its intersection with the eyewall, which would have made for a great set of observations for RAINEX. However, it was not deemed safe, so the pattern was abandoned. Overall, the mission was very good. N43RF accomplished its tasking objectives and found that the storm pressure had dropped while the wind speed had maintained constant strength. There was good coordination with the NRL P-3, with passes on opposite sides of two rainband features at two different times. On the first pass the rainband was within 10 km for much of the leg with N43RF. This close proximity should provide great Dual-Doppler coverage. This mission marked the end of the 12-h intervals for the NOAA P-3掇 being in the system, and thus marked the end of the 12-h portion of the Frequent-Monitoring experiment for this storm. There have been six missions in Ophelia in a three-day time period, each of them including radar and dropsonde observations and two of them including the NRL P-3 as well. Figure 106. Plot of lower fuselage reflectivity (shaded, dBZ) from N43RF and flight tracks of N43RF and NRL P-3 during previous 30 minutes for (a) 1500 UTC; (b) 1530 UTC; and (c) 1800 UTC September 9, 2005 Saturday, September 10, 2005 Today Ophelia has started to lift out slowly away from the Florida coast. The core is still evident from visible satellite imagery (Fig. 107), as is the principal rain band wrapping from the southeast side around the northeast, northwest, and to the west side of the storm. Infrared imagery (Fig. 108) shows convection around the center of the storm, but not very cold cloud tops. It also shows dry air to the west of the system, which may limit any further intensification. Track guidance is widely spread (Fig. 109), though most of the reliable dynamical models suggest that Ophelia will track slowly along the coast of South Carolina. Some models keep the storm in that same general place for the next several days. Figure 107. GOES-East visible image valid 1245 UTC September 10, 2005. Figure 108. GOES-East infrared image valid 1345 UTC September 10, 2005. Figure 109. Track guidance for Ophelia valid 12 UTC September 10, 2005. There were no P-3 flights today. The plan for tomorrow calls for a three-plane IFEX/RAINEX/Ocean Winds experiment. This will be the first time this season that all three planes will be available for a purely research mission Sunday, September 11, 2005 Ophelia continued to linger off the South Carolina coast today (Fig. 110). The infrared satellite image showed that the deepest convection in the core was on the north side of the circulation. There were two primary areas of cold cloud tops: eyewall convection on the north side and a band wrapping around from the southwest around to the north side. The presence of this banded structure around the north side of the storm is also supported by coastal radar (Fig. 111), which was capable of seeing the storm even though it was still well offshore. The storm was a hurricane again, though water vapor imagery (Fig. 112) showed dry air around the west and the southwest side of the storm. The storm was also experiencing light to moderate westerly shear (Fig. 113), which would favor the maximum eyewall convection and rainband orientation on the north (downshear left) side. The dry air, coupled with cold water upwelled by the storm that had been over the same area for several days, would likely limit any further intensification of the storm. Shear may play a slight inhibiting role, but that is probably not the most significant factor that would limit intensification. Track guidance is still spread widely (Fig. 114), which is common for systems that are very slow moving. It continues to suggest that the storm will move slowly for the next several days. Figure 110. GOES-East infrared image valid 1045 UTC September 11, 2005. Figure 111. WSR-88D reflectivity (shaded, dBZ) from Wilmington, NC valid 1047 UTC September 11. Figure 112. GOES-East water vapor image valid 1015 UTC September 11, 2005. Figure 113. CIMSS-derived 850-200 hPa vertical shear (shaded, kt) valid 09 UTC September 11, 2005. Figure 114. Track guidance for Hurricane Ophelia valid 06 UTC September 11, 2005. Today would be the first three-plane research mission. The plan called for an IFEX/RAINEX/Ocean Winds mission into Hurricane Ophelia. N43RF would fly an initial figure-4 pattern with 100-nm leg lengths, starting on the southwest side of the storm. Sondes would be dropped at the turn points, at the outer edge of the eyewall, in the middle of the eyewall, and at the center of the storm. At the completion of the figure- 4, N43RF would set up for coordination with the NRL P-3 on the east side of the storm. There the two aircraft would fly a RAINEX rainband pattern, with N43RF either on the inner or the edge edge of the eyewall. Sondes would be dropped at the end points and the midpoint of each downwind leg. AXBT掇 would be dropped at the turn points, at the eyewall drop, and at the end points of the rainband leg. Both N43RF and the NRL P-3 would try to maintain a close distance to the rainband, which is about 10-15 km away from the edge of the rainband. N43RF would fly at 12,000 ft and descend to 8000 ft if needed. The NRL P-3 would fly at 14,000 ft and descend to 12,000 ft if needed. N42RF would fly an initial figure-4, with leg lengths of 100 nm. After that figure-4 N42RF would fly targeted passes into areas of high wind and rain rates for the Ocean Winds Experiment. The mission was a success. The storm had a steady intensity, but the structure of the storm was constantly evolving. The eyewall was generally open on the south and the southeast side. There were multiple rainbands that were wrapping around the southeast, east, northeast, north, and around the west side. The dominant activity associated with the principal rainband was on the north side. On the north side of the storm between bands some moderate chop was encountered as the plane was flew across a shear zone characterized by low-level inflow and midlevel outflow. Peak flight-level winds of 90 kt were encountered on the north side of the storm toward the end of the mission while the peak SFMR winds was 60-65 kt on the northeast side of the storm. Sea-surface temperatures were quite low in the eyewall and on the northeast, southeast, and southwest sides of the storm. SST掇 as low as 23 C were measured. The only warm SST was measured 100 nm northwest of the storm. A value of 28 C with a deep mixed layer was measured, possibly denoting the Gulf Stream at this location. After the initial figure four was completed, N43RF set up for coordination with the NRL P-3. N43RF flew a series of upwind and downwind legs along the inner edge of the principal rainband (Fig. 115), maintaining a distance of 10-15 km for much of the legs, while the NRL P-3 flew upwind and downwind legs along the outer edge of the same rainband, while N42RF flew a figure-4 and a series of targeted passes for Ocean Winds. At the end of N43RF掇 figure 4 pattern, the NRL P-3 encountered icing at 14,000 ft, so it descended to 12,000 ft and N43RF descended to 10,000 ft. N42RF was operating at 4000 ft the whole time. The initial coordination was a bit confused at first, but eventually good coordination was established. At that point the upwind and downwind legs were flown on the same principal rainband. Several of these had excellent coordination, providing quad-Doppler coverage. The tracks for all three aircraft are shown in Fig. 116. This should be a great dataset for a system with multiple bands and rapidly-evolving features, even though it remained a category 1 storm. (a) (b) (c) (d) Figure 115. Plot of lower fuselage reflectivity (shaded, dBZ) from N42RF and N43RF and flight tracks of all three aircraft during previous 30 minutes for (a) 1925 UTC; (b) 2010 UTC; (c) 2055 UTC; and (d) 2155 UTC September 11, 2005 Figure 116. Tracks of N42RF, N43RF, and NRL P-3 for September 11, 2005. Monday, September 12, 2005 Tropical Storm Ophelia continues to be the dominant feature in the Atlantic basin (Fig. 117). Visible and infrared satellite imagery (Fig. 118) show little inner-core convection in Ophelia and dry air on the west side of the storm inland over Georgia. A broad ring of moderately-cold cloud tops is evident in the infrared image. This may be an eyewall of large radius or a rainband wrapping around the system. Coastal WSR-88D radar from Wilmington (Fig. 119) show a line of high reflectivity associated with this band on the northwest side of the storm. A CIMSS shear analysis shows only 10 kt of northwesterly vertical shear (Fig. 120) impacting the system. Significant intensification is still unlikely despite this comparatively low shear, however, for several reasons: the broad circulation and lack of deep convection within the core, the dry air west of the storm, and lower SSTs under much of the circulation due to the slow movement of the system. It is possible that some convection could fire within the core as the storm moves over the warm Gulf Stream waters, which may strengthen the storm some. Figure 117. Goes-East visible satellite image valid 1345 UTC September 12. Track guidance for Ophelia (Fig. 121) shows that most models predict the storm to continue to move slowly up the coast for a few days before accelerating up the northeast coast. This system may become a good candidate for an extratropical transition experiment, which would satisfy an IFEX goal by collecting observations in a system at the end of its lifecycle. N42RF is flying an Ocean Winds mission into the system today, and it is scheduled to fly another one tomorrow. Elsewhere in the tropics it is fairly quiet. There are some areas of convection located in the central and eastern Atlantic, as indicated by infrared imagery (Fig. 122). No development is anticipated within the next several days. Figure 118. GOES-East infrared image valid 1245 UTC September 12. Figure 119. WSR-88D reflectivity (shaded, dBZ) from Wilmington, NC radar valid 1424 UTC September 12. Figure 120. CIMSS-derived 850-200 hPa shear (contour, kt) valid 09 UTC September 12. Figure 121. Track guidance for Hurricane Ophelia valid 12 UTC September 12, 2005. Figure 122. Meteosat infrared imagery valid 12 UTC September 12. Tuesday, September 13, 2005 Ophelia has continued to linger off the South Carolina coast, where it has moved little for the past several days. Visible satellite imagery (Fig. 123) shows a large area of minimal cloudiness at the center of circulation. Deep convection has begun redeveloping in the north and south sides of the circulation, indicating the likelihood that Ophelia will strengthen some in the next 24 h. The only P-3 flight planned into Ophelia today is N42RF, which will be flying another Ocean Winds mission into the storm. The coastal WSR-88D radar from Wilmington, NC (Fig. 124) shows a solid band of stratiform precipitation with convective elements embedded within it in the northern section of the circulation. The track forecast guidance (Fig. 125) continues to bring Ophelia up the East Coast of the U.S. over the next several days, during which time it would undergo extratropical transition. Such a close proximity to land and its likely impact in Canada would make Ophelia an attractive target for an extratropical transition experiment. Tentative plans call for a two-day single-P3 mission into Ophelia, taking off from Tampa on one day, flying into the core and the environment of the storm on that day and landing in Nova Scotia or Maine. On the following day a similar pattern would be flown, recovering in the same location. The aircraft would then return to Tampa on the following day. Figure 123. GOES-East visible image valid 1315 UTC September 13. Figure 124. WSR-88D reflectivity (shaded, dBZ) from Wilmington, NC radar valid 1226 UTC September 13. Figure 125. Track guidance for Hurricane Ophelia valid 06 UTC September 13, 2005. Another experiment also being considered for Ophelia is an Aerosonde flight. Aerosonde, an unmanned aerial vehicle (UAV) capable of flying at low altitudes, is based in Wallops Island, Virginia. From this location it has a range that extends down off the North Carolina coast. If Ophelia follows its forecasted path, it will move into the range of the Aerosonde, and a flight will be performed that will last about 12 h. This would mark the first time ever that a UAV has been flown into a tropical cyclone. Elsewhere in the tropics, there is a region of isolated convection in the central Atlantic associated with a tropical wave located at around 40 W (Fig. 126). There is no organization to this system and the environment is marginal at best, with stable air to the north and west of the system (Fig. 127). Development of this system, if it occurs at all, will be slow. Figure 126. GOES-East infrared image valid 1145 UTC September 13. Figure 127. CIMSS-derived Saharan Air Layer tracking product valid 12 UTC September 13. Yellow (Red) shades indicate weaker (stronger) SAL. Wednesday, September 14, 2005 Ophelia has shown signs of strengthening a bit today. Infrared imagery (Fig. 128) shows that the eye has contracted from the previous day and deep convection has developed on the southwest side of the eyewall. The storm is just offshore Wilmington, NC, and radar imagery from Wilmington (Fig. 129) clearly shows strong convection on the west and south side of the eyewall. Track forecast guidance (Fig. 130) predicts that Ophelia was begin to accelerate up the East Coast within 1-2 days. For this reason an extratropical transition experiment is being planned, to begin on Friday and continue on Saturday. N42RF will be the plane to fly this mission. Also being planned is an Aerosonde mission. The execution of this mission will depend on when Ophelia clears the longitude of the Outer Banks of North Carolina. Forecasts indicate that this will occur on Thursday or Friday, so the Aerosonde is schedule to fly its approximately 12-h mission beginning Thursday night and finishing Friday morning. Figure 128. GOES-East infrared image valid 1215 UTC September 14. The area of disturbed weather in the central tropical Atlantic (i.e., 95L Invest) remains disorganized (Fig. 131). Water vapor imagery (Fig. 132) shows some upper- level dry air west of the system, but this is not deemed hostile to development. There is strong vertical shear north of the system (Fig. 133), but over the system it is only moderate (about 10 kt). This system will be monitored as a potential target several days down the road. Figure 129. WSR-88D reflectivity (shaded, dBZ) from Wilmington, NC radar valid 1247 UTC September 14. Figure 130. Track guidance for Hurricane Ophelia valid 06 UTC September 14, 2005. Figure 131. GOES-East infrared image valid 12 UTC September 14. Figure 132. GOES-East water vapor valid 1215 UTC September 14. Figure 133. CIMSS-derived 850-200 hPa vertical shear (shaded, kt) valid 09 UTC September 14. Thursday, September 15, 2005 The primary tropical activity in the Atlantic basin is confined to two areas today (Fig. 134): Hurricane Ophelia, which persists off the North Carolina coast, and the tropical wave located at around 45 W. Ophelia has now moved closer to the Outer Banks of North Carolina, as seen by Morehead City radar (Fig. 135). Convection is maximized on the east side of the eyewall. Track forecasts continue to bring it up the coast within the next 1-2 days. The extratropical transition experiment is planned for Friday and Saturday. Airspace issues have delayed the launch of the Aerosonde into Ophelia until tomorrow, with a Friday morning takeoff and Friday evening scheduled. This schedule should put both aircraft in the storm at the same time. Figure 134. GOES-East water vapor image valid 1245 UTC September 15. The 95L Invest system looks a bit better organized today. Visible and infrared satellite imagery (Figs. 136 and 137) show convection more concentrated and some suggestions of banding, while a QuikScat overpass (Fig. 138) shows a pronounced cyclonic shear axis collocated with the convection. The vertical shear is light to moderate (Fig. 139) and northwesterly, while any SAL air is located primarily to the north and east of the system (Fig. 140). The low-level flow indicates that 95L will continue moving toward the west-northwest, approaching the leeward islands in two to three days. Because of this possibility, there is consideration that is being given to deploying to either Barbados or St. Croix over the weekend. If the system does move toward the west-northwest and develops, it may take a track to the northeast of the islands. That would be an ideal track for research flights, since a track to the northeast of the islands would minimize the likelihood of an NHC tasking. Figure 135. Morehead City, NC radar valid 1315 UTC September 15. Figure 136. GOES-East visible image valid 1115 UTC September 15. Figure 137. GOES-East infrared image valid 1215 UTC September 15. Figure 138. QuikScat overpass (barbs, kt) valid 1242 UTC September 15. Figure 139. CIMSS-derived 850-200 hPa vertical shear winds (shaded, kt) valid 09 UTC September 15. Figure 140. CIMSS-derived Saharan Air Layer tracking product valid 09 UTC September 15. Yellow (Red) shades indicate weaker (stronger) SAL. Figure 141. CIMSS-derived 850-700 hPa layer-averaged winds (shaded, kt) valid 09 UTC September 15. Friday, September 16, 2005 There are areas of note in the Atlantic basin. The first is Tropical Storm Ophelia, seen in a water vapor image (Fig. 142) off the North Carolina coast. The second system is 95L Invest, which is a mass of clouds oriented southwest-northeast approaching 55 W, while the third system is an area of deep convection located north or Puerto Rico associated with an upper-level cyclonic circulation. The cloud signature in Ophelia is indicative of a system undergoing extratropical transition. N42RF is currently flying this system for the extratropical transition experiment. It had a takeoff time of 14 UTC from Macdill Air Force Base, and it was expected to be in the system by about 17 UTC. The plan called for N42RF to fly a figure-4 pattern at 10,000 ft through the center of the storm (Fig. 143) and then sample the environment at about 18,000 ft altitude. The plane would then recover in Portsmouth, NH. At the same time, the Aerosonde took off from Wallops Island to sample Ophelia in the low-levels. Its plan was to fly in the periphery of the system, sampling the wind speed, direction, temperature, and moisture, and then penetrate the core of the storm. The majority of the pattern would be flown at 2500 ft, though some of the time it would operate at 1500 ft. Figure 142. GOES-East water vapor image valid 1215 UTC September 16. Figure 143. Proposed flight track for N42RF on September 16, 2005. Green line denotes flight track, green dots denote locations of GPS dropsondes, and red dots denote locations of rawinsonde observations. As can be seen from a plot of flight-level winds from each aircraft (Fig. 144), both aircraft were in the storm at the same time. N42RF was providing Doppler radar and dropsonde coverage from 10,000 ft to the surface, while the Aerosonde was providing flight-level measurements of wind, temperature, and moisture at 1500-2500 ft. This is the first time ever that an unmanned aircraft has flown into a tropical cyclone, and it is the first time that is has flown in a tropical cyclone at the same time a research aircraft was also flying it. This demonstrates the possibility of having coordinated low- level and mid-level research flights in tropical cyclones in the future. Figure 144. Flight-level winds (barbs, kt) from N42RF (red) and Aerosonde (blue) in Tropical Storm Ophelia on September 16. System 95L Invest continues to show significant areas of deep convection (Figs. 145, 146. The primary area of activity is in the southwest region of the line of convection. There is some indication of rotation in the visible image in Fig. 145, though it is not clear is this rotation is in the low levels or the mid levels. This rotation is collocated with relatively cold cloud tops indicative of deep convection, and it is further confirmed by satellite microwave and radar measurements (Fig. 147). The shear is also light over the system (Fig. 148), i.e., less than 10 kt. Some of the GFS ensemble members are also developing a system east of the Leeward Islands in the next few days (Fig. 149). For these reasons, it appears that there is a good chance that this system will become a tropical depression soon. Figure 145. GOES-East visible image valid 1115 UTC September 16. Figure 146. GOES-East infrared image valid 1115 UTC September 16. Figure 147. TRMM TMI/PR overpass valid 0720 UTC September 16. Figure 148. CIMSS-derived 850-200 hPa vertical shear (shaded, kt) valid 09 UTC September 16. Figure 149. Plot of detection of vortices in GFS ensemble members for model runs initialized at 00 UTC 16 September 2005. The final system of interest is located at around 21 N 63 W (Fig. 150). There is a region of fairly concentrated convection located just east of an upper-level cyclonic circulation. The proximity to the upper-level circulation makes development of the system unlikely in the next few days. If the upper-level circulation moves away from the area of convection, there is some chance that this could develop. Figure 150. GOES-East infrared image valid 1215 UTC September 16. Saturday, September 17, 2005 The same three systems that were active in the Atlantic basin continue to be active today. A morning water vapor image (Fig. 151) shows that Ophelia has rapidly moved up the U.S. East coast and is now just off Cape Cod. The 95L Invest system, now upgraded to Tropical Depression #17, is located at around 12 N 55 W. The other area of interest, 96L Invest, is still located just north of Puerto Rico. Tropical Storm Ophelia is finally nearly out of the picture for the United States, after nearly two weeks of being in close proximity to the U.S. East Coast. The system has been transitioning to an extratropical system for the past 24 h or so. The second of the two-day extratropical transition experiment is being flown today. The plan today (Fig. 152) calls for a pass through the core of the system from northwest to southeast, then a sampling of the environment, ending with a figure-4 through the system and returning to Portsmouth. Figure 151. GOES-East water vapor image valid 1215 UTC September 17. The Invest 95L system has developed into Tropical Depression #17. Visible satellite imagery (Fig. 153) shows a concentrated area of convection near 11 N 55 W where T.D. #17 is located. Deep convection within the system is evident in infrared imagery (Fig. 154), and a QuikScat overpass shows a well-defined closed circulation in this area. Many of the wind barbs are rain-flagged, but there are some barbs that are not flagged that indicated southwesterly winds of 40 kt. Wind shear remains light (Fig. 155), and track guidance brings the system just northeast of the Leeward Islands (Fig. 156). The Invest 96L also persists north of Puerto Rico. The water vapor image shown in Fig. 151 shows that the upper-level circulation has shifted a little further west, providing a somewhat more favorable environment for the development of this system. Figure 152. Proposed flight track for N42RF on September 17, 2005. Green line denotes flight track, green dots denote locations of GPS dropsondes, and red dots denote locations of rawinsonde observations. Figure 153. GOES-East visible image valid 1215 UTC September 17. Figure 154. GOES-East infrared image valid 1245 UTC September 17. Figure 155. QuikScat overpass (barbs, kt) valid 1240 UTC September 17. Figure 156. CIMSS-derived 850-200 hPa vertical shear Sunday, September 18, 2005 Today there are two primary systems of interest: Tropical Depression #18 and Tropical Storm Philippe (Fig. 158). Tropical Storm Philippe was upgraded from T.D. #17. It is located northeast of Barbados (Fig. 159). Infrared imagery shows a core of deep convection located over the core, though the pattern of coldest cloud tops does suggest some light westerly and northwesterly shear. The CIMSS shear supports this contention (Fig. 160). Track forecast guidance (Fig. 161) predicts that Philippe will track north-northwestward east of the islands. With such a track it would remain within a 2.5-h ferry range from St. Croix for the next several days. Figure 158. GOES-East water vapor image valid 1915 UTC September 18. The other system, T.D. #18, developed from the system 96L Invest. Visible satellite imagery (Fig. 162) shows that the system has developed banded outflow to the north and south of the center. Infrared imagery (Fig. 163) shows that some deep convection is located within the circulation, but it is somewhat elongated in the west- northwest/east-southwest direction. Vertical shear (cf. Fig. 159) is low over the depression, and SST掇 are high (not shown), indicating a favorable environment for intensification. Track guidance (Fig. 164) brings the system west into the Florida Straits, into the Gulf of Mexico after 2-3 days. Today N43RF ferried down to St. Croix with the NRL P-3 for operations in Tropical Storm Philippe, to begin tomorrow. During the ferry down, it was learned that one of the NOAA P-3掇 was going to be tasked the following day for a SFMR/fix mission into T.D. #18, which was expected to become Tropical Storm Rita by the following day. N42RF, which had originally been planned to fly down to St. Croix on the same day, developed engine trouble at the end of the previous day掇 extratropical transition Figure 159. GOES-East infrared image valid 1915 UTC September 18. Figure 160. CIMSS-derived 850-200 hPa vertical shear (shaded, kt) valid 15 UTC September 18. experiment. For this reason N42RF would remain down in New Hampshire today and return to Tampa the following day. Replacement of the engine would take at least three days, meaning N42RF would not be available for flights until Thursday at the earliest. For this reason N43RF would have to return to Tampa the day after arriving in St. Croix, performing the tasking into Rita on the ferry back. The NRL P-3 would fly along with N43RF, flying along any rainbands that may have formed by the time of the flight. Figure 161. Track forecast guidance for Tropical Storm Philippe valid 12 UTC September 18. Figure 162. GOES-East visible image valid 1915 UTC September 18. Figure 163. GOES-East infrared image valid 1915 UTC September 18. Figure 164. Track forcast guidance for T.D. #18 valid 18 UTC September 18.