3FASTEX AIRCRAFT CHIEF SCIENTIST EVENT LOG

Flight Number: 970205H1 Page 1 of

Date: February 6, 1997 Aircraft ID: 42RF Scientist: Jorgensen

Event Log

  Time      Approx. Location                      Event & Comments                      
  (UTC)        (Lat, Lon)                                                               
20:40:11   Shannon             Engine Start                                             
20:42:30   Shannon             Block out                                                
                               This is mission 7 and IOP11.  Mission is LOW 30.  Will   
                               perform coordinated runs with UK C-130 near low center   
20:54:02   52.709   -8.910     Take off                                                 
21:07:49   53.170   -9.790     radars are up                                            
21:17:14   53.567  -10.512     contact with METMAN                                      
21:51:16                       TA apparently not working correctly - techs working on   
                               it                                                       
21:54:53   55.366  -13.348     in extensive stratiform percip - mostly below 5 km.      
                               See bright band about 1 km above sfc                     
21:55:59   55.426  -13.433     begin descent to 5 kft about 40 km from buoy             
21:58:46                       begin recording radar data-TA still being worked on      
22:02:18   55.821  -13.975     at 5k ft-tracking toward the buoy                        
22:06:42                       contact with 308D-they are still hunting for a good      
                               band to work-we are in extensive stratiform precip       
                               with a strong bright band                                
22:07:48   55.980  -14.445     now tracking 255 to the storm center                     
22:09:49                       TA now apparently up and running                         
22:17:26   55.861  -15.355     curved bands of precip                                   
22:21:59   55.816  -15.757     climbing up 1000 ft to get on top of the shear layer     
22:27:05   55.762  -16.162     temps about 2 degrees warmer at 6k ft than at 5k ft -    
                               turbulence much reduced too-may have cross on top of     
                               the front                                                
22:34:03   55.703  -16.705     more cellular precip as we proceed WSW                   
22:51:15                       TA malfunctioning again radial velocities look bad       
23:00:25   55.424  -18.776     curved bands 200-300 km to the north                     
23:03:40                       G-IV apparently entered the box at the same altitude     
                               as METMAN.  The C-C-130 descended to 24k ft              
23:09:55                       contact with METMAN                                      
23:13:55                       techs will try to replace the Doppler signal processor   
23:25:17   55.122  -20.779     radar system down as the DSP is replaced                 
23:25:44   55.115  -20.822     banded features to the NW might be cold front or bent    
                               back region                                              
23:29:38   55.068  -21.139     sfc pressures continue to fall as we get close to the    
                               trough axis                                              
23:47:47   54.818  -22.688     can't get far enough west to go through the front -      
                               turning to track to our IP with METMAN                   
23:49:59                       TA seems to be working better                            
23:51:17   55.007  -22.672     now tracking 020 toward pt 1                             
0:00:21    55.643  -22.308     descending back down to 5k ft                            
                               position report from 49: 54 44N 23 38W                   
0:10:04    56.214  -21.976     apparently through the front at this level as the        
                               winds have shifted to the north and temps have dropped   
                               to -4.2C                                                 
0:12:55                        apparently 308D is heading back                          
0:31:47    57.401  -21.239     still in extensive stratiform precip-cold front well     
                               marked on LF as band to our SE.                          
0:32:45    57.457  -21.202     at IP starting leg 1 with METMAN                         
0:44:41    57.050  -20.073     cloud deck coming down on TA - temps warming a few       
                               degrees and winds shifting to SW                         
0:49:27    56.874  -19.641     more turbulent as we move into the warm side - more      
                               convective type cells evident on TA                      
0:52:07    56.773  -19.396     pronounced slope to the echoes on the TA from S to N     
1:01:28    56.410  -18.551     winds now up to 70 knots from 225 as we move into the    
                               warmer air on the SE side of the front                   
1:03:34                        METMAN reports sonde system failure, most of the         
                               sondes on this run may be lost                           
1:12:13    55.979  -17.598     going through a field of shallow convective type cells   
1:19:07    55.695  -16.984     going down to 1000 ft to check out the low level jet     
                               strength                                                 
1:23:49    55.509  -16.605     at bottom of descet-climb up to 8 kft                    
1:26:05    55.444  -16.719     out of the turbulent boundary layer at1000 m altitude    
                               (RA)                                                     
1:28:48    55.365  -16.878     now tracking 231 to point 3 end of leg 1                 
1:40:49    55.051  -17.631     at pt 3 turn to track 333 to pt 4 start of leg 2         
1:43:03                        METMAN reports its turn to the NW at 0131                
1:50:11    55.645  -18.133     cold front curves to the east north of us - becoming a   
                               warm front with wave development near us?                
1:54:14    55.903  -18.351     some increase in turbulence                              
1:55:08    55.963  -18.402     back to calmer air                                       
1:57:30    56.106  -18.535     entering stratiform precip                               
2:04:45    56.565  -18.945     very strong bright band now up to 35 dBZ                 
2:13:47    56.565  -18.945     precip decreasing in intensity                           
2:16:25    57.298  -19.637     there has been a change in the orientation of the sea    
                               clutter from a maximum to the south to a maximum to      
                               the north - change in sfc winds reflecting strong        
                               northerlies behind the front?                            
2:17:41    57.375  -19.708     winds dropping off rapidly now                           
2:20:20    57.534  -19.856     small line line on LF immediaately ahead 5 nm            
2:30:45    58.161  -20.462     extended the leg slightly to go through the narrow       
                               thin reflectivity line                                   
2:31:23    58.183  -20.521     end of the leg - turning to track 205 to pt 5            
2:33:09    58.087  -20.625     never did get into the cold air at 8k ft                 
2:42:28    57.525  -21.083     end of cross leg at pt 5-trk 132 on leg 3                
2:47:35    57.311  -20.616     winds now backing around to SW-wind speed now            
                               increasing too-very light stratiform precip              
3:01:38    56.761  -19.252     going through small band-looks fairly stratiform on TA   
3:03:31    56.683  -19.071     sfc position of the front is apparently marked by a      
                               sea clutter minimum                                      
3:12:20    56.326  -18.229     through the last weak band indicating we're into the     
                               warm side of the sfc position of the front.              
                               Descending to 1000 ft in a mini-sounding to map the      
                               low level jet                                            
3:15:08    56.216  -17.981     now in precip free region                                
3:20:39    56.009  -17.533     at 1000 ft in turbulent air - climbing back up to 5k     
                               ft.  Low level jet max of 75 knots at 3000 ft.           
                               Decreasing below                                         
3:25:00    55.851  -17.184     cutting this leg a little short to save a little time.   
                               End of Leg 3.  Turn to trk 255 to new pt. 7              
3:28:20                        at 5k ft for rest of run                                 
3:29:37                        wind direction and the track are the same.  Every bit    
                               of the 72 knot wind is in our face                       
3:41:33                        now trk 337 start of leg 4                               
3:52:25    56.250  -18.685     most turbulence so far as we go through the front for    
                               the last time                                            
3:54:08    56.360  -18.777     entering frontal precip zone                             
4:01:31    56.820  -19.157     turbulence decreasing as we apparantly moved through     
                               the narrow cold front band                               
4:22:45    57.966  -20.142     at the final end point-extending the leg 20 nm farther   
                               NW to examine secondary band of precip                   
4:29:26    58.328  -20.453     end of leg, climb to 15k ft for trek to buoy-the extra   
                               altitude is for fuel economy                             
4:30:32    58.357  -20.366     still in light stratiform precip                         
4:36:53    58.122  -19.668     the frontal width is well marked by the lack of ground   
                               return-approximately 20 nm wide                          
4:51:38                        radar system locked up for a few minutes at 0445 Z       
4:52:46    57.465  -17.936     getting into heavier stratiform precip as we move to     
                               the south-bright band is well defined and >30 dBZ in     
                               spots                                                    
4:58:17    57.226  -17.342     precip decreasing rapidly                                
                               over buoy at 15k ft                                      
6:21:04    53.176   -9.724     begin descent                                            
6:40:06    SNN                 land                                                     
6:45:40    SNN                 block in