Site log - Kwaj (April 2000)

Flags:

1-Satellite coincidence data
2-Scan in TSDIS data
A-Major problem (moderate to strong AP > 25 dBZ &/or widespread coverage > 10%)
B-Minor problem (weak AP &/or very little coverage)

*******************************************************************************
VR mask (V1) applied to all April data
NOTE: +5 Calibration addition may change...radar may have been recalibrated
      during March, so additional calibration offset may not be needed
      at all for April.    
*******************************************************************************

01 Apr 00:    Scattered showers for much of the day.  After 17Z, a few small
              convective clusters & lines. 

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
 
              Sat. Coincidence: 0030Z(483 km), 1150Z(707 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied

 A !!FLAG!!              Atoll clutter specks scattered throughout
                         the day in the normal locations.  Most are
                         corrected, but a few may remain.  Potential
                         2nd trip contamination at 2022Z to the SW,
                         too.

*******************************************************************************

02 Apr 00:    Scattered showers and a few clusters.  Clusters are
              located in S half of scope.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
 
              Sat. Coincidence: 0053Z(369 km), 1038Z(35 km), 2341Z(289 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied

 A !!FLAG!!              Atoll clutter specks scattered throughout
                         the day in the normal locations.  Most specks
                         are corrected.

*******************************************************************************

03 Apr 00:    Some scattered showers.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
 
              Sat. Coincidence: 0925Z(612 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                         Atoll clutter specks scattered throughout
                         the day in the normal locations.  Most specks
                         are corrected.

*******************************************************************************

04 Apr 00:    Some scattered showers.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
 
              Sat. Coincidence: 0004Z(554 km), 0949Z(230 km), 2252Z(92 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                         Atoll clutter specks scattered throughout
                         the day in the normal locations.  Most specks
                         are corrected.

*******************************************************************************

05 Apr 00:    Some scattered showers and a few small convective
              clusters after 12Z.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
 
              Sat. Coincidence: 0837Z(425 km), 2316Z(740 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                         Atoll clutter specks scattered throughout
                         the day in the normal locations.  Most specks
                         are corrected.

*******************************************************************************

06 Apr 00:    Scattered precip most of the day.  No significant
              organized convective systems, though.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-1932Z
                              2052-2352Z
 
              Sat. Coincidence: 0901Z(430 km), 2204Z(104 km)

              OVERPASS CASE: Orbit: 13578, Time: 2204Z, Distance: 104 km
                             PR swath captures a few convective 
                             cells to the N of Kwaj.

              QC notes:  VR mask applied
             
                         No major QC issues.

*******************************************************************************

07 Apr 00:    Scattered individual convective cells and a few
              small convective systems.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
 
              Sat. Coincidence: 0748Z(233 km), 2051Z(565 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                         No major QC issues.

*******************************************************************************

08 Apr 00:    Scattered individual convective cells and convective clusters
              for most of the day, with most widespread activity early in
              the day.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
 
              Sat. Coincidence: 0812Z(630 km), 2115Z(296 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                         No major QC issues.

*******************************************************************************

09 Apr 00:    A few scattered showers before 14Z, then activity increases
              slightly.  A small convective complex forms in the SE quadrant 
              after 20Z and moves to NW for rest of the day.  

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
 
              Sat. Coincidence: 0700Z(41 km), 2003Z(367 km)

              OVERPASS CASE: Orbit: 13615, Time: 0700Z, Distance 41 km
                             Marginal case.  PR may catch some scattered
                             showers to S and SE of Kwaj. 

              QC notes:  VR mask applied
             
                         No major QC issues.

*******************************************************************************

10 Apr 00:    Great precip event after 16Z.  Scattered precip early slowly
              buildly in intensity and coverage.  By 16Z, numerous 
              convective systems form, mature, then dissipate to produce
              large area of stratiform (w/ possible embedded convective 
              elements.  Best case in awhile.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-0032Z
                              0122-2352Z
 
              Sat. Coincidence: 0547Z(682 km), 2027Z(486 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
  A  !!FLAG!!            Perhaps some 2nd trip embedded in legitimate
                         precip after about 18Z in SE quadrant. VR
                         mask eliminates most obvious 2nd trip echo,
                         but can't rule out possibility of embedded
                         spurious echo.  Also could be a few scattered
                         small atoll clutter specks.
*******************************************************************************

11 Apr 00:    Tremendous precip event continues through 11Z.  Widespread
              moderate to intense precip lingers through 10Z, then
              quickly dissipates.  A few scattered showers after 11Z,
              but no significant activity.  

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
 
              Sat. Coincidence: 0611Z(156 km), 1914Z(167 km)

              OVERPASS CASE: Orbit: 13646, Time: 0611Z, Distance: 156 km
                             PR swath captures widespread precip event.

                             Orbit: 13655, Time: 1914Z, Distance: 167 km
                             PR may capture a few scattered showers.

              QC notes:  VR mask applied
             
  A  !!FLAG!!            Perhaps some 2nd trip embedded in legitimate
                         precip near 11-13Z to the S and SSE. VR
                         mask eliminates most obvious 2nd trip echo,
                         but can't rule out possibility of embedded
                         spurious echo.

*******************************************************************************

12 Apr 00:    Scattered convective clusters all day.  The most
              impressive activity occurs late in the day to the W
              and WSW.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2132Z
                              2212-2352Z
 
              Sat. Coincidence: 0459Z(494 km), 1938Z(673 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                         No major QC issues.

*******************************************************************************

13 Apr 00:    A few leftover convective clusters from previous day early
              on, as well as a thin, broken convective line.  Activity
              quiets down after 05Z, then increases again from 13-18Z.
              Not widespread activity, but there are a few small, briefly
              intense convective cells.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 0523Z(355 km), 1826Z(30 km)

              OVERPASS CASE: Orbit: 13686, Time: 1826Z, Distance: 30 km
                             Marginal case.  PR captures a few convective
                             cells.

              QC notes:  VR mask applied
             
                         No major QC issues.

*******************************************************************************

14 Apr 00:    Fairly active day with constant progression of
              convective cells and clusters across the radar
              FOV throughout the day.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 0411Z(303 km), 1714Z(636 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                         No major QC issues.

*******************************************************************************

15 Apr 00:    Scattered convective cells, lines, and clusters
              for most of the day.  Precip is more organized in
              earlier hours, scattered in later hours.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 0435Z(559 km), 1738Z(228 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                         Clutter specks after 22Z corrected.

*******************************************************************************

16 Apr 00:    Scattered showers.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 0322Z(107 km), 1625Z(432 km)

              OVERPASS CASE: Orbit: 13723, Time: 0322Z, Distance: 107 km
                             Marginal case.  PR may capture a few light
                             to moderate showers.

              QC notes:  VR mask applied
             
                         Scattered atoll clutter specks all day are
                         corrected.

*******************************************************************************

17 Apr 00:    Very quiet early, then scattered convective cells 
              develop after 12Z.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 0210Z(744 km), 1649Z(420 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                         Scattered atoll clutter specks before 1232Z
                         are corrected.

*******************************************************************************

18 Apr 00:    Scattered cells and small clusters/lines for most of the day.
              No large, organized areas of precip.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 0234Z(89 km), 1537Z(233 km)

              OVERPASS CASE: Orbit: 13754, Time: 0234Z, Distance: 89 km
                             PR captures a few convective cells to the
                             extreme WSW of radar FOV.

              QC notes:  VR mask applied
             
                         Scattered atoll clutter specks in a few VOSs are
                         corrected.

*******************************************************************************

19 Apr 00:    Scattered convective cells early, then a thin line
              moves in from ESE after 08Z, but dissipates after 12Z.
              After a lull in activity, scattered precip develops
              after 14Z and gradually builds in intensity and areal
              coverage.  Numerous convective lines/clusters form
              after 17Z.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 0122Z(558 km), 1601Z(609 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                         Scattered atoll clutter specks in a few VOSs are
                         corrected.  Perhaps a few 2nd trip echo specks
                         after 15Z in a few VOSs (SW quadrant).

*******************************************************************************

20 Apr 00:    Active day through 11Z, then again after 13Z.  
              Numerous organized convective systems, especially early
              in the day, then again after 16Z.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 0145Z(285 km), 1448Z(41 km)

              OVERPASS CASE: Orbit: 13794, Time: 1448Z, Distance: 41 km
                             PR captures scattered convective cells.

              QC notes:  VR mask applied
             
  A !!FLAG!!             A few embedded clutter specks. No
                         other major QC issues.

*******************************************************************************

21 Apr 00:    MCS's from previous day move out of radar FOV after 04Z. 
              A few broken convective elements and scattered small
              cells for the rest of the day.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 0033Z(374 km), 1336Z(711 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                         A few clutter specks that were corrected.

*******************************************************************************

22 Apr 00:    Scattered individual convective cells.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 0057Z(483 km), 1400Z(154 km), 2344Z(184 km)

              OVERPASS CASE: Orbit: 13825, Time: 1400Z, Distance: 154 km
                             Marginal case. PR captures a couple of small
                             cells to NW of Kwaj radar.

              QC notes:  VR mask applied
             
                         A few clutter specks that were corrected. 

*******************************************************************************

23 Apr 00:    Scattered convective cells and small clusters most of
              the day.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 1247Z(516 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                         A few clutter specks that were corrected.  
                         Also a few 2nd trip specks that are mostly
                         corrected.

*******************************************************************************

24 Apr 00:    A convective cluster to SW and a few other scattered cells
              through 04Z, then a lull in the activity.  Scattered cells
              form after 08Z, followed by a broken convective line. 
              By 16Z, intense convective fires up along an E-W axis
              just S of the Kwaj radar.  By 23X, S half of radar scope
              has a mixture of intense convection and moderate stratiform.
              Great TRMM overpass case near 23Z.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 0008Z(679 km), 1311Z(344 km), 2256Z(10 km)

              OVERPASS CASE: Orbit: 13862, Time: 2256Z, Distance: 10 km
                             PR captures impressive convective system
                             S of the Kwaj radar.   

              QC notes:  VR mask applied
             
                         A few clutter specks that were corrected.  

*******************************************************************************

25 Apr 00:    Widespread precip from numerous convective systems 
              in S half of radar scope through 06Z. A few intense
              convective cells/clusters through about 08Z, then
              precip becomes scattered and smaller in areal coverage.
              Only a handful of showers late in the day.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 1158Z(315 km), 2143Z(637 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                        Numerous clutter specks that were corrected.
 A !!FLAG!!             A couple clutter specks not corrected, but
                        only affect one or two VOSs.   

*******************************************************************************

26 Apr 00:    Very little activity until after 11Z.  After 11Z, scattered
              invidiual cells, small convective lines & clusters in E to
              W flow.  

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 1222Z(528 km), 2207Z(637 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                        Numerous clutter specks that were corrected.

*******************************************************************************

27 Apr 00:    Numerous convective clusters early on provide most significant
              activity of the day.  However, scatttered precip occurs
              all day long, tapering off near the end of the day.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 1110Z(119 km), 2055Z(449 km)

              OVERPASS CASE: Orbit: 13902, Time: 1110Z, Distance: 119 km
                             PR captures scattered small convective cells
                             in SE quadrant of radar FOV.

              QC notes:  VR mask applied
             
                         Numerous clutter specks that were corrected.

*******************************************************************************

28 Apr 00:    Scattered precip all day.  Activity not widespread or
              significant.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 1134Z(717 km), 2118Z(403 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
                         Numerous clutter specks that were corrected.

*******************************************************************************

29 Apr 00:    Scattered individual cells and small lines/clusters all day.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 1021Z(75 km), 2006Z(261 km)

              OVERPASS CASE: Orbit: 13933, Time: 1021Z, Distance: 75 km
                             Marginal case.  PR may capture some scattered
                             small cells, but the swath appears to miss
                             the small cluster located S of Kwaj.

              QC notes:  VR mask applied
             
                         Numerous clutter specks that were corrected.

*******************************************************************************

30 Apr 00:    Scattered individual cells and small lines/clusters all day.

              Calibration adjustment +5 dB.
 
              Data Analyzed:  0002-2352Z
                               
              Sat. Coincidence: 0909Z(591 km), 2030Z(604 km)

              OVERPASS CASE: 

              QC notes:  VR mask applied
             
 A !!FLAG!!              A few small embedded clutter specks.