Site log - Houston (November 1998)

Flags:

1-Satellite coincidence data
2-Scan in TSDIS data
3-Scan not in TSDIS data
A-Major problem (moderate to strong AP > 25 dBZ &/or widespread coverage > 10%)
B-Minor problem (weak AP &/or very litte coverage)

NOTE:  Asterisks surrounding satellite coincidence times &/or distances denote
       overpasses originally affected by bad satellite coincidence tables.  
       Only affects Houston data passed to TSDIS from 980901 thru 981111.

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

01 Nov 98:    Light, scattered precip after 0430Z.  A few intense cells form after 13Z.
              Leading edge of MCS moves in from W after 14Z.  MCS moves through the
	      radar scope from W to E for rest of the day.  Some intense embedded
	      convection and lots of light to moderate stratiform precip associated
	      w/ the MCS. 

              Data processed:  0002-2355Z 

              Satellite Coincidence:  0138Z(118 km), 0315Z(598 km), 0452Z(499 km),
				      0628Z(158 km) 

              QC notes:  0002-0433Z:  Chaff-like echo persists.  No real precip
				      w/in 150 km. 
                               ---->  Corrected.

                         0438-0639Z:  Precip in SW quadrant, some chaff remains
				      to NE. 
   1B, 2B, 3B !!FLAG!!         ---->  Precip is very light & shallow, so raising
				      params removes some small showers. Also, a
				      few specks of light spurious echo remain.
                                      Difficult to find the perfect set of params
				      in this scenario, but both spurious echo and
				      precip are light.

                              0654Z:  Precip to W and SW, some very light chaff to NE.
                               ---->  Corrected.
                           
                         0704-0709Z:  Precip to W and SW, some very light chaff to NE.
                               ---->  Corrected.

                         0739-0744Z:  Precip to W and SW, some very light chaff to NE.
                               ---->  Corrected.

                         0754-0835Z:  Precip to W and SW, some very light chaff to NE.
                               ---->  Corrected.

                         1844-1859Z:  Embedded clutter speck to W of radar.
          3A  !!FLAG!!         ---->  Speck is embedded in light precip, then gets
			              covered by intense precip afterwards.
                     *Clutter Range:  w/in 25 km.

                         1934-2355Z:  Hole in precip surrounding radar.  Also some
				      potential light spurious echo to extreme W 
                                      after about 20Z.
      2B, 3B  !!FLAG!!         ---->  Some improvements made, but flagged for some
				      light precip that is removed in a few VOSs.
                                      Also, there are still additional problems 
				      in the following VOSs:
          3B+ !!FLAG!!         ====>  2109-2129Z:  Embedded clutter specks near 
				      radar.
                     *Clutter Range:  w/in 25 km.
      2B+,3B+ !!FLAG!!         ====>  2229-2250Z:  Embedded clutter specks near 
                                      radar.
                     *Clutter Range:  w/in 25 km.
          3B+ !!FLAG!!         ====>  2305-2325Z:  Embedded clutter specks near 
                                      radar.  Also light spurious echo to SW at
				      2325Z.
                     *Clutter Range:  w/in 25 km.
                         *CAE Range:  near 150 km. 

			 % of data reprocessed:  139/275 VOSs = 51%

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

02 Nov 98:    Some intense convection and scattered light to moderate precip early 
	      in the day associated w/ MCS described in previous day. Remnants of the MCS 
              move out by 08Z.   

              Data processed:  0000-2351Z

              Satellite Coincidence:  0026Z(251 km), 0202Z(457 km), 0339Z(615 km), 
				      0516Z(190 km), 0652Z(733 km), 2313Z(701 km) 

              QC notes:  0050-0331Z:  Scattered, light AP to W & NW.
   1B, 2B, 3B !!FLAG!!         ---->  Corrected, but still may be some
				      spurious echo on fringes of precip
				      when precip is embedded in it.

                         0336-0401Z:  Scattered, light AP to W & NW.  Also some
		             	      intense AP to SW.
                               ---->  Corrected.

                         0407-0541Z:  Scattered, light AP to W & NW.  Also some
                                      intense AP to SW.
   1A, 2A, 3A !!FLAG!!         ---->  AP too intense (& has some vertical depth)
				      to remove w/o eliminating all precip to E.
				      Some improvements, but still a major problem.                      

                         0546-0601Z:  Scattered, light AP to W.
                               ---->  Corrected.

                         0606-0752Z:  Scattered light to intense AP to W.
                               ---->  Corrected inside 150 km.

                         0757-1441Z:  AP, sometimes widespread and intense, w/o
				      any precip inside 150 km.
                               ---->  Corrected.

                         2004-2202Z:  Small moderate to intense speck of strange
				      echo to NE.
                               ---->  Corrected.
                               
			 % of data reprocessed:    174/231 VOSs = 75%
			 
****************************************************************************************

03 Nov 98:    No precipitation.

              Data processed:  0001-2359Z

              Satellite Coincidence:  0050Z(210 km), 0226Z(618 km), 0403Z(444 km),
                                      0540Z(277 km), 2337Z(134 km)

              QC notes:       0239Z:  Light patch of spurious echo. 
                               ---->  Corrected.

                         0545-0704Z:  Light remnants of CAE shield to NW.
                               ---->  Corrected.

                              0843Z:  Light patch of spurious echo.
                               ---->  Corrected.

                         0903-1457Z:  Light remnants of spurious echo, w/
				      some moderate to intense specks.
                               ---->  Corrected.
                               
			 % of data reprocessed:    48/146 VOSs = 33%                               

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

04 Nov 98:    No signicicant precipitation within 150 km of radar. 

              Data processed:  0011-2358Z

              Satellite Coincidence:  0114Z(509 km), 0250Z(592 km), 0427Z(99 km), 
				      2225Z(563 km)

              QC notes:  0011-1109Z:  Scattered, mostly light, spurious echo.
                               ---->  Corrected.

                         1239-1430Z:  Scattered, mostly light, spurious echo.
                                      A lone shower to extreme SW beyond 150 km.
                               ---->  Corrected.
                               
			 % of data reprocessed:    87/207 VOSs = 42%                               
                                      
****************************************************************************************

05 Nov 98:    A few regions of light to moderate precip move in from W after 3Z, but
	      most precip dissipates before reaching the radar.  A larger shield
	      of precip enters from W after 06Z and holds together for many hours,
	      moving S of the radar by 11Z and out of the radar scope by 14Z.
              A few left over showers to S/SE after 15Z, but not significant.
	

              Data processed:  0013-2341Z

              Satellite Coincidence:  0001Z(292 km), 0138Z(629 km), 0314Z(381 km),
				      0451Z(402 km), 2249Z(23 km) 

              QC notes:  0023-0042Z:  A few specks of spurious echo.
                               ---->  Corrected.

                         0907-0912Z:  Clutter speck to NW.
                               ---->  Corrected.

                         0917-1158Z:  Hole in precip surrounding radar.
                                      Also some embedded clutter specks.
     2A-, 3A- !!FLAG!!         ---->  Hole corrected, but persistent, often intense
				      specks cannot be readily removed w/o severely
				      impacting real precip.
                      CLUTTER RANGE:  near 45 km to NW, w/in 25 km elsewhere.

                         1203-1258Z:  Embedded clutter specks.
     2A-, 3A- !!FLAG!!         ---->  A few specks improved in a couple of VOSs,
				      but some specks are too difficult to remove. 
                      CLUTTER RANGE:  w/in 25 km surrounding radar. 

                         0500-1359Z:  After the reprocessing was completed from
				      the previous time periods, range dependenti
                                      holes and gaps in the second tilt images
				      was also observed.  
                               ---->  Corrected.

			 % of data reprocessed:    63/265 VOSs = 24%
			 
****************************************************************************************

06 Nov 98:    Some scattered, extremely light echoes move quickly from SW to NE after
	      15Z. 

              Data processed:  0011-2359Z

              Satellite Coincidence:  0025Z(553 km), 0202Z(560 km), 0339Z(5 km), 
				      2136Z(426 km), 2313Z(368 km)  

              QC notes:  0140-0159Z:  Light CAE specks.
                               ---->  Corrected.

                         1300-1349Z:  Light spurious echo specks.
                               ---->  Corrected.
                               
			 % of data reprocessed:    9/146 VOSs = 6%                               

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

07 Nov 98:    Scattered light showers through 09Z, then a few moderate to intense cells
	      to the N after 10Z.  A small lull in the action after 12Z, then some
	      additional scattered showers and convection after 15Z.  Overpass at 2200
              catches a small convective system to WSW of radar, as well as light precip
	      to NW.

              Data processed:  0009-2357Z

              Satellite Coincidence:  0049Z(630 km), 0226Z(307 km), 0402Z(537 km),
				      2200Z(80 km), 2337Z(587 km) 

              QC notes:  2206-2357Z:  Some holes & chunks in precip as it nears
				      radar.
                               ---->  Corrected, but some clutter specks are 	
                                      embedded in the following VOSs:
         1A-  !!FLAG!!         ====>  2331-2357Z:  Embedded clutter specks.
                     *CLUTTER RANGE:  w/in ~40 km.
                     
			 % of data reprocessed:    23/253 VOSs = 9%                     

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

08 Nov 98:    A broken line of scattered showers and heavier convective cells persists
	      from 00-14Z.  Line breaks up near 15Z, with only a dissipating convective
              system to SE through 17Z.  

              Data processed:  0002-2359Z

              Satellite Coincidence:  0113Z(518 km), *0250Z(117 km)*, *2047Z(303 km)*,
				      2224Z(432 km)

              QC notes:  0002-0247Z:  Light showers embedded in a shield of 
			              light CAE to W and NW of radar.
  1B, 2B, 3B  !!FLAG!!         ---->  A broad, minor flag for this period.  After
				      some experimenting, the default params were
				      not changed.  Some light spurious echo and
				      specks are picked up as light, small showers
				      move to W/NW of radar, but not much can be
				      done to improve the situation w/o affecting
				      real precip. 
                          *AP RANGE:  w/in 100 km.
                     *CLUTTER RANGE:  w/in 25 km.

                         Following VOSs have embedded clutter specks (no 
                         reprocessing attempted): 

    2A, 3A !!FLAG!!    0652-0712Z
    2A, 3A !!FLAG!!    0732-0807Z
        3A !!FLAG!!         0827Z
        3B !!FLAG!!         0837Z
        3A !!FLAG!!    1007-1017Z
    2A, 3A !!FLAG!!    1037-1222Z
                     *CLUTTER RANGE:  w/in 25 km.    

			 % of data reprocessed:    33/276 VOSs = 12%				      

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

09 Nov 98:    A few scattered, mostly light, echoes after 06Z.   A N-S broken line of
	      light showers (a few moderate cells, too) after 17Z.  This line breaks
              up by 20Z and only a few scattered showers remain.
	      

              Data processed:  0004-1251Z	
                               1706-2357Z

              Satellite Coincidence:  0001Z(621 km), 0137Z(*229 km*), 0314Z(674 km),
				      2111Z(*175 km*), 2248Z(*612 km*) 

              QC notes:	 0004-0500Z:  Scattered light to intense AP specks and patches.
				      No signficant precip echoes w/in 150 km.	:w
                               ---->  Corrected.

                         1706-2012Z:  Chaff echoes to the E.  Looks like real precip
				      in a N-S line near radar.
  2A-, 3A-    !!FLAG!!         ---->  Cannot remove chaff w/o severely affecting
				      line of precip nearer to radar.  Chaff has
				      vertical continuity and is located at further
                                      ranges than the precip, thus making this 
				      situation very difficult (and chaff is as or
			              more intense than actaul precip).  Chaff
				      is not too widespread, but still flagged as
				      a significant problem since it persists for
				      three hours.
  
                              2357Z:  Small patch of spurious echo o W. 
                               ---->  Corrected.

			 % of data reprocessed:    99/232 VOSs = 43%
			                  
****************************************************************************************

10 Nov 98:    A few lines of mostly light showers before 09Z. After 09Z, numerous
	      bands of precip form, some containing embedded intense convection.
              An impressive convective line forms to SE near 15Z.  Most precip
	      exits the radar scope by 20Z

              Data processed:  0007-2355Z       

              Satellite Coincidence:  0025Z(467 km), 0201Z(230 km), 1959Z(179 km), 
				      2136Z(490 km), 2312Z(602 km)

              QC notes:  0023-0108Z:  CAE to NE. 
                               ---->  Corrected.

                         1235-1240Z:  Light patches of AP to in NW quadrant.
         3B   !!FLAG!!         ---->  Any attempt to remove AP at such long
				      ranges (w/ precip closer in that's just
				      as intense as the AP) resulted in
				      creating obvious scattered range-dependent
				      holes in light precip.  Thus, params
				      aren't changed and period is flagged. 
                          *AP RANGE:  near 150 km.

                              1245Z:  Light to moderate patches of AP to in NW quadrant.
         3A   !!FLAG!!         ---->  Same as last period, except more intense. 
                          *AP RANGE:  near 150 km.

                              1251Z:  Same as last period.
         3B   !!FLAG!!         ---->  Light AP remains. 
                          *AP RANGE:  near 150 km.

                         1256-1311Z:  Intense AP to N.
         3A+ !!FLAG!!          ---->  Same situation as previous period, only
				      AP is very intense.  Using 1321Z in 
				      1C.HDF since the AP is much less intense.
                          *AP RANGE:  130-150 km.

                         1316-1446Z:  Light to moderate AP scattered in W, N,
				      and NE.  Also evidence of a hole in
			              light precip surrounding radar after 1357Z.
                                      A few holes and gaps in precip outside 50 km
				      to SW, too.
   2A-, 3A-  !!FLAG!!          ---->  Same as previous periods.  Using 1452Z in
				      1C.HDF.     
                          *AP RANGE:  130-150 km.

                         1452-1557Z:  A few holes and gaps in precip away from 
				      radar.
                               ---->  Corrected.

                         2326-2355Z:  Light CAE to N/NW.
                               ---->  Corrected.

                         NOTE:  Including 1321Z in 1C.HDF instead of 1301-1316Z.
                                Including 1452Z in 1C.HDF instead of 1432-1446Z.
                                
			 % of data reprocessed:    56/259 VOSs = 22%
			 
****************************************************************************************

11 Nov 98:    Light echoes to S late in the day.  Not widespread or significant.  

              Data processed:  0015-2346Z

              Satellite Coincidence:  0049Z(135 km), *1847Z(616 km)*, *2023Z(261 km),*
                                      *2200Z(626 km)*, *2336Z(406 km)*
				      

              QC notes:  0015-2256Z:  Combination of mostly light shield of
				      CAE &/or AP specks and splotches.  No
				      precip w/in 150 km. 
                               ---->  Corrected.

                         2306-2326Z:  Same as last period, but some light 
				      echoes (presumably meteorological)
			              move just inside 150 km to the S.
   2B , 3B  !!FLAG!!           ---->  Spurious echo to N is just as intense
				      as presumed real echo to S, also
				      just as deep.  Thus, any attempts
                                      to selectively remove spurious echo
				      and keep precip intact are almost
				      impossible w/o some sort of sector
                                      specific QC capabilities.
                          CAE RANGE:  130-150 km.
 
                         2336-2346Z:  Larger shield of CAE to N and NE.
   2B+, 3B+  !!FLAG!!           ----> Same as previous period, only a
			              more significant problem since 
				      spurious echo is more widespread 
   			 	      than precip.
                          CAE RANGE:  130-150 km.
                          
			 % of data reprocessed:    144/144 VOSs = 100%                           

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

12 Nov 98:    Scattered, light echoes early in the day.  After 08Z, a few heavier
	      cells develop.  After 10Z, a multicell convective system enters from
	      the NW.  Over the next few hours, a NE-SW band of moderate to heavy precip
              continues sliding further into the radar scope from the W and NW.  Embedded
              convection within a broader stratiform continues through 20Z.  The 
              convective system continues building on its SW flank as new convection
              continues to form and reinvigorate the system.  By 23Z, a large
	      area of moderate to heavy precip covers most of the NW quadrant.   Good
              TRMM overpass at 1911Z.

              Data processed:  0006-2347Z

              Satellite Coincidence:  *0113Z(353 km)*, 1911Z(63 km), 2047Z(538 km), 
                                       2224Z(573 km)
				       
              QC notes:  0006-0105Z:  Scattered light patches and specks of
				      CAE w/ some light precip echoes, too.  
   1B, 2B, 3B  !!FLAG!!        ---->  Difficult to remove spurious echo while
			              keeping precip echo to S since they're
				      same intensity and range (& precip isn't
				      deep).  Spurious echo is light, though,
				      and < 10% coverage.
                          CAE RANGE:  130-150 km.

                        0115-0459Z:   Scattered light patches and specks of
                                      CAE w/ some light precip echoes, too.
   1B, 2B, 3B  !!FLAG!!        ---->  Difficult to remove spurious echo while
                                      keeping precip echo to S since they're
                                      same intensity and range (& precip isn't
                                      deep).  Spurious echo is light, though,
                                      and < 10% coverage.
                          CAE RANGE:  Generally between ~35-100 km.             
                             
                         0950-1107Z:  Embedded clutter specks near radar.  Also
                                      light precip near radar missing at 1005Z.
   2A, 3A  !!FLAG!!            ---->  Clutter cannot be removed since it's 
				      embedded in precip.
                      CLUTTER RANGE:  near 45 km to NW, near 20 km to W

                         1302-1533Z:  Some light/shallow precip missing.  
                               ---->  Corrected. 

                         1538-1543Z:  Some light/shallow precip missing.  Also
				      embedded clutter speck near radar.
       3A  !!FLAG!!            ---->  Intense speck cannot be removed.  
                      CLUTTER RANGE:  20 km.

                         1548-1638Z:  Some light/shallow precip missing.
                               ---->  Corrected. 

                         1643-1827Z:  Some light/shallow precip missing.  Also
                                      embedded clutter speck near radar.
2B, 3B, 2A, 3A  !!FLAG!!       ---->  Light to intense clutter throughout
				      period. 
                      CLUTTER RANGE:  w/in 30 km to W, ~45 km to NW.

                         2002-2007Z:  Clutter speck to NW near radar. 
       2A , 3A   !!FLAG!!      ---->  Unable to remove clutter.
                      CLUTTER RANGE:  w/in 30 km.

                         2027-2347Z:  Hole in precip near radar. Also embedded
				      clutter specks near radar.
 1A , 2A , 3A    !!FLAG!!      ---->  Clutter almost constantly embedded in
				      precip near radar.
                      CLUTTER RANGE:  w/in 30 km.

			 % of data reprocessed:    166/273 VOSs = 61% 

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

13 Nov 98:    Band of widespread moderate to heavy precip lingers for much of the day.
              Band slides off to ESE after 20Z, but new pockets of precip move in for 
              rest of the day.  Good TRMM overpass at 0001Z. 

              Data processed:  0002-2352Z

              Satellite Coincidence:  0001Z(34 km), *1759Z(474 km)*, *1935Z(342 km)*,
                                      *2112Z(630 km)*, *2248Z(334 km)*

              QC notes:  0002-0412Z:  Hole in precip near radar.
 1A, 2A, 3A  !!FLAG!!          ---->  Corrected the hole, but clutter specks
				      remain embedded in precip. 
                              RANGE:  w/in 25 km.

                         0617-0759Z:  Hole in precip near radar.
                               ---->  Corrected the hole, but embedded clutter specks
                                      remain during the following time periods:
     2A, 3A  !!FLAG!!          ====>  0617-0739Z
                              RANGE:  w/in 25 km.

                         0914-2352Z:  Various holes and gaps in precip. Not serious,
				      but reprocessing is easy since there's not 
				      widespread spurious echo. Embedded clutter
				      specks during following times:
     2A, 3A  !!FLAG!!          ====>  1249-1530Z
     2A, 3A  !!FLAG!!          ====>  1745-2031Z 
     1A, 3A  !!FLAG!!          ====>  2125-2135Z
         3A  !!FLAG!!          ====>  2347-2352Z
                              RANGE:  w/in 25 km, & ~45 km to NW in a few VOSs.

                         % of data reprocessed:   236/274 VOSs = 86%

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

14 Nov 98:    Early on, scattered pockets of light to moderate precip w/ some embedded 
	      intense convection. After 05Z, a band moderate to heavy precip moves
              from SW to NE.  By 10Z, the NW half of the radar scope is covered by
              moderate to heavy precip.  Areal coverage decreases after 12Z, and
              by 16Z, precip is scattered again (and lighter in intensity).  A
              couple thin lines of light to moderate precip briefly flare up 
              to SE after 21Z. 

              Data processed:  0007-2358Z

              Satellite Coincidence: *0025Z(489 km)*, 1822Z(45 km), 1959Z(576 km), 
                                     2136Z(534 km), 2312Z(74 km)

              QC notes:       0007Z:  Partial scan.  Not included in 1C.HDF.
 
                         0012-0057Z:  A few chunks of light precip missing, mostly
				      on back edges.
    2A, 3A  !!FLAG!!           ---->  Corrected missing light precip, but clutter
				      specks are embedded in precip near radar.
                      CLUTTER RANGE:  w/in 25 km.

                         0202-0959Z:  Various holes and gaps in precip.
                               ---->  Holes in precip corrected, but following
				      periods have embedded clutter specks.
    2A, 3A  !!FLAG!!           ====>  0409-0629Z
                      CLUTTER RANGE:  w/in 25 km.
    2B, 3B  !!FLAG!!           ====>  0824-0839Z
                      CLUTTER RANGE:  near 45 km to NW.
    2A, 3A  !!FLAG!!           ====>  0855-0910Z
                      CLUTTER RANGE:  w/in 25 km, & near 45 km to NW.

                       
                         1024-1105Z:  Intense clutter speck embedded in precip.
    2A, 3A  !!FLAG!!           ---->  Although small, the speck is intense and
				      persistent and cannot be removed w/o
				      affecting precip. 
                      CLUTTER RANGE:  near 20 km.

                         1110-1325Z:  Hole in precip near radar...a few missing
				      chunks of precip on back edges.
 2A, 3A, 2B, 3B !!FLAG!!       ---->  Holes in precip corrected, but embedded 
                                      clutter specks remain.
                      CLUTTER RANGE:  w/in 25 km.

                         1355-1405Z:  Embedded clutter speck to NW.
       3A  !!FLAG!!            ---->  Although small, the speck is intense and  
                                      persistent and cannot be removed w/o
                                      affecting precip.  Using 1410Z in 1C.HDF
			              instead of 1400 and 1405Z.
                      CLUTTER RANGE:  near 45 km.

       3A  !!FLAG!!      1415-1420Z:  Same as 1355-1405Z.
                      CLUTTER RANGE:  near 45 km.

       3A  !!FLAG!!      1541-1556Z:  Same as 1355-1405Z.
                      CLUTTER RANGE:  near 45 km.

       1A  !!FLAG!!           1826Z:  Same as 1355-1405Z.
                      CLUTTER RANGE:  near 45 km.

                         1927-2358Z:  Chunks of light precip missing.  Very
				      minor problem.
                               ---->  Holes in precip corrected, but embedded  
                                      clutter specks remain in following VOSs:
    2A, 3A  !!FLAG!!           ====>  1932-1942Z
                      CLUTTER RANGE:  w/in 25 km.

                         NOTE:  0007 & 0604 moved to bad_vos directory.
                                Including 1410Z in 1C.HDF instead of 1400 & 1405Z.

                         % of data reprocessed:   188/285 VOSs = 74%

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

15 Nov 98:    Scattered patches of precip rotate around apparent center of low pressure
              through 10Z.  Mostly light to moderate precip w/ a few cores of heavier
              convective activity.   

              Data processed:  0008-2342Z

              Satellite Coincidence: 1710Z(*345 km*), 1846Z(410 km), 2023Z(625 km),
                                     2200Z(256 km), 2336Z(624 km)

              QC notes:       1802Z:  Moderate AP speck to E near 150 km. 
                               ---->  Corrected.

                         2312-2342Z:  Light patches of spurious echo to NW.
                               ---->  Corrected.

                         % of data reprocessed:   5/275 VOSs = 2%

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

16 Nov 98:   No precip echoes. 

              Data processed:  0002-2342Z

              Satellite Coincidence: 1734Z(159 km), 1910Z(*604 km*), 2047Z(*488 km*),
                                     2224Z(188 km)

              QC notes:  0002-0051Z:  CAE echo to NW.
                               ---->  Corrected.

                              0150Z:  Light radial spike to NW.
                               ---->  Corrected.

                              0418Z:  Light CAE patch to W.
                               ---->  Corrected.

                              1341Z:  Light CAE speck to NW.
                               ---->  Corrected.

                         2313-2342Z:  Light CAE all over.
                               ---->  Corrected.

                         % of data reprocessed:  13/142 VOSs = 9%

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

17 Nov 98:    No precip echoes. 

              Data processed:  0005-2359Z

              Satellite Coincidence:  1621Z(*226 km*), 1758Z(470 km), 1935Z(610 km),
				      2111Z(*174 km*) 

              QC notes:  0005-0706Z:  Light to moderate CAE, often widespread.
                               ---->  Corrected.

                         0755-0805Z:  A few patches of light CAE.
                               ---->  Corrected.

                              0835Z:  A few patches of light CAE.
                               ---->  Corrected.

                         1231-1253Z:  Spurious echo...bird signature?
                               ---->  Corrected.

                         1310-1357Z:  Scattered light to moderate CAE/AP specks.
                               ---->  Corrected.

                              1553Z:  Light CAE speck.
                               ---->  Corrected.

                              1753Z:  Light CAE speck.
                               ---->  Corrected.

                              1834Z:  Light CAE speck.
                               ---->  Corrected.

                         2003-2359Z:  Scattered CAE/AP specks.
                               ---->  Corrected.

                         % of data reprocessed:   80/156 VOSs = 51% 

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

18 Nov 98:    No precip echoes.  Suspect echoes after 15Z are identified as chaff due
	      to various factors:  (1)  begins as an intense point source, then
	      disperses over time into streamers, (2) little vertical continuity, (3)
              movement similar to previous chaff cases, (4) satellite imagery confirms
              that no cloud formations are near KHGX late in the day. 

              Data Processed:  0019-2344Z

              Satellite Coincidence:  1509Z(664 km), 1645Z(232 km), 1822Z(622 km),
				      1959Z(428 km), 2135Z(310 km) 

              QC notes:  0019-0604Z:  Light to moderate CAE, often widespread (or
				      is it intense AP w/ clutter filter applied
				      by NWS?!). 
                               ---->  Corrected.

                         0643-0812Z:  Light CAE.
                               ---->  Corrected.

                              0841Z:  Light CAE.
                               ---->  Corrected.

                              0931Z:  Light CAE.
                               ---->  Corrected.

                              1318Z:  Light spurious echo to NE.
                               ---->  Corrected.

                         1636-2344Z:  Light to intense chaff returns, plus some
                                      light CAE after 23Z.  Chaff echo appears
			              earlier, but is outside 150 km range.
                               ---->  Corrected.

                         % of data reprocessed:  125/166 VOSs = 75%  

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

19 Nov 98:    Scattered showers after 12Z, although there may be a few earlier in
	      the day.  Lots of chaff contamination.   

              Data Processed:  0004-2349Z

              Satellite Coincidence: 1533Z(103 km), 1710Z(522 km), 1846Z(584 km),
			             2023Z(71 km) 

              QC notes:  0004-0420Z:  Mixture of chaff and AP.
                               ---->  Corrected.

                         0429-0821Z:  Mixture of chaff, AP, CAE, and small, shallow
				      showers.
  2A, 3A  !!FLAG!!             ---->  Awful period to QC.  Since a few showers were
				      so close to radar and shallow, height params
				      couldn't be raised very high.  Also, spurious
				      echo is mostly outside 100 km with some
				      vertical structure & very intense, thus very 
                                      difficult to remove.
                         RANGE OF SPURIOUS ECHO:  mostly between 100-150 km.

                         0826-0841Z:  Some light AP to NE.
                               ---->  Corrected.
                         
                         1527-1543Z:  Chaff to SE w/ scattered precip elsewhere.
     1B  !!FLAG!!              ---->  Chaff is very small and light, but difficult
				      to remove.  Raising params just eliminates
			              precip and doesn't immediately remove chaff.  
                                      Thus, left as is and flagged.
                         CHAFF RANGE: near 140 km. 

                         1548-1958Z:  Chaff to SE w/ scattered precip elsewhere.
  1A, 2A, 3A  !!FLAG!!         ---->  Even more difficult to remove than previous
				      time period since intensity and coverage
				      increase.  Thus, left as is and flagged. 
                         CHAFF RANGE: mostly 100-150 km.

                         2053-2349Z:  Chaff to SE w/ scattered precip elsewhere.
          1B  !!FLAG!!         ---->  Chaff is very small and light.
                         CHAFF RANGE: near 140 km.

                         2058-2349Z:  Chaff to SE w/ scattered precip elsewhere.
     2A, 3A   !!FLAG!!         ---->  More intense and large areal coverage than
				      previous period.  Some improvements made,
				      but still difficult to remove all chaff
				      and keep all precip.
                         CHAFF RANGE: between 100-150 km.

                         % of data reprocessed:  94/239 VOSs = 39% 

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

20 Nov 98:    Line of light showers moves in from NW after 07Z.  Light showers pop
	      up in SW quadrant after 09Z. Broken line to NW continues moving to
	      SE, but largely washes out by 11Z.  Meanwhile, light showers in S
              half of scope intensify into small, intense cells. By 13Z, a line
	      of mostly broken convection is draped in ENE-WSW direction below
              radar.  An MCS forms in S half and edges to ENE from 15-21Z as
              earlier convective line breaks apart.  Light patches of precip
	      behind the MCS after 21Z to S and SE.

              Data Processed:  0004-2358Z

              Satellite Coincidence:  1421Z(524 km), 1557Z(314 km), 1734Z(630 km),
				      1911Z(361 km), 2047Z(438 km)

              QC notes: 0004-0115Z:  Mixture of small showers and chaff.
                              ---->  Some VOSs corrected inside 150 km,
				     but the following VOSs are flagged:
       3A  !!FLAG!!           ====>  Chaff to SE near 150 km.  Using 0019Z
			             in 1C.HDF.

                        0120-0405Z:  Chaff.
                              ---->  Corrected. 

                        0415-0445Z:  Scattered, light CAE.
                              ---->  Corrected.
    
                        0505-0640Z:  Scattered light spurious echo w/in 150 km.
				     Some intense AP specks outside 150 km. 
                              ---->  Corrected.

                             0655Z:  Light patch of CAE.
                              ---->  Corrected.

                             0705Z:  Light patch of CAE.
                              ---->  Corrected.

                        1106-1326Z:  Scattered patches of light spurious echo.
                                     Also some scattered precip.
                              ---->  Corrected, except for possible light
				     CAE contamination in following VOSs:
    2B, 3B  !!FLAG!!          ====>  1106-1311Z:  Perhaps a few small specks of 
				     CAE scattered to N, NW, and SW. 
                             RANGE:  between 100-150 km.

                        1922-1927Z:  Clutter speck to NW embedded in light
				     precip.
        1A !!FLAG!!           ---->  Clutter is very small, but intense,
				     thus flagged as major.
                             RANGE:  near 45 km.

                             1947Z:  Clutter speck to NW embedded in light
                                     precip.
        3A !!FLAG!!           ---->  Clutter is very small, but intense,
                                     thus flagged as major.
                             RANGE:  near 50 km.

                        2253-2358Z:  Scattered light spurious echo.
                              ---->  Corrected.

                         NOTE:  Including 0019Z in 1C.HDF instead of 0004-0014Z.

                         % of data reprocessed:  132/285 VOSs = 46%

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

21 Nov 98:    Light scattered precip to S and SE through 08Z, although much of it is
	      outside 150 km.  Scattered light to moderate precip enters from NW
	      after 09Z.  This precip gradually organizes into a band of moderate
              precip after 1330Z.  Band largely holds together through 19Z, then
              all precip moves out of range by 21Z.  Good TRMM overpass at 1444Z.

              Data Processed:  0004-2350Z

              Satellite Coincidence:  1444Z(5 km), 1621Z(*563 km*), 1758Z(550 km),
                                      1934Z(31 km) 

              QC notes: 0004-0219Z:  Scattered patches of light CAE.
                              ---->  Corrected.

                             0626Z:  Light patch of CAE. No precip w/in 150 km.
                              ---->  Corrected.

                             0636Z:  Light patch of CAE. No precip w/in 150 km.
                              ---->  Corrected.

                        2327-2332Z:  Scattered light spurious echo.
                              ---->  Corrected.

                        2340-2350Z:  Scattered light spurious echo
                              ---->  Corrected.

                         % of data reprocessed:  37/286 VOSs = 13%

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

22 Nov 98:    No precip. 

              Data Processed:  0003-2346Z

              Satellite Coincidence:  1332Z(396 km), 1508Z(384 km), 1645Z(629 km),
                                      1822Z(288 km), 1958Z(569 km)

              QC notes:  0006-0246Z:  Scattered light CAE.
                               ---->  Corrected.

                              0315Z:  Light CAE.
                               ---->  Corrected.

                         0345-0355Z:  Light CAE.
                               ---->  Corrected.

                              0504Z:  Light CAE.
                               ---->  Corrected.

                         2337-2346Z:  Light spurious echo.
                               ---->  Corrected.

                         % of data reprocessed:  37/158 VOSs = 23%

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

23 Nov 98:    No precip. Chaff after 16Z. 

              Data Processed:  0006-2358Z

              Satellite Coincidence:  1356Z(104 km), 1532Z(594 km), 1709Z(506 km),
				      1846Z(142 km) 

              QC notes:  0719-0838Z:  Light to moderate AP specks to NE.
                               ---->  Corrected.

                         1027-1037Z:  Light spurious echo to NE.
                               ---->  Corrected.

                              1056Z:  Light spurious echo to NE.
                               ---->  Corrected.

                         1126-1156Z:  Scattered light spurious echo.
                               ---->  Corrected.

                         1225-1302Z:  Scattered light spurious echo.
                               ---->  Corrected.

                              1338Z:  Light spurious echo to E.
                               ---->  Corrected.

                         1536-2358Z:  Chaff and AP mix.
                               ---->  Corrected.

                         % of data reprocessed: 108/191 VOSs = 57%

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

24 Nov 98:    Scattered showers after 0630Z.    

              Data Processed:  0010-2354Z

              Satellite Coincidence:  1243Z(267 km), 1420Z(449 km), 1557Z(617 km),
				      1733Z(203 km), 1910Z(713 km) 

              QC notes:  0010-0627Z:  Persistent AP to NE and some remaining chaff.
                               ---->  Corrected.

                         0637-0815Z:  Light to moderate AP to NE...appears to be a
				      few light, shallow showers to W and NW, too.
    2B, 3B !!FLAG!!            ---->  Most spurious echo corrected, but a few specks
				      remain in some VOSs.  Also flagged because some
				      light precip echoes may have been removed.  They
				      are small and shallow and probably not significant.
                              RANGE:  scattered between 100-150 km.            

                         1013-1023Z:  Small, light specks of spurious echo.
                               ---->  Corrected.

                         1251-1350Z:  Scattered light CAE.
                               ---->  Corrected.
 
                         1410-1429Z:  Scattered light CAE.
                               ---->  Corrected.

                              1455Z:  Scattered light CAE.
                               ---->  Corrected.

                         1612-1623Z:  Chaff to S + light precip to W.
         1B !!FLAG!!           ---->  Very difficult to remove chaff since it has
                                      some vertical structure and is as intense
                                      as precip to W/SW (and it's located at
                                      longer ranges).
                              RANGE:  ~125 km.

                         1629-2156Z:  Chaff to S + light precip to W.
 1A, 2A, 3A !!FLAG!!           ---->  Same as previous period, only chaff echo
				      more intense and widespread. 
                              RANGE:  between 100-150 km.

                         2202-2354Z:  Chaff to S, light to intense AP to ENE,
			              precip to W.
     2A, 3A !!FLAG!!           ---->  Bad situation.  Precip is still light and
				      shallow.  Other spurious echo is as or
				      more intense than precip and located outside
				      100 km (making it more difficult to QC).  
			              Tried bumping up a few params, but precip
				      gets eliminated and most of the false echo
				      remains. Great case for sector QC option. 
                                      No reprocessing done since it didn't help.
                              RANGE:  AP and chaff between 100-150 km.

                         % of data reprocessed: 122/183 VOSs = 67%

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

25 Nov 98:    A few light showers before 02Z.  Scattered, small convective cells after
	      17Z.  Chaff early and late in the day. 

              Data Processed:  0000-2350Z

              Satellite Coincidence:  1131Z(721 km), 1307Z(198 km), 1444Z(616 km), 
				      1621Z(452 km), 1757Z(260 km) 

              QC notes: 0000-0116Z:  Light shower to W + Chaff to S + AP to E/NE.
   2A, 3A  !!FLAG!!           ---->  Keeping showers intact while removing other
				     regions of spurious echo impossible w/o sector
				     specific QC capability.  Still some showers
				     after 0116Z, but deemed insignificant since
			             areal coverage is minimal and intensity less
			             than 20 dBZ.  Using 0023Z & 0122Z in 1C.HDF.  
                             RANGE:  80-150 km.  

                        0122-0549Z:  Chaff & AP w/o precip.
                              ---->  Corrected.

                             0618Z:  Light spurious echo to NE.
                              ---->  Corrected.

                             1510Z:  Moderate clutter speck near radar...w/in 15 km.	
                              ---->  Corrected.

                        1540-1620Z:  Chaff to S and SE. 
                              ---->  Corrected.

                        1629-2153Z:  Chaff to S and SE w/ precip to W/SW.
   1A, 2A, 3A !!FLAG!!        ---->  Chaff contamination too intense and at too
			             far a range to fully eliminate. 
                             RANGE:  100-150 km.

                        2159-2209Z:  Chaff to S and SE w/ precip to W/SW.
                              ---->  Corrected.

                        2214-2229Z:  Chaff to S and SE w/ precip to W/SW.
       2B, 3B !!FLAG!!        ---->  Chaff contamination too intense and at too 
                                     far a range to fully eliminate.
                             RANGE:  ~150 km.

                        2340-2350Z:  Light spurious echo to W.
                              ---->  Corrected.

                        Note:  Including 0023Z in 1C.HDF instead of 0000-0017Z.
                               Including 0122Z in 1C.HDF instead of 0105-0116Z.

                        % of data reprocessed: 135/199 VOSs = 67%

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

26 Nov 98:    A few scattered showers early, then again to S and SE from 07Z-23Z.

              Data Processed:  0014-2348Z

              Satellite Coincidence:  1155Z(150 km), 1331Z(502 km), 1508Z(596 km),
				      1645Z(112 km) 

              QC notes:      0014Z:  Partial scan.  Moved to bad files directory.
                        0018&0028Z:  Light CAE to W w/ small shower directly to
				     W of radar.
                             0033Z:  Light CAE to W w/ small shower directly to
                                     W of radar.
                             0131Z:  Light CAE to NW w/ small shower directly to
                                     W of radar.
                        0220-0259Z:  Light CAE to NW.
                        0309-0318Z:  Light CAE to NW and N.
                             0348Z:  Light CAE to E.
                        0418-0428Z:  Light CAE to NW
                        0507-0547Z:  Scatttered light CAE.
                             0626Z:  Light CAE to NW.
                             0656Z:  Light CAE speck to N.
                        2242-2247Z:  Light AP specks to E.
                              ---->  All above problems corrected.

                        2252-2307Z:  AP to E w/ small showers to SW.
     2B, 3B !!FLAG!!          ---->  Partial correction, only small speck of
				     light AP inside 150 km.
                             RANGE:  near 150 km.

                        2313-2348Z:  Intense AP splotch to ENE.  Small shower
				     persists to SW.
     2A, 3A !!FLAG!!          ---->  Difficult to QC since AP is intense and
				     at far ranges...also has some vertical
				     continuity in a few VOSs, enough to make
				     if hard to use height thresholds only to
				     QC it. 
                             RANGE:  100-150 km.

                        % of data reprocessed: 34/218 VOSs = 16%

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

27 Nov 98:    No significant precip echo w/in 150 km. 

              Data Processed:  0038-2349Z

              Satellite Coincidence:  1042Z(584 km), 1218Z(279 km), 1355Z(628 km),
				      1532Z(392 km), 1708Z(381 km)

              QC notes:  0038-0308Z:  Mostly light to moderate scattered CAE.
                         0328-0338Z:  Mostly light CAE.
                         0357-0407Z:  Light CAE.
                              0457Z:  Light CAE.
                              0516Z:  Light CAE.
                              0555Z:  Light CAE.
                              0615Z:  Light CAE.
                         0635-0705Z:  Light CAE.
                              0734Z:  Light CAE.
                         1250-1315Z:  Light spurious echo.
                              1325Z:  Light AP specks. 
                         1340-1505Z:  Light to moderate AP specks/splotches.
                              1725Z:  Small, moderate AP speck. 

                               ---->  All above problems corrected.

                        % of data reprocessed: 68/176 VOSs = 39%
 

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

28 Nov 98:    Light scattered showers to W after 16Z. 

              Data Processed:  0008-2349Z

              Satellite Coincidence:  1106Z(40 km), 1243Z(547 km), 1419Z(566 km),
				      1556Z(13 km) 

              QC notes:      0018Z:  Light specks of AP. 
                              ---->  Corrected.

                        0147-1119Z:  Scattered light to moderate AP to E/ENE.
                              ---->  Corrected.

                        1129-1440Z:  Scattered patches of light to moderate
				     AP to E/NE (a bit more severe than previous
                                     period).  Also some light, small showers to
			             SW and W.  
 1B, 2B, 3B  !!FLAG!!         ---->  Corrected, although light precip is removed.
				     Precip is small, very light, so not considered
                                     significant.  Flagged as minor, though, since
                                     precip was eliminated.

                        1446-1539Z:  AP lessens, but some light to moderate
			 	     specks remain.  Still very small, light
				     showers to NW.
 1B, 2B, 3B  !!FLAG!!         ---->  Mostly corrected, although small showers
			             may be removed to NW &/or small, light speck
			             of AP may remain to SE.  Not significant
			             problems.       
                             RANGE:  ~130 km.

                        2243-2253Z:  Strange speck to SE near 150 km.
         3B  !!FLAG!!         ---->  Very light...actually moves light small
			             shower, so it's very questionable. 
                             RANGE:  near 150 km.

                        2258-2303Z:  Same as previous period, but speck is intense.
         3A  !!FLAG!!         ---->  Again, echo to SE is questionable.  Using 2308Z
				     in 1C.HDF.
                             RANGE:  near 150 km.

                             2313Z:  Light speck to SE.
         3B  !!FLAG!!         ---->  Same as 2243-2253Z.
                             RANGE:  near 150 km.

                             2318Z:  Small, intense speck to SE.
         3A  !!FLAG!!         ---->  Same as 2253-2303Z.

                        2328-2349Z:  Light AP speck to NE.
      2B, 3B !!FLAG!!         ---->  Very light, not worth removing since light
				     precip is removed, too.

                        NOTE:  2308Z included in 1C.HDf instead of 2303Z.

                        % of data reprocessed: 98/192 VOSs = 51%

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

29 Nov 98:    Scattered precip, mostly small showers and a few moderate to intense
	      small convective cells, after about 16Z.   

              Data Processed:  0004-2349Z

              Satellite Coincidence:  0954Z(446 km), 1130Z(357 km), 1307Z(630 km),
				      1444Z(318 km), 1620Z(516 km) 

              QC notes:      0009Z:  Light AP to NE.
                             1124Z:  Light AP to NE.
                             1302Z:  Radial spike to SE in 2nd tilt (solar?)
                        2309-2314Z:  Radial spike to SW in 2nd tilt (solar?)
                              ---->  All problems corrected.

                        % of data reprocessed: 5/188 VOSs = 3%

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

30 Nov 98:    Scattered precip for most of day.  Mostly smaller cells, often organized
              into broken lines.  A few solid lines with moderate to intense precip after
              18Z. 

              Data Processed:  0000-2044Z
                               2220-2345Z

              Satellite Coincidence:  1018Z(65 km), 1154Z(583 km), 1331Z(525 km), 
                                      1507Z(96 km) 

              QC notes:  2235-2345Z:  Scattered, light specks of CAE.
                               ---->  Corrected.

                        % of data reprocessed: 15/267 VOSs = 6%