Site log - Darwin (Jan 1998) Flags: 1-Satellite coincidence data 2-Scan in TSDIS data 3-Scan not in TSDIS data A-Major problem (moderate to strong AP &/or widespread coverage) B-Minor problem (weak AP &/or very little coverage) ************************************************************************************************** 01 Jan 98: Scattered convection early on quickly organizes into an impressive leading line/ trailing stratiform convective system which treks off to the NE over the course of the day. Data processed: 0711-1136 Z 1332-2348 Z Satellite coincidence: 0936Z(127 km), 1920Z(429 km) QC notes: 0711-0800Z: weak/moderate/intense AP remaining -----> corrected 0824-0924Z: removal of light precipitation 1A !!FLAG!! -----> light precip was re-introduced to the field but unfortunately so was some moderate clutter from both Gunn Pt and Melville Island. It I increased the parameters to remove the clutter, the light precip was also removed. So, the clutter had to remain....hence the major flag. 0936-0948Z: intense clutter specks remaining near radar 1B+ !!FLAG!! -----> could not removed small clutter specks without removing precip. Although the specks are small, they are intense...hence the B+ flag. 1024-1036Z: moderate AP remaining near radar -----> corrected 1136Z: intense clutter embedded within precip near radar 3A !!FLAG!! -----> it is impossible to remove AP embedded in precip without removing the precip as well. The AP stays and the VOS is given a major flag. VOS 1136Z was moved to bad_files_not_in_1C.hdf directory so as not to be included in TSDIS ingest. 1332-1445Z: weak/moderate AP remaining immediately NW of radar, mostly embedded in precip 2A !!FLAG!! -----> all the VOS's where the AP was embedded in precip are a lost cause (see above flag). Could not remove the AP from the non-embedded VOS's either....the AP was wedged in the smallest clear zone between showers so it might as well be embedded. Any attempt to remove this AP results in the removal of precip as well. Very frustrating.... given a major flag. 1459-1600Z: moderate/intense clutter from northern islands remaining 2B !!FLAG!! -----> vastly improved. Prominent island ground clutter has been removed from majority of VOS's in this time period. Minor flag is for the weak clutter specks which still persist in 2-3 VOS's....this can still be considered a success. 1524-1536Z: intense AP embedded within line 3A !!FLAG!! -----> Once again, can not remove AP which is embedded within precip. Thus, the intense AP near the radar remains and the VOS's are given a major flag. Moved VOS 1536Z to bad_files_not_12C.hdf directory which downgraded the flag from a 2 to a 3. 1612-1624Z: intense clutter over radar remains, some embedded within precip 2A !!FLAG!! -----> only marginally improved. Nothing could be done about the intense clutter specks embedded in the precipitation. Was able to slightly reduce the coverage of the AP outside of the precip but some non-embedded AP still remains. This latter false echo could not be removed without drastically reducing the precip in the field. 1624-1748Z: intense clutter speck W of radar, often embedded within precip 2A !!FLAG!! -----> could not remove intense specks embedded in precip....that is always impossible with this algorithm. But, even stand-alone AP could not be removed with the normal fail-safe parameters because of the large aerial coverage of light precip. Any attempts to remove the AP drastically reduced the light precip in the field. Therefore, the AP/clutter was left untouched and given a major flag. 1648-1700Z: intense clutter near radar embedded within precip 2A !!FLAG!! -----> AP embedded in precip can not be fixed and is always given a major flag....such is the case here. 1700-1736Z: moderate island clutter NW of radar remains; often embedded within precip 2A !!FLAG!! -----> could not remove/reduce island clutter specks without removing light precipitation from the field. These VOS's were already given major flags for a different problem (see previous QC notes involving this time period)....add this problem to it and it makes you want to stand even further away from them. 1812-1836Z: moderate AP remaining near radar 2A !!FLAG!! -----> only slightly improved and still deserves a major flag. The AP shield immediately west of the radar is often embedd in precip and even when it is not, it is difficult to remove without removing significant amounts of light precip. So, the AP was reduced but a significant amount still remains. 1824-2112Z: intense clutter speck W of radar remains, often embedded within precip 1A !!FLAG!! -----> when the speck is not embedded within precip it is removed. But, this was not the case for most of the VOS's....the intense clutter is mostly embedded within precip and the only thing that can be done for this scenario is to give it a major flag. 1924-2224Z: moderate/intense AP/clutter remains near radar, often embedded within convection 1A !!FLAG!! -----> slightly improved, but AP remains, embedded and not-embedded within precip. Any attempt to remove embedded AP is a lost cause but even the stand-alone AP was only slightly reduced because any more aggressive attacks started removing significant amounts of precip. *************************************************************************************************** 02 Jan 98: Widespread convection from 00 --> 17Z moving North over the radar. Several lines with moderate / intense convection move directly over radar. An additional small area of convection develops E of radar at far range ~2336Z. Data Processed: 0000-0112Z 0309-2348Z Satellite Coincidence: 0824Z(518km), 1808Z( 208km) QC notes: 0000-0436Z: moderate/intense island clutter specks NW of radar, occasionally embedded within light/moderate precip. Also, intense clutter specks near radar embedded within light precip. 2A,2B,3A,3B !!FLAG!! ----> Limited success in removing AP close to radar and near island to the north. The tradeoff is that some minor shower activity was removed. The majority (95%) of the precip echo remains in-tact. Stronger parameters could not be implemented because too much precip was being removed. Some major and some minor clutter specks still exist near and to the NW of the radar in every VOS in this time period. ------------------------------------------------------------------------------- 0448-0524Z: Intense clutter specks near radar embedded in light/moderate precip. 3A !!FLAG!! 0448Z: Some clutter specks were removed (along with a couple minor showers) but intense clutter specks still remain. Clutter is embedded in light to moderate showers. Stronger parameters cannot be used because too much precip will be removed. 0500Z: Corrected. 3A !!FLAG!! 0512-0524Z: Some clutter specks were removed (along with a couple minor showers) but intense clutter specks still remain. Clutter is embedded in light to moderate showers. Stronger parameters cannot be used because too much precip will be removed. -------------------------------------------------------------------------------- 0536-0700Z: Moderate AP from Melville Island (NW of Gunn Pt.) Also, some intense clutter specks embedded within light/moderate precip near radar. 2A,3A,2B,3B !!FLAG!! ----> AP from Melville Island was almost entirely removed. Some light/ moderate AP remains. Intense clutter specks embedded within light/ moderate precip near radar continues to be a problem which cannot be resolved. This clutter can only be removed at the expense of removing the precip also. Therefore, these clutter specks remain. --------------------------------------------------------------------------------- 1A !!FLAG!! 0836Z: Moderate/Intense clutter specks near radar with embedded precip. Clutter cannot be removed without removing precip, therefore, clutter remains. 1A,2A,3A !!FLAG!! 0912-1000Z: Moderate/Intense clutter specks near radar embedded within light / moderate precip. Because the clutter is embedded within precip, it cannot be removed without removing the precip also - clutter remains. 3A !!FLAG!! 1012-1036Z: Intense AP SW of radar could not be removed due to the presence of light precip near radar. The 1036Z uf file was placed in a "bad files" directory so it would not be ingested by TSDIS. This changes the flag to type 3. 1124Z: Intense AP E of radar (not embedded in precip ----> Corrected 2B,3A !!FLAG!! 1300-1312Z: Intense clutter specks near radar. These specks cannot be removed due to proximity of light/moderate precip. If stronger parameters are used, precip echos are removed, therefore, clutter remains. The 1300Z file has been placed in "bad files" directory so it is not sent to TSDIS. 2A,3A !!FLAG!! 1336-1548Z: Intense clutter specks near radar embedded in light/moderate precip. Also, moderate/intense island clutter NW of radar. 3B !!FLAG!! 1612Z: Small patch of AP SW of radar at far range cannot be removed due to presence of precip surrounding radar. The AP is minor in coverage compared to the widespread precip. 1700-1712Z: Small patch of moderate AP W of radar at far range. ----> Corrected - a couple minor showers were also removed, but the tradeoff is worth it. I was able to remove the AP because it was not embedded in precip and there was no intervening precip between radar and AP. 1748-1800Z: Small patches of AP SE and W of radar at mid/far range (not embedded) ----> Corrected - a couple minor showers were also removed, but the tradeoff is worth it. I was able to remove the AP because it was not embedded in precip and there was no intervening precip between radar and AP. 1812-1924Z: Moderate/Intense AP surrounding radar. The tail end of a squall line is still evident at far range N of radar. ----> Corrected - all AP was removed and the majority of the squall line was left in-tact. This was a success! 1936-2148Z: Moderate/Intense AP surrounding radar - no precip. ----> Corrected *************************************************************************************************** 03 Jan 98: Scattered convection from 00Z ~ 1130Z. Isolated convection at far range 22Z ~ 23Z Data Processed: 0000-1224Z 1500-2348Z Satellite Coincidence: 0848Z(315km), 1832Z(632km) QC notes: 2A,2B,3B !!FLAG!! 0200-0236Z: Moderate AP from islands to the NW of radar. This AP cannot be removed due to proximity of precip. Harsh parameter setting appear to only remove precip echo without removing false echo. QC alg behaves poorly. 0300Z: Moderate AP from islands to the NW of radar. ----> Corrected 0312Z: Minor clutter specks near radar and intense speck near islands to NW. ----> Corrected - a couple minor showers removed in the process, but it is worth the tradeoff. --------------------------------------------------------------------------------- 0336-0548Z: Moderate AP from islands to the NW of radar, and occasionally to the W of radar. (moderate in intensity, but not coverage) ----> Corrected except for flags below 3A !!FLAG!! 0348Z: Moderate clutter NW of radar cannot be removed due to presence of precip. 2B !!FLAG!! 0400Z: Minor clutter speck NW of radar cannot be removed due to presence of precip. -------------------------------------------------------------------------------- 0636-0648Z: Moderate AP from islands to the NW of radar ----> Corrected - a couple minor showers removed in the process, but it is worth the tradeoff. 0712Z: Moderate AP from islands to the NW of radar ----> Corrected - a couple minor showers removed in the process, but it is worth the tradeoff. 0736-0748Z: Moderate AP from islands to the NW of radar ----> Corrected - a couple minor showers removed in the process, but it is worth the tradeoff. 0848-0900Z: Moderate AP from islands to the NW of radar ----> Corrected - a couple minor showers removed in the process, but it is worth the tradeoff. 0936Z: Light AP SW of radar ----> Corrected - a couple minor showers removed in the process, but it is worth the tradeoff. ---------------------------------------------------------------------------------- 0948-1148Z: Moderate/Intense AP surrounding radar and from islands to North. Real precip echo exiting scope to the NE of radar. 2A,3A,2B !!FLAG!! 0948-1100Z: AP could not be entirely removed due to presence of precip. Some AP was successfully removed. Harsher parameters results in the removal of real echo. 1112-1148Z: Corrected ----------------------------------------------------------------------------------- 1200-2348Z: AP of varying intensities surrounding radar - no precip. ----> Corrected. ************************************************************************************************************* 04 Jan 98: Isolated convection W of radar at far range 00 ~ 0230Z. Isolated convection develops S of radar near 05Z and dissipates by 11Z. More isolated convection NW of radar from ~14Z to 16Z. No other significant precip for the remainder of day. Data Processed: 0000-1224Z 1412-2348Z Satellite Coincidence: 0053Z(543km), 1037Z(235km), QC notes: 0036Z: Moderate Island clutter NW of radar ----> Corrected - a minor shower was removed in the process, but it is worth the trade-off. 0200Z: Moderate Island clutter NW of radar ----> Corrected 0224-0236Z: Moderate Island clutter NW of radar ----> Corrected - a minor shower was removed in the process, but it is worth the trade-off. 0500Z: Moderate clutter speck near radar. ----> Corrected ----------------------------------------------------------------------------- 0612-0748Z: Light AP SW of radar (with moderate/intense convection nearby) ----> Corrected except for minor flag below - a couple very minor showers were removed in the process, but it was worth the trade-off. 2B !!FLAG!! 0700Z: Very minor AP at far range could not be removed without removing real precip echo. It is questionable as to whether this VOS should be flagged at all. ------------------------------------------------------------------------------ 0912Z: Intense clutter speck near radar. ----> Corrected 1A,2A !!FLAG!! 1012-1036Z: Intense clutter near radar embedded within light precip. ----> Intense clutter cannot be removed because it is embedded in precip. All attempts to remove clutter also remove significant precip, therefore, clutter remains. 1124-1412Z: Light/Moderate AP E and W of radar - no precip. ----> Corrected 2A,2B,3A,3B !!FLAG!! 1424-1512Z: Moderate AP E of radar at far range (with precip to NW). ----> AP cannot be removed due to presence of precip. Harsh parameters remove both real and false echo. 1524-1600Z: Moderate island clutter NW (with precip NW of radar) ----> Corrected - 1548Z and 1600Z VOSs may contain light AP E of radar at far range. These echos do have vertical depth and quite possibly are real precip echo. 1612-2348Z: Light/Moderate AP surrounding radar - no precip ----> Corrected *********************************************************************************************************** 05 Jan 98: Scattered convection in NW quadrant through 04Z, then in SE quadrant after 06Z. Thin, intense squall line moves in from SE after 09Z. Continues moving to NW and weakens through 1130Z. A brief flare-up in the NE segment of the squall line occurs between 1312-1424Z, then quickly dissipates. Scattered convection mostly in SW quadrant after 18Z, then a large convective complex forms after 21Z. Data Processed: 0000-2348Z Satellite Coincidence: 0800Z(498km), 1607Z(629km), QC notes: 0000-0036Z: Clutter specks near radar and embedded AP to NW. 2B, 3B !!FLAG!! ----> Clutter specks near radar fixed, as well as some AP to NW. Still may be some embedded AP,though. 0100Z: Clutter specks near radar and embedded AP to NW. ----> Corrected 0248Z: Embedded AP to NW. 3B !!FLAG!! ----> Able to shave away some of the AP around the cores of the precipitation (upper tilts distinctly show the vertical structure of some cells near the islands to the NW). Still appears to be some embedded AP, though. 0324-0336Z: AP to NW 2B, 3B !!FLAG!! ----> Most of the AP eliminated, but still appears to be some embedded AP. 0448Z: AP to NW ----> Corrected 0500-0724Z: Light AP to S and E. ----> Corrected 2000-2012Z: Embedded moderate AP to NW. 2B, 3B !!FLAG!! ----> Some AP removed, but still some embedded AP that is difficult to remove without adversely affecting the precip in the SW quadrant. 2100Z: Moderate to intense AP to NW. ----> Corrected 2200Z: AP speck to NW. ----> Corrected 3A !!FLAG!! 2224Z: Embedded intense AP to SW **************************************************************************************************** 06 Jan 98: Considerable area of convection and stratiform precipitation west of radar early on but out of range by 03Z. Another region of convection skirts the SW fringe of the scope around 16Z and is completely out of range by 20Z. Widely scattered convection finishes out the day. Data processed: 0000-0300 Z 0448-2348 Z Satellite Coincidence: 0647Z, 1631Z QC notes: 0000-0012Z: intense Gunn Pt. clutter speck remaining -----> corrected 0548-1036Z: second-trip echo remaining 1B,2B !!FLAG!! -----> vastly improved and almost completely corrected except for some renegade weak second-trip splotches remaining in a handful of VOS's. These splotches could not be removed without affecting light precip cells present. Problem is considered minor. 1048-1124Z: second-trip echo remaining (no precip present) -----> corrected 1136-1148Z: second-trip echo remaining -----> corrected 1512Z: second-trip echo remaining (no precip present) -----> corrected 1712-1736Z: second-trip echo remaining 2B- !!FLAG!! -----> much improved but still a couple of weak splotches of 2nd-trip remaining in the final two VOS's of this time period. A very minor problem. 2324Z: intense Gunn Pt. clutter speck remaining 3A- !!FLAG!! -----> could not remove intense speck because (1) it is embedded in light precip moving over the radar nad (2) the light precip present in this scan curtails any aggressive parameter manipulations. **************************************************************************************************** 07 Jan 98: Widely scattered showers and convective cells N of the radar early on. No significant precipitation after these showers dissipate. Data processed: 0000-1500 Z 2236-2348 Z Satellite coincidence: 0711Z, 1519Z QC notes: 0512-0524Z: weak island clutter remaining -----> corrected 0636-0748Z: moderate/intense island clutter remaining -----> corrected 0800-0900Z: second-trip echo remaining E of radar -----> corrected 1112-1312Z: scattered weak/moderate/intense AP remaining (no precip present) -----> corrected 1336-1400Z: scattered weak/moderate AP specks remaining (no precip present) -----> corrected 1436Z: scattered moderate AP specks remaining 3B !!FLAG!! -----> improved, but could not completely remove AP without significantly affecting precipitation present. Problem is minor and VOS has been moved to bad_files_not_in_1C.hdf directory...hence the 3B flag 1448-1500Z: scattered weak/moderate AP specks remaining (no precip present) -----> corrected **************************************************************************************************** 08 Jan 98: Convection and moderate showers form along the SE fringe of the scope early on (~07Z) and move off to the N and increase in coverage. This precip, along with some hectors, dissipate by 15Z. Convection once again fires east of the radar around 20 Z. Soon after this, convective cells begin firing over the rest of the mainland and persist through the end of the day. Data processed: 0000-2348 Z Satellite coincidence: 0559Z(64 km), 1542Z(364 km) QC notes: 0324-0912Z: second-trip echo remaining 2B !!FLAG!! -----> vastly improved. The only negative was that some small splotches of weak second-trip could not be removed from a handful of VOS's. Any more aggressive approach resulted in the removal of precip, but only flagged as minor because (1) the AP is weak and of little aerial coverage and (2) only a small minority of the VOS's in this time period are affected. 0436-0500Z: moderate/intense island clutter remaining -----> corrected 1224-1448Z: second-trip echo giving way to horrifically intense AP, often embedded within precip 2A !!FLAG!! -----> second-trip fully corrected...unfortunately, this was the much smaller problem. The intense AP problem was improved in that most of the non-embedded AP was removed but there is a significant amount of embedded, intense AP remaining....hence the major flag. **************************************************************************************************** 09 Jan 98: Strong convection and copious amounts of rainfall present early on but moves out of range or dissipates by 09Z. Scattered showers and convection left in the wake of early day storms. Convection really picks up strength and coverage by day's end. Data processed: 0000-2348 Z Satellite Coincidence: 0446Z(587 km), 1430Z(275 km) QC notes: 0036-0100Z: intense clutter splotch W of radar remaining -----> corrected 0200-0248Z: horrifically intense AP and clutter embedded within precip near and E of radar 2A !!FLAG!! -----> improved but intense AP still remains. All embedded AP remains since nothing can ever be done to remove embedded false echo with this algorithm. Some non-embedded intense AP splotches also remain (although a considerable amount was removed) 0300-0312Z: intense clutter specks remaining near radar -----> clutter 0336-0436Z: intense AP embedded in precip SW of radar 1A !!FLAG!! -----> improved in that all the non-embedded AP was removed. But, still given a major flag due to all the intense AP still present and embedded in precip...nothing can be done about that short of removing precip as well. 0336-0636Z: intense Gunn Pt. clutter specks embedded in precip 1A !!FLAG!! -----> all non-embedded clutter removed but a major flag is still given for all the embedded clutter which remains. 0500-0600Z: intense AP remaining E of radar, often embedded in precip 1A,2A !!FLAG!! -----> all non-embedded clutter removed but a major flag is still given for all the embedded clutter which remains. 0700-0948Z: horrifically intense AP remaining N of radar, mostly embedded within precip 2A !!FLAG!! -----> vastly improved and still ghastly and in need of a major flag. Almost all non-embedded AP was removed but VOS's duing this time period are still basically unusable for the significant amounts of intense, embedded AP remaining behind. Nothing can be done about embedded AP except blowing everything away (which is not an option) 1212-1224Z: moderate clutter/AP remaining N of radar -----> corrected 1300-1312Z: moderate AP splotch remaining E of radar -----> corrected 1348Z: moderate AP splotch remaining E of radar -----> corrected 1348-1436Z: second-trip echo remaining SW of radar -----> corrected 1524-1612Z: second-trip echo remaining SW of radar 2B- !!FLAG!! -----> a couple VOS's still contain a splotch of weak second-trip which could not be removed without compromising precip also present at the time. Very small problem...almost negligible. 1648-1748Z: scattered weak/moderate AP remaining E of radar 2A !!FLAG!! -----> the improvement of this time period can be broken down into two categories: 1648-1724Z: vastly improved but still some isolated AP splotches of moderate intensity in the field. 1736-1748Z: AP much weaker to begin with during these VOS's but little could be done to remove it due to the rapid development of small shower cells which were very sensitive to parameter tweaking. AP left in. 1812-1936Z: weak/moderate/intense AP remaining E of radar 2A !!FLAG!! -----> much improved but still bad enough to earn a major flag. Could not further remove remaining AP (which is often intense) without greatly affecting precip also present in the field. Moved VOS 1936Z to bad_files_not_in_1C.hdf directory. 2148-2224Z: intense clutter splotch remaining W of radar -----> corrected 2212-2224Z: intense Gunn Pt. clutter specks remaining, embedded within precip 3A !!FLAG!! -----> embedded AP can not be corrected. Clutter specks within precip are small but at the same time intense. **************************************************************************************************** 10 Jan 98: Early on, widespread convection and showers with locally heavy rainfall. Some of the cells look pretty impressive. Convection begins to shrink in coverage and decrease in reflectivity by 09Z. More isolated convective cells begin firing around 17Z and persist until the end of the day. Data processed: 0000-2348 Z Satellite Coincidence: 0510Z(244km), 1453Z(553km) QC notes: 0124-0136Z: Minor clutter specks NW of radar (moderate/intense precip nearby) ----> Corrected - clutter removed; a couple minor showers were removed in the process 0512-0536Z: Moderate clutter NW of radar (moderate/intense precip nearby) ----> Corrected - clutter removed; a couple minor showers were removed in the process 3B !!FLAG!! 0548Z: Intense clutter specks near radar ----> Clutter cannot be removed due to presence of precip near radar. 60 dBZ clutter, but coverage is very minor therefore a B flag is warrented. 0624Z: Intense clutter specks near radar ----> Corrected ---------------------------------------------------------------------------- 1000-1248Z: Light/Moderate AP surrounding radar at various ranges (some precip nearby) - AP is not embedded. The 1000Z VOS contains intense AP ----> Corrected except for flags below - some light showers were removed in the process 3A !!FLAG!! 1012Z: Intense AP S of radar cannot be entirely removed due to presence of precip near radar. 3A !!FLAG!! 1100Z: Intense AP S of radar cannot be entirely removed due to presence of precip near radar. This uf file has been placed in a "bad_files" directory so it will not be included in 1C.HDF for TSDIS. Therefore, ---------------------------------------------------------------------------- 1300-1512Z: Moderate/Intense AP - no precip ----> Corrected 1A,2A,3A !!FLAG!! 1524-1712Z: Moderate/Intense AP SW of radar embedded in developing precip. ----> AP cannot be removed without removing precip. 1924-1948Z: Moderate/Intense AP SE of radar (not embedded) ----> Corrected - AP removed A couple minor showers were removed in the process. 2B,3B !!FLAG!! 2236-2324Z: Moderate clutter SW of radar masked by light/moderate precip ----> Clutter cannot be removed because it is embedded within precip. ********************************************************************************************************** 11 Jan 98: Unorganized convection moving west to east throughout the day. No precipitation after 1848Z. Data processed: 0000-0124 Z 0812-1848 Z 2236-2348 Z Satellite Coincidence: 0357Z(399 km), 1341Z(98 km) QC notes: 0000-0024Z: intense clutter splotch W of radar -----> corrected 0048-0124Z: intense clutter splotch W of radar, often embedded within precip 2A !!FLAG!! -----> nothing can be done about AP embedded within precipitation. The intense clutter splotch west of the radar is embedded within precip during this time period and therefore remains...hence the major flag. 0836-0900Z: moderate island clutter splotch remaining -----> corrected 0936-1336Z: moderate island clutter remaining (NW of radar) -----> corrected 1424-1436Z: moderate island clutter remaining (NW of radar) -----> corrected 1836-1848Z: intense Gunn Pt. clutter specks remaining -----> corrected ************************************************************************************************************ 12 Jan 98: Unorganized convection over Mainland and strong convective cluster over Islands, early on. By 08Z, convection over Islands weakens but cells over land merge to form strong cluster, located east of Gunn Point. This strong convection is gone by 16Z, leaving only scattered cells for the rest of the day. Data processed: 0000-2348 Z Satellite Coincidence: 0421Z(418 km), 1228Z(710 km), 1404Z(741 km) QC notes: 0348-0912Z: moderate/intense island clutter remaining -----> corrected 2200-2236Z: scattered weak AP remaining -----> corrected 2312Z: moderate clutter splotch remaining near radar -----> corrected ************************************************************************************************************* 13 Jan 98: Scattered, unorganized convection develops ~02Z in various directions surrounding radar. A large convective cluster develops over the Islands (N of radar) near 05Z. By 12Z, all convective activity has diminished. No additional activity for the remainder of the day. Data Processed: 0000-2348Z Satellite Coincidence: 0308Z(212km), 1252Z(86km) QC notes: 0536-0748Z: Moderate Island clutter masked by light/mod/intense precip echo. 2B,3B !!FLAG!! ----> This is a very bad combination. The clutter cannot be removed without also removing the real precip echo. In this particular case, a minor flag is given because the precip echo is almost the same dBZ magnitude as the clutter. The precip is masking the clutter. 2136-2324Z: Scattered light AP - no precip ----> Corrected ************************************************************************************************************* 14 Jan 98: Scattered convection develops ~05Z and dissipates by 10Z. An isolated convective cluster moves into the radar scope from the S near 13Z and dissipates by 1530Z. Data Processed: 0000-2348Z Satellite Coincidence: 0332Z(597km), 1140Z(530km) QC notes: 0200-0400Z: Scattered light AP - no precip ----> Corrected - AP removed 1036-1224Z: Moderate / Intense AP at far range - no precip ----> Corrected - AP removed 1236-1536Z: Moderate AP at far range with convective cluster at far range (not embedded) ----> Corrected - AP removed while precip remains in-tact!! 1548-2348Z: Occasional Light / Moderate AP surrounding radar - no precip ----> Corrected - AP removed ************************************************************************************************************* 15 Jan 98: Scattered convection develops near 05Z and dissipates by 09Z. New convection appears on the radar scope ~ 0930Z quickly moving from SE to NW. By 16Z, numerous convective clusters are present E and S of radar. Clusters combine to form one large squall line which propagates NW. By 1924Z, a moderate sized area of stratiform precip develops behind the squall line and then detaches from it. By ~23Z, the squall line has exited the radar scope and the stratiform shield has dissipated over the radar. Data Processed: 0000-0200Z 0500-0600Z 0709-2348Z Satellite Coincidence: 0220Z(15km), 1204Z(284km) QC notes: 0500-0600Z: Moderate intensity Island clutter NW of radar (scattered convection nearby) ----> Corrected - clutter removed 1324Z: Moderate intensity Island clutter NW of radar (scattered convection nearby) ----> Corrected - clutter removed 1400Z: Moderate intensity Island clutter NW of radar (scattered convection nearby) ----> Corrected - clutter removed 1436-1812Z: Moderate/Intense clutter near radar when convection develops very near radar and moves directly over radar. Some minor Island clutter NW of radar is also present in a few of these VOSs. ----> Some clutter was removed (at the expense of removing a few light showers). The intense clutter could not be removed without removing too much real precip echo. The minor island clutter was removed. 2A,2B, !!FLAG!! 1448-1648Z: Moderate/Intense clutter near radar cannot be removed due to the presence of precip. 2B !!FLAG!! 1836Z: Intense clutter specks embedded within light precip near radar (minor coverage). Because the clutter is embedded, it cannot be removed without also removing the precip. 2048Z: Intense clutter speck near radar (not embedded in precip) ----> Corrected - AP removed 2112-2148Z: Moderate/Intense Island clutter NW of radar (not embedded) ----> Corrected - AP removed. Some minor showers at far range were also removed in the process. 2212-2312Z: Moderate/Intense AP surrounding radar. Some AP embedded within light /moderate precip shield. Island clutter NW of radar ----> Some AP was removed ( along with a few light showers). AP could not be totally removed due to the presence of precip. Island clutter was mostly removed. See flags below. 3A !!FLAG!! 2212Z: Intense AP at far range cannot be removed due to presence of precip. 2B,3B !!FLAG!! 2224-2248Z: Moderate AP at far range cannot be removed due to presence of precip. 2A,3A !!FLAG!! 2300Z: Intense AP at moderate/far range cannot be removed due to presence of precip. 2312-2348Z: Intense AP - no significant precip ----> Corrected - AP removed ************************************************************************************************************* 16 Jan 98: Scattered covection develops mainly S of radar near 02Z. By 04Z, the main activity remains S of radar while some isolated convection develops N of radar near Melville Island. This activity dissipates by 0824Z. New isolated convective cells develop E of radar near 0836Z and dissipate by 1148Z. No additional activity for the remainder of the day. Data Processed: 0000-2348Z Satellite Coincidence: 0108Z(666km), 1052Z(347km) QC notes: 0000-0036Z: Scattered moderate/intense AP surrounding radar - no precip ----> Corrected - AP removed 0736-0812Z: Light second trip echo S of radar ----> Corrected - false echo removed - a couple minor showers also removed in the process 1024-1048Z: Light second trip echo SE of radar ----> Corrected - false echo removed - a couple minor showers also removed in the process 1200-2348Z: Scattered moderate/intense AP surrounding radar - no significant precip. ----> Corrected - AP removed ************************************************************************************************************* 17 Jan 98: Isolated convection E of radar from 00 ~ 01Z. Scattered convection develops mainly S of radar (over land) near 03Z, and quickly organizes into large convective clusters by 06Z. Additional convection forms near Melville Island N of radar. Precip moves slowly to the E and NE. By 10Z, convection has diminished greatly in coverage and intensity and is now in a scattered pattern. There is a large gap in the data flow after 10Z. The next image is 2148Z, and shows a large area of intense convection with a trailing stratiform shield directly over radar. Precip moves NW while additional intense convection and heavy stratiform rain develops W and SW of radar. This pattern continues through the remainder of the day. Data Processed: 0000-1000Z 2148-2348Z Satellite Coincidence: 0132Z(175km), 1116Z(481km) QC notes: 0024Z: Moderate clutter speck near radar ----> Corrected - speck removed 0336-1000Z: Moderate clutter from Melville Island NW of radar, also occasional second trip echo S of radar at far range. ----> Corrected - island clutter and second trip echo removed. A few minor showers were also removed in the process. Only one flag - see below. 2B !!FLAG!! 0336Z: Minor clutter speck near Melville Island could not be removed without also removing a significant amount of real precip echo. 2148-2348Z: Intense clutter specks near radar masked by moderate/intense precip. There is no qc fix for this problem. No flags are given because precip coverage is widespread and virtually the same intensity as the clutter. ************************************************************************************************************* 18 Jan 98: Widespread convection with trailing stratiform shield mainly W and SW of radar propagating NE from 00~05Z. Scattered convection and light showers continue after 05Z and dissipate by 09Z. An isolated convective cell is N of radar at far range near 16Z. Scattered light showers develop W of radar near 1724Z. These showers move E and continue for the remainder of the day. Data Processed: 0000-2348Z Satellite Coincidence: 0020Z(467km), 1003Z(161km) QC notes: 0000-0248Z: Moderate/Intense clutter specks near radar masked by moderate/intense precip. There is no qc fix for this problem. No flags are given because precip coverage is widespread and virtually the same intensity as the clutter. 0348-0436Z: Moderate clutter near radar and NW from Melville Island (not embedded) ----> Partially corrected - Clutter near radar could not be entirely removed due to presence of light precip. Island clutter was completely removed. 3B !!FLAG!! 0348Z: Moderate clutter near radar cannot be removed due to presence of precip. 2B !!FLAG!! 0400Z: Moderate clutter near radar cannot be removed due to presence of precip. 0548-0612Z: Moderate clutter specks near radar with very light second trip echo at far range W of radar. ----> Partially corrected - Cluter reduced in intensity and coverage. Second trip echo removed. A few minor showers were removed in the process. 2B !!FLAG!! 0600Z: Moderate clutter specks remain. Coverage is minor. Clutter cannot be entirely removed due to the presence of precip. 3B !!FLAG!! 0612Z: Moderate clutter specks remain. Coverage is minor. Clutter cannot be entirely removed due to the presence of precip. 1024-1436Z: Moderate/Intense AP S and E of radar - no precip ----> Corrected - AP removed 1448-1636Z: Scattered light AP SE of radar at far range (with lone precip cell NW at far range) ----> Corrected - AP removed. The lone precip cell diminished to 10 dBZ by 1612Z and was also removed with the AP. 1724-1812Z: Moderate Island clutter NW of radar (some embedded in light precip -bad combination for qc) ----> Clutter could successfully be removed from the 1812Z VOS only. When attempts were made to remove clutter from the other VOSs, too much precip was removed without removing any clutter. 2A,3A !!FLAG!! 1724-1800Z: Clutter cannot be removed because it is embedded in light precip 1900-2048Z: Moderate Island clutter NW of radar (some embedded in light precip -bad combination for qc) ----> 2000-2048Z VOSs corrected - clutter removed. 1900-1948Z - Clutter embedded within light precip - no qc fix 2A,3A !!FLAG!! 1900-1948Z: Mod/Intense clutter embedded within light precip. Clutter cannot be removed without also removing precip. ************************************************************************************************************* 19 Jan 98: Isolated convection N of radar near Melville Island at the beginning of the day evolves into widespread convection and convective clusters surrounding the radar by 04Z. By ~07Z, the convective activity N of radar tends to diminish in intensity and coverage while more widespread and intense convection develops over land S of radar. This activity propogates NE but tends to remain mostly W of radar. A stratiform shield forms in the wake of the convection but quickly diminishes in coverage as it approaches the radar. By ~12Z, more intense convection comes into view at far range NW of radar. After 1230Z, there is a large data gap until 2120Z. At 2120Z, intense convection with a large area of heavy precip is occurring W and NW of radar. An E-W oriented convective line develops S of radar near 2300Z. Most activity remains W of radar through the end of the day. This is a very active day for the Gunn Pt. radar. Data Processed: 0000-1230Z 2120-2350Z Satellite Coincidence: 0044Z(359km), 1027Z(678km), 2331Z(273km) QC notes: 0000Z: Light second trip echo at far range ----> Corrected - false echo removed 0024-0048Z: Light second trip echo at far range ----> Corrected - false echo removed 2B,3B !!FLAG!! 0324-0336Z: Moderate Island clutter embeded within developing convection NW of radar. This is a bad qc combination. Because the clutter is embeded, it cannot be removed without removing significant areas of real precip echo. These VOSs have been given minor flags because the coverage is small, and the clutter intensity is virtually the same magnitude as real precip echo which is very close. 1100-1130Z: Moderate clutter embeded within light precip SW of radar. ----> The 1100Z image was corrected. The other VOSs are flagged below. 2A,3A !!FLAG!! 1110-1130Z: Clutter could not be removed from these images because it is embeded within precip. Coverage is small, but magnitude is large. A slight improvement was made to the 1130Z VOS. Harsher parameter settings only removed precip echo without removing the clutter. 2150-2220Z: Moderate/intense clutter specks/globs near radar (not embeded) ----> Corrected - clutter removed or significantly reduced in intensity 2340Z: Intense clutter speck near radar (not embedded) ----> Corrected - clutter speck removed ************************************************************************************************************* 20 Jan 98: Periods of intense convection and large stratiform precip shields surround radar throughout entire day. This is an extremely active monsoon day. Data Processed: 0000-0600Z 0706-2350Z Satellite Coincidence: 0915Z(24km), 2355Z(536km) QC notes: 0030-0130Z: Moderate/intense clutter specks near radar (not embeded) ----> The 0030Z VOS was the only image where the clutter was removed enough not to flag. 2B,3B !!FLAG!! 0040-0130Z: Clutter near radar cannot be entirely removed due to presence of precip. Stronger parameters only removed the precip and not the clutter. These VOSs have been given a "B" flag because moderate/heavy precip is close to the radar during these times, and the clutter should have very little affect on rain maps. 2A,3A !!FLAG!! 0340-0600Z: Intense AP embeded within light precip shield NW of radar. There is no QC solution to this problem. Entire period must be flagged. 3A !!FLAG!! 0706-0712Z: Sector scanning only in these two VOSs. A large precip area is missing from these VOSs. The corresponding uf files have been placed in a "bad_files" directory so that they will not be bundled into 1C.HDF for TSDIS ingest. 0730-0810Z: Moderate island clutter NW of radar. ----> Corrected - clutter removed 0830-0910Z: Moderate/intense clutter near radar and just to the SW of radar. ----> Clutter reduced or removed in all VOSs. However, some clutter remains and cannot be removed due to presence of precip - see flags below 2B !!FLAG!! 0830Z: Clutter specks remain near radar and cannot be removed due to presence of precip. 2A !!FLAG!! 0840Z: Instense clutter near radar remains and cannot be removed without also removing significant areas of precip. 2A,3A !!FLAG!! 1000-1240Z: Moderate/Intense AP embeded within light precip NW of radar. There is no QC solution to this problem. Entire period must be flagged. 1250-1810Z: Moderate/intense AP NW of radar near island (some embeded) ----> Most AP removed - see flag below A few light showers were removed during the reprocessing. 2A,3A !!FLAG!! 1620-1630Z: Moderate AP embeded in light precip NW of radar. AP cannot be removed without removing precip. 1840-1910Z: Moderate/intense AP NW of radar near island (not embeded) ----> Corrected - AP removed (because it is not embeded) A few light showers were removed in the reprocessing ************************************************************************************************************* 21 Jan 98: Widespread convective and stratiform precipitation early on dumps considerable amounts of rain over Northern areas of radar scope. Begins dissipating and moving out of the region by 10Z. Scattered showers and convective cells present til about 13Z, when another convective impulse moves in from the NW. Impulses of convective and stratiform precip continue through to move through the region throught the end of the day. Data processed: 0000-2350 Z Satellite Coincidence: 0802Z(593 km), 2242Z(86 km) QC notes: 0000-0410Z: intense Gunn Pt. clutter specks remaining, mostly embedded within precip 2A !!FLAG!! -----> Embedded AP remains in almost every VOS...nothing can be done about embedded AP/clutter without removing the precip....hence the major flag. (even VOS's which had some clutter removed from one troublespot (i.e., Islands or Gunn Pt.) are still bad because of embedded clutter or AP some place else in the VOS) 0140-0630Z: intense clutter splotch W of radar remaining, mostly embedded within precip 2A !!FLAG!! -----> major flag given for intense, embedded clutter and AP which remains since there is no solution. 0300-0400Z: moderate/intense Island clutter remaining; mostly embedded within precip 2A !!FLAG!! -----> embedded clutter remains. There is no solution for embedded AP short of removing the precip the AP is embedded in. THe AP and precip remains and the VOS's are given major flags. 0410-0450Z: intense clutter remaining S of radar; mostly embedded within precip 2A !!FLAG!! -----> embedded AP remains and is flagged as major. 0450-0710Z: moderate/intense clutter and AP near radar remaining, mostly embedded within precip 2A !!FLAG!! -----> embedded AP remains since it could not be removed without removing the precip as well....VOS's given major flag 0550-1220Z: moderate/intense Island clutter remaining, mostly embedded within precip 1B+,2A !!FLAG!! -----> improved in that most of the non-embedded clutter was removed. Unfortunately, most of the clutter was embedded in precip to begin with and all of this false echo remains. The coastline of the islands is often evident as a stationary line of moderate clutter embedded in the stratiform precipitation north of the radar. 1000-1240Z: moderate/intense AP and clutter in and around Gunn Pt. 2A,2B !!FLAG!! -----> AP and clutter embedded in precip and remains since it is not desired to remove precipitation. Furthermore, don't be fooled by the minor flag that things aren't that bad because they definitely are not peachy....the minor flag is for the last three VOS's (1220-1240Z) where most but not all of the clutter was removed....by that I mean that the embedded clutter remains and the non-embedded clutter was removed. 1320Z: intense clutter splotch W of radar remaining -----> corrected 1340-1410Z: weak/moderate AP near Gunn Pt. remaining -----> corrected 1350-1410Z: intense clutter splotch W of radar -----> corrected 1440-1500Z: intense clutter splotch W of radar remaining 2B !!FLAG!! -----> vastly improved....some small specks of moderate clutter in VOS 1500Z is the reason for the minor flag. I would move this Vos to a non-TSDIS inclusive directory but considering how bad this day has been, I am afraid of what the following VOS holds for us. 1510-2350Z: moderate/intense clutter and AP in and around Gunn Pt. remaining (including clutter splotch W of radar) 2A,1A !!FLAG!! -----> improved in that some of the non-embedded clutter and AP was removed but this time period is still riddled with problems. A significant amount of embedded, moderate/intense AP remains. Recall, nothing can done to remove embedded AP and keep precipitation. During the hour surrounding the close TRMM overpass, the intense clutter splotch W of the radar remains embedded within light precip for the majority of the VOS's...along with some intense, embedded Gunn Pt. clutter specks at times....hence the major 1A flag. 1650-1820Z: moderate/intense Island clutter remaining 2A- !!FLAG!! -----> improved in that all non-embedded clutter was successfully removed. However, consdierabel embedded clutter remains. The flag is an A- rather than the solid major flag because the clutter does have a small areal coverage and is sometimes masked by the precip in the vicinity of the Island. On the other hand, the flag is not a solid minor flag because the clutter is still considered in the moderate range (20-35 dB). 1930-2030Z: moderate/intense Island clutter remaining -----> this problem has been corrected but note that these VOS's are still given a major flag for embedded clutter in and around Gunn Pt. which remains (see flag for 1510-2350Z time period) *************************************************************************************************** 22 Jan 98: Light showers with some embedded convection early on (00-03Z). More widespread convective cells begin to fire after 03Z and continue on until roughly 11Z, when all convection dissipates or moves out of range. Only widely scattered showers for the rest of the day. Data processed: 0000-2350 Z Satellite Coincidence: 0826Z(210 km), 2130Z(746 km) QC notes: 0050Z: intense Gunn Pt. clutter specks remaining -----> corrected 0430-0434Z: sector scan misses convection near Islands 3A !!FLAG!! -----> nothing can be done about missing precipitation due to scanning strategy. Given a major flag for missing precip. Moved VOS's to bad_files_not_in_1C.hdf directory 0440Z: moderate/intense Island ground clutter remaining -----> corrected 0450-0454Z: sector scan misses convection near Islands 3A !!FLAG!! -----> nothing can be done about missing precipitation due to scanning strategy. Given a major flag for missing precip. 0500Z: moderate/intense Island ground clutter remaining -----> corrected 0510-0514Z: sector scan misses convection near Islands 3A !!FLAG!! -----> nothing can be done about missing precipitation due to scanning strategy. Given a major flag for missing precip. 0520Z: moderate/intense Island ground clutter remaining -----> corrected 0530-0534Z: sector scan misses convection near Islands 3A !!FLAG!! -----> nothing can be done about missing precipitation due to scanning strategy. Given a major flag for missing precip. Moved VOS's to bad_files_not_in_1C.hdf directory. 0540Z: moderate/intense Island ground clutter remaining -----> corrected 0550-0554Z sector scan misses convection near Islands 3A !!FLAG!! -----> nothing can be done about missing precipitation due to scanning strategy. Given a major flag for missing precip. 0600-0640Z: moderate/intense Island ground clutter remaining -----> corrected 0720-0750Z: moderate/intense Island ground clutter remaining -----> corrected 0810-0840Z: weak/moderate AP immediately W of radar intermingling with precipitation in this region 1B !!FLAG!! -----> improved, but it appears that some weak AP still borders the precipitation close to the radar....flagged as minor. 1130-1230Z: weak AP remaining SE of radar -----> corrected 1700-1720Z: weak second-trip echo remaining NW of radar -----> corrected 2030-2040Z: intense clutter speck W of radar, adjacent to convective cell 3B !!FLAG!! -----> coorected except for a small clutter specks which still remains in VOS 2030Z....this VOS moved to bad_files_not_in_1C.hdf and the entire time period is flagged as minor. 2200-2210Z: intense clutter speck W of radar, adjacent to convective cell -----> corrected *************************************************************************************************** 23 Jan 98: Strong convection over mainland and Islands early on (~02-09Z). Larger clusters begin to dissipate, leaving only widely scattered cells by 10 Z and these to are gone shortly thereafter. A stationary line of cells develops east of the radar after 22Z. Data processed: 0000-2350 Z Satellite Coincidence: 0713Z(422 km), 2153Z(94 km) QC notes: 0420-0424Z: sector scan misses strong convection off N. Islands 3A !!FLAG!! -----> nothing can be done about missing precipitation due to scanning strategy. Given a major flag for missing precip. 0440-0444Z: sector scan misses strong convection off N. Islands 3A !!FLAG!! -----> nothing can be done about missing precipitation due to scanning strategy. Given a major flag for missing precip. 0500-0504Z: sector scan misses strong convection off N. Islands 3A !!FLAG!! -----> nothing can be done about missing precipitation due to scanning strategy. Given a major flag for missing precip. Moved VOS's to bad_files_not_in_1C.hdf directory. 0520-0524Z: sector scan misses strong convection off N. Islands 3A !!FLAG!! -----> nothing can be done about missing precipitation due to scanning strategy. Given a major flag for missing precip. 0530Z: moderate/intense island clutter remaining -----> corrected 0540-0544Z: sector scan misses strong convection off N. Islands 3A !!FLAG!! -----> nothing can be done about missing precipitation due to scanning strategy. Given a major flag for missing precip. 0550Z: moderate/intense island clutter remaining -----> corrected 0600-0604Z: sector scan misses strong convection off N. Islands 3A !!FLAG!! -----> nothing can be done about missing precipitation due to scanning strategy. Given a major flag for missing precip. Moved VOS's to bad_files_not_in_1C.hdf directory. 0610Z: moderate/intense island clutter remaining -----> corrected 0620-0624Z: sector scan misses strong convection off N. Islands 3A !!FLAG!! -----> nothing can be done about missing precipitation due to scanning strategy. Given a major flag for missing precip. 0630-0850Z: moderate/intense island clutter remaining 1B,2B+ !!FLAG!! -----> all non-embedded clutter was completely removed. Near the time of the overpass, soem very small clutter specks may still exist along the very fringe of the precip...hence the 1B flag. Near 0800Z, more disernible, embedded clutter remains, although the coverage is small and the clutter is mostly masked by the precip of same intensity....hence the B+ flag. VOS 0800Z moced to bad_ files_not_in_1C.hdf directory. 1020-1030Z: intense clutter splotch W of radar remaining -----> corrected 1050Z: intense clutter splotch W of radar remaining -----> corrected 1610-1640Z: intense clutter splotch W of radar remaining 2B !!FLAG!! -----> vastly improved but a small speck of embedded clutter remains in a couple of the VOS's. Not a major concern and only draws a minor flag because the areal coverage is so small and the reflectivity is roughly equivalent to the clutter, thus acting like a mask. ************************************************************************************************** 24 Jan 98: Rapid development of unorganized convective cells early on (00-06Z). Precipitation from this convection begins to dissipate by 07Z and is all but gone by 0930Z. New round of convection fires in vicinity of Gunn Pt. around 15Z and is finished by ~20Z. Hints of a larger, more organized system SE of the radar as stratiform rain peeks into outer ranges near 20Z. Data processed: 0000-2350 Z Satellite Coincidence: 0737Z(395 km), 2041Z(558 km) QC notes: 0000-0120Z: moderate/intense radial spike remnant E of radar; embedded in a couple of convective cells at times. 2A- !!FLAG!! -----> improved, but some moderate AP remains, embedded in the real convective cells in the vicinity. At times, it is difficult to determine which "cells" are true or false. This uncertainty coupled with the AP known to exist is the reason for the A- flag. 0240-0700Z: moderate/intense island clutter (NW of radar) remaining 2A !!FLAG!! -----> improved, in that almost all non-embedded clutter was removed. Unfortunately, numerous VOS's contain embedded clutter which can not be removed with this algorithm without removing the precip as well. So, the embedded clutter was left in and this time period is given a major flag. VOS 0600Z was moved to the bad_files_not_in_1C.hdf directory. 0310-0610Z: intense clutter speck W of radar remaining 2A !!FLAG!! ----> see previous qc note for reason behind this major flag. 0400-1410Z: weak second-trip echo remaining E to SE to S of radar -----> corrected 1540-1800Z: weak AP remaining E to SE of radar -----> corrected 1550-1600Z: intense Gunn Pt. clutter specks remaining 3B !!FLAG!! -----> improved, but not completely corrected because VOS 1550Z still contains a very small speck of clutter which could not be removed. VOS 1600Z was completely corrected. 1710-1740Z: intense Gunn Pt. clutter specks remaining 2A !!FLAG!! -----> improved, but intense clutter embedded in precip remains....hence the major flag. 1830-1920Z: weak AP remaining E to SE of radar -----> corrected 1850-2040Z: moderate/intense island clutter remaining; often embedded within light precipitation 2A,1A !!FLAG!! -----> improved but still deserving of a major flag for all the intense island clutter which remains embedded within precip. All clutter no embedded in precip was removed but unfortunatley this constitutes the minority of clutter which remained after first- pass level_1 processing....hence the major flag 2120-2140Z: moderate/intense island clutter remaining -----> corrected ************************************************************************************************** 25 Jan 98: Large stratiform precipitation shield persists along the eastern edge of the scope. Around 04Z, convection erupts and intensifies near Gunn Pt. and over the Islands. By 07Z, strong convection is also present west of the radar, embedded in the stratiform rain shield. From 10-16Z, no convection is present but precip is not lacking due to the persistent presence of the stratiform rain shield W-SW of the radar. After 16Z, convection once again fires, with cells soon scattered throughout the scope. The large shield of moderate precipitation moves northward, carving out more areal coverage so that by days end, a significant rain event is in progress for Northern Australia. Data processed: 0000-2350 Z Satellite Coincidence: 0624Z(249 km), 2104Z(271 km) QC notes: 0320Z: moderate/intense Island clutter remaining -----> corrected 0340-0400Z: moderate/intense Island clutter remaining -----> corrected 0420-0440Z: moderate/intense Island clutter remaining -----> corrected 0510-0710Z: moderate/intense Island clutter + moderate AP near Gunn Pt. remaining 2A,1A !!FLAG!! -----> improved, but unfortunatley not enough to avoid a major flag. The reason for the flag is for moderate AP and moderate/intense ground clutter which remains embedded within precipitation. Nothing can be done about embedded AP short of removing everything, including the precip. 0750Z: intense clutter splotch W of radar -----> corrected 1100Z: moderate Island clutter remaining -----> corrected 1230Z: moderate Island clutter remaining -----> corrected 1350Z: moderate Island clutter remaining -----> corrected 1550Z: intense Gunn Pt. clutter specks remaining -----> corrected 1810-1900Z: Gunn Pt. clutter specks + moderate AP also remaining in this immediate area 2A !!FLAG!! -----> slightly improved but unfortunately, most of the AP and clutter found during this time period was embedded within precip. The major flag is for the moderate, embedded AP which remains and could not be removed without removing precipitation. 1910-2020Z: moderate/intense Island clutter remaining 3A- !!FLAG!! -----> much improved but two VOS's, 1950 and 2000Z, still contain a speck of moderate clutter which is embedded within precip... VOS 2000Z was moved to bad_files_not_in_1C.hdf directory which leaves us with a 3A- flag. 2030-2100Z: weak/moderate AP remaining near radar 2A-,1A- !!FLAG!! -----> improved but some small splotches of moderate AP remain embedded within light precipitation. Flagged as A- which is somewhere between a major and minor flag because the coverage is so small and at times masked by precip. 2120-2350Z: moderate/intense AP + intense clutter specks in and around Gunn Pt. (including intense clutter splotch W of radar) 1A,2A !!FLAG!! -----> improved in that almost all of the non-embedded AP/clutter was removed. However, there is enough embedded AP/clutter remaining to warrent major flags...any attempt to remove this embedded false echo would greatly compromise the precip in the field. *************************************************************************************************** 26 Jan 98: Widepsread precipitation during the entire day. Copious rainfall amounts as convective cells, clusters, and lines, as well as large stratiform rain shields batter Northern Australia. Data processed: 0000-2350 Z Satellite Coincidence: 0648Z(585 km), 1952Z(363 km) QC notes: 0000-0200Z: intense Gunn Pt. clutter specks and moderate AP near Gunn Pt. remaining, often embedded within precipitation 2A !!FLAG!! -----> slightly improved but most of the clutter was embedded in precip to begin with and therefore never had a solution of its removal (at least not with this algorithm)....the major flag is for the intense clutter which remains, embedded within precipitation. 0000-0410Z: moderate/intense Island clutter remaining, often embedded within precipitation 2A- !!FLAG!! -----> much improved in that most, if not all, of the non-embbedded ground clutter was successfully removed. However, some embedded clutter still remains and is the reason for the A- flag. 0310-0330Z: intense clutter splotch W of radar, often embedded within precip 3A !!FLAG!! -----> nothing could be done about the clutter splotch since it was embedded in light precipitation the entire time. VOS 0330Z was moved to bad_files_not_in_1C.hdf directory and the time period was flagged as major. 0530-0610Z: weak/moderate AP and intense clutter specks remain in the vicinity of Gunn Pt. 2B+ !!FLAG!! -----> only a slight improvement in removing AP and clutter. The remaining false echo is embedded in precipitation and cannot be removed. The good news though is that most is masked by precip of similar intensity and AP which does become discernible possesses a small areal coverage....these two characteristics are the reason this time period escaped a major flag. 0620-0800Z: moderate/intense Island clutter remaining, often embedded within precipitation 3B !!FLAG!! -----> vastly improved in that all the clutter before and including 0710 was removed. From 0720-0750Z, moderate clutter becomes embedded within precip and can not be removed. Fortunately though, the precip it is embedded in is of relatively similar intensity and effectively masks most of the clutter....hence the minor flag 0630-0730Z: intense clutter splotch W of radar remains embedded within light precipitation 1A !!FLAG!! -----> nothing can be done about embedded ground clutter without removing the precipitation it is embedded within. The 1A major flag is for VOS's 0630-0720Z where the intense splotch is clearly visible in the light and then moderate precip in this region. 1A !!FLAG!! -----> nothing can be done about embedded clutter or AP without removing precipitation. The clutter splotch remains and the VOS's are given a major flag 0910-0920Z: moderate/intense Island clutter remaining, mostly embedded within precipitation 3B !!FLAG!! -----> improved...the only clutter that remains is that which is embedded within precip....but similar intensities act to mask most of the false echo and helps the time period escape a major flag 1040-1750Z: moderate/intense Island clutter remains embedded within light precipitation 2A !!FLAG!! -----> nothing can be done about embedded clutter without removing precipitation. The Island clutter remains and the VOS's are given a major flag 1100-1620Z: intense clutter splotch W of radar embedded within precip 2A !!FLAG!! -----> nothing can be done about embedded clutter or AP without removing precipitation. The clutter splotch and AP remain and the VOS's are given a major flag. (recall that these VOS's were already flagged as major becuase of the embedded island ground clutter (see above)) 1310-1600Z: intense Gunn Pt. clutter and moderate AP in the same vicinity remain, mostly embedded within precipitation 2A !!FLAG!! -----> only slight improvement in one or two VOS's, where clutter was on the edge of the precip and able to be removed. nothing can be done about embedded clutter or AP without removing precipitation. The clutter and AP remain and the VOS's are given a major flag. 3B+ !!FLAG!! 1740Z: sector from ~170-290 degrees void of data in 3rd tilt scan (and perhaps higher). Flagged as B+ but keep in mind that this VOS already has a major flag attached to it do to embedded Island ground clutter (see above) 1830-1940Z: moderate/intense island clutter remains embedded in light precip 1A !!FLAG!! -----> nothing can be done about embedded clutter without removing precipitation. The Island clutter remains and the VOS's are given a major flag. 2010-2110Z: embedded intense clutter splotch W of radar remains. Also, moderate AP near the radar remains, embedded within precipitation. 2A !!FLAG!! -----> nothing can be done about embedded clutter or AP without removing precipitation. The clutter splotch and AP remain and the VOS's are given a major flag. 2150-2350Z: moderate/intense Island clutter remains, embedded within light precipitation 2A !!FLAG!! -----> nothing can be done about embedded clutter without removing precipitation. The Island clutter remains and the VOS's are given a major flag. 2300-2350Z: intense clutter splotch W of radar remains, embedded within precipitation. 2A !!FLAG!! -----> nothing can be done about embedded clutter or AP without removing precipitation. The clutter splotch and AP remain and the VOS's are given a major flag. ******************************************************************************************************** 27 Jan 98: Widespread convection and light to moderate stratiform rain soak the Darwin area throughout the entire day. Several small convective lines move quickly over the radar as larger, slower moving convection and rain shields bubble up from the SW. Data Processed: 0000-2350Z Satellite Coincidence: 0536Z(61km), 2016Z(457km) QC notes: 2B,3B !!FLAG!! 0000-0050Z: moderate/intense clutter SW of radar embeded within light precip- Clutter cannot be removed without also removing the precip. This period has been given a minor flag because moderate convection with virtually the same magnitude reflectivity is very close. 2A,3A !!FLAG!! 0210-0230Z: moderate/intense clutter SW of radar embeded within light precip- Clutter cannot be removed without also removing the precip. Therefore, the clutter remains. 1A,2A,3A !!FLAG!! 0300-0920Z: moderate/intense clutter NW and SW of radar embeded within light precip- Clutter cannot be removed without also removing the precip. Therefore, the clutter remains. 2B !!FLAG!! 0930Z: moderate/intense clutter very close to light precip. It may be possible to remove some of this clutter. Also, moderate clutter near radar. There is moderate AP just West of the radar in a sector type pattern. The AP has 30 dBZ intensity and is somewhat embeded in light precip. Some of the clutter was removed, but not all of it. 0940-0950Z: moderate/intense clutter very close to light precip. It may be possible to remove some of this clutter. Also, moderate clutter near radar. There is moderate AP just West of the radar in a sector type pattern. The AP has 30 dBZ intensity and is somewhat embeded in light precip. ----> Corrected - Most AP removed. 2A !!FLAG!! 1000Z: moderate/intense clutter very close to light precip. It may be possible to remove some of this clutter. Also, moderate clutter near radar. There is moderate AP just West of the radar in a sector type pattern. The AP has 30 dBZ intensity and is somewhat embeded in light precip. Some of the clutter was removed, but not all of it. 2A,3A !!FLAG!! 1010-1240Z: moderate/intense clutter SW and occasionally NW of radar. Most of this clutter is embeded within light precip, therefore, it cannot be removed. Some additional AP is located just West of radar in a sector type pattern originating from the radar. This AP has ~ 30 dBZ magnitude and is also embeded within precip near the radar. It may be possible to remove some of the clutter which is not embeded, but this entire period must be flagged anyway. Some of the AP from 1010Z -> 1050Z, and from 1140-1200Z was removed. 1250-1320Z: Clutter near radar and NW of radar (not embeded) ----> Only the 1250 VOS was totally corrected - see flags below 2A,2B !!FLAG!! 1300-1320Z: Clutter could not be removed due to presence of precip. Attempts to remove clutter resulted in too much precip being removed. Therefore, these VOSs must be flagged. 2A,3A !!FLAG!! 1330-1410Z: Clutter near radar embeded within light precip. Some of this clutter is just the typical specks. Just to the west of the radar is additional clutter in a sector pattern. It has ~ 30 dBZ magnitude and is embed within light/moderate precip. It cannot be removed without removing the precip. Some light precip near the radar is missing. An attempt will be made to restore the missing precip, but this entire period is flagged due to the embeded clutter. ----> Precip restored from 1350Z -> 1410Z. 2A,3A !!FLAG!! 1440-2130Z: Embeded clutter SW of radar - clutter cannot be removed without also removing precip. Also, the 30 dBZ sector type AP West of radar is present in all VOSs. Most of this AP is embeded within light/moderate precip. and cannot be removed. This entire period must be flagged. ----> Some clutter was removed from 2100 -> 2130Z. 2140-2330Z: Moderate clutter near radar and NW of radar from Melville Island. This clutter is not embeded, but it is very close to precip which makes it difficult to remove. ----> Some clutter was removed, but the embeded clutter was not. See flags below 2A,3A !!FLAG!! 2140-2220Z: Embeded clutter NW of radar cannot be removed without removing significant areas of precip. ******************************************************************************************************** 28 Jan 98: Another very active monsoon day in Australia. From 0000 through ~ 1430Z, a large area of stratiform rain with embeded convective cells tends to remain to the S/SW of Gunn Pt. radar, while NW-SE oriented lines of intense convection slide to the SE passing near and over the radar. After ~1430Z, the stratiform shield somewhat dissipates while intense convection continues to propogate from NW to SE near and over the radar for the remainder of the day. By 2120Z, an interesting pattern develops where two intense convective lines (both oriented NW-SE) are located to the NE and SW of radar. There is a break in the action directly over the radar site. By the end of the day (~2350Z), an intense squall line is approaching the radar from the SW. Data Processed: 0000-2350Z Satellite Coincidence: 0423Z(669km), 1904Z(166km) QC notes: 2A,3A !!FLAG!! 0000-0040Z: Holes in light precip near radar plus intense embedded clutter near radar ----> Precip restored, but embedded clutter cannot be removed without removing precip, therefore this period is given a major flag. 2A,3A !!FLAG!! 0200-0220Z: Moderate/intense embedded clutter near radar. Some of this clutter is in a sector type shape just W of radar. Because it is embedded within light precip, it cannot be removed. 2A,3A !!FLAG!! 0240-0340Z: Clutter near radar (some embedded). Some of this clutter is in a sector type shape just W of radar. Even though some of this clutter is not embedded, it cannot be removed without removing significant areas of light/moderate precip near radar. Therefore, the clutter remains and this period is flagged. 0730-0820Z: Moderate/intense clutter near radar as precip moves close to radar. Also, intense embedded clutter SW of radar from 0750-0820. An attempt will be made to remove some of the clutter near the radar. Embedded clutter NW of radar from Melville Island, and also SW of radar. ----> Only the 0730 VOS was corrected - clutter removed. The other VOSs are flagged below. 2A,3A !!FLAG!! 0740-0820Z: Clutter near radar could not be removed due to presence of precip near radar. Also, moderate/intense clutter embeded in precip NW and SW of radar cannot be removed without also removing significant areas of precip. Therefore, clutter remains and the period is given a major flag. 2A,3A !!FLAG!! 0830-1020Z: Moderate/intense clutter embedded within light precip SW of radar. Some clutter near the radar is also present. Clutter cannot be removed without also removing precip. Therefore, the clutter remains and the period is given a major flag. 1230-1300Z: Moderate/intense clutter SW of radar located in a small precip gap. ----> Some of the clutter was removed. Sometimes the clutter is located very close to light precip and cannot be removed without also removing the precip - see flags below 3A !!FLAG!! 1240Z: Clutter SW of radar could not be removed due to proximity to precip and because it is partially embedded. 2A !!FLAG!! 1300Z: Clutter SW of radar could not be entirely removed due to proximity to precip and and because it is partially embedded. 3A !!FLAG!! 1410Z: Intense clutter near radar as precip moves very close. Clutter cannot be removed without also removing significant areas of precip. 2A,3A !!FLAG!! 1530-1620Z: Moderate/intense clutter near radar. Clutter is in the form of intense specks near the radar, and a 30 dBZ sector pattern just West of the radar. Clutter cannot be removed because it is embedded within light precip. 1630-1720Z: Moderate/intense clutter SW and NW of radar (some of which is not embedded) ----> Partial correction - some of the clutter was removed. Some clutter could not be removed without removing too much precip - see flags below 2A !!FLAG!! 1630Z: Intense clutter could not be removed due to presence of precip. 2A,3A !!FLAG!! 1650-1720Z: Intense clutter could not be removed due to presence of precip. Some of this clutter is embedded within light precip. 1740-1820Z: Moderate/intense clutter near radar. Clutter is also found SW and NW of radar. Some clutter is embedded and some is not embedded. ----> Partially corrected - some of the clutter was removed. 1800-1810Z VOSs were corrected. The other VOSs could not be completely corrected - see flags 3A !!FLAG!! 1740-1750Z: Moderate embedded clutter could not be removed without removing too much precip. These VOSs must be flagged. 3A !!FLAG!! 1820Z: Intense clutter near radar could not be removed due to proximity of precip. 1900-1910Z: Moderate Island clutter NW of radar (partially embedded) ----> Corrected! 2050-2110Z: Moderate Island clutter NW of radar ----> Corrected! ******************************************************************************************************** 29 Jan 98: Widespread moderate/intense convection and heavy stratiform rain from 00 ~ 07Z. After ~07Z, the activity becomes more scattered in coverage. By ~1900Z, an intense squall line moves directly over Gunn Pt. radar and weakens. Scattered convection continues for the remainder of the day. Data Processed: 0000-2350Z Satellite Coincidence: 0448Z(130km), 1928Z(636km) QC notes: 1A,2A,3A !!FLAG!! 0320-0440Z: Moderate/intense clutter embedded within light precip SW of radar. Also, some intense clutter specks near radar embedded in light precip. Clutter cannot be removed without also removing precip, therefore, the clutter remains and this period is given a major flag. 0450-0510Z: Moderate clutter NW of radar near Melville island (not embedded). ----> Corrected - AP removed 1A,2A,3A !!FLAG!! 1940-2020Z: Moderate/intense clutter embedded within light precip SW of radar. Clutter cannot be removed without also removing precip, therefore, the clutter remains and this period is given a major flag. 2030-2100Z: Moderate clutter NW and SW of radar. Clutter SW is partially embedded within light precip, while clutter NW is not embedded. ----> Partial correction - clutter NW of radar was removed (masked) while the embedded clutter SW could not be removed without also removing precip. See flags below. 2130Z: Small area of intense island clutter NW of radar (not embedded) ----> Corrected - AP removed 3B !!FLAG!! 2040-2050Z: Light embedded clutter SW of radar cannot be removed without removing significant precip. ******************************************************************************************************** 30 Jan 98: Scattered/isolated convection throughout entire day. Several intense convective cells move directly over radar. All precip moves NW to SE. Data Processed: 0000-2350Z Satellite Coincidence: 0335Z(492km), 1815Z(23km) QC notes: 0220Z: Intense clutter speck W of radar ----> Corrected - AP removed 3A !!FLAG!! 0450Z: Intense clutter specks near radar embedded in precip. Clutter cannot be removed without also removing precip. 3B !!FLAG!! 0520Z: Moderate clutter from Melville island NW of radar; moderate clutter speck embedded in light precip SW of radar ----> Clutter NW from island removed; embedded clutter cannot be removed without removing precip. This is given a minor flag because clutter is not intense 0540-0900Z: Moderate/intense clutter from Melville island NW of radar; clutter specks near radar at 0610Z; intense clutter near radar at 0740Z; second trip echo at mid/far range from 0740-0830Z ----> Some of the clutter from Melville Island was removed; some is embedded within light/moderate precip; some clutter near radar was removed; second trip echo was partially removed - see flags 2A,3A !!FLAG!! 0730-0900Z: Intense clutter NW of radar near Melville island could not be removed. This is the main reason why this period receives a major flag. Other problem such as intense specks near radar and occassional light AP S of radar still exist. Although some of the AP was removed, the images could not be totally cleaned up due to presence of precip. 0910-1520Z: Moderate/intense AP S and E of radar. A few convective cells are present E and SW of radar. ----> Corrected!!! AP was removed (masked) while the precip cores were basically left in-tact. Precip with reflectivities < 30 dBZ were chopped out pretty bad, but precip cores are OK. This is an acceptable compromise. 1800Z: AP SW of radar ----> Corrected - AP removed 1920-2230Z: Moderate AP SW of radar - a few AP specks NW also. ----> It has proven to be very difficult to remove the AP from the VOSs in this time period. Since the clutter covers such a small area, and is not very intense, the VOSs will get a minor flag. Harsher parameter settings only removed the real precip echo. 2B,3B !!FLAG!! 1940-2040Z: Minor AP SW of radar cannot be removed without also removing precip. 3B !!FLAG!! 2210-2220Z: Minor AP SW of radar cannot be removed without also removing precip. ******************************************************************************************************** 31 Jan 98: Scattered convection develops near 0230Z N and S of the radar. Intense convection develops on coastline of Melville Island. This convection remains nearly stationary and dissipates by ~11Z. A small area of showers pushes into view E of radar at far range near 17Z. No additional precip for the remainder of the day. Data Processed: 0000-2350Z Satellite Coincidence: 0359Z(322km), 1703Z(628km) QC notes: 0000-0230Z: Scattered light AP NW of radar - no precip ----> Corrected - AP removed 0410-0450Z: Moderate AP NW of radar near Melville Island ----> Corrected - AP patches removed 1010-1110Z: Scattered AP surrounding radar with small decaying convective cell SE of radar. ----> Corrected - AP removed; precip cell remains in-tact 1120-1610Z: Moderate/intense AP surrounding radar (mainly S) - no precip ----> Corrected - AP removed 1620-1850Z: Moderate/intense AP S of radar with an area of decaying precip E of radar. ----> Partially corrected - some moderate/intense AP remnants remain S of radar of radar in many VOSs - see flag below. For the 1830-1850 VOSs, the minor decaying cell was removed in order to remove 60+ dBZ AP. This is a compromise which is justified in this case. 1A,2A,3A !!FLAG!! 1640-1820Z: Intense AP remnants S of radar cannot be removed due to presence of precip E of radar. The AP remains so this period is given a major flag. Harsher parameter settings only resulted in the removal of real precip echo. 1900-2350Z: Light/moderate AP S and E of radar - no precip ----> Corrected - AP removed ********************************************************************************************************