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 litte coverage) *********************************************************************************************** 01 Feb 98: Only precipitation is some very weak showers of the coast late in the day (after 23Z). Data processed: 0000-2355 Z Satellite coincidence: 0149Z, 0326Z, 2123Z, 2259Z QC notes: 1336-1425Z: scattered weak AP S of the radar ----> corrected 2325-2355Z: removal of light precipitation E of radar -----> corrected *********************************************************************************************** 02 Feb 98: Weak showers in the form of small shields loiter on the western fringe of the radar while small showers move in from the Atlantic for most of the day. However, change comes quickly as a large sheild of moderate precipitation moves in around 20Z and by 24 Z has covered most of the scope with heavy rain. Data processed: 0005-2359 Z Satellite coincidence: 0213Z(221 km), 2010Z(403 km), 2147Z(452 km) QC notes: 0005-0331Z: removal of light precipitation -----> corrected 1310-1559Z: removal of light precipitation 2B !!FLAG!! -----> precip removal problem completely corrected but in doing so, a weak to sometimes moderate clutter speck near the radar was re-introduced. Flagged as minor because most of the time it is weak and regardless of intensity it covers a very small area. 1631-1936Z: removal of light precipitation 2B !!FLAG!! -----> exact same flag as the last one regarding the weak AP speck 2012-2159Z: removal of light precipitation 2B !!FLAG!! -----> exact same flag as the last two flags regarding the persistent clutter speck near the radar 2225-2357Z: 10 km ring of missing precip surrounding radar (Z2 is too high) -----> corrected *********************************************************************************************** 03 Feb 98: From 00-08Z is one of the biggest rain events I have ever seen....at one point the entire scope is filled with heavy rain while a strong bow echo moves through the southern end of the scope. Eventually the backside of this immense shield moves off the eastern edge of the scope but plenty of precip in its wake in the form of a convective line off the coast, scattered convective cells throughout the scope, and still some light stratiform precipitation with significant areal coverage....what an amazing day. Data processed: 0002-2356 Z Satellite coincidence: 0100Z(514 km), 0237Z(291 km), 2034Z(134 km), 2211Z(708 km) QC notes: 0002-0525Z: 10 km ring of missing precip surrounding radar (Z2 is too high) -----> corrected 0550-0707Z: removal of light precipitation -----> corrected 0732-1509Z: removal of light precipitation -----> corrected *********************************************************************************************** 04 Feb 98: Early on, convection still lingering off the coast while some scattered light to moderate precipitation makes its presence known over land. Most significant precipitation is gone by 08Z, leaving behind some very light echoes/showers resembling some type of boundary layer rolls. A neat side note: the echo north of the radar in VOS 2319Z looks amazingly similar to the space shuttle. Data processed: 0018-2359 Z Satellite coincidence: 0124Z, 1921Z, 2058Z QC notes: 0018-1018Z: removal of ligh precipitation 2B !!FLAG!! -----> almost completely corrected except for some of the very light, extremely shallow boundary layer-type echoes which were partially removed at times when they were west of the radar. I set the parameters to a very light settign which still removed the moderate ground clutter but some echoes still would not return. Left it this way since the validity of these echoes being actual precip is suspect and the echoes which are missing are less than 10 dB. 0247-0349Z: 10 km ring of missing precip surrounding radar (Z2 is too high) 2B !!FLAG!! -----> removal of precip was corrected but in doing so, some weak AP was also re-introduced which could not be removed without affecting precip. 2309-2359Z: removal of light precipitation -----> corrected *********************************************************************************************** 05 Feb 98: Only precipitation in the form of bands of weak, extremely shallow showers (if in fact it is reaching the ground) which trek across the scope throughout the day. Data processed: 0032-2352 Z Satellite coincidence: 0148Z, 1945Z, 2122Z, 2259Z QC notes: 0032-0141Z: removal of light precipitation -----> corrected 0918-1155Z: removal of light precipitation 2A !!FLAG!! -----> all precip removal problems were corrected. However, from 1116 on (to 1155Z), the precip band became so shallow that all the key parameters had to be considerably lightened and Z0 had to be turned off for no removal of precip to occur. Unfortunately, the biproduct of this is re-introducing some moderate ground clutter/AP near the radar which could not be helped given the specifics of this situation. 1719-2352Z: removal of light precipitation 2B,1B !!FLAG!! -----> as in previous flag, all precip removal was corrected but as the very shallow showers approached the radar, the parameters had to be cranked way down and Z0 turned completely off to put all precip back in the field. Unlike the previous flag though, this parameter lightening resulted in re-introducing some weak AP/ground clutter and some pretty coverage of what is believed to be true 0-5 dB echo (which would normally be ignored)....hence the minor flag. *********************************************************************************************** 06 Feb 98: No real significant precipitation until after about 19Z when a large MCS begins to move in from the southwest. The precip starts out as mostly moderate showers (and a lot of coverage) but convection soon begins to fire in and around the showers and by the end of the day, there are a good number of convective cells and a couple of convective lines present. Data processed: 0002-2359 Z Satellite coincidence: 0036Z(7 km), 1833Z(140 km), 2010Z(592 km) QC notes: 0002-0220Z: removal of light precipitation -----> corrected 1002-1053Z: intense, horrendous AP remaining W of radar(no precip) -----> corrected 1124-1139Z: scattered weak-to-moderate AP specks remaining -----> corrected 1154-1255Z: scattered weak-to-moderate-to-intense AP remaining -----> corrected 1939-2136Z: 10 km ring of missing precip surrounding radar -----> corrected 2045-2101Z: moderate AP remaining near and S of radar 1B !!FLAG!! -----> AP greatly reduced from original DZ image but some moderate AP specks remain embedded in light precip which at this point in time is impossible to rectify without affecting the precip. 2202-2359Z: removal of light precipitation -----> corrected 2227-2308Z: 10 km ring of missing precip surrounding radar (Z2 too high) -----> corrected *********************************************************************************************** 07 Feb 98: Upper low continues to pull off to the NE as strong convection and copious amounts of rain hit the Florida caost and spin off to sea. Most rain out of range by 16Z. Data processed: 0005-2358 Z Satellite coincidence: 0100Z(571 km), 1721Z(598 km), 1857Z(336 km), 2211Z(603 km) QC notes: 0005-0521Z: 10 km ring of missing precip surrounding radar -----> corrected 0005-0906Z: removal of light precipitation -----> corrected 1424-1943Z: removal of light precipitation -----> corrected ************************************************************************************************ 08 Feb 98: Light showers NE of radar over the ocean ~10Z, and move out of range by 14Z. No precip for the remainder of the day. Data Processed: 0013-2358Z Satellite Coincidence: 1745Z, 1922Z, 2059Z, 2235Z QC notes: Default qc params did a wonderful job in removing all clutter and some minor CAE. No changes to any qc params for any VOS for this day. ************************************************************************************************ 09 Feb 98: Showers and isolated convection developes over land near 1800Z and streams toward the SE in several NW-SE oriented parallel bands. Some of the showers are extremely shallow. Data Processed: 0008-2353Z Satellite Coincidence: 0012Z, 1633Z, 1809Z, 2123Z, 2259Z QC notes: 0008Z: Intense clutter speck NW of radar ----> Corrected. 1859-2057Z: Light showers removed ----> Corrected. 2107-2353Z: Extremely shallow showers close to radar removed. Showers were successfully reinstated but ground clutter was also reinstated with the showers in many VOS's. ----> Most NOT CORRECTED due to clutter (see flags below) 1A !!FLAG!! 2107-2156Z: Intense clutter specks and coastline clutter reinstated with showers. 1B !!FLAG!! 2205Z: Coastline clutter (minor) reinstated with showers. 1A !!FLAG!! 2215Z: Intense clutter specks and coastline clutter reinstated with showers. 1B !!FLAG!! 2225-2304Z: Minor clutter and coastline clutter specks reinstated with showers. 1A !!FLAG!! 2314-2353Z: Intense clutter specks and coastline clutter reinstated with showers. ************************************************************************************************** 10 Feb 98: Only precip on this day in the form of bands of light showers which seem to have become commonplace in Melb. Data processed: 0004-1320 Z 2004-2354 Z Satellite coincidence: 1657Z, 1823Z, 2010Z, 2147Z QC notes: 0004-0508Z: removal of light precipitation 2B !!FLAG!! -----> precip removal problem completely corrected but as shallow shower cell approaches radar, the parameters had to be turned way down (and Z0 off) to put all precip back in the field. This resulted in some weak AP being re-introduced to the scope as well. Although nothing can be done about it, this case is not serious at all...hence the minor flag 2004-2354Z: removal of light precipitation 2A- !!FLAG!! -----> the removal of light precip problem has been rectified but some weak to sometimes moderate AP was unfortunately re-introduced in the process. This AP could not be removed without removing the precip in the field. Flagged as barely major because the is enough moderate AP specks and areal coverage of weak AP to cause mild concern. ************************************************************************************************** 11 Feb 98: Very light showers scattered about the scope (but mainly to the east) throughout the day. A larger, more significant shield of showers moves in from the west late in the day but quickly weakens as it approaches the radar. Data processed: 0004-2357 Z Satellite coincidence: 1544Z, 1721Z, 2034Z, 2211Z QC notes: 0004-0103Z: removal of light precipitation -----> corrected 0410-0805Z: removal of light precipitation 2A !!FLAG!! -----> All removal of light precip problems were corrected. However, from 0528-0805Z, the extremely light, shallow precip was close enough to the radar that it was removed unless the parameters were turned way down (and Z0 off). With that done, the missing precip was corrected but it brought back quite a bit of scattered AP specks. The major flag is due to the fact that at times, several intense AP specks could be found in one particular VOS. The 0805Z VOS was moved to the bad_files_not_in_1C.HDF directory since it had several intense AP specks and the VOS after it was clean. 1013-2357Z: removal of light precipitation -----> fixing this problem was extremely difficult for a number of reasons so the best way to lay it out it to break it down one problem at a time: 2A !!FLAG!! 1013-1112Z: precip removal problem corrected (which is always the top priority, no matter what) but in doing so, re-introduced moderate-to-intense AP specks which were scattered about the scope at the time. Nothing could be done about the AP without affecting the light precip. 2A !!FLAG!! 1132-1201Z: precip removal problem corrected but in doing so, re-introduced moderate-to-intense AP specks. Nothing could be done about the AP without affecting the light precip. 2A !!FLAG!! 1230-1300Z: first attempt to fix precip-removal problem was not completely successful since some extremely shallow precip near the radar was still being wiped out. So, had to turn the parameters way down to bring this precip back (which I did) but some nasty AP was also brought back. Being at the time of the birds morning take off only made things worse. 1B !!FLAG!! 1517-1625Z: once again, had to reprocess twice since the very shallow precip wasn't caught the first time. Turning the parameters further down fixed the problem and only brought back some scattered weak AP 2A, 1A !!FLAG!! 1635-2157Z: Had to turn the parameters way down (and Z0 off) to prevent the removal of very light, shallow cells near the radar. unfortunately, this also brought back some moderate AP which was present for most of this time period. ************************************************************************************************** 12 Feb 98: Widely scattered light showers early on. The coverage of these light showers increases, particularly south of the radar, later in the day with some isolated convection present by day's end. Data processed: 0002-2356 Z Satellite coincidence: 1608Z, 1745Z, 1922Z, 2058Z QC notes: 0002-0141Z: removal of light precipitation -----> corrected 0216-2206Z: removal of light precipitation 2B,1B !!FLAG!! -----> all precip removal problems are corrected....but with some side effects. There are ~20 VOS's which now contain one speck of clutter remaining. These specks are considered negligible and the flag is not related to them. The flag is for the following times when more than one speck of clutter is present, and is usually embedded in light precip near the radar and can not be removed: 0526-0536Z, 0736Z, 0846-0946Z, 1547Z Flagged as minor because the coverage is still quite small. The 1B flag is for VOS 1547Z. 0846-0941Z: 10 km ring of missing precip surrounding radar (Z2 is too high) -----> corrected 1257-1307Z: weak-to-moderate AP NNW of radar (near 150 km cut off) 3B !!FLAG!! -----> could not remove AP without affecting the light precip present. Flagged as minor since most, if not all, of AP is beyond 150 km. Hard to tell without range rings, but this may not even deserve a flag if all AP is beyond 150 km. 2356Z: intense AP splotch remaining near radar -----> corrected *************************************************************************************************** 13 Feb 98: Large area of light to mostly moderate precipitation moves into the region after 17Z and persists for the rest of the day. Data processed: 0001-1259 Z 1705-2357 Z Satellite coincidence: 1456Z(185 km), 1632Z(569 km), 1946Z(384 km), 2122Z(518 km) QC notes: 0001-0006Z: moderate-to-intense AP splotch remaining near radar -----> corrected 0026-0121Z: widespread weak-to-moderate-to-intense AP scattered over land portion of scope (no precip present within 150 km range) -----> corrected 0215-0230Z: widely scattered AP remaining (intense specks, weak-to-moderate splotched near fringe) -----> corrected 0255Z: moderate AP splotch remaining N of radar -----> corrected 0305-0725Z: scattered weak-to-moderate-to-intense AP remaining -----> corrected 0923-1052Z: scattered weak-to-moderate-to-intense AP remaining -----> corrected 1141-1259Z: scattered weak-to-moderate-to-intense AP remaining -----> corrected 1705-2128Z: removal of light precipitation -----> corrected 2103-2357Z: 10 km ring of missing precip surrounding radar (Z2 too high) -----> corrected 2133-2253Z: weak-to-moderate-to-intense radially-oriented AP remaining SSE of radar 1B,2A !!FLAG!! -----> it proved futile to remove the AP without affecting the light precip which is abundant during this time period. No matter what parameters and/or combination of parameters were tried, the AP could not be removed without removing some light precip within the scope. The AP was left in. 2303-2357Z: holes and gaps in light precipitation -----> corrected *************************************************************************************************** 14 Feb 98: Moderate precip shield with some embedded convection continues to move off to the east and, other than some lingering light showers to the SE, is just about out of range by 10Z. No other significant precipitation occurs during the rest of the day. Data processed: 0003-2351 Z Satellite Coincidence: 1343Z(655 km), 1519Z(300 km), 1833Z(625 km), 2009Z(68 km) QC notes: 0003-0148Z: 10 km ring of missing precip surrounding radar (Z2 too high) -----> corrected 0003-0138Z: removal of light precipitation -----> corrected 0158-1119Z: removal of light precipitation -----> corrected 0218-0407Z: 10 km ring of missing precip surrounding radar (Z2 too high) -----> corrected 1010-1039Z: weak-to-moderate-to-intense AP S to SW of radar 2A- !!FLAG!! -----> could not remove AP due to presence of light precip. After first-pass processing, there were holes in light precip which had top priority to be corrected. Only on the rarest occassions is it possible to remove AP while putting back precip which was erroneously removed and this is not one of those cases. VOS 1039Z was moved to the bad_files_not_in_1C.HDF directory and the remaining VOS's were flagged as A- since there is significant areal coverage of the AP but the intensity remains in the 10-15 dB range. 1305Z: intense AP splotch W of radar (no precip present) -----> corrected 1345Z: intense AP splotch W of radar (no precip present) -----> corrected 1400Z: weak AP remaining SW of radar -----> corrected **************************************************************************************************** 15 Feb 98: Scattered light showers for most of the day until after 20 Z when large moderate precip shield begins moving in from the west. Data processed: 0002-2358 Z Satellite coincidence: 1407Z(65 km), 1543Z(626 km), 1857Z(297 km), 2023Z(659 km) QC notes: 1732-1949Z: removal of light precipitation -----> corrected 2059-2358Z: removal of light precipitation -----> the removal of precip problem was corrected but their is a downside outline in the following flags: 2A !!FLAG!! 2059-2243Z: the precip in the immediate vicinity of the radar which was moving off to the north was extremely weak and shallow. Thus we are faced with our old enemy, the shallow precip, and have to turn all the pertinent parameters way down (and Z0 off) to get all the precip back in the field. THis meant little QC was done on the ground clutter/CAE near the radar which was in the moderate intensity category...hence the major flag 3A !!FLAG!! 2258-2318Z: moderate Ap embedded in precip near the radar....nothing can be done about embedded AP. ***************************************************************************************************** 16 Feb 98: Copious amounts of rain as a large MCS moves over KMLB. Large shield of moderate to heavy rain along with embedded convection (some bow echoes to the south early on) persists for most of day. Coverage decreases towards close of day but intensity increases as strong storms roll through mainly north and west of the radar. Data processed: 0003-2356 Z Satellite coincidence: 1254Z(515 km), 1430Z(386 km), 1744Z(568 km), 1920Z(187 km) QC notes: 0003-0248Z: removal of light, shallow precipitation 3A !!FLAG!! -----> precip removal problem corrected. The Flag is for one Vos: 0018Z, which had moderate clutter specks embedded in light precip in the immediate vicinity of the radar. Keep in mind that the flag is major, but it is only for one Vos so the overall problem may be considered minor. 0058-0647Z: 10 km ring of missing precip surrounding radar (Z2 too high) -----> corrected 0512-2356Z: precipitation being removed by way of (1) shaving away of light precip on edge of shield, (2) possible precip-eating mode (Z0 problem) from 0752-1026Z, and (3) standard removal of light precip towards end of this period. -----> precip removal completely corrected but with the following repercussions which are flagged accordingly: 3B !!FLAG!! 0707-0737Z: to correct precip holes which were present near the radar, had to turn Z0 off and Z2 and Z3 off which resulted in some small, weak to slightly moderate clutter specks being put back in the field. Nothing could be done about them without re-instating the precip holes. 0717-1257Z: 10 km ring of missing precip surrounding radar -----> corrected 1731-1746Z: 10 km ring of missing precip surrounding radar -----> corrected ***************************************************************************************************** 17 Feb 98: Scattered, strong convection with stratiform precip present early on with significant coverage. The convection organizes by mid-day into a squall line which treks across the scope from west to east, taking on a classic, Line Echo Wave Pattern (LEWP) around 13Z, when it is over the radar. Stratiform precip becomes slightly more dominant towards the end of the days as the system slips off to the SE but strong convective cells are still present right up until 24Z. Data processed: 0001-2356 Z Satellite coincidence: 1318Z(50 km!), 1455Z(676 km), 1632Z(730 km), 1808Z(199Z) QC notes: 0001-1119Z: removal of light precipitation -----> corrected 1004-1452Z: 10 km ring of missing precip surrounding radar (Z2 too high) -----> corrected 1124Z: precip-eating mode (unexplained removal of chunking of precip within a ~50 km radius of the radar...usually due to Z0 and easily handled) -----> corrected 1212-1257Z: removal of light precipitation -----> corrected 1712Z: note that there is some weak-to-moderate radially-oriented AP remaining to the SW but it is not a concern since it is beyond 150 km. 1752-2101Z: weak-to-moderate-to-horrifically intense AP remains scattered about, North of the true precip (may be a major headache) 1A, 2A !!FLAG!! -----> improved but far from perfect. Most AP still remains with nothing able to be done due to the presence of precipitation. At first glance, most VOS's appear worst than they are since the majority of remaining AP is beyond 150 km. Other VOS's, particularly those around 1920Z are as bad as they look, with intense AP of significant areal coverage remaining in close proximity to true precip echo. Nothing more could be done to reduce this AP without removing precip....hence the major flags. ****************************************************************************************************** 18 Feb 98: Strong convection and heavy rain still present south of the radar, early on. Significant precipitation out of range by 05Z. Some streamers of weak, shallow precip streak across the northern end of the scope after 17Z. Data processed: 0001-2357 Z Satellite coincidence: 1206Z(371 km), 1342Z(470 km), 1656Z(496 km), 1832Z(323 km) QC notes: 0001-0133Z: weak-to-moderate-to-horrifically intense AP remaining. The precip which is also present makes me dread reprocessing 2A !!FLAG!! -----> Slightly improved but that is me just being kind to myself. This period of AP was a character-builder. Let me break down the remaining problems by time: 0001-0031Z: intense AP, both stand alone and embedded, remains. nothing further could be done without removing precip in the field. If the precip was all strong convective and that light stratiform precip was not there, things may be better but you can't alter reality and the light precip puts the clamps on our QC efforts. Given major flag. Moved VOS 0031Z to bad_files_not_in_1C.hdf directory. 0036-0133Z: weak AP embedded in precip in addition to moderate-to- intense AP splotches present N of radar. Given major flag. Moved VOS 0133Z to bad_files_not_in_1C.hdf directory. 0113-0203Z: 10 km ring of missing precip surrounding radar (Z2 too high) -----> corrected 0326-0511Z: widespread weak-to-moderate-to-intense AP remaining as well as a couple of shower cells being present (not a good combo) 2A !!FLAG!! -----> slight improvement but still quite bad. The reason it is bad is due to the presence of one lonely shower SW of the radar. I was so tempted to just remove this cell and blow away all AP by cranking up the parameters but I couldn't; the cell had decent vertical depth and moderate reflectivities in the base scan and thus argued well for its inclusion. Therefore, several VOS's, particularly later in this period, are given major flags due to the presence of intense AP specks. These specks could not be removed without affecting our hero, the Lone Shower (can you hear the exasperation in my voice?). VOS 0501Z was moved to the bad_files_not_in_1C.HDF directory. 0521-1424Z: widespread weak-to-moderate-to-intense AP remaining (no precip) -----> corrected 1744-2150Z: removal of light precipitation -----> corrected 2259-2357Z: removal of light precipitation -----> corrected ****************************************************************************************************** 19 Feb 98: Streamers of light "precip" N of radar early on. (I use quotes on precip after a recent discussion with Dave jacobs at NWS Melbourne who informed me that these streamers may in fact be chaff disharge....just another fly in the ointment). Moderate showers begin moving in from the SW around 13Z. A more pronounced area of convection enters the western fringes of the scope later in the day while other isolated convective cells fire S of the radar. (note: this day is probably the worst day in terms of AP I have seen for Melb so reprocessing should be fun) Data processed: 0007-2356 Z Satellite coincidence: 1230Z(162 km), 1407Z(718 km), 1543Z(692 km), 1720Z(90 km) QC notes: 0007-0324Z: removal of light streamers (precip or chaff?) 2A !!FLAG!! -----> all kinds of problems with this time period. The now present uncertainty of how much, if any, of these precip streamers are actually precip or chaff greatly complicates things. NOTE: PI INPUT ON THIS IS VERY IMPORTANT TO HOW WE WILL HANDLE THIS IN THE FUTURE! Let me break it down: 0007-0037Z: all "precip" re-introduced with only negligible false echo present....flag has no bearing on these VOS's. 0046-0145Z: some moderate-to-intense AP specks remain as the parameters were reduced to re-introduce the "precip" A third reprocessing which removed some of the more offensive AP specks but this caused some very minor holes to be present in the precip/chaff streamers... still flagged as major. 0155-0324Z: some moderate-to-intense AP specks remain. Upon reprocessing to put "precip" back in, parameters were reduced too low (namely H2) which resulted in the re-introduction of weak-to-moderate AP of significant coverage. A third reprocessing was done where H2 was raised to remove the AP but this resulted in significant removal of the streamers within the 100-150 km range. Flagged as major for this removal as well as the moderate specks and weak AP which still persist. And I thought this would be the easiest time period to handle. 0602Z: widely scattered moderate AP specks -----> corrected 0631-1256Z: scattered weak-to-moderate-to-intense AP remaining (no precip) -----> corrected 1306-1356Z: scattered weak-to-moderate-to-intense AP remaining with moderate precipitation present SW of the radar 2B,1B !!FLAG!! -----> vastly improved. Flagged as minor because I am concerned, although not completely certain, if the there is any AP embedded within the precip to the SW. Therefore, the flag is there just to bring it to your attention. The good news is the the remaining intense AP to the west of the radar is not a concern since it is beyond 150 km. I ran a couple VOS's through 2A-54 to make sure no AP was evident in the 150km-truncated convective-stratiform map and sure enough there was not. We may routinely use the 2A-54 as a test in this manner and will inform you when we do so. 1406-1430Z: imagine the most awful AP you can and that is this half hour period. Moderate showers SW of radar in there somewhere but lost in AP shield. 1A !!FLAG!! -----> the only thing that could be done was to crank the parameters up to ridiculous values and wipe the slate clean. The precip which is in there somewhere was masked by the AP anyways so everything was wiped out. The major flag is due to this missing precip which is in the SW sector of the scope near the 150 km range. 1435-1900Z: weak-to-moderate-to-horrifically intense AP scattered about scope with precip present well within 150 km. 1A !!FLAG!! -----> vastly improved but for this day, that doesn't mean it escaped a major flag. The major flag (which unfortunately occurs before, during, and after two satellite coincident times) was given for two reasons: (1) the scattered moderate-to-intense specks and splotches which still exist inside the 150 km cutoff and (2) some very light showers were chunked out in the process of removing moderate-to- intense AP. The images look a lot worse than they are because most of the AP present is beyond 150 km (keep that in my mind). Felt it was a fair trade-off in this case to allow for some minor reduction in light precip in order to remove the strong AP which had a significant areal coverage. 2035-2135Z: scattered weak-to-moderate-to-intense AP specks and splotches with considerable precip present (much of it light which will make things more difficult) 3A !!FLAG!! -----> Vastly improved. Flag is for 1-2 moderate and intense AP specks and/or splotches present in VOS's 2035-2040 and 2050-2055Z. Any light precip which is reduced during this reprocessing is not a concern since it is beyond 150 km. 2151-2206Z: scattered weak-to-moderate AP. Worse though is the incredibly intense, radially-oriented AP NW of radar. To make matters worse, convective cells and some weaker stratiform precipitation is prevalent at this time as well. 3A !!FLAG!! -----> only slightly improved. THe weak-to-moderate AP was successfully removed but little could be done about the intense radial spike without greatly compromising the precip within 150 km. Luckily, (1)about half of the spike is outside of 150 km and (2) none of this data goes to TSDIS. 2211-2311Z: weak-to-moderate-to-intense AP specks and splotches present NNW of radar (much precip present as well) 2A !!FLAG!! -----> much improved but given a major flag for the following VOS's which still contain a weak-intense AP splotch NNW of the radar: 2236-2246, 2245-2301 Z 2221-2336Z: 10 km ring of missing precip surrounding radar (Z2 too high) -----> corrected ****************************************************************************************************** 20 Feb 98: Intense convection starts north of the radar early on in the form of strong isolated cells, along with large moderate rain shield north of these cells. A mesocyclone is evident in one of cells from 0001-0056Z. Eventually, cells merge to form an intense line of convection which tracks southward and overtakes KMLB by 06Z. Convection looks serious with high reflectivities and several bow echoes within the line from time to time. All precip is gone by 1221Z (due to large data gap). Data processed: 0001-1211 Z 2008-2350 Z Satellite coincidence: 1117Z(235 km), 1254Z(543 km), 1608Z(417 km), 1744Z(463 km) QC notes: 0556-0721Z: 10 km ring of missing precip surrounding radar (Z2 too high) -----> corrected 0751-1031Z: 10 km ring of missing precip surrounding radar (Z2 too high) -----> corrected 0856-1031Z: holes in light precip and "chunking" of moderate precip on the back-side of the squall line -----> corrected ****************************************************************************************************** 21 Feb 98: No precipitation on this day. Data processed: 0000-2353 Z Satellite coincidence: 1005Z, 1141Z, 1318Z, 1455Z, 1632Z QC notes: 0336Z: intense AP speck remaining -----> corrected 0929-0939Z: weak AP speck remaining -----> corrected 1147-1255Z: scattered weak AP remaining -----> corrected 2323-2353Z: scattered weak AP remaining -----> corrected ****************************************************************************************************** 22 Feb 98: No precipitation until 1730Z. Small showers quickly intensify and erupt into numerous convective cores. As these cells persist, the environment takes on a supercell-dominant character as two large supercells quickly catch your eye by 20Z. A mesocyclone is evident in the northern cell from ~2001-2046Z while a mesocyclone is evident in the southern supercell during the hour of 21Z. Both cell race off to the northeast and eventually weaken. Intense convection associated with a strong MCS (Mesoscale Convective System) skirts the northern fringe of the scope from 21Z+. Data processed: 0002-2356 Z Satellite coincidence: 1029Z(110 km), 1205Z(606 km), 1519Z(331 km), 1656Z(605 km) QC notes: 0002-0902Z: scattered weak-to-moderate-to-intense AP remaining (no precip) -----> corrected 1031-1951Z: removal of light precipitation -----> corrected 2041-2226Z: 10 km ring of missing precip surrounding radar (Z2 too high) -----> corrected ***************************************************************************************************** 23 Feb 98: *The night of the killer tornadoes in Florida* Strong cells ahead of incoming MCS move out of range to the NE early on (00-02Z). Intense squall line system enters scope from NW around 02Z. Very strong supercell, embedded within the line, becomes evident at 03Z. Hook echo and >60 dB returns evident at 0316-0351Z. Further south in the line, another supercell is present at 04Z with hook echo evident at 0421Z and possible mesocyclone (from VR images) from 0421-0434Z. A third supercell-like storm with hook appendage and possible mesocyclone present near center of line at 0420Z. Line of storms lines out to form more typical squall line by 0530Z. The line continues to propogate eastward as individual cells within the line move off to the NE. Line breaks down into a couple smaller bands of intense convection after 1130Z. All convection is out of range by 15Z. Streamers/chaff evident W of radar at 22Z and quickly increase in coverage throughout the scope by the end of the day. Data processed: 0001-2359 Z Satellite coincidence: 0916Z(566 km), 1053Z(355 km), 1406Z(590 km), 1543Z(142 km) QC notes: 0011-0021Z: weak-to-moderate AP speck remaining near radar -----> corrected 0735-1110Z: shaving away of precip on backside of squall line -----> corrected 0810-0935Z: 10 km ring of missing precip surrounding radar (Z2 too high) -----> corrected 1125-1245Z: removal of light precipitation -----> corrected 1303-1318Z: removal of light precipitation -----> corrected 1413-1443Z: removal of light precipitation -----> corrected 2225-2359Z: removal of streamers/chaff 2A !!FLAG!! -----> most of streamers re-introduced (although this in itself may now be a reason for the major flag given the recent chaff discussions) but as they got close to the radar, the parameters had to be turned way down (and Z0 off) to return all of these shallow echoes. The major flag is due to the moderate ground clutter which is also re-introduced from 2319-2359Z, when the parameters were set very low to accomodate the phantom echoes. Hoping satellite data will be a useful and efficient resource to help in determining beyond a shadow of a doubt whether the echoes are chaff or not. ***************************************************************************************************** 24 Feb 98: Only "precip" on this day (if we can call it that) is in the form of streamers early in the day (00-06Z) and late in the day (20-24Z). Once again, a word of caution that all these echoes may be from chaff. Data processed: 0009-2352 Z Satellite coincidence: 0940Z, 1117Z, 1253Z, 1430Z QC notes: 0009-0602Z: removal of streamers 2A !!FLAG!! -----> major flag is for the period of 0009-0137Z, where the shallow streamers got close enough to the radar that the parameters had to be turned way down (and Z0 off) to bring them all back. This also brought back some of the moderate clutter which was also present at the time. Moved Vos's 0038Z and 0137Z to the bad_files_not_in_1C.hdf directory. The most disconcerting thing continues to be whether we should really be re-introducing these streamers back to the field since they stand a good chance of being chaff. 2055-2352Z: removal of streamers -----> corrected in that the streamers/chaff were completely restored to the scope. Questions still abound as to whether the streamers are definitively desirable or not. ***************************************************************************************************** 25 Feb 98: No precipitation. Data processed: 0002-2356 Z Satellite coincidence: 0827Z, 1004Z, 1317Z, 1454Z QC notes: 0002-1356Z: chaff echoes and scattered weak-to-moderate-to-intense AP present (no precip). *NOTE* -----> corrected. This is a historic event in Melb QC. The streamers which were previously left in all VOS's at all cost are now removed due to recent findings which leads us to now consider them as non-meteorological, chaff echoes. For this case and in future cases of suspicious streamer echoes, they will only be removed if the following are true: (a) the radar is in clear-air mode (b) the archived visible or IR satellite image shows clear skies in central Florida (true for every chaff streamer case occurring in February) (c) the archived NCEP merged-radar/rain gauge precip estimate for the U.S. shows no precipitation in the vicinity of central Florida. (d) echoes do in fact exhibit the now characteristic streamer signature (i.e., thin streamers which may be numerous in number, moving with upper level wind flow) 2147-2356Z: chaff echoes present N of radar -----> corrected (see above note) ***************************************************************************************************** 26 Feb 98: Only precipitation on this day is the edge of a weak rain shield moving into the scope from the south after 23Z. Data processed: 0006-2359 Z Satellite coincidence: 0851Z, 1028Z, 1205Z, 1341Z QC notes: 0006-1410Z: chaff echoes and scattered weak-to-moderate-to-intense AP present (no precip present) -----> corrected. Chaff echoes removed. Considered chaff because (1) radar was operating in clear-air mode, (2) displayed characteristic chaff streamer appearance moving with westerly flow aloft, (3) no clouds were visible in central Florida and (4) the NCEP merged radar/rain gauge precip estimate for the US shows no precip in Florida (http://sgi62.wwb.noaa.gov:8080/verf/ pcpver.0226.html) ***************************************************************************************************** 27 Feb 98: Area of very weak showers near coast (SE of radar) early on. Scattered showers and isolated convective cells begin forming around 10Z. Some stronger convection in the form of a small line west of the radar later on but all in all, convection remains unexplosive (for now). Data processed: 0010-1207 Z 1421-2356 Z Satellite coincidence: 0739Z, 0915Z, 1229Z, 1406Z QC notes: 0010-0345Z: scattered weak-to-moderate AP remaining (mainly N of radar) 2A !!FLAG!! -----> corrected from 00-0157Z because the precip was beyond 150 km (determined by creating a quick 2A-54 c/s image). The flag is for the VOS's from 0207-0345Z. During this time the light precip was within 150 km which necessitated a much less aggressive approach. Therefore, the precip was left untouched (even improved) but that left specks and splotches of weak, moderate, and intense AP as well as weak AP "shields" of considerable areal coverage in the field. 0207-0345Z: removal of light precipitation -----> corrected. Although the satellite and NCEP merged radar/gauge precip estimate were clear for central Florida and the radar was operating in clear-air mode, the precip shield did not behave like typical chaff streamers. It moved straight north (yes, the upper level wind flow ahead of a strong low pressure system could be southerly but...) and only had weak streamer-echo signatures. Therefore, it is considered real precip and totally re-introduced to the field. 0355-0811Z: scattered weak-to-moderate AP remaining (no precip present) -----> corrected 0850-1008Z: scattered weak-to-moderate AP remaining -----> corrected 1047Z: very intense AP remaining -----> corrected. Using 2A-54 c/s image, it was determined that all but the very fronge of the intense AP was betond 150 km. Therefore, I was able to increase the parameters just enough to push the AP beyond 150 km and not remove the light shower cells in the vicinity. 1712-1842Z: removal of light precipitation -----> corrected ***************************************************************************************************** 28 Feb 98: Line of convection fires up from KMLB off to the NE, early on. Precip from these cells is out of range by 05Z. Larger Mesoscale convective system begins moving in from the NW around 13Z. Convective cells quickly fire ahead of line of already strong storms around 1530Z. By 19Z, squall line has ingested many of the smaller cells while other cell mergers take place out ahead of the line. The result is widespread convection with heavy rain, mostly south and east of the radar. A beautiful gust front is visible out ahead of the line from 1843-2001Z. Possible mesocyclone evident in cell SE of line from 1936-2011Z. Strong convection continues off to the east and is just about completely out of range by the end of the day. Data processed: 0002-2359 Z Satellite coincidence: 0803Z(223 km), 0940Z(737 km), 1117Z(665 km), 1253Z(23 km) QC notes: 0939-1034Z: weak-to-moderate-to-intense AP remaining S of radar -----> corrected. Only remaining AP is well beyond 150 km and therefore not a concern. From 0939-0959Z, could not just blow everything away because of the presence of the one lone cell west of the radar....but the chosen parameters worked nicely (particularly raising dBZ noise). After 10Z, the cell is gone and I could crank all the parameters way up to remove all AP, even that which is beyond 150 km (just to make it more aesthetically pleasing). 1104-1341Z: weak-to-moderate AP remaining 3B !!FLAG!! -----> corrected except for VOS 1139Z which still contains a splotch of AP within 150 km of the radar. The rest of the remaining AP (and precip for that matter) is beyond 150 km and therefore not a concern. However, besides the one problem VOS, this flag does help bring attention to the fact that some out of reach AP does remain but keep in mind that AP beyond 150 km is just as good as no AP (even though it doesn't look as good). The 150 km range was verified for VOS's with AP by creating quick convective/stratiform (c/s) images (2A-54 output) and noting the outer limit cutoff. 1401-1411Z: weak AP remaining NE of radar (look like second-trip echoes) -----> corrected 1758-2006Z: 10 km ring of missing precip surrounding radar (Z2 too high) -----> corrected 1946-1956Z: weak AP splotch remaining N of radar 3B !!FLAG!! -----> could not be removed without reducing (removing) light precip which is also present. Good news is that most northern spec is beyond 150 km for majority of VOS's in this time preiod and the AP specks which are within range are very weak (~10 dB)...hence the minor flag. 1946-2016Z: removal of light precipitation -----> corrected 2021-2041Z: intense AP speck remaining N of radar 3A !!FLAG!! -----> much improved but flag exists for VOS's 2021-2026 where an embedded intense speck and stand-alone speck , respectively could not be removed without greatly compromising the precip field. So, the AP specks were left in. *****************************************************************************************************