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TC Best Tracks History at RSMC Nadi, Fiji. Alipate Waqaicelua RMSC Nadi. IBtrACS Workshop, Asheville, North Carolina, USA, May 5 th - 7 th 2009. Outline. Pre-satellite era Early satellite era Latter days practices Concluding remars . Fiji AOR. Equator. 25 South. 120 West.
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TC Best Tracks History at RSMC Nadi, Fiji Alipate Waqaicelua RMSC Nadi IBtrACS Workshop, Asheville, North Carolina, USA, May 5th - 7th 2009
Outline Pre-satellite era Early satellite era Latter days practices Concluding remars
Fiji AOR Equator 25 South 120 West 160 East 40 South
First GMS satellite imageries 03 UTC on September 8, 1977 00 UTC on April 6, 1978 (Vis)
TC Tracking in the late 70’s • Heavily biased towards synoptic observations, when/where available. • 3-hourly WEFAX low-resolution satellite imagery • No parallax error corrections • Conventional radar data positioning using manual trig-point calculation • Essentially estimation • No “ground truth” or “standard” to verify position forecasts against. Fiji New Caledonia Aust NZ WEFAX IR sat imagery of TC Raja
Early 80’s • Still heavily biased towards synoptic observations, when/where • available. • WEFAX low-res GMS and GOES-W • No parallax error corrections • Conventional radar data positioning using manual trig-point • calculation • Still no “ground truth” or “standard” to verify position forecasts • against.
Mid 80’s Designation by WMO as RSMC for TCs in the SW Pacific basin • following GTS and satellite compliance • Still heavily biased towards synoptic • observations, when/where available. • H-res GMS satellite imageries with • 3-hourly WEFAX back-up • WEFAX low-res GOES-W • Application of parallax error corrections • Conventional radar data positioning using • manual trig-point calculation • Sig change in accuracy of initial positioning • Still no “ground truth” or “standard” to • verify position forecasts against. • - BT data sent to BoM for verific and archival H-res sat imagery of TD south of New Caledonia
Best Tracking methodology – absence of ground truth • Positions from all warning centres manually plotted on track map. • Final best position biased towards obs data if system went overhead or nearby • In absence of obs, final best position biased towards location of strongest • agreement, for given time.
H-res GMS and GOES with animation and navigation capabilities as well • as parallax corrections • Access to scatt and microwave data via internet • Near-real time diagnostics via internet • Sounding data AMSU • Surveillance radars with navigation capabilities • Still a heavy dependence and bias towards observational data • Manual plotting of fixes and numerical output data on multi-layered • plastic overlays (courtesy of Honolulu WFO) • Manual Consensus TC Tracking in the latter 90s through to early 2000s Multi-layered overlays for manual plotting & consensus
Best Tracking • Availability of “ground truths” for BT and verific purposes • Bias towards obs (radar, microwave, scatt and satellite). • Manual plotting and final best position biased towards strongest • agreement of locations when none of above offers clear-cut solution • Still very subjective as microwave and scatt locations data were • estimated to 1 decimal point. • Verification done at RSMC Nadi using ATCW verific application • authored by Mr Frank Woodcock • Archival
BT in .tca – ATCW format . . DAMAN 2007 12 04 1200 12.0 -179.6 999 12.9 -178.6 999 0.0 0.0 1009 0.0 0.0 1009 0.0 0.0 1009 0.0 0.0 1009 DAMAN 2007 12 04 1800 12.0 179.5 997 12.0 179.5 997 0.0 0.0 1009 0.0 0.0 1009 0.0 0.0 1009 0.0 0.0 1009 DAMAN 2007 12 05 0000 12.0 178.2 997 11.9 178.2 997 0.0 0.0 1009 0.0 0.0 1009 0.0 0.0 1 009 0.0 0.0 1009 DAMAN 2007 12 05 0600 12.3 177.1 990 12.3 177.2 990 13.1 175.3 1009 14.6 174.8 1009 15.5 175.4 1009 16.4 176.8 1009 DAMAN 2007 12 05 1200 12.8 176.4 987 12.8 176.4 985 14.5 175.3 1009 15.9 175.8 1009 15.5 175.4 1009 16.4 176.8 1009 DAMAN 2007 12 05 1800 13.9 175.9 985 13.9 175.9 985 15.1 175.2 1009 16.0 175.6 1009 16.5 176.4 1009 17.3 177.5 1009 DAMAN 2007 12 06 0000 14.6 175.8 980 14.7 175.8 985 16.3 176.5 1009 17.2 177.8 1009 17.9 178.8 1009 18.8 179.7 1009 DAMAN 2007 12 06 0600 15.2 175.9 975 15.3 175.8 975 16.4 176.1 1009 17.0 177.1 1009 17.7 178.4 1009 19.1 179.5 1009 DAMAN 2007 12 06 1200 15.4 176.2 965 15.4 176.2 970 16.4 177.1 1009 17.3 178.5 1009 18.0 180.0 1009 19.3 -179.2 1009 DAMAN 2007 12 06 1800 15.5 176.9 955 15.5 176.9 955 16.2 178.1 1009 17.1 179.1 1009 18.3 -179.9 1009 20.1 -179.5 1009 DAMAN 2007 12 07 0000 15.5 177.9 940 15.6 177.8 925 15.9 178.9 1009 16.9 179.9 1009 18.2 -179.1 1009 19.6 -179.6 1009 DAMAN 2007 12 07 0600 15.5 178.6 925 15.5 178.7 925 16.0 -179.8 1009 17.3 -178.3 1009 18.8 -177.4 1009 20.1 -177.0 1009 . .
BT in txt form =============++++++++++++=================================== NAME Y M D H LAT LON CP KT Cat =========================++++++++++++======================= Tropical Depression (TD) Phase DAMAN 2007 12 03 0000 12.0 -174.5 1004 15 DAMAN 2007 12 03 0600 12.1 -175.0 1004 15 DAMAN 2007 12 03 1200 12.3 -175.5 1004 15 DAMAN 2007 12 03 1800 12.5 -176.5 1002 20 DAMAN 2007 12 04 0000 12.5 -177.5 1000 25 DAMAN 2007 12 04 0600 12.2 -178.5 1000 25 DAMAN 2007 12 04 1200 12.0 -179.6 999 25 DAMAN 2007 12 04 1800 12.0 179.5 997 30 DAMAN 2007 12 05 0000 12.0 178.2 997 30 TC Phase Named by RSMC Nadi DAMAN 2007 12 05 0200 12.1 177.7 995 35 1 DAMAN 2007 12 05 0600 12.3 177.1 990 40 1 DAMAN 2007 12 05 1200 12.8 176.4 987 45 1 DAMAN 2007 12 05 1800 13.9 175.9 985 50 2 DAMAN 2007 12 06 0000 14.6 175.8 980 50 2 DAMAN 2007 12 06 0600 15.2 175.9 975 60 2 DAMAN 2007 12 06 1200 15.4 176.2 965 70 3 DAMAN 2007 12 06 1800 15.5 176.9 955 80 3 DAMAN 2007 12 07 0000 15.5 177.9 940 90 4 DAMAN 2007 12 07 0600 15.5 178.6 925 100 4 Peak Intensity DAMAN 2007 12 07 1200 15.6 179.7 935 90 4 DAMAN 2007 12 07 1800 15.9 -179.5 940 90 4 DAMAN 2007 12 08 0000 16.3 -178.6 950 80 3 DAMAN 2007 12 08 0600 16.8 -178.0 965 70 3 DAMAN 2007 12 08 1200 17.4 -177.9 975 60 2 DAMAN 2007 12 08 1800 17.6 -177.9 985 50 2 DAMAN 2007 12 09 0000 18.1 -178.0 992 40 1 Downgraded to TD by RSMC Nadi DAMAN 2007 12 09 0600 18.5 -178.1 997 30 DAMAN 2007 12 09 1200 18.9 -178.1 1000 25 DAMAN 2007 12 09 1800 19.4 -178.2 1002 20 DAMAN 2007 12 10 0000 19.9 -178.5 1003 15 Remnant lost into quasi-stationary frontal system to south.
TC Tracking from mid 2000s • H-res GMS and GOES with animation • and navigation capabilities as well as • parallax corrections • Access to scatt and microwave data via • internet • Scatt and microwave data navigation • capability • Near-real time diagnostics via internet • Sounding data – AMSU retrievals • Surveillance radars with navigation • capabilities • Still a heavy dependence and • bias towards synop obs data • Guidance from other global centres • TC Module v4.13 then v7.4 in 2009 and • Image Navigate 4d
Best Tracking to date • Biased towards obs (synops, radar, • microwave, scatt and satellite). • Auto plotting and final best • position biased towards strongest • agreement of locations when none • of above offers clear-cut solution • Sig change to accuracy (to 2 • decimal points) of revised posits • using Image Navigate 4d.
TC Module v7.4 incorporates Knaff-Zehr wind-pressure relationship • BT and verification done using TC Module • Allows for BT while systems still active