JTWC Report PDF - Weather Underground

CHAPTER 11- RECONNAISSANCE AND FIXES1. GENERALThe Joint Typhoon Warning Center dependson reconnaissance to provide necessary,accurate, and timely meteorologicalinformation in support of each warning. JTWCrelies primarily on three reconnaissanceplatforms: aircraft, satellite, and radar.In data rich areas synoptic data are alsoused to supplement the above. Optimumutilization of all available reconnaissanceresources is obtained through the SelectiveReconnaissance Program (SRP); various factorsare considered in selecting a specificreconnaissance platform including capabilitiesand limitations, and the tropicalcyclone’s threat to life and property bothafloat and ashore. A summary of reconnaissancefixes received during 1984 is includedin Section 6 of this chapter.2. RECONNAISSANCE AVAILABILITYa. AircraftAircraft weather reconnaissance for theJTWC is performed by-the 54th WeatherReconnaissance Squadron (54th WRS) located atAndersen Air Force Base, Guam. The 54th WRSis presently equipped with six WC-130aircraft and, from July through October, isaugmented by three additional aircraft fromthe 53rd WRS, Keesler Air Force Base,Mississippi, bringing the total number ofavailable aircraft to nine. The JTWCreconnaissance requirements are provideddaily to the Tropical Cyclone AircraftReconnaissance Coordinator (TCARC), whomarries the tasking from the JTWC with theavailable airframes from the 54th WRS.As in previous years, aircraftreconnaissance provided direct measurementsof height, temperature, flight-level wi?ds,sea-level pressure, estimated surface wln~s(when observable), and numerous additionalparameters. The meteorological data aregathered by the Aerial Reconnaissance WeatherOfficer (~WO) and dropsonde operators ofDetachment 3, 1st Weather Wing who fly withthe 54th WRS. These data provi#e the TyphoonDuty Officer (TDO) with indications afchanging tropical cyclone characteristics,radii of associated winds and currenttropical cyclone position and intensity.Another important aspect is the availabilityof the data for research on tropical cycloneanalysis and forecasting.b. SatelliteSatellite fixes from USAF/USN groundsites and USN ships provide day and nightcoverage in the JTWC area of responsibility.Interpretation of this satellite imageryprovides tropical cyclone positions andestimates of current and forecast intensitiesthrough the Dvorak technique.c. RadarLand radar provides positioning data onwell developed tropical cyclones when in theproximity (usually within 175 nm (324 km))of the rqdar sites in the Philippines,Taiwan, IfongKong, Japan, South Korea,Kwajalein, and Guam.d. SynopticIn 1984 JTWC also determined tropicalcyclone positions based on the analysis ofthe surface/gradient level synoptic data.These positions were helpful in situationswhere the vertical structure of the tropicalcyclone was weak or accurate surfacepositions from aircraft or satellite werenot available.3. &RJw;REcoNNAlssANcEDuring the 1984 tropical cvcloneseason, the JTWC levied ~10 .vor~ex fixes and53 investigative missions of which 14 wereflown into disturbances which did notdevelop. In addition to the levied fixes,251 intermediate fixes were also obtained.The average vector error for all aircraftfixes received at the JTWC during 1984 was12 nm (22 km).Air”&raft reconnaissance effectivenessis summarized in Table 2-1 using thecriteria set forth in CINCPACINST 3140.1(series).?ASLE2-1. AIRCSAFTRECONNAISSANCEFFECTIVENESS!NUMSEROFEFFECTIVENESS LEVIEDFIXES PERCENT;OMPLSTEDON TIME 202 96.1lAF.LY 2 1.0ATE 4 1.9U SSED 2 1.0TOTAL 210 100.0LEVIEDVS. MISSEDFIXESLEVIED MISSED PERCENTiVERAGE1965-1970 507 10 2.01971 802 7.61972 624 1:: 20.21973 227 13 5.71974 358 30 8.41975 217 7 3.21976 317 111977 203 3 H1978 29o 2 0.71979 289 141980 213 4 :::1981 201 3 1.51982 276 17 6.21983 157 1.91984 210 : 1.05