Observation impact on forecast error of binary interacted typhoons TEMBIN (201214) and BOLAVEN (201215)

Typhoon (TY) TEMBIN (201214) and BOLAVEN (201215) occurred in the western North Pacific showed very interesting tracks from 19 August 2012 to 29 August 2012. TEMBIN (201214) generated at 00 UTC 19 August 2012 in 17.6° N, 124.8°E showed ‘α-type' track near the Taiwan and Hong Kong due to Fujiwhara effect with BOLAVEN (201215) generated 30 hours later in 17.4° N, 141.4° E. The mid-latitude trough merged with BOLAVEN was located over the Korean Peninsula and two high pressure systems were located at both sides of the Korean Peninsula. As a result, TEMBIN moved northward following BOLAVEN, and then TEMBIN made a landfall on the Korean Peninsula two days later compared to BOLAVEN's landfall.

In this study, the observation impact on both TY forecast errors was investigated using the forecast sensitivity to observation (FSO) tool in the Korea Meteorological Administration (KMA) Unified Model (UM). The TEMP, Wind profiler, PILOT, SYNOP, BUOY, SHIP, TCBOGUS, AIRCRAFT, AMSUA, MHS, IASI, AIRS, GPSRO, SSMIS, AMV of Communication, Ocean and Meteorological Satellite (COMS) of KMA, MTSAT, MFG, GOES, MSG, and ASCAT observations were used for TY forecasts. ASCAT and GPSRO observations around TY centers contribute greatly to reduce TY track errors. More detailed results will be presented in the conference.