Review of Regional Weather Conditions for First Fortnight of July 2019
1. Review of Regional Weather Conditions for First Fortnight of July 2019
1.1 In the first fortnight of July 2019, moderate to strong southwesterly or westerly winds prevailed over the northern ASEAN region. In particular, anomalously strong southwesterly winds were observed to the east of Viet Nam during the first half of the fortnight under the influence of Tropical Storm Mun (Figure 2). In the southern ASEAN region, the prevailing winds blew mainly from the southeast or southwest, with wind anomalies observed west of Sumatra. Figure 1 shows the average and anomalous winds at 5000 feet.
1.2 Southwest Monsoon conditions prevailed in the first half of July 2019. Much of the northern ASEAN region received above-average rainfall except for northern Philippines and Thailand. In the southern ASEAN region, below-average rainfall was observed over many areas (Figures 3 and 4).
1.3 Throughout the first fortnight of July 2019, the Madden-Julian Oscillation (MJO) was in the Western Hemisphere and Africa, and it did not significantly influence the weather over the ASEAN region (Figure 5).
1.4 The state of the El Niño-Southern Oscillation (ENSO) is currently neutral (neither El Niño nor La Niña). While the sea-surface temperature (SST) anomalies were slightly above average across the tropical Pacific Ocean Nino 3.4 region, other atmospheric indicators continued to show neutral conditions.