National Weather Service

[Wayan]

What happened to the wetest rainy season in 30 years ?

[KaptainRob]

13 minutes ago, Wayan said:

What happened to the wetest rainy season in 30 years ?

It isn't over yet but forecasts are not promising. The North is technically in drought, dams are very low, so we need major rainfall.

From: https://asmc.asean.org/asmc-seasonal-outlook/

"For the July to September 2021 period, models predict an increased chance of above-normal rainfall for most of the equatorial ASEAN region from 8°N to 10°S. ENSO-neutral conditions are forecast to continue for the next three months. The Indian Ocean Dipole (IOD) is close to the negative state and models are forecasting a negative IOD for the July to September 2021 period. A negative IOD tends to bring above-average rainfall for the southern ASEAN region for this time of the year. Warmer-than-usual temperature is expected for most of the ASEAN region except for Borneo and southern Sumatra where near- to above-normal temperature is predicted.
The dry season for the southern ASEAN region is expected to extend from July to October 2021. During these months, isolated to scattered hotspots are likely during dry periods and widespread hotspots can be expected during extended dry periods which may lead to an increased risk of transboundary haze occurrence. Nonetheless, due to predicted above-normal rainfall for the southern ASEAN region in July-September 2021, a recurrence of a similar 2015 (El Niño year) or a 2019 (positive IOD year) severe haze event is unlikely. Shower activities are expected to persist for the northern ASEAN region during this period, and help to subdue hotspot and smoke haze activities.

 

The El Niño Southern Oscillation (ENSO) monitoring system state is “Neutral”. The 1-month Nino3.4 sea surface temperature index continues to indicate neutral conditions. Atmospheric indicators (cloudiness and wind anomalies) over the tropical Pacific Ocean are generally consistent with neutral conditions. The Nino3.4 index was -0.37°C for June 2021 and -0.57°C for the April – June 2021 three-month average.

Neutral conditions are expected to remain for the next three months. Some models predict La Niña conditions towards the end of the year.

Another key driver that may influence rainfall over the region in the next few months is the Indian Ocean sea-surface temperature anomalies. Currently an Indian Ocean-related index monitored, called the Indian Ocean Dipole (IOD) index, is in the negative phase and models are forecasting the negative IOD to remain for the next three months (August to October). A negative IOD can lead to above-average rainfall parts of Southeast Asia."

 

[thai3]

Phone apps are hopeless predicting the rain as well, if it say 80% chance of rain it's usually OK to put the washing out, if no rain forecast don't do the washing!