1. Climate Outlook (MAY – SEPTEMBER 2017) JOSEPH BASCONCILLO
Climate Monitoring and Prediction Section (CLIMPS)
Climatology and Agrometeorology Division (cad)
Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA)
Updated: 24 April 2017

2. INTERNATIONAL PREDICTION CENTERS
GLOBAL
ADVISORIES
INTERNATIONAL PREDICTION CENTERS
SUMMARY
CPC/ International Research Institute (IRI), USA
As of : 13 April 2017
ENSO-neutral conditions are favored to continue through at least the NH spring 2017 (MAM), with increasing chances for El Niño development by late summer and fall.
ENSO Alert System Status: Not Active
Bureau of Meteorology (BOM)-Australia
As of : 11 April 2017
El Niño WATCH continues; eastern tropical Pacific waters warm
The tropical Pacific remains neutral with respect to the El Niño-Southern Oscillation (ENSO); however, there are signs that El Niño may develop in 2017.
Tokyo Climate Center/JMA -Japan
As of: 10 April 2017
Although sea surface temperatures (SSTs) have been above normal in the eastern equatorial Pacific, ENSO neutral conditions continue.
The probability of occurrence of El Niño event by the end of boreal summer is 50%. based from SSTA averaged over NINO.3 (5°N-5°S, 150°W-90°W)
APEC Climate Center,
Busan, S. Korea
As of : 24 March 2017
persistent positive temperature anomaly across the equatorial and off-equatorial Pacific and Atlantic with the positive El Niño-Southern Oscillation (ENSO) phase. 
It is important to note that El Niño and La Niña (ENSO) are not the only factors that drive global climate patterns, but ENSO is the dominant mode of climate variability that affect our rainfall pattern
Also, there is typically high uncertainty in forecasts made at this time of the year because of spring predictability barrier.
Seven of eight models indicate that sea surface temperatures will exceed El Niño thresholds during the second half of However, some caution must be exercised as models have lower accuracy at this time of year.
Spring Predictability Barrier,” which is when the models have a harder time making accurate forecasts. 
WMO-LC-LRFMME
based in S. Korea
as of:15 February 2017
Second half of tropical Pacific Ocean surface temperatures were at borderline weak La Niña/cool-neutral levels;
ENSO prediction: Neutral-ENSO conditions and El Niño both possible during the second half of 2017.
PAGASA: ENSO-neutral conditions are present in the tropical Pacific and favored to continue through at least March-April-May 2017 season. Though majority of the models predict reaching El Nino threshold during the second half of 2017, there is high uncertainty in forecast made at this time of the year.

3. Niño Region SST Departures (oC) Recent Evolution
Recent conditions
The latest weekly SST departures are:
Apr. 3
Apr. 10
Apr. 17
Apr. 24
Niño 4
0.0
0.3
Niño 3.4
0.2
0.5
Niño 3
0.8
0.7
0.6
Niño 1+2
1.8
0.9
1.1
Niño 4
-0.3ºC
Niño 3.4
-0.2ºC
Niño 3
0.4ºC
Niño 1+2
2.1ºC
During the last 4 weeks, the SST has warmed in all Nino regions, Nino 4 or Nino west started from negative anomaly but still within ENSO-neutrall levels

4. PAGASA ENSO Alert System Status is
INACTIVE

5. Monthly Mean Rainfall Distribution
Neutral
El Niño
La Niña
Wetter in the western part
Wetter in the eastern part

7. Monthly Rainfall Average by Climate Type

8. Actual Rainfall for April 1-23, 2017
Normal RR(mm) ( )
Actual Rainfall
Observed (mm)
% Normal

10. WEATHER SYSTEMS THAT MAY AFFECT THE COUNTRY DURING THE PERIOD (May-September 2017)
Easterlies
Thunderstorms
Inter tropical Convergence
Zone (ITCZ)
Ridge of High Pressure Area (HPA)
Low Pressure Areas (LPAs)
Tropical Cyclones
SW monsoon (around May-June)

11. About our Rainfall Maps…
Forecast Rainfall
WBN - More than 60% reduction from the normal rainfall
BN % reduction from normal rainfall
NN – less than 20% reduction from normal rainfall
AN – surplus of rainfall

12. Monthly Rainfall Forecast
Updated: April 3, 2017
Normal (mm) ( )
MAY 2017
Forecast (mm)
% Normal
0 Province/s to be affected
80 Province/s to be affected

13. Monthly Rainfall Forecast
Updated: April 3, 2017
Normal (mm) ( )
JUNE 2017
Forecast (mm)
% Normal
0 Province/s to be affected
77 Province/s to be affected
3 Province/s to be affected

14. Monthly Rainfall Forecast
Updated: April 3, 2017
Normal (mm) ( )
JULY 2017
Forecast (mm)
% Normal
0 Province/s to be affected
5 Province/s to be affected
59 Province/s to be affected
16 Province/s to be affected

15. Monthly Rainfall Forecast
Updated: April 3, 2017
Normal (mm) ( )
AUGUST 2017
Forecast (mm)
% Normal
0 Province/s to be affected
7 Province/s to be affected
71 Province/s to be affected
2 Province/s to be affected

16. Monthly Rainfall Forecast
Updated: April 3, 2017
Normal (mm) ( )
SEPTEMBER 2017
Forecast (mm)
% Normal
0 Province/s to be affected
1 Province/s to be affected
62 Province/s to be affected
17 Province/s to be affected

17. Monthly Rainfall Forecast
Rainfall Condition (based on recent conditions):
MAY– SEPTEMBER 2017
Rainfall Forecast:
April– below normal to way below normal (Luzon and Western Visayas) near normal rainfall ( Eastern Visayas and Mindanao)
May – near normal generally near normal rainfall
June – near normal rainfall with patches of above normal RR in Luzon
July- near to above normal (Luzon); below to near normal (Visayas and Mindanao)
Aug-Sep – near to above normal (Visayas and Mindanao); near to below normal (Western section of Luzon)

18. RAINFALL PROBABILITY FORECAST
Lighter shades indicate high uncertainty in the forecast that a category is going to happen

19. Lighter shades indicate high uncertainty in the forecast that a category is going to happen

20. MONTHLY AVERAGE TEMPERATURE FORECAST
MAY– SEPTEMBER 2017
Slightly warmer
Slightly warmer
warmer
Slightly cooler
cooler
Slightly warmer
Slightly warmer
Slightly cooler
Slightly warmer
Slightly warmer
Slightly warmer
Slightly cooler
Slightly cooler
Slightly warmer
Slightly warmer
Slightly warmer

21. Wet & Dry Days Forecast
Wet day is defined as a day with ≥ 1 mm of rain.
WET DAY FORECAST – being issued from May – January
Dry day is defined as a day with < 1 mm of rain.
DRY DAY FORECAST – being issued from February to April

22. WET DAY FORECAST

23. Tropical Cyclone Forecast 8 – 12 TCs from April-September 2017
MONTH
Number of TC
MAY 2017
1 or 2
JUNE 2017
1 to 2
JULY 2017
2 to 3
AUGUST 2017
2 to 4
SEPTEMBER 2017
8-12
8 – 12 TCs from April-September 2017

24. Average tropical cyclone tracks (1948-2005)
MAY
0-1
JUNE
1-2
JULY
2-4
AUGUST
SEPT
May
June
September
July
August

25. SUMMARY
ENSO-neutral conditions are present in the tropical Pacific and favored to continue through at least March-April-May 2017 season;
ENSO Alert System Status – INACTIVE
Rainfall Forecast: Generally near normal

26. SUMMARY
Slightly warmer than average surface temperature is expected over the coming months as the dry season just started;
Normal onset of the rainy season (2nd half of May to 1st half of June) is expected for areas under Climate Type I (western sections of the country);
8 to 12 tropical cyclones may develop or enter the Philippine Area of Responsibility (PAR) during the forecast period.

27. MARAMING SALAMAT! (THANK YOU VERY MUCH)
The Weather and Climate Authority
MARAMING SALAMAT!
(THANK YOU VERY MUCH)