Gale Warning
Issued at: 05:00 AM TODAY , 11 November 2017
Gale Warning # 3 (Final)
For: Strong to Gale force winds associated with TROPICAL STORM "salome" (HAIKUI)

Gale Warning in PDF file

Dams Water Level Update
As of 6 AM, 26 SEPTEMBER 2017

General Flood Advisories - Regional
Issued as of 7AM 07 August 2017

Daily Basin Hydrological Forecast
Issued 21 FEBRUARY 2017

Monthly Climate Assessment and Outlook

Issued: 05 June 2017

Monthly Rainfall Forecast
RAINFALL FORECAST  (October 2017 - March 2018) 
UPDATED: 20 September 2017 (next update October 2017)

Regional Rainfall Forecast
Issued: 20 September 2017
Valid for: October 2017 - March 2018
Farm Weather Forecast and Advisories
ISSUED              : 8AM, THURSDAY, SEPTEMBER 7, 2017
FWFA:  N0. 17-251

Ten-Day Regional Agri-Weather Information
DEKAD NO. 25 SEPTEMBER 1-10, 2017

The weather systems that will affect the whole country are southwest monsoon, intertropical convergence zone (ITCZ) and low pressure area (LPA).
Seasonal Climate Outlook
Issued:  06 July 2017
FOR July - December 2017

Astronomical Diary
Issued for November 2017
On November 13 at 5:00 AM, Venus and Jupiter will be located low in the eastern horizon among...

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 Impact Assessment for Agriculture full document

     The Impact Assessment and Applications Section (IAAS) of Climatology and Agrometeorology Division (CAD) regularly issue this monthly/bulletin which will provide users such as food security managers, economic policy makers, agricultural statisticians and agricultural extension officials with qualitative information on the current and potential effects of climate and weather variability on rainfed crops, particularly rice and corn. This bulletin, entitled “Climate Impact Assessment for Agriculture in the Philippines”, represents a method for converting meteorological data into economic information that can be used as supplement to information from other available sources.

    For example, an agricultural statistician or economist involved in crop production and yield forecast problems can combine the assessment with analysis from area survey results, reports on the occurrence of pests and diseases, farmers’ reports and other data sources.

  The impact assessments are based on agroclimatic indices derived from historical rainfall data recorded for the period 1951 to the present. The indices, expressed in raw values percent of normals and percentile ranks, together with real time meteorological data (monthly rainfall, in percent of normal), percent of normal cumulative rainfall, as well as the occurrence of significant event such as typhoons, floods and droughts are the tools used in the assessment of crop performance. Crop reports from PAGASA field stations are also helpful.

The narrative impact assessment included in the bulletin depicts the regional performance of upland, 1st lowland and 2nd lowland palay; and dry and wet season corn crops, depending on the period or the season. Tabulated values of normal rainfall and generalized monsoon and yield moisture indices are provided for ready reference. Spatial analysis of rainfall, percent of normal rainfall and the generalized monsoon indices in percentile ranks are also presented on maps to help users visualize any unusual weather occurring during the period. The generalized monsoon indices in particular, are drought indicators; hence, the tables (see Appendices) together with the threshold values can be used in assessing drought impact, if there are any. It also helps assess any probable crop failure.

It is hoped therefore that this bulletin would help provide the decision-makers, planners and economist with timely and reliable early warning/information on climatic impact including the potential for subsistence food shortfalls, thereby enabling them to plan alternate cropping, if possible, food assistance strategies/mitigation measures to reduce the adverse impact of climate and eventually improve disaster preparedness.

     Impact assessment for other principal crops such as sugarcane and coconut, for energy and for water resources management, are from time to time will be included in the forthcoming issues of this bulletin.

  The IAAS of CAD will appreciate suggestions/comments from end-users and interested parties for the improvement of this bulletin.

Definition of Terms

The Generalized Monsoon Index (GMI) helps determine the performance of the rains during the season and serves as a good indicator of potential irrigation supplies. It is a tool used to assess rainfed crops.

The GMI for the southwest monsoon (GMIsw) in an area during June to September is defined as follows:
GMIsw = W6P6 + W7P7 + W8P8 + W9P9

The GMI for the northeast monsoon (GMIne) in an area during October to January is defined as:
GMIne = W10P10 + W11P11 + W12P12 + W1P1
W = weight coefficient of monthly rainfall for the season;
P = rainfall amount in the ith month
(i = 1 for January, 2 = for February, etc.)

The Yield Moisture Index (YMI) is a simple index that helps the users assess agroclimatic crop conditions during the crop season. The YMI for a particular crop is defined as follows:
n YMI =  [Pi Ki] i
i = crop stage (1 = planting/transplanting,
2 = vegetative, 3 = flowering, 4 = maturity, etc.)
n = total no. of crop stages;
P = rainfall during the ith crop stage; and
K = appropriate crop coefficient for the ith crop stage.
Tentatively, the threshold values of categories of indices for interpretation being adopted for both YMI and GMI are as follows:

> 80 Potential for flood damage
41 - 80 Near normal to above-normal crop condition
21 - 40 Moderate drought impact with reduced yield
11 - 20 Drought impact with major yield losses
< 10 Severe drought impact with crop failure and potential food shortages




       In most parts of the country, harvesting of July-planted 1st lowland palay has just begun, good to normal yield is expected in the areas of CALABARZON, MIMAROPA, Masbate, Central Visayas, Zamboanga del sur, Northern Mindanao, and Autonomous Region in Muslim Mindanao (ARMM). In contrast, below normal yield is anticipated in most of Ilocos Region, Cordillera Administrative Region(CAR), Cagayan Valley, Central Luzon,  Negros Island Region, and Panay Island.

       Assessment of rainfall for the month showed that near to below normal rainfall conditions were experienced in most parts of the country, except for Romblon, western Panay Island, Eastern Samar, and Sulu Archipelago which received below to way below normal rainfall.

      The weather systems that affected the country during the month were the inter-tropical convergence zone (ITCZ), southwest (SW) monsoon, low pressure areas (LPAs), easterlies and the passage of four (4) tropical cyclones (TCs).  These TCs were Typhoon (TY) ”Igme” (Oct 1-3), Tropical Storm (TS) “Julian” (Oct 4-6), TY “Karen” (Oct 12-16), and Super Typhoon (STY) “Lawin”) with tracks over northern Luzon that brought moderate to occasionally heavy rains and thunderstorms along their path. Notably, STY “Lawin” is the first tropical cyclone of its category to be recorded in the Philippines based on the new PAGASA Tropical Cyclone Warning System (TCWS).  Latest reports confirm damages in both agriculture and infrastructure at about Php 3.73 billion along with declaration of state of calamity in many areas in northern Luzon (NDRRMC Situation report No. 9).

REGION I (Ilocos Region)

    The generally stormy weather which prevailed over the Ilocos region is not favorable for the harvesting of July-planted lowland palay.  Likewise, a decrease in yield of rice crops this season is expected due to windy conditions experienced by the crops, particularly in those in the maturing stage.

CAR (Cordillera Autonomous Region)

     The maturing July-planted lowland palay, harvestable during the month, is affected by the strong winds brought by TY ”Lawin” passing across the region upon exiting. Below normal yield is anticipated.

REGION II ( Cagayan Valley)

     The harvestable July-planted lowland palay, which were in good crop conditions on the previous month, were devastated by strong winds brought by typhoon “Lawin”. The leads to a reduction in the expected yield.

REGION III (Central Luzon)

       Harvesting of July-planted lowland palay now begun in Zambales and Cabanatuan. Below normal yield is anticipated due to water logging experienced by the crops during the reproductive stage of growth


      Harvesting of July late-planted lowland 1st palay has just started in Tayabas and Batangas Yield is anticipated to be good because crops experienced favorable conditions during the reproductive stage of growth and development.


      The harvestable July-planted lowland palay showed good crop condition in most parts of the region, as evident on the percentile rank. Good to normal yield is anticipated during the season.

REGION V  (Bicol Region)  

     Harvesting of July-planted 1st lowland palay in Masbate had just begun. Good to normal yield may be expected because crops experienced sufficient moisture from planting to maturity.

REGION VI (Western Visayas) 

      Harvesting of July-planted lowland palay is on-going across the region. Below normal yield is expected because crops experienced moisture stress, although the crops recovered in their reproductive stage

REGION VII (Central Visayas)

    Harvesting of July-planted lowland palay is starting in most parts of the region: good to normal yield is anticipated due to sufficient moisture and favorable weather experienced by the crops during the critical stage of growth.

REGION VIII (Eastern Visayas)

     Good to normal yield is expected in harvestable July-planted lowland palay in Tacloban. This is due to sufficient moisture and good crop conditions in the entire growing season.  On the other hand, in Catbalogan, below normal yield is estimated because crops experienced slight moisture stress during the flowering stage.

 REGION IX (Zamboanga Peninsula)

   Harvesting of July-planted 1st lowland palay in Zamboanga del Sur is now in progress: yield is predicted to be good due to adequate moisture experienced by the crops during the critical stage of growth.

REGION  X (Northern Mindanao)

     Near normal harvest of July-planted lowland Palay is expected in the region due to relatively sufficient moisture that favored the crops during the entire growing period.

REGION XI (Davao Region)

    Sun drying and stocking of post-harvested, late-planted upland palay has already occurred for a week or two. These activities were favored by the good weather that prevailed during the month.


     The accumulated rainfall during the month is better than previous months, but still inadequate for farming activities to commence.


     The good weather during the month favored the sun-drying and stocking activities for the post-harvested, June-planted lowland palay which completed days ago.

ARMM ((Autonomous Region of Muslim  Mindanao)

     Harvesting of July-planted lowland palay has now begun: yield is estimated to be near-normal to normal because of the sufficient moisture received by the crops from planting to maturity.


For Particulars, please contact:

Impact Assessment and Applications Section (IAAS)
Climatology and Agrometeorology Division (CAD)
Telefax No.: 434-58-82




It has come to the attention of the Office of the Administrator of PAGASA that a certain person has been using the name of Dr. Vicente B. Malano to solicit money from the contractors of PAGASA.

Dr. Malano wishes to inform the public that he has not authorized anyone to solicit money on his behalf and to warn everyone against dealing with unscrupulous activities of certain individuals.

payong pagasa on android The latest version of the official PAGASA app can now be downloaded on Google play store

Weather Division is now  ISO 9001:2008 Certified
Proof has been furnished by means of an audit that the requirements of ISO 9001:2008 are met.

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24 May 2017


Southwesterly windflow has been dominant over the West Philippine Sea for several days now. This is due to the formation of semi-permanent trough over Northern Luzon-Taiwan area and the eastward migration of the North Pacific High Pressure Area which are the prominent indicators of the southwest monsoon onset in the country. 

Likewise, the prevailing weather condition in most parts of Luzon and Visayas particularly the western section is now warm and humid as characterized by occasional to frequent occurrences of afternoon-evening or early morning rainshowers and thunderstorms. These developments signify the approaching onset of rainy season under Type 1 climate covering the western parts of Luzon and Visayas.

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17 May 2017

To further strengthen its weather forecasting capabilities, the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA), in partnership with the Korea International Cooperation Agency (KOICA), inaugurates the new Communication, Ocean and Meteorological Satellite (COMS) Data Analysis System at the PAGASA Weather and Flood Forecasting Center in Quezon City.
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