Gale Warning
Issued at: 5:00 PM TODAY , 05 April 2017
Gale Warning # 10 (Final)
For:

Gale Warning in PDF file





Monthly Climate Assessment and Outlook

Issued: 07 April 2017

Monthly Rainfall Forecast
RAINFALL FORECAST  (April - September 2017) 
UPDATED: 05 April 2017 (next update 26 May 2017)


Regional Rainfall Forecast
Issued: 05 April 2017
Valid for: April-September 2017
Farm Weather Forecast and Advisories
ISSUED              :  8AM, THURSDAY, APRIL 27, 2017
VALID UNTIL      :  8AM, FRIDAY, APRIL 27, 2017
FWFA:  N0. 17-117


Ten-Day Regional Agri-Weather Information

DEKAD NO. 12 April 21 - 30, 2017

PHILIPPINE AGRI-WEATHER FORECAST

      The weather systems that are expected to affect the whole country within the ten-day period are ridge of high pressure area, easterlies and low pressure area.

Partly cloudy to cloudy skies with isolated rainshowers and thunderstorms mostly in the afternoon or evening are expected over the whole country during the early and the middle days of the forecast period. On the latter part of the period, a possible low pressure area will affect the eastern section of Visayas and Mindanao which will bring cloudy skies with light to moderate rains. The rest of the country will have partly cloudy to cloudy with isolated rainshowers and thunderstorms mostly in the afternoon or evening.

Winds blowing from the southeast to south will prevail over Luzon and Visayas and coming from the east to northeast over Mindanao. The whole archipelago will have slight to moderate seas during the early and middle days of the dekadal period. On the latter part of the dekad the seaboards of Northern Luzon, eastern Visayas and Mindanao will have moderate to occasionally rough seas while the rest of the country will have slight to moderate seas.

            The eastern and central equatorial Pacific is in neutral condition.


Seasonal Climate Outlook
Issued:  20 January 2017
FOR January - June 2017
PDF 




Astronomical Diary
Issue for April 2017
Lyrids Meteor, Jupiter, Saturn will be found at about 19 degrees above the east southeastern horizon and...




   PAGASA webmail  Learning Tools  Bidding 

  Training Activities  Vacancy  Research-and-Development

  Engineering  faqupdate  Publications 

A. Cloud Description

 

SKY CONDITIONDEFINITION/DESCRIPTION

Clear or Sunny Skies

  • State of the sky when it is cloudless, totally clear or with a few small light clouds visible.
  • Has a total cloud cover of less than one okta.

Partly Cloudy

  • State of the sky is within 2-5 oktas total cloud cover or has between 30% to 70% cover of the celestial dome.

Partly Cloudy to at Times Cloudy

  • Mostly partly cloudy but there are times when more than 70% of the celestial dome is covered with clouds.

Mostly or Mainly Cloudy

  • The sky is mostly covered with clouds but with possible brief periods of sunshine.
  • The total cloud cover is between 6 to 8 oktas.

Cloudy

  • The sky is covered with clouds between 6 to 8 oktas or has more than 70% cloud cover.
  • Predominantly more clouds than clear sky.
  • For a longer period during the day, the sun is obscured by clouds.

Overcast

  • The sky is totally or completely covered with thick and opaque clouds, 8 oktas or around 100% cloud cover.

A. Cloud Description

 

SKY CONDITIONDEFINITION/DESCRIPTION

Clear or Sunny Skies

  • State of the sky when it is cloudless, totally clear or with a few small light clouds visible.
  • Has a total cloud cover of less than one okta.

Partly Cloudy

  • State of the sky is within 2-5 oktas total cloud cover or has between 30% to 70% cover of the celestial dome.

Partly Cloudy to at Times Cloudy

  • Mostly partly cloudy but there are times when more than 70% of the celestial dome is covered with clouds.

Mostly or Mainly Cloudy

  • The sky is mostly covered with clouds but with possible brief periods of sunshine.
  • The total cloud cover is between 6 to 8 oktas.

Cloudy

  • The sky is covered with clouds between 6 to 8 oktas or has more than 70% cloud cover.
  • Predominantly more clouds than clear sky.
  • For a longer period during the day, the sun is obscured by clouds.

Overcast

  • The sky is totally or completely covered with thick and opaque clouds, 8 oktas or around 100% cloud cover.

Precipitation (Rain & Rainshowers) Description

B. Precipitation (Rain & Rainshowers) Description

1. Rains

  • Overcast sky with continuous or steady precipitation that may last several hours.
  • Has a water droplets of 0.5 mm or greater in size but if widely scattered the drops may be smaller.
  • Associated with meso-scale (synoptic) system or macro-scale (large scale) system like TC's, Easterly Waves, Monsoons, Fronts and ITCZ.

 

RAIN CLASSIFICATIONDEFINITION/DESCRIPTION

Very Light Rains

  • Scattered drops that do not completely wet an exposed surface regardless of duration.

Light Rains

  • The rate of fall is from trace to 2.5 mm per hour.
  • Individual drops easily identified and puddles(small muddy pools) form slowly.
  • Small streams may flow in gutters.

Moderate Rains

  • The rate of fall is between 2.5 mm to 7.5 mm per hour.
  • Puddles rapidly forming and down pipes flowing freely.

Heavy Rains

  • The rate of fall is greater than 7.5 mm per hour.
  • The sky is overcast, there is a continuous precipitation.
  • Falls in sheets, misty spray over hard surfaces.
  • May cause roaring noise on roofs.

Monsoon Rains

Other Descriptions:

  • Heavy and continuous precipitation attributed to either the Southwest or Northeast Monsoon.

Occasional Rains

  • Not frequent but is recurrent precipitation.

Widespread Rains

  • Precipitation occuring extensively throughout an area.

Frequent rains

  • Precipitation occuring regularly and often throughout the time duration.

Intermittent Rains

  • Precipitation which ceases at times and re-occur again.

 

2. Rainshowers

  • Precipitation of short duration but usually of greater intensity from convective clouds(primarily cumulus or cumulonimbus)
  • Characterized by sudden start and sudden end of precipitation, rapid change in intensity.

 

RAINSHOWERSDEFINITION/DESCRIPTION

Scattered Rainshowers

  • The rain-bearing clouds is distributed spatially resulting to rainshowers occuring to the bigger part of the forecasted area.

Isolated Rainshowers

  • The rain-bearing clouds is small and isolated resulting to rainshowers occuring only to a small part of the forecasted area.

Occasional Rainshowers

  • There is a large amount of convective clouds and precipitation occur in most parts of the forecasted area occasionally, and varying in rainfall amount.

Squally Rainshowers

  • Showers accompanied by brief but sudden strong or gale force winds.




C. Wind Description(Based from the Beaufort Wind Scale and the Saffir-Simpson Scale)

 

WIND DESCRIPTION

UNITS in KPH

UNITS in KNOTS

DESCRIPTION AS OBSERVED

Light Winds

19 or less

10 or less

  • Wind felt on face.
  • Ordinary wind vanes moved by wind.
  • Leaves rustle.

Moderate Winds

20-29

11-16

  • Wind raises dust and loose paper.
  • Small branches are moved.

Moderate to Occasionally Strong

   
  • Moderate winds mostly persist but there are instances during the forecast period that it reaches strong wind force.

 Fresh Winds*

30-39

17-21

  • Small trees in leaf begin to sway.
  • Crested wavelets appear on inland waters.
 Strong Winds 40-50 22-27
  • Large branches in motion.
  • Whistling heard in telephone wires.
  • Umbrellas used with difficulty.

Gale:

1 Near Gale*

2 Gale
3 Strong Gale*

 

51-62

63-75
76-87

 

28-33

34-40
41-47

 

  • Whole trees in motion.
  • Inconvenience felt when walking against wind.
  • Twigs break off road.
  • Cars veer on road.
  • Larger branches break off.
  • Slight structural damade occurs-roofing dislodged.

Stormy:

1 Storm

2 Violent Storm*

3 Typhoon*

 

88-102

103-117

118 or more

 

48-55

53-63

64 or more

 

  • Trees uprooted.
  • Considerable structural damage.
  • Widespread damage.
  • Widespread damage.

  • *Terms that are not normally used by meteorological centers in forecasts formulation and communication
  • Gust - any sudden brief increase of wind speed usually less than 20 seconds followed by a lull or slackening in wind speed




D. Sea Condition as affected by Wind Force (Based from the Beaufort Wind Scale)

 

WIND FORCEUNITS in (MPS)UNITS in (KTS)WAVE HT.(METERS)SEA CONDITION
 Calm 0-1.5 0-3.0 0.1
  • Ripples with the appearance of scales are formed but without foam crests.
 Smooth 1.5-4.0
 
3.0-8.0
 
0.1-0.5
 
  • Small wavelets, still short but more pronounced.

 

  • Crest have glassy appearance and do not break.
 Slight 4.0-8.0
 
8.0-16.0
 
0.5-1.25
 
  • Small waves, becoming longer.
  • Fairly frequent white horses.
 Moderate 8.0-11.0
 
16.0-22.0
 
1.25-2.5
 
  • Moderate waves taking a more pronounced long form.
  • Many white horses are formed-a change of some spray.
 Rough 11.0-16.0 22.0-32.0 2.5-4.0
  • Large waves begin to form.
  • Sea heaps up and white foam from breaking waves begin to be blown in streaks along the direction of wind.
 Very Rough 16.0-20.0

 
32.0-40.0

 
4.0-6.0

 
  • Moderately high waves of greater length.
  • Edges of crest begin to break into spindrift.
  • Foam is blown in well-mark streaks along the direction of the wind.
 High 20.0-26.0

 
40.0-52.0

 
6.0-9.0

 
  • High to very high waves with long overhanging crests.
  • The surface of the sea takes on white appearance.
  • The thumbling of the sea becomes heavy with visibility affected.
 Very High 26.0-34.0


 
52.0-68.0


 
9.0-14.0


 
  • Exeptionally high waves.
  • Small and medium size ships occasionally lost from view behind waves.
  • The sea is completely covered with long white patches of foam.
  • The edges of wave crest are blown into froth.
 Phenomenal >34.0

 
>68.0

 
>14.0

 
  • The air is completely filled with foam and spray.
  • Sea completely white with driving spray.
  • Visibility very seriously affected.

 


PUBLIC WARNING 

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.

Read more ...


PAGASA S&T RELEASE
PRESS STATEMENT
10 April 2017
               
SPECIAL WEATHER OUTLOOK FOR THE LENTEN SEASON


Starting today (April 10) until Maundy Thursday (April 13), warm and dry weather conditions associated with sunny weather will prevail over the entire archipelago, with chances of some isolated rainshowers or thunderstorms due to the Ridge of High Pressure Area (HPA) and Easterlies.

Read more ...
PAGASA S&T Release
PRESS STATEMENT
05 April 2017


TERMINATION OF THE NORTHEAST MONSOON

The resurgence of the Northeast Monsoon that affected the Northern and Central Luzon during the last few days has weakened.  Latest weather map analyses and numerical model outputs indicate
Read more ...