METEOROLOGICAL
HAZARDS

WHAT IS METEOROLOGICAL HAZARDS?
• Meteorological hazardsareextremeweatherevents
causedbychangesintheEarth'satmosphere.

HAZARDS ASSOCIATED WITH METEOROLOGICAL
PHENOMENA AFFECTING THE PHILIPPINES
1. TROPICALCYCLONES- Hazardsassociatedwith tropicalcyclonesare:
• RAINS(intense,heavyrainfall)ofalltropicalcyclones,whichcancause
flashfloods,floodsandlandslides.Theheavyrainofsometropicalstormsare
notoriouslynotedformassiveflashfloods.
• WINDS(high, strong, destructivewinds)ofsupertyphoons,typhoonsandsevere
tropicalstorms.
• STORMSURGES-sudden,rapid,riseof seawater atshallow coaststriggeredby
thestrongwinds andlow pressurestyphoons.

HAZARDS ASSOCIATED WITH METEOROLOGICAL
PHENOMENA AFFECTING THE PHILIPPINES
2. MONSOONS- areseasonal, regionalweather system capableofproducing heavyrains
resultinginflashfloods, flood, andlandslides. ThePhilippinesisinfluencedbythe:
SOUTHWEST (SW) MONSOON- affect thewestern partof thePhilippines( lateMayto September).
NORTHEST (NE)MONSOON- affects theeastern partofthe Philippines(late October to early
March).
MARITIMECONTENINTAL MONSOON- affect Central andSouthern Mindanao.
Hazardsassociatedwiththemonsoonsare:
• RAIN (intense, heavy rainfall) due to intensified monsoons caused by the presence of a nearb
topicalcyclone.
- a tropical cyclone/ typhoon north or northwest of Luzon would intensify the SW monsoon causin
flash floods, floods or landslides in the western parts of the country, particularly, western Luzo
includingMetro Manila.

HAZARDS ASSOCIATED WITH METEOROLOGICAL
PHENOMENA AFFECTING THE PHILIPPINES
• INTERTROPICALCONVERGENCE ZONE(ITCZ)
amigratorylarge-scaleweathersystem,thatislocated
northofthePhilippinesduringthenorthernhemisphere(NH)
summerandsouthofthePhilippinesduringsouthern
hemisphere.
HAZARDS ASSOCIATEDWITHITCZARE:
• RAINS (intensive,heavyrainfall)
• LOWPRESSURE AREAS (LPAs)

HAZARDZ ASSOCIATED WITH
OTHER METEOROLOGICAL
PHENOMENA
• Thunderstorms-heavyrainsthatmaycauseflashfloods,floods,lightningwhich
maycausedeathduetoelectrocution.Lightingcouldalsostartawildfire.
• Tornado/waterspout-characterizedbystrongwhirlingwindsoverland(tornado)
andovertheseaorotherwatersurface.Thepathofdestruction isusuallya
narrowzoneofmore orleeakilometerlongandwouldlastforonlyafew
minutes.
• MesoscaleConvectiveSystem(MCS)-consistofaclutterofheavythunderstorms
cells,coveringanareaof50t0100 squarekilometersormore andcapableof
producingheavytoveryheavyrainsforhours,resultingwidespreadflashfloods.

CLIMATOLOGICAL HAZARDS
• HazardsassociatedwithENSO(ElNinoSouthernOscillation)
• ElNino, usuallycausesdroughtin thePhilippines,thatcouldeffectagriculture
• HAZARDS ASSOCIATED WITH CLIMATE CHANGE
• Extremeweather/climate events
Heatwaves
Strongertyphoons(strongerwinds,heavier rainfall,higherstorm
surges)
Moresevere andlongerdroughts(ElNino)
• Accelerated sealevel rise,etc.

CLIMATOLOGICAL HAZARDS
• HazardsassociatedwithENSO(ElNinoSouthernOscillation)
• ElNino,usuallycausesdroughtin thePhilippines,thatcouldeffectagriculture
andfoodsupply,andfreshwaterdeficiency.(Theprimarycauseofanydroughtis
belowaveragerainfall.Droughtisdifferentfromotherhazardsin thatis
developsslowly,anditsonsetcanbemaskedbyanumberoffactors.Drought
PERCURSORY SIGNS OF TROPICAL CYCLONES
OCCURENCE
CIRRUSCLOUDS
The most common form of high- level clouds
arethin andoftenwispycirrusclouds.
A cirrus cloud shield or canopy ( very high, thin
hooked clouds) is a part and appears ahead of
a tropical cyclone (typhoon). It could be
hundreds of kilometers away from an
advancing storm. The convergence of these
clouds points towards the direction where the
stormislocated.

PERCURSORY SIGNS OF TROPICAL CYCLONES
OCCURENCE
Dark, brick- red- orange coloration of the sky
at the horizon during sunrise or sunset is
consideredasasignthatsomewhere,ina not
so distant region, a weather disturbance
exist.
Red Sky at night, traveler's delight; Red sky
is morning, traveler's take warning.
Only the reed light of the visible spectrum
is now scattered away during sunrise or
sunset.

PERCURSORY SIGNS OF TROPICAL CYCLONES
OCCURENCE
When a halo or ring around the moon is
observe thought the night “Ring around the
moon means rain soon” according to some
sayings . There’s truth to this saying because
high cirrostratus clouds often come before a
storm.

•Regularincomingseaswells,increasinginheightand
frequencyforbodethedistanttempest. Atropicalcyclonein
theoceangeneratesbigwavesupto 35to40feet highare
developinordinarystorms.
•Unusualgradualrisingofsealeveloutsidethepredicted
periodforhightide,withwindwavesformingwhitecapisa
signoftheexistenceofaweatherdisturbancenearby,
•Theskieswillgraduallydarken,andthewindswillcontinueto
increaseinspeed,asatropical cycloneapproaches.

• Fast- moving low clouds (scuds) beneath the dark overcast sky are observe within the
24- hour period before the full storm hits a locality, and gusts strengthening and
occurringmorefrequently andrapidly.
• Seasonality as a precursory sign of occurrence of hydrometeorological hazards. The
occurrence of meteorological or hydrometeorological hazards in the Philippines is
quitepredictable withrespect totheir seasonality.
o Tropical cyclones are expected from May to December, with its peak season in July
and August, although, tropical cyclones my occur any time of the year but leaser
frequency.
o The southwest monsoon starts late May or early June and ends in September and the
northern monsoon starts in November and may last up to March of the succeeding
year.

oThe location of the ITCZ can be detected and monitored as it
transits from thenorthernhemisphere to thesouthernhemisphere
andback.
oEnhanced rainfall with the possibility of flash floods, floods, and
landslides over eastern Mindanao AND THE Visayas could be
attributetothenortheastmonsoonandtheITCZoverthese region.
oThe presence of the ITCZ and tropical cyclones during the
southwest monsoon could increase the flood- causing rains over
northernPhilippines.

THE END
REPORTER: Marie Vil G. Soterio
SECTION: JADE