Raymarine gS Series - Page 384

TermDenition
Precipitation
Moisturethatisreleasedfromtheatmosphereasrain,drizzle,hail,sleetorsnow,aswellasdewandfog.
PressureCentreAregionofhighorlowpressure.
SqualllineAnon-frontalband,orline,ofthunderstorms.
SupertyphoonAtyphoonthatreachesmaximumsustained1minutesurfacewindsofatleast65m/s(130kt,150mph).
Thisistheequivalentofastrongcategory4or5hurricaneintheAtlanticbasinoracategory5severe
tropicalcycloneintheAustralianbasin.
Tornado
Afunnelshapedwhirlwindwhichextendstothegroundfromstormclouds.
Tropicalcyclone
Alowpressuresystemthatgenerallyformsinthetropics.Thecycloneisaccompaniedbythunderstorms
and,intheNorthernHemisphere,acounterclockwisecirculationofwindsneartheearth'ssurface.
Tropical
depression
Anorganizedsystemofcloudsandthunderstormswithadenedsurfacecirculationandmaximumsustained
windsof38mph(33kt)orless.
Tropicalstorm
Anorganizedsystemofstrongthunderstormswithadenedsurfacecirculationandmaximumsustained
windsof3973mph(3463kt).
Tropics
AnareaontheEarth'ssurfacethatliesbetween30ºnorthand30ºsouthoftheequator.
Trough
Anelongatedareaofrelativelylowatmosphericpressure,usuallyextendingfromthecentreofalow
pressureregion.
Typhoon
ThenameforatropicalstormoriginatinginthePacicOcean,usuallytheChinaSea.Theyarebasicallythe
sameasthehurricanesoftheAtlanticOceanandthecyclonesoftheBayofBengal.
Wavecyclone
Astormorlowpressurecentrethatmovesalongafront.
Waveperiod
Theperiodisthetimegapbetweensuccessivewavesandthelongertheperiodthefasterthewavestravel.
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gSSeries