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ClimatologyofExtratropical Cyclones

JimSteenburghUniversityofUtah

Jim.Steenburgh@utah.edu

SupplementalReading:Lackmann (2011)Chapter5throughSection5.2

ClassActivity

• Onthewhiteboardprojectionoftheslidethatfollowsidentify:– Wherecyclonesaremostcommon(GreenMarker)– Wherecyclogenesisismostcommon(Redmarker)– Wherecyclolysis ismostcommon(BlueMarker)

• Donotlookattheslidesthatfollow

• ExplainyourthinkingtoJim

GroupProject

mapsforfree.com

NHMeanCycloneFrequencies(%)

Wernli andSchwierz (2006)

BorealFall(SON)

NHMeanCycloneFrequencies(%)

Wernli andSchwierz (2006)

BorealWinter(DJF)

NHMeanCycloneFrequencies(%)

Wernli andSchwierz (2006)

BorealSpring(MAM)

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NHMeanCycloneFrequencies(%)

Wernli andSchwierz (2006)

BorealSummer(JJA)

SHMeanCycloneFrequencies(%)

Wernli andSchwierz (2006)

AustralWinter(JJA)

AustralSummer(JJA)

AustralSpring(SON)

AustralFall(MAM)

NHWinterGenesisFrequencyLysis Frequency

Wernli andSchwierz (2006)

AnotherPerspective

Alps/Genoa

HimalayaAlbertaColorado

Intermountain?Greenland

HoskinsandHodges(2002)

SHWinterGenesisFrequencyLysis Frequency

Wernli andSchwierz (2006)

AnotherPerspective

GenesisLysis

Andes

NZAlps GreatDividingRange

AntarcticPeninsula

HoskinsandHodges(2005)

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NAJanCycloneEventsandVariability

Zishka andSmith(1980)

NAJanGenesisandLysis

Zishka andSmith(1980)

NAJulyCycloneEventsandVariability

Zishka andSmith(1980)

NAJulyGenesisandLysis

Zishka andSmith(1980)

Mesoscale TerrainEffects

Chungetal.(1976)

IntermountainCyclonesCyclone Density IC-Genesis

ERA

NARR

Jeglum etal.(2010)

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Seasonality

Jeglum etal.(2010)

Seasonality

Jeglum etal.(2010)

ClassActivity• Onthewhiteboardprojectionoftheslidethatfollowsplotthepositionandtrackofeachmajorcycloneoverthepast5daysasidentifiedwiththeIDVbundle“Bundles->Real-Time-WX->Analyses->Global-10day”

• Howdotheselocationsandtrackscomparetotheclimatologicalexpectations?

• Explaindepartures

Wernli andSchwierz (2006)