RainShadowLesson: Name_______________________________________

WhyisLasVegasaDesert? Period________

IntroductionIngeneral,weatherpatternsmovefromwesttoeastacrosstheUnitedStates.IntheSouthwesternUnitedStates,weatherpatternsmoveacrossthePacificOceanoverSouthernCaliforniaandNevada,

whichareapartoftheMojaveDesert.TheMojaveDesertislocatedmostlyinCalifornia,thesouthernportionofNevadaandthewesternedgeofArizona.Inthefollowinglesson,youwilldiscoverhowtopographycausesarainshadoweffectresultingintheMojaveDesert.

MapsofArea

WeatherPatternMovementinSouthwestUS

(MapcourtesyofLandsatandGoogleMaps)

Figure1-1Weatherpatterns(representedbyblackarrow)movefromthePacificOceanoverSouthernCaliforniaandSouthernNevada.TheyellowrectanglerepresentstheareashowninFigure1-2.

SpringMountainsandLasVegasRegion

(MapcourtesyofLandsatandGoogleMaps)

Figure1-2MapofSpringMountainsandLasVegasregion.TheSpringMountainsRangeiswest-northwestoftheLasVegasregion.

Usingthedatabelow,generateadouble-linegraphthatshowsthemonthlyprecipitationatthetwodifferentlocations. PrecipitationData

MountCharlestonMonthlyPrecipitation(in.)

LasVegasRegionMonthlyPrecipitation(in.)

January 14.45 January 0.54February 5.88 February 0.76March 3.33 March 0.44April 0.65 April 0.15May 0.80 May 0.12June 0.00 June 0.07July 3.59 July 0.40August 8.31 August 0.33September 1.05 September 0.25October 2.78 October 0.27November 0.04 November 0.36December 0.24 December 0.50

(Datacourtesyofwrh.noaa.gov–2005PrecipitationRecord)

SpringMountainsRange

LasVegasRegion

Mt.Charleston

PrecipitationModel

DataAnalysis1. WhatisthetotalyearlyamountofprecipitationforMt.Charleston?____________________2. WhatisthetotalyearlyamountofprecipitationforLasVegasValley?___________________3. Duringwhichmonthistherethegreatestdifferenceinprecipitationforthetwolocations?

_______________________________________________________________________4. Duringwhichmonthistheretheleastdifferenceinprecipitationforthetwolocations?

_______________________________________________________________________5. Whatisthegreatestdifferenceinprecipitationforthetwolocations?______________6. Whatistheaveragemonthlyprecipitationforeachlocation?RecordAnswerBelow.

MountCharlestonAverageMonthlyPrecipitation(in.)

LasVegasValleyAverageMonthlyPrecipitation(in.)

00.51

1.52

2.53

3.54

4.55

5.56

6.57

7.58

8.59

9.510

10.511

11.512

12.513

13.514

14.515

PrecipitaD

on(in.)

MonthlyPrecipitaDonTotals

MtCharleston

LasVegasValley

RainShadowDiagramInthediagrambelow,labelthefollowing:

• PacificOcean• SpringMountains/Mt.Charleston• MojaveDesert/LasVegasValley• Moistair• Dryair• TotalPrecipitation(fromdataanalysis)forMt.Charleston• TotalPrecipitation(fromdataanalysis)forLasVegasRegion

directionofwindWindwardSideLeewardSideWestEast

SummarizeUsingthediagramaboveandyourknowledgeofthewatercycle,describethehowtheSpringMountainscausesarainshadoweffectontheLasVegasregion.

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AdditionalRainShadows

Usingthemapbelowandyourknowledgeofweatherpatterns,labelthemapwithastarwhereadditionallocationsintheUnitedStatesmightexperiencearainshadoweffect?

Justifytheadditionalrainshadowlocationsyouhaveaddedtothemapabove.

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Extension:LakeEffectSnow

Inadditiontorainshadows,somelocationsneartheGreatLakesandotherlargebodiesofwater,suchasLakeTahoe,experiencelakeeffectsnow.Whenwindsmoveoverabodyofwater,waterwillevaporate,developlargestormcloudsandgeneratesignificantsnowfallandsometimeblizzards.

LakeEffectSnow

(Photocourtesyof:http://scijinks.jpl.nasa.gov/review/lake-snow/lake-effect-diagram.png)

Usingthediagramaboveandmapbelow,listthreestatesorregionsthatmightexperiencelarge

snowfallsandpotentialblizzardsbasedontheirlocation.(Note:windsgenerallymovefromwesttoeast).

GreatLakesRegion

(Mapcourtesyofhttp://glakesonline.nos.noaa.gov/images/great_lakes.gif)

Threestatesorregionsthatmightexperiencelakeeffectsnow:_____________________________________________________________________________________

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EastWest