border climate summary - welcome | climas

Training on tropical cyclones and their passage across the border

Border Climate Summary

The information in this packet is available on the web: http://climas.arizona.edu/outlooks/bcs

Resumen del Clima de la FronteraIssued: June 21, 2010

1 Trainingontropicalcyclonesandtheirpassageacrosstheborder

3 Flash-FloodForecastingatAmbosNogales

RecentConditions6 Temperature7 Precipitation8 NorthAmericanDroughtMonitor9 SonoranReservoirLevels

Forecasts10 StreamflowForecast11 PrecipitationForecast12 ENSO

Table of Contents:

ByLuisM.Farfán,CentrodeInves-tigaciónCientíficaydeEducaciónSuperiordeEnsenada(CICESE),GracielaB.Raga,andFernandoOropeza,UniversidadNacionalAutónomadeMéxico(UNAM)

Tropicalcyclonesareimportantweath-ersystemsthatdevelopoverseveralre-gionsoftheglobe.Whiletheyoccuroverrelativelywarmoceans,theeast-ernNorthPacificbasinisaremark-ablyprolificregion,wheremoresys-temsdevelopperunitareathananyotherregionintheworld.Theirde-velopmenthasthepotentialtoaffectcountriesinCentralandNorthAmer-ica.Ingeneral,theapproachoftropi-calcyclonesbringschangesinmois-turecontentoverrelativelylargeareasandtheybecomeasignificantsourceofrainfallovermountainousterrain.

Onaverage,15tropicalcyclonesde-velopeveryseason,whichextendsfrom

lateMayuntilmid-November.ThewestcoastofMexicoisespeciallyvulnera-bletothesesystemsand,evenmore,tothosethatmoveclosetothecoastline.Landfallisdefinedasthepassageofthesystemcenteracrossthecoast.Tropi-calcyclonesthatmakelandfallarelike-lytobeaccompaniedbystrongwinds,coastalstormsurges,andheavyrainfall,withthepotentialforextensiveproper-tydamageandfloodingincoastalareas.NorthwesternMexicohasthehighestfrequencyoflandfallintheentireeast-ernPacificbasin.ThisregionincludesthestatesofNayarit,Sinaloa,Sonora,andtheentireBajaCaliforniaPenin-sula.Mostlandfallsarelateinthesea-son,fromAugustthroughOctober,andtheytendtooccuroverBajaCalifor-nia,oroverSinaloaonthemainland.

Training coursesIncomparisontodevelopedcountries,inLatinAmericathereisalackofme-teorologyandclimatologyprofessionals

withadequateknowledgeoftropicalcy-clonesandmajorimprovementsarere-quiredtobuildcapacityinthesedisci-plines.Aspartofaninternationalre-searchproject,fundedbytheInter-AmericanInstituteforGlobalChangeResearch(IAI,http://www.iai.int),wedesignedaseriesofshortcours-esbasedonthecurrentunderstand-ingoftropicalcyclonesintheeasternPacific.Ourmaingoalistotrainstu-dentsfrominstitutionsofhigheredu-cationinMexico,theCaribbean,Cen-tral,andSouthAmerica,wherecapac-itybuildingisintheearlystagesofdevelopment.These4-5daycourseshavebeenofferedduringthelastthreeconsecutiveyearsinMexico(LaPaz,BajaCaliforniaSur,in2008and2010andAcapulco,Guerrero,in2009).

Ourapproachincludesabriefreviewofclimatologicalfeaturesonformation,in-tensification,anddissipationoftropical

Figure1. Participants from the spring 2010 training course in La Paz, Baja California Sur, Mexico.

continued on page 4


2 | Executive Summary

ExecutiveSummary

In General – ThetransitionfromstrongElNiñotoneutralconditionsinthePacificOceanwasaccompaniedbyatransitionfromawetwinterinourregiontoamost-lydrylatespring.Regionaltemperatureswereneartobelowaverageforthespringmonths.LargereservoirsinSonora’sBavispe-Yaquiriversystemareat55-68%ofcapacity.Summerprecipitationforecastsalwayshavehighuncertainty;thisyear’sSMNforecastsindicatenear-averageprecipitationformostoftheborderregion.

Temperature –Springseasontemperaturesweremostlybelow-averageacrosstheregion.CooltemperaturesaffectedagricultureinCalifornia.AMayheatwaveinSonorawasassociatedwithheat-relatedillnesses.

Precipitation – Springprecipitationwasbelowaverageinmostoftheborderregion.Precipitation Forecast–SMNsummerprecipitationforecastsshownear-averageprecipitationformostnorthernMexicostates.NOAAprecipitationoutlooksshow“equalchances”fortheborderstates,indicatingalackofskillorconsensusamongforecasttools.

ENSO –Forecastsshowagreaterthan55percentchanceofneutralconditionsde-velopingduringthesummermonths,andanapproximately40percentchanceofLaNiñadevelopingduringtherestof2010.LaNiñaisassociatedwithlowerthanav-eragePacifictropicalcyclonedevelopment,andbelowaveragewinterprecipitation.

Disclaimer–Thispacketcontainsofficialandnon-officialforecasts,aswellasotherinformation.Whilewemakeeveryefforttoverifythisinforma-tion, please understand that we do not warrantthe accuracy of any of these materials. The userassumestheentireriskrelatedtotheuseofthisdata.CLIMASdisclaimsanyandallwarranties,whetherexpressedorimplied,including(withoutlimitation)anyimpliedwarrantiesofmerchantabilityorfitnessforaparticularpurpose.InnoeventwillCLIMASorTheUniversityofArizonabeliabletoyouortoanythirdpartyforanydirect,indirect,incidental,consequential,specialorexemplarydamagesorlostprofitresultingfromanyuseormisuseofthisdata.

Staff:Aaron Banas, UA Graduate Research AssistantJason Criscio, UA graduate research assistantStephanie Doster, Institute of the Environment Associate EditorLuis Farfan, CICESE Research ScientistGregg Garfin, Institute of the Environment Deputy Director for OutreachDavid Gochis, NCAR Research ScientistRebecca Macaulay, Graphic ArtistAndrea Ray, NOAA Research ScientistFundingfortheBorderClimateSummary/ResumendelClimadelaFronterawasprovided

byInterAmericanInstituteforGlobalChangeResearch(IAI)andtheNOAASectorApplicationsResearchProgram.

Climate Assessment for the Southwest


3 | Executive Summary

ByLauraM.Norman

Scientistsandexpertsfromaca-demiaandpublicandprivateagen-ciesfromtheUnitedStatesandMexicoareexpandingamodelde-signedtoevaluatethewatershedofNogales,AZ,andNogales,Sono-ra,andassessfloodvulnerability.

Theproject,partofalargerefforttodevelopanEarlyWarningHaz-ardSystemfortheregion,willincor-poratereal-timerainfalldatainputandcomputevolumesofrunoff,peakflow,andwatersheddischargerate.

ThecitiesofNogales,Sonora,andNo-gales,Arizona,arelocatedintheAm-bosNogalesWatershed,anorth-southorientedareaofvariedtopogra-phythatspanstheU.S.-Mexicobor-der.Throughouthistory,residentsinbothcitieshavebeenaffectedbyflood-ing.Actionstocontrolandregulatedangerousflowsintotheurbanar-easofAmbosNogalesarebeingcar-riedoutprimarilyupstreaminMexico.

Themodelthescientistsareworkingwith,KINEROS2(K2),usesmath-ematicalequationstodescribewa-tershedhydrologyprocesses,suchasinfiltrationofwaterintothesoillayers,erosion,streamflowhydro-graphs,andsedimenttransport.

LivedatawillbestreamedintotheK2modeltosupportthepilotfloodwarn-ingsystem.Themodelestimatesbothraingage-derivedrainfallandpredictsassociatedrunoff.Arunoffgraphwillshowstageofflowsandequivalentdis-chargerateinstreams,andindicatesthepeakstage(discharge)andtimeofpeak.

AraingagenetworkisbeingadaptedinNogales,Sonora,tomeasureprecip-itationandprovideelectronicallyre-cordedprecipitationmeasurements

straighttoanonlinerainfallmonitoringnetworkinitiallydevelopedforNogales,Arizona(http://rainlog.org,seeFigure1).

Gageswillbewell-distributedthrough-outtheupperwatershedatNogales,Sonora,tocitizensofthecommuni-ty,drawingoncollectivelocalknowl-edgeandsupporttodeterminethebestlocations.Membersofthere-searchteamarerecruitingresidentswhohaveInternetaccessandsafeloca-tionsfortheraingagesandelectron-icequipmenttobegintheprocessofreceivingprecipitationdataandcon-veyingittotheRainlogwebsite.

Currently,oneraingagehasbeenin-stalledattheNogales,SonoraWaterandWastewaterUtility(Figure2).In-formationfromthisnewstationhasbeendisplayedonlinesinceApril5.

Themodelsystemincludesanalarmca-pabilitytoalerttheforecasteroroth-erdesigneeswhenthemaximumpre-dictedstagelevelexceedsthecriticalstageorstagesoftheNogalesWashinNogales,Sonora,asdesignated.

TheK2modelalsowillbeusedtoeval-uatefuturefloodhazardsacrossthewatershedusingalternativeland-usescenariosasinputs.Forexample,theprimarymethodproposedforregu-latingrunoffisaseriesofdetentionbasinsinNogales,Sonora;theim-pactsofthesearebeingmodeled.

Raingagedatawillbeusedtocali-bratetheK2modelforadvancedfloodmodelingandhelpinformlanduseplanningforfuturescenariodevelop-ment,suchasurbangrowthandde-velopment.Raingagedataalsowillbe

continued on page 5

Flash-Flood Forecasting at Ambos Nogales

Figure1. A map from the Rainlog Web site (http://rainlog.org) showing the location of the first precipitation gage online in Nogales, Sonora (May 4).


4 | Articles

cyclones.Keyaspectsarethestagesofformationandintensification,withpar-ticularemphasisonthedevelopmentoffthewestcoastofMexicoduringthelastdecade.Moreadvancedtopicsin-cludelecturesonthermodynamicmod-els,air-seainteractions,oceanicrespons-es,long-termvariability,climate-relatedpredictions,andgeology-relatedtech-niquestostudycoastalimpactsdur-ingthelast100-500years.Additionally,practicalsessionsareofferedtoanalyzecasestudiesoftropicalcycloneapproachandlandfallovernorthwesternMexi-co.Duringthesesessions,studentsap-plyahistoricaldatabase,issuedbytheUnitedStatesNationalHurricaneCen-ter(http://www.nhc.noaa.gov),toana-lyzeeasternPacificbasinactivitydur-ingtheperiod1970-2009.Casestud-iesofcyclonesthatresultedinlandfallovernorthwesternMexicoareexploredinmoredetailbyincludingobservationsfromtheseasons2006through2009.

CourseinstructorsareaffiliatedwithacademicandresearchinstitutionsfromMexico(UNAM,IMTA,IPN,UABCS,andCICESE*),theUnitedStates(NewMexicoInstituteofMin-ingandTechnology,LouisianaStateUniversity,andUniversityofCalifor-niaatLosAngeles),Cuba(InstituteofMeteorology),andCostaRica(Uni-versityofCostaRica).StudentshavecomefromMexico,theUnitedStates,CostaRica,Colombia,Cuba,Brazil,DominicanRepublic,Argentina,andChile(Figure1).Thestudentsareorga-nizedintogroupstodiscussrecentpub-licationsonclimatechangeanditsim-pactontropicalcyclonedevelopment.Duringthelastdayofthecourse,thereisaforuminwhichthestudentspres-enttheirfindings.Formoreinforma-tiononthetrainingcourses,seethefol-lowingwebsite:http://cabernet.atmos-fcu.unam.mx/IAI/3th_spc_tc.html

Inadditiontothecourse,wehavecon-venedsymposia,todiscusssocialand

Training on tropical cyclones, continued

CaliforniaPeninsula,GulfofCalifor-nia,andMexicanmainlandand,af-tercrossingtheinternationalborder,theymovedacrossthestatesofCalifor-nia,Arizona,NewMexico,orTexas.

ThedescriptionofHurricaneNora’slifecycleprovidesavaluableillustration.The1997seasonwasconsideredjustaveragetoabove-average,with17sys-temsintheeasternPacificbasin.Fourofthemmadelandfalloversouthern(Olaf,Pauline,andRick)ornorthern(Nora)Mexico.HurricaneNoradevelopeddur-ingtheperiod16-26SeptemberandaffectedBajaCalifornia,northwest-ernSonora,andtheArizona-Califor-niaboundary.OnSeptember24,1997,Noramadelandfallinnorth-centralBajaCalifornia,asacategory-onehurri-cane,withawell-definedareaofintensecloudcover;andalargeareaofmoistairmovedintotheborderregion(Figure3).

DuringNora’spassage,strongwinds(35-45mph;55-75km/h)werere-portedatPuertoPeñasco,Sonora,andYuma,Arizona,whilemaximumrainfallaccumulationsexceeded5inches(125

economicissuesthatareassociatedwiththelandfalloftropicalcyclones.Top-icsincludecoastalimpactsandflooding,thelinkbetweencyclonesandwaterre-sources,flowofweatherandclimatein-formationfromscientiststopolicy-mak-ers,theroleofemergencymanagers,andimpactsonpublichealth.Speak-ersonthehumandimensionsoftropi-calcyclonesrepresenteducationalin-stitutionsandpublicandprivateagen-cies,includingemergencymanagementagenciesfromregionswithfrequentcy-cloneactivityduringthestormseason.ThisincludespersonnelfromthestatesofBajaCaliforniaSurandGuerrero,andfromthenationalcenterfordisas-terpreventioninMexico(CENAPRED,http://www.cenapred.unam.mx).

Tropical cyclones crossing the Mexi-co-United States borderFrom1970through2009,morethan90tropicalcyclonesmadelandfallacrossthePacificcoastofMexico.Even-tually,fiveofthemmovedintotheUnitedStates:Kathleen(1976),Ray-mond(1989),Lester(1992),Lidia(1993),andNora(1997)(Figure2).ThesestormsfirstmovedovertheBaja

continued on page 5

Figure2. Tracks of the 97 tropical cyclones that made landfall over the west coast of Mexico, during the period 1970-2009. Lines in color are from storms that crossed the Mexico-United States border: Kathleen (1976, blue), Raymond (1989, red), Lester (1992, green), Lidia (1993, yel-low), and Nora (1997, purple).


5 | Articles

Flash-Flood Forecasting, continued

usedinademonstrationprojecttolocatethemostadvantageoussitesformoreextensiveweathermoni-toringequipmentthatwillpro-videemergencymanagerswiththemostreliablealertsystem.

CollaborationThisprojectispartofalargecollab-orationofagenciesandpeople,in-cludingtheArizonaDepartmentofEnvironmentalProtection-Of-ficeofBorderEnvironmentalPro-tection,Tucson,Arizona(ADEQ-OBEP;HansHuth);Nogales,So-noraWaterandWastewaterUtility(OOMAPAS-NS;FranciscoGaste-lum);Nogales,SonoraInstitutoMu-nicipaldeInvestigaciónyPlaneación(IMIP;ClaudiaZulemaGilAnaya);theU.S.DepartmentofAgricul-ture,Tucson,Arizona(USDA-ARS-SWRC;DavidGoodrich);theUni-versityofArizona,Tucson,Arizona

Figure2. The Nogales, Sonora Water and Wastewater Utility building, site of the first community rain gage in the network (left). Electronic connection that conveys precipitation data from the rain gage directly to the Internet (right).

(UA;GaryWoodard,D.PhillipGuertin);LaSecciónmexicanadelaComisiónInternacionaldeLímitesyAguas,Nogales,Sonora(CILA;JesúsQuintanarGuadarrama);U.S.SectionoftheInternationalBound-aryandWaterCommission,ElPaso,Texas(IBWC;JoseNunezandDon-aldAtwood);Mexico’sNationalWa-terCommission,Hermosillo,Sonora

(CONAGUA;GilbertoOliveros);Sonora’sWaterCommissionHer-mosillo,Sonora(CEA;RobertoMo-lina);CityofNogales,Sonora,Mex-ico-DepartmentofEmergencyRe-sponse(EduardoCanizales);andcolleaguesfromtheU.S.Geologi-calSurvey,Tucson,Arizona(USGS;FloydGrayandJamesCallegary).

mm)atseveralstationsoverwesternAr-izona.ThisamountismuchgreaterthanaverageannualprecipitationinYuma(3inches;75mm).Accordingtopost-stormsurveys,thiseventwasrespon-sibleoftwodeathsand350-400home-lessinBajaCalifornia.Therewerere-portsofagriculturallosses,trafficfatali-ties,poweroutages,andurbanfloodinginsouthernCalifornia.Improvedinte-grationofforecastuseanddissemina-tion,andintegrationofdecision-mak-ers,suchasemergencymanagers,mayhavehelpedreducethetragiclossoflifeassociatedwithHurricaneNora.

Insummary,tropicalcyclonesmovingacrossNorthAmericamaybeassociatedwithintenseprecipitation,winddam-age,andfatalitiesinbothnorthwesternMexicoandthesouthwesternUnitedStates.Buildingscientificandprofes-sionalcapacitytomonitor,predict,andprepareforchangesinstormstructure

Training on tropical cyclones, continued

andmotionisanimportantpartofreducingprop-ertydamageandsavinglives.Theeffortsdescribedaboveareparticu-larlyimportantbe-causetheybuildbridgesacrossmultipledisci-plinesandgeo-graphicareasand,asaresultwork-shopparticipantsandoperation-alagenciescanimprovecommunica-tionacrosstheMexico-U.S.border.

*UNAM:UniversidadNacionalAutónomadeMéxico;IMTA:In-stitutoMexicanodeTecnologíadelAgua;IPN:InstitutoPolitécnicoNa-cional;UABCS:UniversidadAutóno-madeBajaCaliforniaSur;CICESE:CentrodeInvestigaciónCientíficaydeEducaciónSuperiordeEnsenada

Figure3. Image from the GOES-9 weather satellite, at 1700 (5:00 PM) MST on 24 September 1997. Hurricane Nora is located off the west coast of the Baja California peninsula, just a few hours prior to landfall.


6 | Recent Conditions

TemperatureInthelatespring,mid-latitudestormsarerareinourre-gion;however,severalmadetheirwaydownthePacificcoast,coolingtemperaturesintheborderregion.Maytem-peraturesweresubstantiallylowerthanthe1971-2000av-erageformuchofArizona,southernNevadaandUtah,andnorthwesternNewMexico(Figures1aandc).InMex-ico,temperatureswerenearaveragethroughoutChihua-hua,SonoraandSinaloa,but1-2degreesC(2-4degreesF)aboveaverageinDurango.Mexicanhealthauthoritiesan-nouncedpreventivealertsthroughoutthecountryduetoheatrelatedillnesses.Healthauthoritiessitedcasesofintes-tinalillnesses,diarrheaandvomiting,manyofwhichwererelatedtoMayheatwaves.AccordingtotheMexicanNa-tionalWeatherService,temperaturesreached40degreesC(104degreesF)inseveralnorthernMexicostates,including

Notes:Maps of recent temperature conditions were produced by the National Oceanic and Atmospheric Administration’s Climate Prediction Center (NOAA-CPC). Temperature anomalies refer to departures from the 1971–2000 arithmetic average of data for that period.

Figure 1a. Mean temperature at 2-m elevation for May.

Degrees Celsius30 6 9 12 1815 21 24 25

Figure 1c. Mean temperature at 2-m elevation for March–May 2010.

Degrees Celsius30 6 9 12 1815 21 24 25

Figure 1d. Mean temperature departure from 1971-2000 average at 2-m elevation for March–May 2010.

Degrees Celsius -3.5 -3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2

Figure 1b. Mean temperature departure from 1971-2000 average at 2-m elevation for May.

Degrees Celsius -5 -4.5 -4 -3.5 -3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2

OntheWeb:For more information: http://www.cpc.ncep.noaa.gov/products/Drought/Atm_Circ/2m_Temp.shtml

Sonora(El Imparcial,May8,2010).Springseasontempera-turesweremoreuniformlybelowaverageacrosstheregion(Figures1bandd),duetoastrongElNiñoepisodedur-ingthefirsthalfof2010.Coolerthanaveragespringtem-peratureshamperedtheemergenceandgrowthofsummercropplantings,suchasriceandcotton,andwetweathercomplicatedsprayingofsomefruitandnutcropsinCal-ifornia(USDAWeeklyWeatherandCropBulletin).

OntheWeb:For more information: http://www.cpc.ncep.noaa.gov/cgi-bin/US_anom_realtime.sh

Precipitation



ThetransitionfromstrongElNiñotoneutralconditionsinthePacificOceanwasaccompaniedbyatransitionfromawetwinterinourregiontoamostlydrylatespring.BoththemonthofMayandthespringseasonbroughtonlyscantpre-cipitationacrossmostoftheMexico-USborderregion(Fig-ures2a-b).NotableexceptionsincludednorthernMexico,neartheRioGrande’sBigBendregionontheTexas-Coahuilaborder,NorthernBajaCalifornia,northwesternSonoraandcentralNewMexico,whereprecipitationtotalswereaboveaverage(Figure2d).ExtremeeasternandnortheasternNewMexicoreceivedsomeMayprecipitation(Figure2c).Mayprecipitationtotals,however,wererelativelylow,whichistypicalforthisdrytimeofyear.ThepresidentoftheRegionalCattleUnionofSonora,LuisSierraMaldonado,statedthat

Figure 2a. United States and Mexico precipitation for May 2010.

Figure 2c. United States and Mexico precipitation percent of 1971-2000 average for May 2010.

2001501005025

mm

Figure 2d. United States and Mexico precipitation percent of 1971-2000 average for March–May 2010.

125150175200

755025

per

cen

t

125150175200

755025

per

cen

t

Figure 2b. United States and Mexico precipitation for March–May 2010.

500400300200100

mm

unlikeinyearspast,themajorityofSonoranrangelandsareingoodcondition,andrancherswillnotfaceseveredrought-relatedproblems.Overall,Maldonadocommentedthattherewasneitheraproblemwithwaternorpastures(El Imparcial,May15,2010).InpartsofNewMexico,springdrynesshasoccasionallybeenaccompaniedbystrongwinds,whichhavedamagedcrops(USDAWeeklyWeatherandCropBulletin).

Notes:Maps of recent precipitation conditions were produced using data from the National Oceanic and Atmospheric Administration’s Climate Prediction Center (CPC). Precipitation anomalies refer to departures from the 1971–2000 arithmetic average of data for that period. Percentage of normal is masked out where normal precipitation is less than 0.1 mm per day.

OntheWeb:For more information: http://www.cpc.ncep.noaa.gov/products/Drought/Atm_Circ/2m_Temp.shtml


NorthAmericanDroughtMonitor



OntheWeb:For more information: http://www.ncdc.noaa.gov/oa/climate/monitoring/drought/nadm/

DroughtstatusisvariedacrosssoutheasternNevadaandAr-izonaandextremedroughtconditionsdominateinsouth-ernSonoraandSinaloa.ThewesternportionsofNewMex-icowereabnormallydry(Figure3).ThesouthwesternUnit-edStatesexperiencedunusuallycooltemperaturesduringthewinterandspring,accompaniedbyabove-averagewin-terrainandsnow,whichbenefitteddryareasandboost-edstorageatanumberofreservoirs.However,thenorth-wardshiftofstormsinAprilandMayledtobelow-averageseasonalprecipitationtotalsintheSouthwest.Through-outtheborderregion,droughtconditionshaveimprovedsinceJanuary,duetowinterprecipitation,butpartsofnortheasternArizonaremaininseveredroughtstatus.

AprilisusuallyadrymonthfornorthernMexico;howev-er,April2010wasthethirdwettestin70yearsaccordingtotheMexicanNationalWeatherService(SMN).Thismayhavecontributedtoadecreaseinforestfiresinthelastsev-eralmonths.AccordingtoJuanManuelTorresRojo,direc-toroftheNationalForestCommission(CONAFOR),dur-ing2010only3majorforestfireshavebeenrecordedinthestateofSonora.Rojoaddedthattheareasaffectedbyfireswere80percentlessthanduring2009(El Imparcial,May15,2010).Precipitationwasregisteredmainlyinthenortheast-ernregionofthecountryaswellasalongtheGulfofMex-icocoast.AbnormallydryconditionsdissipatedinNorth-ernSonora,whereassouthernSonora,northernSinaloa,andsouthwesternChihuahuacontinuedtoexperiencedroughtconditions.TheNationalWaterCommissionofMexico(CONAGUA)reportedthatwaterstorageinnorthwest-ernandcentral-northernMexicodecreasedduringApril.

Notes:The North American Drought Monitor maps are based on expert assess-ment of variables including (but not limited to) the Standardized Precipi-tation Index, soil moisture, streamflow, precipitation, and measures of vegetation stress, as well as reports of drought impacts. It is a joint effort of several agencies, including NOAA’s National Climatic Data Center, NOAA’s Climate Prediction Center, the U.S. Department of Agriculture, the U.S. National Drought Mitigation Center, Agriculture and Agrifood Canada, the Meteorological Service of Canada, and the National Meteo-rological Service of México (SMN - Servicio Meteorológico Nacional).

Figure 3. North American Drought Monitor (releasedMay 21).

Drought Impact Types

Delineates Dominant Impacts

A = Agricultural (crops, pastures, grasslands)

H = Hydrological (water)

AH = Agricultural and Hydrological

D3 Extreme Drought

D4 Exceptional

Drought Intensity

D0 Abnormally Dry

D1 Moderate Drought

D2 Severe Drought

SonoranReservoirLevels


OntheWeb:For more information: http://www.elimparcial.com



Sonoranreservoirstoragedeclinedduringthespringsea-son.TotalstorageinthereservoirsdisplayedinFigure4de-clinedbyalmost900cubichectometers.Thelargestper-centofcapacitylosswasintheA.RuizCortinesreservoir.

Inreservoirrelatednews,highstoragelevelsarepresentingnewopportunitiesforsomeSonoranagriculturalproduc-ers.AquilesSouqueBrito,presidentoftheIrrigationDis-trictoftheRioYaqui,announcedthatafternearly16yearsoflimitedproductionofsecondarycropsintheYaquiVal-ley,aprojected40,000hectaresofcrops,suchassoyplanta-tionslikethoseofthemid1990s,willbeirrigatedfromres-ervoirsthisseason.BritostatedthatthisalternativewasmadepossiblebythecontributionsofaRioYaquireservoirsystemthatisat80percentofaveragecapacity,storingmorethan5billioncubicmetersofwater(El Imparcial,May1,2010).

TheSouthernNevadaWaterAuthority(SNWA)re-centlyunveileda$25millioncustom-madetunneling

Notes:The map gives a representation of current storage levels for reservoirs in Sonora. Reservoir locations are numbered within the blue circles on the map, corresponding to the reservoirs listed in the table. The cup next to each reservoir shows the current storage level (blue fill) as a per-cent of total capacity. Note that while the size of each cup varies with the size of the reservoir, these are representational and not to scale. The table details more exactly the current capacity level (listed as a percent of maximum storage, and percent of average storage). Current and maximum storage levels are given in cubic hectometers for each reservoir. One cubic hectometer is one billion liters.

This map is based on reservoir reports updated daily in El Imparcial (http://www.elimparcial.com), using data provided by Comisión Nacio-nal del Agua.

Rio Conce p c i ón

R i o S

onor

a

Rio M

atape

Rio

Bavi

s pe

Rio Yaqui

R io May

o

Legend

Reservoir Average

0%

100%

50%Current Level

size of cups is representational of reservoir

size, but not to scale

8

7

6

5

4

3

2

1

Figure 4. Sonoran reservoir levels for June 1, 2010, as a percent of capacity. The table lists current, average, and maximum storage levels.

1. Cuauhtémoc

2. El Molinito

3. A.L. Rodríguez

4. I.R. Alatorre

5. Álvaro Obregón

6. A. Ruiz Cortines

7. P. Elías Calles

8. Lazaro Cárdenas

* cubic hectometers

Reservoir Name

Max Storage*

66.1

233.9

284.5

31.1

4,200.0

1,822.6

3,628.6

1,116.566%

68%

55%

25%

0%

0%

7%

2%

CapacityLevel

733.1

2,470.2

2,309.9

464.2

1.0

0.0

4.9

0.6

Current Storage*

703.4

2,874.1

2,989.2

950.3

130.2

219.5

42.5

17.8

AverageStorage*

CLIMASwww.climas.arizona.edu

machinethatwillbeusedtocreateadeeperwaterintakefromLakeMead(Las Vegas Business Press,May10).ThenewintakeprovidestheSNWAwithinsuranceincasethelakelevelcontinuestodrop—waterlevelsinLakeMeadhavedropped110feet(33.5m)since2000.


10 | Forecasts

OntheWeb:For more information: http://www.hydro.washington.edu/forecast/westwide/sflow/index.6mons.shtml#seas_vol

StreamflowForecast

Notes:The forecast information provided in Figure 5 is updated monthly by the University of Washington and Princeton University using ensemble streamflow prediction (ESP) techniques. The average of a group (ensemble) of forecasts is generated by using recent meteo-rology to initialize the Variable Infiltration Capacity (VIC) hydrologic model. Streamflow volume estimates are based on 40 VIC model runs, using meteorological data from the period 1960–1999. These esti-mates, shown in Figure 5, are expressed in terms of the percent of the 1960–1999 average streamflow at each gage.

Thesix-monthEnsembleStreamflowPrediction(ESP)fore-cast,releasedMay17bytheUniversityofWashingtonandPrincetonUniversity,predictsnear-averageMay-OctoberstreamflowforgagesonbothsidesoftheMexico-U.S.bor-derregion.Theaverageflowisbasedontheperiodfrom1960through1999.Mostofthestreamflowforecastsfortheregionpredictsix-monthstreamflowvolumesof90to110percentofaverage(Figure5).However,thegageslo-catedinnorthernArizonaalongtheVirginRiver(num-bers8-10inFigure5)andalongtheColoradoRiver(num-bers12-13)arepredictedtohavebelow-averagestream-flow(70-90percentofaverage).OnlytheSanJoaquin(number1)andBoquillaRivers(number2)areforecasttohaveextremeconditions,at147percentofaveragefortheSanJoaquinand50percentofaveragefortheBoquilla.

37

36

35

34

3332

31

30

29

282726

25

2423

22

21201918

17

16

15

14 13121110 98

7

65

4

3

2

11. San Joaquin2. Boquilla3. Hoover Dam4. Davis Dam5. Parker Dam6. Alamo Dam7. Imperial Dam8. Virgin, UT 9. Near Hurricane, UT10. Little�eld, AZ11. Paria River12. Desert View, AZ13. Near Cameron, AZ14. Near Grand Canyon15. Imuris16. Near Blu�, UT17. Oviachic18. La Junta19. Novillo20. Cubil

21. Paso Nacori22. Angostura23. Guadalupe24. Huapaca25. Casas Grandes26. Near Mcphee, CO27. Near Bay�eld, CO28. Navajo Reservoir29. Abraham Gonzalez30. Albuquerque31. Ixpalino32. Near Del Norte, CO33. Near Lobatos, CO34. Near Chamita35. Villalba36. Las Sardinas37. Zacatecas

>170150–170130–150110–13090–11070–9050–7030–50<30

% of normal

Figure 5. United States and Mexico stream�ow forecast for May–October.

OntheWeb:For more information: http://smn.cna.gob.mx/productos/map-lluv/p-clim02.gif

PrecipitationForecast


11 | Forecasts

Notes:This forecast was prepared by the Servicio Meteorológico Nacional (SMN). The forecast methodology was developed by Dr. Arthur Douglas (Creighton University, retired) in collaboration with SMN scientists.

The forecasts are based on the average of precipitation values from analogous years in the historical record. Selection of analogous years is based on statistical analysis of factors in oceanic and atmospheric circulation known to influence precipitation in Mexico. Unique com-binations of climate indices are used in the forecasts each month. A statistical method known as cluster analysis is used to identify evolving climate patterns observed in the historic record and place each year in historical context; the years with the evolving climate patterns most similar to the current year are selected. Average atmospheric flow patterns and surface precipitation anomalies are constructed with the historic data and compared with the climatological average.

Examples of atmospheric and oceanic factors used in identifying ana-logue years, include: Pacific and Atlantic Ocean temperatures, tropical upper atmosphere oscillations, the position and strength of persistent high and low atmospheric pressure centers, and other factors.

The maps show predicted percent of monthly average precipitation. The legend shows the ranges of predicted percent of average precipita-tion associated with each color. Blues and greens indicate above-aver-age precipitation; yellows and reds indicate below-average precipita-tion. White indicates precipitation within 20% of the climatological average (based on data from 1941-2002).

TheServicioMeteorológicoNacional(SMN)forecasts,is-suedinApril2010,arebasedonyearswithsimilarpatternsofprecipitation,atmosphericcirculation,andoceantemper-atures,whichaffecttheclimateoftheregion.Forthefore-castsshowninFigures6a–b,theyearsare1958,1969,1980,1983,1988,and1992.SMNpredictsbelow-averagepre-cipitationformostofMexicoinJune.BajaCalifornia,ex-tremenorthwesternSonora,andsouthernChihuahuaareex-pectedtobeextremelydry.DryconditionsinsouthernBaja,northernCoahuila,andpartsofnorthwesternSonoraareex-pectedtogivewaytoabove-averageprecipitationthroughJuly.JulyforecastsforNorthernBaja,easternChihuahuaandwesternCoahuilaindicatelessthanaverageprecipita-tion.ForecastsforAugustshowabove-averageprecipitationformostoftheBajapeninsulaandnorthwesternSonora.

SummerseasonoutlooksfromtheNOAAClimatePre-dictionCenter(CPC;notshown)predictcontinuedde-creasingSSTanomalies.Mostnumericalmodelspre-dictacompletetransitiontoENSO-neutralconditionsby

Figure 6a. Precipitation forecast for April 2010.

Figure 6b. Precipitation forecast for May 2010.

50.0

20.0

-20.0

-50.0

-100.0

%

50.0

20.0

-20.0

-50.0

-100.0

%

Figure 6c. Precipitation forecast for May 2010 (released May 2010).

50.0

20.0

-20.0

-50.0

-100.0

%

June(Figure7).Theseconditionsareexpectedtocontinuethroughthesummer,althoughthereisaslightchancethatLaNinaconditionsmaybegininthelatterhalfofthesum-mer.ForecastsofaverageprecipitationinJulyareconsis-tentwithcontinuedweakeningofElNiñoandprogressiontowardsneutraloceantemperaturesduringthesummer.

Notes:Figure 7a shows the standardized three-month running average values of the Southern Oscillation Index (SOI) from January 1980 through May 2009. The SOI measures the atmospheric response to sea surface temperature (SST) changes across the tropical Pacific Ocean. The SOI is strongly associ-ated with climate effects in parts of Mexico and the United States. Values greater than 0.5 represent La Niña conditions, which are frequently associ-ated with dry winters and sometimes with wet summers in the southwest-ern U.S. and northwestern Mexico. Values less than -0.5 represent El Niño conditions, which are often associated with wet winters in those regions.

Figure 7b shows the IRI probabilistic El Niño-Southern Oscillation (ENSO) forecast for overlapping three month seasons. The forecast expresses the probabilities (chances) of the occurrence of three ocean conditions in the ENSO-sensitive Niño 3.4 region, as follows: El Niño is defined as the warm-est 25 percent of Niño 3.4 SSTs during the three month period in question, La Niña is defined as the coolest 25 percent of Niño 3.4 SSTs, and neutral conditions are defined as SSTs falling within the remaining 50 percent of observations. The IRI probabilistic ENSO forecast is a subjective assess-ment of monthly model forecasts of Niño 3.4 SSTs. The forecast takes into account the indications of the individual forecast models (including expert knowledge of model skill), an average of the models, and other factors.

Figure 7a. The standardized values of the Southern Oscillation Index from January 1980–May 2010. La Niña/El Niño occurs when values are greater than 0.5 (blue) or less than -0.5 (red) respectively. Values between these thresholds are relatively neutral (green).

Year

SOI V

alue

El Niño

La Niña2.52.01.51.00.5

0-0.5-1.0-1.5-2.0-2.5-3.0-3.5-4.0-4.5

CLIMASwww.climas.arizona.edu

1990

2000

1982

1984

1986

1988

1992

1994

1996

1998

2002

2004

2006

1980

2008

2010

Figure 7b. IRI probabilistic ENSO forecast for El Niño 3.4 monitoring region (released May 20). Colored lines represent average historical probability of El Niño, La Niña, and neutral.

El NiñoNeutralLa Niña

Time Period

100

90

80

70

60

50

40

30

20

10

0

Prob

abili

ty (%

)

May– Jul

2010

Jun– Aug

Jul– Sep

Aug– Oct

Sep– Nov

Oct– Dec

Nov– Jan

Dec– Feb

Jan– Mar

Feb– Apr

2011

OntheWeb:For more information: http://iri.columbia.edu/climate/ENSO/currentinfo/update.html


12 | Forecasts

ElNiñoconditionscontinuedtowinddownthroughApril,andseasurfacetemperatures(SSTs)acrossmuchoftheequatorialPacificOceanarebacktoaveragevaluesforthistimeoftheyear.TheInternationalResearchInstituteforClimateandSociety(IRI)reportedthatSSTsinthemid-Pacificwerenearaverage(approximately-0.2F),indicatingthatENSO-neutralcondi-tionshavereturned(Figure7b).Manyofthestrongconnectionsbetweentheoceanandatmospherehavequicklydissipatedinthepastseveralweeks,includingthunderstormactivityinthecentralPacificOceanthatwasevidentmostofthewinter.TheSouthernOscillationIndex(SOI)alsoshiftedfromanegativetoapositivevalueinrecentweeks,furtherindicatingashifttoENSO-neutralconditions(Figure7a).Additionally, thereis some indication that a La Niña event is on the horizon.TheIRIstatesthatthereisasignificantamountofunusuallycoolwaterjustbelowthesurfacethathasaccumulatinginthewesternPacificOceanandhasbeenmovingeastward.Oftencoolwatertemperaturesbelowthesurfaceprecedecoolingofsurfacewater.ThissuggeststhatthedevelopmentofaLaNiñaeventisnottoofarinthefuture.

TheIRIENSOforecastindicatesthatthereisan80percentchancethattherecentshifttoneutralconditionswillcontinuethroughtheMay–Julyperiod.Bythemiddletolatesummer(August–October), the chance that neutral conditions willpersistfallsto55percent,whiletheprobabilitythatLaNiñaconditionswilldevelopincreasesto42percent.Chancesremain

around42percentthroughthefallthataLaNiñaeventwilldevelop.SeasonalforecastsproducedbytheNOAAClimatePredictionCenter(CPC)reflecthigherchancesforaLaNiñaevent.CPCassignsincreasedchancesforbelow-averagepre-cipitationforthelatefallandwinterfortheSouthwest,whichistypicalduringLaNiñaevents.

ENSO(El Niño – Southern Oscillation)

border climate summary - welcome | climas

Documents