A Multi-Radar, Multi-Sensor-based Hail Climatology for the CONUS: 2000-2011 Derek Rosseau, Kiel Ortega, Anthony Reinhart, and Holly Obermeier

OU/CIMMS & NOAA/OAR/NSSL

Introduction •  ThisprojectusesdatafromMul4-YearReanalysisofRemotelySensedStorms(MYRORSS)

foryears2000-2011.•  MYRORSSwasaprojectthatinvolvedreprocessingthearchiveofWSR-88Dlevel-IIdata

forthecon4guousUnitedStates•  MYRORSSdatacombinesWSR-88DradardatawithRUC/RAPmodelanalysesand

producesMul4-RadarMul4-Sensor(MRMS)grids,suchasMaximumExpectedSizeofHail(MESH).

Quality Control (QC)

•  Analyze daily accumulations of MESH. •  Errors in reflectivity data result in erroneous MESH values. •  The bad data were removed, if possible, then reprocessed the day. •  Once a full year was reprocessed, the data was accumulated. •  Accumulations ran through a series of smoothers to clean up the field.

Results

Issues Future Work

•  Persistent QC problems (e.g. coastal interaction, radar spikes) affect the hail days per year climatology •  Cannot manually remove some errors due to other precipitation in the area

IncorrectMESHvaluesduetocoastalinterac4onleadtonoiseintheclimatology

ThisposterwaspreparedbyDerekRosseauwithfundingprovidedbyNOAA/OfficeofOceanicandAtmosphericResearchunderNOAA-UniversityofOklahomaCoopera4veAgreement#NA11OAR4320072,U.S.DepartmentofCommerce.Thestatements,findings,conclusions,andrecommenda4onsarethoseoftheauthor(s)anddonotnecessarilyreflecttheviewsofNOAAortheU.S.DepartmentofCommerce.

12yearAccumula4onMaximumMESH(unsmoothed)

12yearAccumula4onMaximumMESH(smoothed)

DaysperYearAnyHail

DaysperYearSevereHail

JanuaryAnyHail FebruaryAnyHail MarchAnyHail AprilAnyHail MayAnyHail JuneAnyHail

JulyAnyHail AugustAnyHail SeptemberAnyHail OctoberAnyHail NovemberAnyHail DecemberAnyHail

Radarspikesduetoterrain:anothercommonQCissue

•  Explorevariabilityofhailes4matespergivennear-stormenvironment

•  Developaclimatologythates4matesthelikelihoodofseverehailusingcoarsergridspacing

•  CompareMESHtootherMRMSgridstoseeifanymajordifferencesinaradar-derivedhailclimatologyexistbetweenproducts

•  RawMESHfieldswereaccumulatedwithamul4plehypothesistechnique.Accumula4onsweresmoothedusingmul4pledila4onanderosionfilters,preservingsmallertrackswhileelimina4ngnoise,andfinishedwithaGaussianfilter.