Day 2: WSR-88D Data Quality and Impacts on Interpretation Paul Schlatter (CIMMS/WDTB) Jami Boettcher...

Day 2: WSR-88D Data Quality and Day 2: WSR-88D Data Quality and Impacts on InterpretationImpacts on Interpretation

Day 2: WSR-88D Data Quality and Day 2: WSR-88D Data Quality and Impacts on InterpretationImpacts on Interpretation

Paul Schlatter (CIMMS/WDTB)Paul Schlatter (CIMMS/WDTB)

Jami Boettcher (WDTB)Jami Boettcher (WDTB)

Metr 4803Metr 4803

April 14, 2005April 14, 2005

OverviewOverviewOverviewOverview

• Data QualityData Quality– Product characteristicsProduct characteristics– Operator interventionOperator intervention

• Non-Meteorological ReturnsNon-Meteorological Returns

• Data Quality and the NWS Warning ProcessData Quality and the NWS Warning Process

Where’s the Weather?Where’s the Weather?Where’s the Weather?Where’s the Weather?

WSR-88D Data QualityWSR-88D Data QualityWSR-88D Data QualityWSR-88D Data Quality

• Ground Clutter and Anomalous PropagationGround Clutter and Anomalous Propagation

• Range FoldingRange Folding

• Velocity Folding => Improperly Dealiased Velocity Folding => Improperly Dealiased VelocitiesVelocities

Ground ClutterGround Clutter(Normal)(Normal)


• Reflectivity: high power, lacking smooth gradientsReflectivity: high power, lacking smooth gradients



• Velocity: generally near zeroVelocity: generally near zero

Anomalous Propagation (AP)Anomalous Propagation (AP)Anomalous Propagation (AP)Anomalous Propagation (AP)

• Transient form of clutter contaminationTransient form of clutter contamination

• Beam is refracting more than standardBeam is refracting more than standard– Nocturnal cooling in valleysNocturnal cooling in valleys– Behind cold fronts, dry linesBehind cold fronts, dry lines

Anomalous PropagationAnomalous Propagation(Transient)(Transient)


• Reflectivity: high power, lacking smooth gradients, Reflectivity: high power, lacking smooth gradients, radially orientedradially oriented



• Velocity: generally near zeroVelocity: generally near zero



• Spectrum Width: generally lowSpectrum Width: generally low

Clutter SuppressionClutter SuppressionOperator DefinedOperator Defined




• Geographic regions definedGeographic regions defined– Type of suppressionType of suppression

– Bypass Map for normal clutter Bypass Map for normal clutter – All Bins for transient clutter (AP)All Bins for transient clutter (AP)

– Level of suppressionLevel of suppression

AP Removal ExampleAP Removal ExampleReflectivityReflectivity


AP Removal ExampleAP Removal ExampleVelocityVelocity

AP Removal ExampleAP Removal ExampleVelocityVelocity



AP Removal ExampleAP Removal ExampleVVelocityelocity

AP Removal ExampleAP Removal ExampleVVelocityelocity

Data Quality ImprovementData Quality ImprovementData Quality ImprovementData Quality Improvement


AP and Normal Clutter RemovalAP and Normal Clutter RemovalReflectivityReflectivity


• No suppression appliedNo suppression applied

AP and Normal Clutter RemovalAP and Normal Clutter RemovalVeVelocitylocity


• No No suppressionsuppression appliedapplied



• Normal clutter suppression appliedNormal clutter suppression applied

AP and Normal Clutter RemovalAP and Normal Clutter RemovalVVelocityelocity

AP and Normal Clutter RemovalAP and Normal Clutter RemovalVVelocityelocity

• Normal clutter suppression appliedNormal clutter suppression applied



• AP and Normal clutter suppression appliedAP and Normal clutter suppression applied



• AP and Normal clutter suppression appliedAP and Normal clutter suppression applied



Inappropriate Suppression AppliedInappropriate Suppression AppliedInappropriate Suppression AppliedInappropriate Suppression Applied

• All Bins, High suppression in Batch tiltsAll Bins, High suppression in Batch tilts





Inappropriate Suppression Inappropriate Suppression CorrectedCorrected

Inappropriate Suppression Inappropriate Suppression CorrectedCorrected

• Bypass Map suppression in Batch tiltsBypass Map suppression in Batch tilts

Range FoldingRange FoldingRange FoldingRange Folding

• Result of multiple trip echoes Result of multiple trip echoes

• For velocity data, high PRFs needed to For velocity data, high PRFs needed to minimize velocity foldingminimize velocity folding– Doppler Dilemma: high PRFs mean short RDoppler Dilemma: high PRFs mean short Rmaxmax

• Purple typically used to denote velocity data Purple typically used to denote velocity data unavailable due to range foldingunavailable due to range folding

Range FoldingRange FoldingRange FoldingRange Folding

Range FoldingRange FoldingWarning Forecaster’s NightmareWarning Forecaster’s Nightmare




Range FoldingRange FoldingOperator InterventionOperator Intervention

Range FoldingRange FoldingOperator InterventionOperator Intervention

• Doppler PRFs can be Doppler PRFs can be manually selectedmanually selected– Will shift RWill shift Rmaxmax andand

distribution of purpledistribution of purple

PRF SelectionPRF SelectionPRF SelectionPRF Selection

BWER


PRF #8Rmax ~ 63 nm


PRF #4Rmax ~ 95 nm

Velocity FoldingVelocity FoldingVelocity FoldingVelocity Folding

• WSR-88D uses a Velocity Dealiasing AlgorithmWSR-88D uses a Velocity Dealiasing Algorithm– Sometimes velocities are improperly dealiased Sometimes velocities are improperly dealiased

Improperly Dealiased VelocitiesImproperly Dealiased VelocitiesImproperly Dealiased VelocitiesImproperly Dealiased Velocities

• Most likely on “leading” edge of stormsMost likely on “leading” edge of storms


• Most likely on “leading” edge of stormsMost likely on “leading” edge of storms


• Next higher elevationNext higher elevation


• Next volume scanNext volume scan

Improperly Dealiased VelocitiesImproperly Dealiased VelocitiesOperator InterventionOperator Intervention

Improperly Dealiased VelocitiesImproperly Dealiased VelocitiesOperator InterventionOperator Intervention

• Environmental Winds Environmental Winds TableTable

Non-Meteorological ReturnsNon-Meteorological ReturnsNon-Meteorological ReturnsNon-Meteorological Returns

• ChaffChaff

• Dust StormDust Storm

• SunspikesSunspikes

• InterferenceInterference

• Biological TargetsBiological Targets

ChaffChaffChaffChaff

• Lightweight, highly reflective targetsLightweight, highly reflective targets

Dust StormDust StormDust StormDust Storm

• West Texas: 2 fatalitiesWest Texas: 2 fatalities

SunspikesSunspikesSunspikesSunspikes

• Sun is CW Sun is CW emitteremitter

• Contiguous Contiguous returns along returns along radials at radials at sunrise and sunrise and sunsetsunset

InterferenceInterferenceInterferenceInterference

• Internet transmitter at Huntington BeachInternet transmitter at Huntington Beach

InterferenceInterferenceInterferenceInterference

• Privately owned ATC radar 2 mi from ILNPrivately owned ATC radar 2 mi from ILN

Biological TargetsBiological TargetsBirds Birds

Biological TargetsBiological TargetsBirds Birds

• Nocturnal migrationNocturnal migration

Data Quality and the NWS Warning Data Quality and the NWS Warning ProcessProcess

Data Quality and the NWS Warning Data Quality and the NWS Warning ProcessProcess

• Anticipation/ExpectationsAnticipation/Expectations• Product selectionProduct selection

– Thousands of choices!Thousands of choices!

• Feature recognitionFeature recognition– Aha! The intuitive responseAha! The intuitive response

• Spotter reports/ground truthSpotter reports/ground truth• Warning generation/disseminationWarning generation/dissemination

– Effective wordingEffective wording

• Non-meteorological factorsNon-meteorological factors– Situation Awareness (SA)Situation Awareness (SA)

Situation Awareness: The Ability to Situation Awareness: The Ability to Maintain the Big PictureMaintain the Big Picture

Situation Awareness: The Ability to Situation Awareness: The Ability to Maintain the Big PictureMaintain the Big Picture

What SA is NotWhat SA is NotWhat SA is NotWhat SA is Not

“Howdy. My name is John. I am 18 years old and live in the USA.

I was born with brown hair, green eyes, and situation awareness.”

SA is not an inherent ability. It is acquired for different domains, such as driving a car

Situation AwarenessSituation AwarenessLevel 1Level 1


• Perception of the elements in the environment of the elements in the environment within a volume of space within a volume of space

Is this what your decision is based on?

Or did you see this as well?

Same time…different radar



• Comprehension of their meaning of their meaning

Did you see this?

Perceive

Hook echo with 65 dBZ in the hook debris

Now that you’ve seen this, do you understand what this is?



• Projection of their status in the near futureof their status in the near future

Did you see this?

Perceive

Do you understand what this is?

(Hook echo with 65 dBZ in the hook: debris)

Comprehend

Now do you realize what is likely to happen? And what you should do?

Project

…Tornado Emergency for the OKC Metro……...

SA and WorkloadSA and WorkloadSA and WorkloadSA and Workload

• Low SA, low workloadLow SA, low workload– Don’t know anything, don’t want to knowDon’t know anything, don’t want to know

• Low SA, high workloadLow SA, high workload– Don’t know anything, but am tryingDon’t know anything, but am trying

way too hard to find outway too hard to find out

• High SA, high workloadHigh SA, high workload– Do know plenty, but at great effortDo know plenty, but at great effort

(can’t keep this up for long!)(can’t keep this up for long!)

• High SA, low workloadHigh SA, low workload– Do know, and it comes steadilyDo know, and it comes steadily

– If you are not operating here….If you are not operating here….find out why and fix it!find out why and fix it!

SA Demons: Workload, Anxiety, SA Demons: Workload, Anxiety, Fatigue, and Other StressorsFatigue, and Other Stressors

SA Demons: Workload, Anxiety, SA Demons: Workload, Anxiety, Fatigue, and Other StressorsFatigue, and Other Stressors

• Stress and anxiety are Stress and anxiety are likelylikely issues in the issues in the warning environmentwarning environment– Lives are at stake (sometimes office Lives are at stake (sometimes office

staff and/or family members)staff and/or family members)– Shift work and chaotic environmentShift work and chaotic environment– Humans often misjudge their own Humans often misjudge their own

ability to cope ability to cope

• WAFOS taxes attention and working WAFOS taxes attention and working memorymemory

Level 1 Failures: Poor Data Level 1 Failures: Poor Data QualityQuality

Level 1 Failures: Poor Data Level 1 Failures: Poor Data QualityQuality

• Most relevant data not available or obscuredMost relevant data not available or obscured– Radar sampling issues; PRF change?Radar sampling issues; PRF change?– Spotter reports?Spotter reports?

RDA

RDA

RDA

RDA

Level 2 Failures: What May Level 2 Failures: What May Prevent Comprehending DataPrevent Comprehending Data

Level 2 Failures: What May Level 2 Failures: What May Prevent Comprehending DataPrevent Comprehending Data

• Storm from radar A with veryStorm from radar A with veryhigh dBZs: hail suspected high dBZs: hail suspected as a threatas a threat

3 body scatter spike, which indicates very large hail

• Storm from radar B: do you Storm from radar B: do you know what the appendageknow what the appendagemeans?means?

Level 3 Failures: What May Level 3 Failures: What May Prevent Correctly Projecting DataPrevent Correctly Projecting Data

Level 3 Failures: What May Level 3 Failures: What May Prevent Correctly Projecting DataPrevent Correctly Projecting Data• Limited understanding of conceptual modelLimited understanding of conceptual model• Inability to assimilate strengths and limitationsInability to assimilate strengths and limitations

– Data sampling limitations may result in incorrect or Data sampling limitations may result in incorrect or ambiguous expected storm behaviorambiguous expected storm behavior

– Radar data conflicts with expectations from storm environment Radar data conflicts with expectations from storm environment

• Limited experienceLimited experience– Knowledge of local areaKnowledge of local area– Population centers, outdoor eventsPopulation centers, outdoor events

• Distractions, workloadDistractions, workload

Emergency Managers (EMs) and Emergency Managers (EMs) and Data Quality IssuesData Quality Issues

Emergency Managers (EMs) and Emergency Managers (EMs) and Data Quality IssuesData Quality Issues

• Modern EMs utilize radar as one of their toolsModern EMs utilize radar as one of their tools– Training?Training?

• Types of decisions EMs make: Types of decisions EMs make: – Positioning spottersPositioning spotters– Close roads/bridges preemptively for floodingClose roads/bridges preemptively for flooding– Monitor conditions for safety of spotters, Monitor conditions for safety of spotters,

responders, etc. responders, etc. – Making decisions of how best to alert the public of Making decisions of how best to alert the public of

severe weather (outdoor sirens, police sirens, severe weather (outdoor sirens, police sirens, cable TV override, etc.)cable TV override, etc.)

Data Quality Issues for EMs Data Quality Issues for EMs Data Quality Issues for EMs Data Quality Issues for EMs

• AP can lead to:AP can lead to:– misdirection of spottersmisdirection of spotters– spurious rainfall accumulationsspurious rainfall accumulations– no reset of storm-total rainfallno reset of storm-total rainfall

• Velocity Dealiasing/Range Folding:Velocity Dealiasing/Range Folding:– obscure significant featuresobscure significant features– misdirection of spotters due to false signaturesmisdirection of spotters due to false signatures

Rainfall Products are used by EMsRainfall Products are used by EMs

Severe AP problems: spurious 3+” rainfall total!

Rainfall Products are used by EMsRainfall Products are used by EMs

Problem could have been much worse!

AP from nearby research radar

What Might an Untrained EM think?What Might an Untrained EM think?

“Man, that’s the biggest circulation I ever saw!!!”

The Real Problem for the EMThe Real Problem for the EM

Velocity dealiasing failure masks real circulation difficult to direct spotters.

Supercell Masked at TimesSupercell Masked at Times

Velocity Dealiasing Failures and Range Folding

Other Data Quality Issues for EMs Other Data Quality Issues for EMs Other Data Quality Issues for EMs Other Data Quality Issues for EMs

• Emergency managers often use algorithm Emergency managers often use algorithm output output – Mesos, TVS, Hail sizeMesos, TVS, Hail size

• Any data quality issue that affects the Any data quality issue that affects the performance of Mesocyclone, TDA, SCIT, performance of Mesocyclone, TDA, SCIT, Hail, or Rainfall algorithms may impact EM Hail, or Rainfall algorithms may impact EM operationsoperations– Impact dependent on training of EMImpact dependent on training of EM

Questions?Questions?Questions?Questions?

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