Improving Weather Forecast Office Performance in the Polygon Warning Era

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Improving Weather Forecast Office Performance in
the Polygon Warning Era

• Ken Cook SOO ICT
• NOAA/National Weather Service Office
• 2142 South Tyler Road
• Wichita, KS 67209
• Phone [phone] Fax [phone]
• Email kenneth.cook_at_noaa.gov

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Outline

• Polygon (Storm Based) Warnings FY08
• Identify Challenges Ahead
• Demonstrate Training and Review Program (TARP) at
  WFO Wichita
• Software/Other Deficiencies
• Mitigations Developed from the TARP
• Results
• Recommendations/Conclusions

Ken Cook SOO NWS Wichita, KS (ICT)
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Polygon-Based Tornado Warnings Improve
ServiceArea Warned is Appropriately Reduced
In the current system, four full counties are
warned. Polygon-Based Tornado Warnings provide
much improved service.
Source Eli Jacks, National Program Management
Committee
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Challenges

• Probability of Detection (POD) for Tornadoes
  15-20 percentage points less Nationwide (Polygons
  vs. Counties)
• Local POD of Severe Weather Events (1 Hail)
  about 15 points less
• No Comprehensive Training Plan available yet for
  implementation

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Challenges

• Lead Time Will Be Lost
• Old 3 separate warnings
• New One warning

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24 April 2006
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24 April 2006
3 Hail
City of Wichita
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24 April 2006

• 80-100 Million Dollars in Damage In Sedgwick
  County
• County-Based Paradigm, Warnings Verified
• Polygon-Based Paradigm, Largest Hail Not Warned
  (Bulk of the Damage Area)

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Challenges

• Local (ICT) POD of Severe Weather Events (1
  Hail)
• January through April 15 Points Less
• May through August Nearly Equal
• What changed?

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Training and Review Program

• A Training and Review Program Created
• Identified shortfalls
• Developed methods of improvement
• Software Used
• ArcGIS 9
• Paint Shop Pro 9
• Microsoft Access
• Presentation Software
• Datasets Used
• Storm Reports - Storm Prediction Centers (SPC)
  web site
• Warning Polygon Shapefiles - Iowa State Mesonet
  web site

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Training and Review Program

• Findings
• Reports that fell outside the warning polygon
  were the result of
• Boxology of warning (gt90)
• Majority were gaps between warning polygons
• Software limitations

Lets Look at a Sample Review
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(No Transcript)
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Software Limitations

• LSR Program
• Resolution not high enough
• WarnGen
• Cannot incorporate detail of CWA boundaries
• Suggest working out a local agreement with local
  media and adjacent WFOs
• Right clicking county to include in warning
  results in portions being excluded!!
• Rounding of Warning Lat/Lon
• Outdated/Poor Shapefile Resolution/Mapping
• EAS/NWR/etc
• Not using GPS

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Software Limitations

• LSR Program
• Distance and direction resolution was too coarse
• Result wind report fell out of the polygon
• Persons should examine these and make corrections
  as needed

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Software Limitations

• Poor Shapefile Resolution Lat/Lon Rounding
• WarnGen polygon coordinates when applied to the
  map background will appear slightly different

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Software Limitations

• EAS/NWR
• Is this area warned or not?
• Polygon - Yes
• County - No
• Even though we are shifting paradigms, public
  safety must be highest priority
• Re-issue warning

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Mitigations

• Always be thinking ahead to the next box (1st box
  very critical).
• Don't be too cute, leave yourself plenty of room.
  
• Avoid right clicking to include an entire county.
• Zoom and edit vertices appropriately.
• Zoom to examine new warnings in relation to the
  ones currently in effect to avoid gaps (it is a
  must to have local warnings overlay loaded w/
  warngen).
• Slightly overlap polygons. This will eliminate
  gaps and any problems associated with mapping and
  lat/lon rounding.
• For Bow echoes, polygons that replicate the
  outline of the linear convection are best, as is
  carpet bombing for the large area of
  convection.
• When writing SVSs, in regards to readjusting a
  polygon for an SVS Only readjust the polygon
  when a polygon includes more than one county and
  you wish to cancel one or more counties in the
  warned polygon.

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Mitigations

• Always be thinking ahead to the next box (1st box
  very critical).
• Leave yourself plenty of room.
• Avoid right clicking to include an entire county.
• Zoom and edit vertices appropriately.
• Avoid gaps between polygons Zoom!!!
• It is a must to have local warnings overlay
  loaded w/ warngen).

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Mitigations

• Slightly overlap polygons.
• For Bow echoes, replicate linear convection.
• Only adjust SVS Polygon when canceling portion of
  county.

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Results

• Polygonology has seen remarkable improvement at
  WFO ICT
• POD between the 2 paradigms within a few points
• FAR remains 10 percentage points lower for
  Polygons

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Recommendations/Conclusions

• Developing a local training and review program
  will improve
• Transition to Polygon Warnings
• Warning Meteorology and Service
• Metrics (GPRA Goals)
• Utilize Mitigations
• Instructions for the ICT TARP are available upon
  request or on WFO ICTs Science and Training Page
  at http//204.194.227.45/soo/Training/Polygonolog
  y/Polygonology-TARP.htm
• Change is certain, be prepared!!!

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Recommendations/Conclusions

• Developing a local training and review program
  will improve
• Transition to Polygon Warnings
• Warning Meteorology and Service
• Metrics (GPRA Goals)
• Utilize Mitigations to improve polygon warnings
• Instructions for the ICT TARP are available upon
  request or on WFO ICTs Science and Training Page
  at http//204.194.227.45/soo/Training/Polygonolog
  y/Polygonology-TARP.htm
• Change is certain, be prepared!!!
• Thank you Questions?

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Resources

• Cook, Kenneth (SOO ICT), 2006 WFO Wichita
  Science and Training Intranet Page
  (http//204.194.227.45/soo/soopage.htm)
• Training Materials Also Available
• Herzmann, Daryl, 2006 Iowa State University
  (http//mesonet.agron.iastate.edu/current
• National Program Management Committee
• SPC Storm Reports (http//www.spc.noaa.gov/climo/r
  eports)
• PANDA (http//panda.crh.noaa.gov)