CLIQR Rainfall analog

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CLIQR Rainfall analog
David Roth Kyle Griffin NOAA Hydrometeorological
Prediction Center Camp Springs, MD
Last Updated June 4, 2009
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HPC role in the NWS tropical cyclone program

• Backup center for NHC advisories in the event NHC
  cannot issue their products
• Provider of rainfall statements for any landmass
  bordering the Atlantic and eastern Pacific
  basins. Over the US, this is augmented by
  graphical QPF
• Writes inland advisories for tropical cyclones
  which have been downgraded to tropical depression
  status, outside of Florida
• GS 13 and 14 forecasters keep current on ATCF
  software used by NHC by going through a practice
  exercise each May

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HPC role in the NWS tropical cyclone program

• HPC conducts one or two scheduled backup days for
  NHC each season, normally involving systems far
  from land
• HPC backups up eastern Pacific tropical weather
  outlooks the first Tuesday of each month during
  the hurricane season
• Collaborate during the medium range period for
  systems which have yet to form, or on days 6-7
  for active tropical cyclones each day at 1600
  UTC. Have the authority to change what was
  coordinated overnight, if the NHC track differs
  significantly from their track from 1600 UTC the
  previous day.
• Create storm total rainfall graphics for tropical
  cyclones which have moved inland into the United
  States and dissipated

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Characteristics of TC precipitation

• Stratiform and Convective mechanisms
• Stratiform rain 50 of total rain from TC.

WSR-88D DPA daily accumulations
Hurricane Irene (15 October 1999)
Frank Marks (HRD)
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United StatesUnits in cm

• 2005 US Summer rain

2005 US TC rain
Frank Marks (HRD)
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Picking an analog for a TC event

• Size is importantlook at the current rain shield
  and compare it to storm totals/storms from the
  past
• How fast is it moving?
• Vertical wind shear in current/past events?
• Look for storms with similar/parallel tracks
• Is topography/prism data a consideration?
• Look for nearby fronts/depth of nearby upper
  troughs for current and possible analogs
• Not all TC events will have a useful analog

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Storm Size
Determined by distance from center to outermost
closed isobar
lt2 degrees Very small/ midget Charley
2-3 degrees Small Allison
3-6 degrees Average Frances
6-8 degrees Large Wilma
gt8 degrees Very large Gilbert
Joint Typhoon Warning Center
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How Mountains Affect the Precipitation
Distribution
http//www.prism.oregonstate.edu/index.phtml
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Size and Topography
Hurricane Frances (2004)
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CLIQR

• Scripts utilize extended best track database from
  NHC, modified by additional information from
  HPC/NHC map series and NHC Atlantic
  non-developing system database
• Storm matches made primarily upon current
  position, forward motion, and storm size. In
  2009, plans are to try to include NHC five day
  track
• Uses a 9 point system. The systems point total
  can be seen in the last column of text output
• Output generated using CHGHUR/objective guidance
  messages from NHC, but can also be utilized using
  manual input
• Simplified output online for active systems at
  http//www.hpc.ncep.noaa.gov/tropical/rain/web/cli
  qr.html
• Utiltizes storm total rainfall graphics created
  in-house and available on our website at
  http//www.hpc.ncep.noaa.gov/tropical/rain/tcrainf
  all.html

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CLIQR GUI using manual input
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CLIQR output via magenta View Rainfall Graphics
button
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CLIQR web output for active systems

• http//www.hpc.ncep.noaa.gov/tropical/rain/web/cli
  qr.html

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CLIQR matching storm list (Rainfall Matches
hyperlink)

• Simplified list links to relevant storm total
  rainfall graphic through hyperlink. Future
  revisions include columns separating the Puerto
  Rico impacts from North American impacts to help
  web user.

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Model Forecast Biases/Verification relating to
Tropical Cyclone QPF
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Pattern comparisons for U.S. landfalling
stormsFrom Rogers, Black, Marchok, 2005 IHC
Equitable Threat Score
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Day 1 Threat Scores and Bias
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Day 2 Threat Score/Bias
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Day 3 Threat Score/Bias
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Summary

• Tropical cyclone QPF pattern depends on storm
  size, forecast track, vertical wind shear,
  topography, depth of upper trough causing
  recurvature, and SST field the cyclone moves over
  prior to landfall
• While climatology is important to keep in mind,
  TC QPF is heavily based on the guidance which has
  the best verification and is closest to expected
  TC track (usually GFS). NAM and ECMWF both show
  low biases for higher rainfall amounts.