Transcript Forecasting process, issues and the future

Forecasting process, issues and
the public
Joe Koval
Senior Software Developer
The Weather Channel, Atlanta, GA
DICast - Dynamic, Integrated
ForeCAST System
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System that generates forecasts for userdefined sites and times using a host of
meteorological data and variety of forecasting
techniques
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Initially developed by NCAR/WITI
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Significant enhancements by WSI
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Further development at TWC
DICast Detail-what happens when DICast
runs
Integrator
00Z NAM-WRF DMOS
12Z NAM-WRF DMOS
00Z GFS/AVN DMOS
12Z GFS/AVN DMOS
Data
Ingest
00Z GFS/MRF DMOS
12Z GFS/MRF DMOS
Spatial Interpolation
00Z ECMWF DMOS
12Z ECMWF DMOS
Local Day Max/Min
00Z NGM MOS
12Z NGM MOS
Final QC
00/12Z MAV MOS
06/18Z MAV MOS
Units Conversion
00Z MEX MOS
00Z ETA MOS
12Z ETA MOS
To Digit
Climatology
Climo Editor
Station List Manager
Integration Editor
Web Viewer
System Monitor
Who are our customers?
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All Business to Consumer
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Cable subscribers
Online – weather.com
Mobile devices
Portals, etc – Yahoo, Google Earth, others
USA Today
Factors that affect our forecast
process
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Our forecast intervention focus is on high
impact weather
Focus on where the weather matters
most and guidance typically performs
worst
We’ve developed verification and other
tools that help forecasters identify
locations and weather situations where
the guidance is not likely to perform well
Forecast verification is important to TWC
We have a comprehensive, worldwide six
year archive of forecast verification
 Verification serves three purposes
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◦ Ongoing forecast quality assurance
◦ Feedback to human forecasters for training
purposes (ADVISOR product)
◦ R & D – how can we improve our forecasts
through development of new/innovative
verification products?
…but from surveys we know that traditional
verification measures aren’t everything to the public!
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Forecast skill as measured by statistics such as Root
Mean Square Error, Mean Absolute Error, contingency
tables is only one part of how the public measures the
value of a forecast
The other three:
◦ Reliability – is the forecast always available when the
customer expects it?
◦ Low latency – the forecast needs to be available to the
customer almost immediately after it is created…no old
forecasts sitting around!
◦ Consistency – The forecast isn’t flip flopping with each
update
Other societal aspects of forecast
verification
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Near misses don’t “verify” with traditional
verification measures, but can still impact
society
◦ Heavy rain falls in the mountains, but floods
the valley
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Sensible weather verification
◦ Verification that captures very high impact
weather
 How do we perform in weather situations that are
very dangerous to the public – derechos, tornado
outbreaks, blizzards?
Probabilistic forecasting and The
Weather Channel
Like much of the weather forecasting community,
The Weather Channel is exploring ways to
include additional measures of uncertainty in the
forecast
• This is a debated topic at The Weather Channel
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– One view is that time constraints limit the feasibility
of specifically adding probabilistic information to
products on the network broadcast
• On camera meteorologists are already time constrained by
small time slots
• Further, the on-camera meteorologist often already presents
some uncertainty information verbally, so while it is not in the
product, it is added when the product is presented by the on
camera meteorologist
Probabilistic forecasting (continued)
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Another view believes that The Weather
Channel should include additional
information about forecast confidence or
uncertainty
◦ Still recognize the limitations and complexity
of adding uncertainty information to the
forecast
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Maybe the place to begin is with less
time-constrained platforms, like
weather.com??
The End