Global Weather Services in 2025-Progress toward the Vision Richard A. Anthes University Corporation for Atmospheric Research October 1, 2002 GOES User’s Conference II Boulder, CO

Global Weather Services in 2025 Richard A. Anthes January 1999 Available on CD from UCAR

GWS2025-Summary By 2025 the data problem for weather prediction will be solved. Observational errors as we know them today will have been eliminated. Global weather prediction models with 1 km horizontal resolution will have reached the theoretical limits of predictability theory.

GWS2025-Summary Numerical predictions in the 0-2 day time frame will be essentially perfect. One week forecasts will be as accurate as 2-3 day forecasts are today. Weather information will be hundreds of times more useful to society than today and at less cost per person.

Depiction of Weather Data n Smart analysis software will combine data from different observing systems to provide a composite view of the atmosphere’s cloud, precipitation and water vapor structure from a three-dimensional perspective.

Time-Weather Travel n Weather and climate data, past, present and future, at any place on Earth and at any time, will be presented to the customer as if he/she were at that place and time and viewing the weather personally.

Global Mesoscale Models

Ensemble Forecasts n Every six hours these forecasts will be shared and grouped to form an ensemble of 200 forecasts.

Three Keys to Progress n Increased computer power –Horizontal resolution –Ensemble forecasting –Data assimilation –Computational algorithms n Improved observations –Better use of existing observations –New observations –Combination of independent observations n Improved understanding –For better physical parameterizations

Operational & Research Satellites in a variety of orbits An evolving in-situ and space based global observing system

GPS Ground BasedSpace Based (Radio Occultation)

GPS Observations n Space based (radio occultation) –Completely independent atmospheric sounder –High accuracy and vertical resolution (~300 m) demonstrated (GPS/MET, CHAMP, SAC-C) –Strong complement to GOES and POES sounders –COSMIC (2005) to provide 3000 soundings per day n Ground based –Precipitable water –Slant-path water

Hualien Ishigakijima CHAMP 2000 UTC July 29, 2001 CHAMP RO Sounding through Typhoon Toraji (2001)

CHAMP RO sounding 2008 UTC, July 29, 2001 Ishigakijima radiosonde 1800 July 29 and 0000 UTC July 30

SAC-C RO Sounding Indian Monsoon Depression 23.3N 82.8E 0604 UTC 8/8/01 Radiosonde 1200 UTC 8/8/01

Hemispheric Forecast Skill at 90%, 85%, 80%, 75%, 70%, 65%, 60% The curves are parallel: above a certain size, errors amplify at ~constant rate To improve medium range: Extend the “small-error phase” as far as possible.

NWS Early 2002 Flash Flood Warnings Tornado Warnings Severe Thunderstorm Warnings Hurricane Path Improvement No Flash Flood data prior to 1987

Hurricane Herb (1996)

Comparison between 2 km and 60 km model topography

Prediction of Herb by MM mm 399 mm 2.2 km60 km

MM5 Prediction of Herb 2.2 km

The Vision is On Track! n Progress continues based on increased computational power, observations and understanding n Sat and ground obs systems advancing –By 2005, 4 gigabytes of satellite data to operational centers each day. –National mesonet developing –Everything, everywhere, all the time! n Weather Research and Forecast Model

But much more needs to be done! n Integration/assimilation of independent observing systems to produce 4-D, gridded, digital analyses on a global basis n More and more (and more) computer power n Research to improve understanding and models n Improved research to operations transition pathways n Education and Training

Thank You!