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The Use of GPM/IMERG atThe Weather Company

Todd HutchinsonDirector of Numerical Weather Prediction

Global Forecasting ServicesThe Weather Company

The Weather CompanyThe Weather Company is one of the world’s largest private weather companies. We provide services to a large number of consumers and broad spectrum businesses

•Direct Consumer PortalsThe Weather ChannelWeather.comWeather Underground

•Indirect Consumer PortalsAppleYahoo!GoogleMajority of US local TV broadcasters

•B2B servicesAviation: 55,000 flights a day, 85% in US.Energy: Forecasts and analytics to Energy TradersInsurance and Reinsurance: Broad suite of weather svcs

•Services to Governments and Agencies

Forecasting at The Weather Company• We create our own global forecasts.

• We collect data from governments and partners to fuel our forecast generation• Standard WMO data• NWP data from global centers• Remotely sensed data (Radar, Satellite,

profilers, etc)• Short-fuse government warnings

• We augment the acquired data with our own proprietary content (global lightning, mesonets, A/C data).

• We run our own NWP models (WRF-ARW, with 3D Var/Warm Cloud initialization) and climate models (CSM).

• Humans can influence or augment the forecasts through an efficient editing environment.

• We package the end result in useful and compelling ways.

Broad Input DataWe acquire weather and

forecast data from governments and

partners around the globe

Proprietary DataWe have our own sources

for additional weather data, and we run our own

NWP models

Forecast EnginesWe have invested heavily

in market specific analytical and statistical

forecasting processes

Human TouchHumans can improve,

augment and enrich the forecasts

Useful ProductsWe contain our forecasts

in compelling ways in market specific products

General Use of Satellite Data at TWC

In general, satellite data drives TWC content in the following expected ways:

• Forecasting Situational Awareness: Location and evolution of important weather features, primarily using geostationary data.

• Through Indirect Forecasting Applications: Assimilation of satellite imagery and derived products into NWP in our own models; Use of satellite-initialized models from government centers; Use in automated nowcasting systems.

• “Story Telling”: Satellite imagery and derived products as a direct method to convey weather and forecasting stories and their impacts.

But, Use of POES data is increasing

• Mapping the Global state of precipitationo We want to tell users what the weather is

“now”:o “Outside, the temperature is currently 75 degrees with

light rain falling”o And, if precipitation is imminent (nowcasting)o Requires melding of POES, GOES, NWP (and

other) data sources

• Graphical animations of global precipitationo Provides unique content (oceans, international)o Compelling global precipitation graphics

• Numerical weather prediction initializationo Currently, TWC incorporates POES through

analyses from National NWP centerso By assimilating POES data directly, we can

o Reduce forecast latencyo Incorporate the latest science from state-of-the-art data

assimilation systems

Recent Analysis of GPM/IMERG: Stats

• How well does distribution of GPM/IMERG precipitation match radar (“truth”)?o Analyzed GPM/IMERG data valid at 06 and 18 UTC between 12 March and 30

June 2014o Converted GPM precipitation rate to reflectivity (dBz) using Marshall-Palmer (Z = 200 * R ^ 1.6)o Binned number of GPM “reflectivity” values depicted at each observing site (~1000 CONUS sites)

o Similarly, analyzed WSI/TWC NOWRad Mosaic:o Binned reflectivity obs depicted at same observing sites

X 10

0

X 10

0X

100

TWC NOWRad IMERG

Same counts of “no precip” = same count of all precip

IMERG too much heavy precip – Z-R might explain

a few dBz

IMERG too little light precip

GPM/IMERG Analysis1. Nice representation

of overall precipitation field

2. Correspondence of Kalman Weights to snow/cold areas

3. Some areas of lighter precipitation well depicted

4. Some areas of lighter precip not well depicted

5. Some discontinuities in GPM

100% GEO

100% GPM

1”

0

GPM/IMERG Final – 27 Nov. 2014

Kalman Weights Precip Accum.

NOWrad (“truth”)12 UTC June 5 2015

Compare “Early” to NOWrad12 UTC 5 June 2015

Compare “Late” to NOWrad12 UTC 5 June 2015

Current usage at TWC and Wish List for future

• GPM will offer many new products that enhance the usability of the products for TWC use:– Better global near real-time precipitation analysis– Better data assimilated within models– Potential particle discrimination / volcanic ash (?)

• Broader use at TWC is occurring with these recent enhancements:– Regular Real-time internet data streams of

GPM/IMERG– Self-service portal to “research quality” data analysis

and product/graphical generation.– Relationships with GPM core science organizations

for better “use of opportunity”.– Availability of “Early” run

• Even Broader use at TWC would occur with:– High-availability data streams – Reduced latency for “Early” run to < 4 hrs– More MW coverage and smoother transition to IR

coverage– Smoother transition from MW to IR– Improved depiction of light precip in GPM/IMERG