The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

1. introduction

2. products of the DWD radar network

3. tornado detection by automatic algorithms

4. GuST - an automatic guidance prototype

5. the future of nowcasting severe weather

0

OVERVIEW

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

today, Doppler radar is by far the most efficient andhighest resolution data source for thunderstorm andtornado nowcasting

1

INTRODUCTION

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

today, Doppler radar is by far the most efficient andhighest resolution data source for thunderstorm andtornado nowcasting

1

INTRODUCTION

comparison radar -> satellite

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

today, Doppler radar is by far the most efficient andhighest resolution data source for thunderstorm andtornado nowcasting

1

INTRODUCTION

comparison radar -> satellite

+ better resolution (in time and space)

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

today, Doppler radar is by far the most efficient andhighest resolution data source for thunderstorm andtornado nowcasting

1

INTRODUCTION

comparison radar -> satellite

+ better resolution (in time and space)+ more information about storm structures

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

today, Doppler radar is by far the most efficient andhighest resolution data source for thunderstorm andtornado nowcasting

1

INTRODUCTION

comparison radar -> satellite

+ better resolution (in time and space)+ more information about storm structures

comparison radar -> conventional ground observations

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

today, Doppler radar is by far the most efficient andhighest resolution data source for thunderstorm andtornado nowcasting

1

INTRODUCTION

comparison radar -> satellite

+ better resolution (in time and space)+ more information about storm structures

comparison radar -> conventional ground observations

+ better coverage (in time and space)

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

today, Doppler radar is by far the most efficient andhighest resolution data source for thunderstorm andtornado nowcasting

1

INTRODUCTION

comparison radar -> satellite

+ better resolution (in time and space)+ more information about storm structures

comparison radar -> conventional ground observations

+ better coverage (in time and space)- less information about storm threads

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

today, Doppler radar is by far the most efficient andhighest resolution data source for thunderstorm andtornado nowcasting

1

INTRODUCTION

IT IS (ALMOST) NOT POSSIBLE TO SEE A TORNADODIRECTLY IN CONVENTIONAL DOPPLER RADAR DATA!

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

the DWD Doppler radar network

-> 16 stations

-> full coverage withina 125 km radius

-> all of them havedoppler functionality

-> resolution up to 1 kmand 5 minutes

2

PRODUCTS

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

reflectivity composite

June 23rd 20051645 UTC

2

PRODUCTS

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

standard products

• low-res reflectivity (~250 km radius ,6 classes)

2

PRODUCTS

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

standard products

• low-res reflectivity (~250 km radius ,6 reflect. classes)

2

PRODUCTS

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

standard products

• low-res reflectivity (~250 km radius ,6 classes)

• high-res reflectivity (~125 km radius, 16 classes)- characteristic cell structures- hook echoes

2

PRODUCTS

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

radar signatures in tornadic environments

• high-res reflectivity- hook echo

2

PRODUCTS

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

radar signatures in tornadic environments

• high-res reflectivity- hook echo

2

PRODUCTS

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

standard products

• low-res reflectivity (~250 km radius ,6 classes)

• high-res reflectivity (~125 km radius, 16 classes)- characteristic cell structures- hook echoes

• high-res Doppler velocity (~125 km radius)- mesocyclones, TVS- bow echoes

2

PRODUCTS

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

radar signatures in tornadic environments

• Doppler velocity mesocyclone

2

PRODUCTS

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

radar signatures in tornadic environments

• Doppler velocity mesocyclone

2

PRODUCTS

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

radar signatures in tornadic environments

• Doppler velocity bow echo

2

PRODUCTS

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Automatic detection and nowcasting of radar signatures

• goals

- maximizing POD while minimizing FAR

- minimizing RMSE of the output

3

DETECTION

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Automatic detection and nowcasting of radar signatures

• predefined set of rules and thresholds- thresholds/assumptions may be suboptimal/incorrect

3

DETECTION

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Automatic detection and nowcasting of radar signatures

• predefined set of rules and thresholds- thresholds/assumptions may be suboptimal/incorrect

• discriminant analysis- assumption: distributions are Gaussian

3

DETECTION

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Automatic detection and nowcasting of radar signatures

• predefined set of rules and thresholds- thresholds/assumptions may be suboptimal/incorrect

• discriminant analysis- assumption: distributions are Gaussian

• multiple linear regression- assumption: relations are linear+ physical understandable and configurable transformations of predictors

3

DETECTION

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Automatic detection and nowcasting of radar signatures

• predefined set of rules and thresholds- thresholds/assumptions may be suboptimal/incorrect

• discriminant analysis- assumption: distributions are Gaussian

• multiple linear regression- assumption: relations are linear+ physical understandable and configurable transformations of predictors

• polynomial regression- assumption: relations are polynomial

3

DETECTION

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Automatic detection and nowcasting of radar signatures

• predefined set of rules and thresholds- thresholds/assumptions may be suboptimal/incorrect

• discriminant analysis- assumption: distributions are Gaussian

• multiple linear regression- assumption: relations are linear+ physical understandable and configurable transformations of predictors

• polynomial regression- assumption: relations are polynomial

• neural networks+ detects patterns out of “noisy” data- qualitative physical understanding is difficult

3

DETECTION

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• intentions:

- integrating as much data sources as possible

4

GUIDANCE

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• intentions:

- integrating as much data sources as possible

- calculation of forecasts by MLR approach

4

GUIDANCE

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• intentions:

- integrating as much data sources as possible

- calculation of forecasts by MLR approach

- providing guidance information about current cells

4

GUIDANCE

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• intentions:

- integrating as much data sources as possible

- calculation of forecasts by MLR approach

- providing guidance information about current cells

- creating unique warnings and advisories for all counties and locations

4

GUIDANCE

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• system structure

4

GUIDANCE

OBSRAD/LIGHT NWPDET

pd

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• predictands:

- cell forecast motion vectors up to 2 hours

- hail size

- precipitation amount

- wind gusts

- lightning frequency

- possibility of rotation/tornado embedded in the storm

4

GUIDANCE

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• system structure

4

GUIDANCE

OBSRAD/LIGHT NWPDET

pd

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• input:- radar and lightning data- CONRAD cell detection- CONRAD hail categories, shear detection- NWP data (GME)- spotter network observations

4

GUIDANCE

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• input:- radar and lightning data- CONRAD cell detection- CONRAD hail categories, shear detection- NWP data (GME)- spotter network observations

• derived predictors:- up to 10 past motion vectors- hail size- rain rate, wind gusts- lightning frequency- fields of numerical model- some others

4

GUIDANCE

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• system structure

4

GUIDANCE

OBSRAD/LIGHT NWPDET

pd

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• system structure

4

GUIDANCE

OBSRAD/LIGHT NWPDET

pd MLR cof

(HIST)

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• system structure

4

GUIDANCE

OBSRAD/LIGHT NWPDET

pd MLR cof OPER fc

(OPER)(HIST)

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• system structure

4

GUIDANCE

OBSRAD/LIGHT NWPDET

pd MLR cof OPER fc

POST-PROC

Products,Displays,Warnings

(OPER)(HIST)

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance System for Severe Thunderstorms - a prototype

• output:

- guidance text for every current (detected) cell

- unique warning texts for more than 80.000 counties and locations including predictands and arrival times

- graphical displays

4

GUIDANCE

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance Systemfor SevereThunderstorms

guidance displayof the tornadicthunderstormproducing theMichelnF3-tornado

4

GUIDANCE

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Guidance Systemfor SevereThunderstorms

guidance displayof the tornadicthunderstormproducing theMichelnF3-tornado

4

GUIDANCE

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

4

GUIDANCE

*******************************************************************************SEVERE THUNDERSTORM CELL INFORMATIONISSUED at 16.45 UTC 23.06.2004ID 200406231645 14 51.8567 11.8965NEAREST RADAR STATION umd*******************************************************************************

VALID immediately

A severe thunderstorm has been detected in countyKöthen...

...near Rajoch or about 11 km W of Aken or about 24 km W of Dessau...moving to the NE with 30 km/h

This severe thunderstorm is capable of producing...HEAVY PRECIPITATION OF ABOUT 30 L/QM WITHIN SHORT TIME...LARGE HAIL OF ABOUT 3 CM IN DIAMETER...STRONG GUSTS OF ABOUT 100 KM/H...SIGNIFICANT LIGHTNING

***STRONG ROTATION IS OBSERVED WITH THIS STORM***

The following counties may be affected with this storm within two hours:Schönebeck at 17.10 UTC with PROB 75Jerichower Land at 16.45 UTC with PROB 95Anhalt-Zerbst at 17.10 UTC with PROB 50

And the following locations may be affected within one hour:Barby at 17.00 UTC with PROB 85Zerbst at 17.10 UTC with PROB 60Genthin at 18.25 UTC with PROB 60*******************************************************************************

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

The future of radar nowcasting tornadoes in Germany

• further improvement of the radar network andthe related products

- 5-minute update cycle- 1km resolution or using polar coordinates

5

FUTURE

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

The future of radar nowcasting tornadoes in Germany

• further improvement of the radar network andthe related products

- 5-minute update cycle- 1km resolution or using polar coordinates

• using automatic algorithms for tornado detectionand tracking as guidance

- NinJo, CONRAD, GuST

5

FUTURE

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

The future of radar nowcasting tornadoes in Germany

• further improvement of the radar network andthe related products

- 5-minute update cycle- 1km resolution or using polar coordinates

• using automatic algorithms for tornado detectionand tracking as guidance

- NinJo, CONRAD

• integration of spotter network data andstorm chaser sightings in those guidancesystems

5

FUTURE

The use of Doppler radar products for nowcasting tornadoesDWD workshop on tornado forecasting, February 24th 2005, Langen

Thank you very much for your attention!

5

FUTURE