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Update on NCAR Auto-Nowcaster. Juneau, AK. The Auto-Nowcaster System. An expert system which produces short-term (0-1 hr) forecasts of thunderstorm initiation, growth and decay using fuzzy logic.

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The Auto-Nowcaster System

  • An expert system which produces short-term (0-1 hr) forecasts of thunderstorm initiation, growth and decay using fuzzy logic.

  • Recent developments have allowed human users (i.e. forecasters) to input information into the system in a relatively quick and simple fashion.

  • A test of the updated system in an operational environment is taking place at the Dallas/Fort Worth WFO.


The Auto-Nowcaster System

is unique in its ability to providenowcasts of storm initiationby…..

Detection and extrapolation of surface convergence boundaries ….

….that trigger

thunderstorm initiation and impact storm evolution.


Initiation

nowcasts

extrapolation

nowcasts

Example of Auto-Nowcaster

Initiation Forecast

1 hour forecast

Verification


Flow Chart for the

Auto-Nowcaster System

Forecaster Input

Data Sets

Radar

WSR-88D

Satellite

Mesonet

Profiler

Sounding

Numerical

Model

Lightning

Predictor Fields

Analysis Algorithms

Fuzzy Logic Algorithm

- Membership functions

- weights

- Combined likelihood field

Final Prediction


Flow Chart for the

Auto-Nowcaster System

Forecaster Input

Data Sets

Radar

WSR-88D

Satellite

Mesonet

Profiler

Sounding

Numerical

Model

Lightning

Predictor Fields

Analysis Algorithms

Fuzzy Logic Algorithm

- Membership functions

- weights

- Combined likelihood field

Final Prediction


Membership Function

Yes

Convergence line

Likelihood

.5

.5

Lifting Zone

Likelihood

No

0

Lifting Zone

Example of fuzzy logic

Predictor Field 1


Membership Function

Convergence

.1

Likelihood

.2

.3

.2

Likelihood

.1

Convergence

Predictor Field 2


Predictor Field 3

Membership Function

Cumulus clouds

1

Likelihood

.8

-.5

.4

.4

Likelihood

-.5

-.5

-1

Cumulus cloud type


Weight 1

Weight 2

Weight 3

Likelihood 1

Likelihood 3

Likelihood2

Σ

Final combined

likelihood

of initiation


Predictor Fields used for Combined Likelihood of Initiation

Blue Regions - Little chance of storm development

Green Regions - Moderate likelihood

Red Regions - Areas of forecast initiation

  • Environmental conditions (RUC)

    • Frontal likelihood

    • Layered stability

    • CAPE (max between 900 and 700 mb)

    • Mean 875 to 725 mb Relative Humidity

  • Boundary-layer

    • Convergence

    • LI (based on METARS)

    • Vertical velocity along boundary (maxW)

    • Boundary-relative steering flow

    • New storm development along boundary

  • Clouds

    • Clear or Cumulus

    • Vertical develop as observed by drop in IR temps


60 Minute Initation (rules with satellite data)

Wt: 0.10

Range: 0 to 0.10

Wt: 0.17

Range: -0.085 to 0.17

Wt: 0.20

Range: -0.20 to 0.02

Wt: 0.17

Range: -0.17 to 0.17

Wt: 0.08

Range: -0.02 to 0.08

Wt: 0.16

Range: -0.08 to 0.16


60 Minute Initation (rules with satellite data) Cont.

Wt: 0.20

Range: -0.2 to 0.2

Wt: 0.20

Range: 0 to 0.20

Wt: 0.20

Range: 0 to 0.20

Wt: 0.15

Range: 0 to 0.15

Wt: 0.25

Range: 0 to 0.25


60 Minute Initation (rules with satellite data) Cont.

Boundary Collision:

Wt: 0.12

Range: 0 to 0.12

Sat_Clear:

Wt: 0.40

Range: -0.40 to 0

Lake:

Wt: 0.10

Range: -0.10 to 0

Initiation Levels:

0.70 => Init 1

0.90 => Init 2

1.20 => Init 3


Predictor fields

Cumulus

development

Boundary

characteristics

Satellite Cloud Typing

B-L characteristics

Storm motion and trends

Large-ScaleEnvironment

Predictor Fields


Predictor fields1

Cumulus

development

Boundary

characteristics

Satellite Cloud Typing

B-L characteristics

Storm motion and trends

Large-ScaleEnvironment

Predictor Fields


Why do we need a forecaster in the loop
Why do we need a forecaster in the loop??

  • Forecasters see the larger picture

    • Conceptual Models

    • Ignore bad data points

    • Understand limitations of NWP and observations


Forecaster Entered Boundary

FAA RCWF

Domain

June 12, 2003




Draw Tool

Entering a convergence boundary in real time

is as simple as this demonstration!


Forecaster tools boundary entry
Forecaster-tools: Boundary Entry



Where has the Auto-nowcaster been demonstrated ?

  • Weather Forecast Office Washington DC (Sterling, VA)

  • Sydney Australia Forecast Office

  • U. S. Army White Sands Missile Range

  • Central U. S. for the FAA

Process of being transferred to:

  • Bureau Meteorology Beijing China

  • U.S National Weather Service – Dallas/Fort Worth Weather Forecast Office

  • AWIPS



Auto nowcaster at ft worth wfo 05 april 2005
Auto-Nowcaster at Ft. Worth WFO05 April 2005

On this day, dryline was moving in from the west. Below is an example of one of the Area Weather Updates that they put out on that day:

AREA WEATHER UPDATE

NATIONAL WEATHER SERVICE FORT WORTH TX

310 PM CDT SUN APR 10 2005 >

WARNING DECISION UPDATE FOR NORTH TEXAS

MESOANALYSIS PROGRAMS SHOW 1000-1500 J/KG CAPE ALONG AND JUST AHEAD

OF DRYLINE. THUS...CU/DEVELOPING STORMS ALONG/E OF DRYLINE SHOULD

CONTINUE TO INTENSIFY. STORM INITIATION TOOL ALSO SUGGESTS HIGH

POSSIBILITY OF DEVELOPMENTFARTHER SW...OVER CORYELL/LAMPASAS COUNTY

AREA. DEEP-LAYER SHEAR MORE THAN SUFFICIENT FOR ORGANIZED STORMS AND

AT LEAST MID-LEVEL MESOS. AS STORMS EVOLVE INTO THE EVENING...A MORE

LINEAR MODE IS EXPECTED.


Ft worth wfo 05 april 2005
Ft. Worth WFO 05 April 2005

Forecast: 2003 Z

Radar Image: 2003 Z

Forecast: 2003 Z

Radar Image: 2108 Z


Ft worth wfo 05 april 20051
Ft. Worth WFO 05 April 2005

Forecast: 2044 Z

Radar Image: 2044 Z

Forecast: 2044 Z

Radar Image: 2142 Z



Ft worth wfo 25 april 2005
Ft. Worth WFO 25 April 2005

  • On this day there was a dryline moving in from the west.

  • Storms developed a couple of hours earlier than originally thought.

  • The ANC system captured the initiation of this event with about a 40-50 minute lead time.

  • The storms went severe within 30 minutes of initiation (about 50 miles west of DFW Metroplex) with quarter sized hail, strong winds and several mesocyclones.


Ft worth wfo 25 april 20051
Ft. Worth WFO 25 April 2005

Forecast: 1831 Z

Radar Image: 1831 Z

Forecast: 1831 Z

Radar Image: 1929 Z


Ft worth wfo 25 april 20052
Ft. Worth WFO 25 April 2005

Forecast: 1842 Z

Radar Image: 1842 Z

Forecast: 1842 Z

Radar Image: 1941 Z


Ft worth wfo 25 april 20053
Ft. Worth WFO 25 April 2005

Forecast: 1854 Z

Radar Image: 1854 Z

Forecast: 1854 Z

Radar Image: 1952 Z


Ft worth wfo 25 april 20054
Ft. Worth WFO 25 April 2005

Forecast: 1905 Z

Radar Image: 1905 Z

Forecast: 1905 Z

Radar Image: 2003 Z


Ft worth wfo 25 april 20055
Ft. Worth WFO 25 April 2005

Forecast: 1917 Z

Radar Image: 1917 Z

Forecast: 1917 Z

Radar Image: 2020 Z


Ft worth wfo 25 april 20056
Ft. Worth WFO 25 April 2005

Forecast: 1929 Z

Radar Image: 1934 Z

Forecast: 1929 Z

Radar Image: 2030 Z


Ft worth wfo 25 april 20057
Ft. Worth WFO 25 April 2005

Forecast: 1941 Z

Radar Image: 1940 Z

Forecast: 1941 Z

Radar Image: 2042 Z


Ft worth wfo 25 april 20058
Ft. Worth WFO 25 April 2005

Forecast: 1952 Z

Radar Image: 1951 Z

Forecast: 1952 Z

Radar Image: 2054 Z


Ft worth wfo 25 april 20059
Ft. Worth WFO 25 April 2005

Forecast: 2003 Z

Radar Image: 2003 Z

Forecast: 2003 Z

Radar Image: 2107 Z


Ft worth wfo 25 april 200510
Ft. Worth WFO 25 April 2005

Forecast: 2020 Z

Radar Image: 2020 Z

Forecast: 2020 Z

Radar Image: 2119 Z


Ft worth wfo 25 april 200511
Ft. Worth WFO 25 April 2005

Forecast: 2030 Z

Radar Image: 2030 Z

Forecast: 2030 Z

Radar Image: 2129 Z


Ft worth wfo 25 april 200512
Ft. Worth WFO 25 April 2005

Forecast: 2042 Z

Radar Image: 2042 Z

Forecast: 2042 Z

Radar Image: 2142 Z


Ft worth wfo 25 april 200513
Ft. Worth WFO 25 April 2005

  • This was one of the first events after some modifications had been made to the system based on forecaster feedback (i.e. a CIN predictor field was added to the forecast logic).

  • Had this information not been included, the ANC system would have produced several hours of false alarms prior to storms initiating.

  • Several forecasters consulted the system during this event and it was used to help with spotter activation.


Our impressions of the ft worth wfo deployment
Our Impressions of the Ft. Worth WFO Deployment

  • Users have been very accommodating of new technology.

  • Users have done a really good job of entering boundaries.

  • Use the system most often early on in the convective events during initiation/development phase.

  • Received a lot of very useful feedback from the users.

  • Have incorporated some of the forecasters ideas which we feel have led to improved forecasts and are in the process of implementing others.


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