National Convective Weather Forecast (NCWF)

NCWF-2– Currently available on

Experimental ADDs – Operational in ’07 replacing

NCWF-1– Automated graphical display – User-requested 0-2-hour

probabilities– 4 km resolution with updates

every 5 minutes at 30 minute increments.

– This product is intended for strategic use by dispatchers, AOCs, and pilots (pre-flight and cockpit).

Experimental ADDsFlight Path Tool

National Convective Weather Forecast – 2hr

Experimental ADDsFlight Path Tool

T= 0 min

+120 min

+90 min

+60 min

+30 min

Darker to lighter shades of pink :

Higher to lower Probabilities

RTVS Verification

0

0.2

0.4

0.6

0.8

1

0 1 2 3 4

% Area Coverage of Forecast

True

Ski

ll Sc

ore

1hr NCWF-22hr NCWF-21hr CSigmets2hr CSigmets2hr CCFP

0

0.05

0.1

0.15

0.2

0 1 2 3 4

% Area Coverage of Forecast

Crit

ical

Suc

cess

Inde

x

1hr NCWF-22hr NCWF-21hr CSigmets2hr CSigmets2hr CCFP

10%10%

10%

10%

40%

40%

40%

40%

Validation Observation: 4km NCWD

April 1 to Oct 1, 2005

NCWF–6: Blends Observation and Model Forecasts(1) Observation-based

Forecast skill vs lead timeAug 1 to Aug 14, 2005

Forecast Hours

Fore

cast

Ski

ll - C

SI

(3) NCWF-6 Blended forecast

(2) NWP-based 0.5

0.4

0.3

0.2

0.1

0.00 1 2 3 4 5 6

ForecastProbabilities

Verification

5 30 50 70%

National Convective Weather Forecast - 6hr• 1-6 hour probabilistic forecast

blends RUC and NCWF• Complimentary

– Initiation• RUC: good • NCWF: not handled

– Motion• RUC: improves with lead time • NCWF: degrades with lead time

– Dissipation based on diurnal climatology

• Available as a test version next summer,

• Experimental ADDs in 2007– Operational in 2010 replaces NCWF-2

Darker to lighter shades of pink :

Higher to lower Probabilities

Yellow areas forecast regions of echo tops over 30,000 ft

Texture – convective organization and orientation – line, broken line, scattered