NCWF Plans

Cindy Mueller (NCAR)Steve Weygandt (FSL)

Marilyn Wolfson (MIT/LL),Barb Brown (NCAR), and

Jesse Sparks (AWC)

Goal: 0-6hr Probablistic Forecasts that combine automation, NWP, and forecaster input

Photo courtesy of Gregg Thompson

NCWF-219z + 2h

NCWF DemonstrationsNCWF DemonstrationsProbability Forecasts (strategic planning)Probability Forecasts (strategic planning)

• NCWF-2NCWF-2– 1 & 2-h observation based– Radar mosaics, lightning, & RUC– ExADDs– NCAR

• Extended NCWF (E-NCWF)Extended NCWF (E-NCWF)– 2, 4 & 6-h RUC based– WWW page (next summer)– FSL/NOAA

• Future– Fused observations, NWP and

forecaster, 0-6 hr forecast– Test in summer 05

E-NCWF

– 1-2 hr probability forecasts

– Capture regions of growth

– Trend dissipation

– 1 hr Extrapolation (cyan)

– Binary yes/no

Operational NCWF NCWF-2

NCWF-2

RTVS Verification – 1hr

Large-scale Trending of Dissipation

2-hr without Trending 2-hr with Trending

1-hr without Trending 1-hr with Trending

Black contours NCWD verification observation

CSI1-hr Forecast

Black – Without trendingMagenta – With trending

NCWF-210z + 1h

NCWF-209z + 2h

CIWS VIL11 Z

July 14, 2004 Valid - 11Z

E-NCWF, NCWF-2,

andForecaster

Input

Forecaster:- Strong upper-tropospheric divergence over the western NY/PA, weak low-level jet and warm-air advection provides additional forcing, thus elevated convection likely to persist throughout the early morning hours.

ANC Forecast loop

Finally One Last Slide…PROBABILITIES

• Forecaster/developer perspective – Quantify uncertainty– Provide a methodology (or common unit) to combine observational-

based forecasts with NWP.– Requires additional research to better quantify predictability of

convective events and associated environmental processes.

• User perspective – Calibrate decisions based on probability and risk– Maps of probabilities of convection alone not entirely useful

(information about echo tops or convective organization very helpful)

• Verification – Problems that arise in current verification techniques due to off-set

errors and difference in scales between forecast and observations are not alleviated by probability forecasts.

Thank You!