Visualizing Uncertainty in Mesoscale Meteorology APL Verification Methodology 21 May 2002 Scott Sandgathe

Human Forecaster Decision Interface Decision Driven Auto-Product Generation Automated Meteorological Information Evaluation System A New Paradigm for Weather Forecasting MURI/UW 2/13/02 Decision Interface is comprised of: Verification of Global and Meso Models past forecasts Evaluation of Current Met. Analyses Rule-based evaluation of model predictions

NOGAPS centroid ETA Output Eval. MM5 evaluation Wt. Ensemble Products Global and Regional RMSE Evaluation – Recent, Historical and Synoptic Evaluation of Ensemble members and combinations – recent, historical and synoptic Evaluate current analyses based on observations, satellite and radar Reform ensemble or chose “most- representative” member based on user evaluation Products are automatically generated based on user-selected ensemble or member. Verification and Evaluation

Global RMS Error Analysis OBS Forecast hr Forecast hr Forecast hr Forecast 6 hr Forecast 6 hr OBS 00Z 06Z 12Z 18Z 00Z...

Regional RMS Error Global models are often “tuned” to the region of national interests or to the predominate natl weather pattern, and global skill may not reflect regional skill. The region between 110E and 110W accounts for the majority of 0 – 48h weather.

Mesoscale Verification O O OO F F F F All equivalent?! POD=0, FAR=1 (Brown, 2002)

Mesoscale Verification O OF F (After Brown, 2002) O POD >> 0, FAR < 1 Is this a better forecast? Or is this?

Mesoscale Verification

Total Error = Displacement Error + Amplitude Error + Residual Error –MSE and CCF give equivalent results –Hoffman, et. al., 1995, for satellite data assimilation. MSE(tot) = MSE(disp) + MSE(amp) + MSE(pattern) –Elbert and McBride, 2000, for precipitation pattern verif. Implementation (Du and Mullen, 2000): –Calculate MSE(tot) = (Forecast – Analysis) 2 –Shift forecast field to minimize total MSE and calculate MSE(disp) = MSE(tot)-MSE(shift) –Adjust amplitude to minimize MSE(shift). MSE(amp) = MSE(shift) – MSE(shift-min) –MSE(residual) = MSE(tot) – MSE(disp) – MSE(amp) MSE(res) =? MSE(pattern) =? MSE(rotation)

Phase Shift

Phase and Amplitude Error

Rotational Error

Total Error

Future Research Issues Need to test on “real” data. Many computational solutions: –Correlation Coef., Mean absolute difference, etc. –Rapid ‘image motion’ search techniques Map verification or “feature” verification: –Phase and amplitude suitable for both –Rotation requires “feature” and more complex search Need to examine usefulness Evaluation of “goodness” –Relative weight of phase vs amplitude vs rotational err –Will test “table” approach often seen in software or “service” evaluation.

Questions and Comments?

References Hoffman, R. N., Z. Liu, J.-F. Louis, and C. Grassotti, 1995: Distortion representation of forecast errors. Mon. Wea. Rev., 123, Brown, B., 2002: Development of an Object-based Diagnostic Approach for QPF Verification. USWRP Science Symposium, April Ebert, E. E., and J. L. McBride, 2000: Verification of precipitation in weather systems: determination of systematic errors. J. Hydro., 239, Du, J., and S. L. Mullen, 2000: Removal of Distortion Error from an Ensemble Forecast. Mon. Wea. Rev., 128, Chan, E., 1993: Review of Block Matching Based Motion Estimation Algorithms for Video Compression. CCECE/CCGEI. Lim, D.-K., and Y.-S. Ho, 1998: A Fast Block Matching Motion Estimation Algorithm based on Statistical Properties of Object Displacement. IEEE.

BACKUP SLIDES SLIDES FROM 31 Jan 2002 Meeting

36km Ensemble Mean and Selected Members SLP, mb Thickness 2002 Jan 2200Z

12km Ensemble Mean and Selected Members SLP, Temperature, Wind 2002 Jan 2200Z

Verification of Mesoscale Features in NWP Models Baldwin, Lakshmivarahan, and Klein 9 th Conf. On Mesoscale Processes, 2001

Tracking of global ridge-trough patterns from Tribbia, Gilmour and Baumhaufner

Current global forecast and climate models produce ridge- trough transitions; however, the frequency of predicted occurrence is much less than the frequency of actual occurrence

Creating Concensus From Selected Ensemble Members - Carr and Elsberry

Necessary Actions for Improved Dynamical Track Prediction No forecaster reasoning possible. Help needed from modelers and data sources to improve prediction accuracy Recognize erroneous guidance group or outlier, and formulate SCON that improves on NCON No forecaster reasoning required -- use the non-selective consensus (NCON) Recognize situation as having inherently low predictability; must detect error mechanisms in both outliers to avoid making SCON>>NCON (48 h) Small Spread (229 n mi) Large Error Large Spread (806 n mi) Large Error Large Spread (406 n mi) Small Error Small Spread (59 n mi) Small Error

References Cannon, A. J., P.H. Whitfield, and E.R. Lord, 2002: Automated, supervised synoptic map- pattern classification using recursive partitioning trees. AMS Symposium on Observations, Data Assimilation, and Probabilistic Prediction, pJ103-J109. Carr. L.E. III, R.L. Elsberry, and M.A. Boothe, 1997: Condensed and updated version of the systematic approach meteorological knowledge base – Western North Pacific. NPS-MR , pp169. Ebert, E.E., 2001: Ability of a poor man’s ensemble to predict the probability and distribution of precipitation. Mon. Wea. Rev., 129, Gilmour, I., L.A. Smith, R. Buizza, 2001: Is 24 hours a long time in synoptic weather forecasting. J. Atmos. Sci., 58, -. Grumm, R. and R. Hart, 2002: Effective use of regional ensemble data. AMS Symposium on Observations, Data Assimilation, and Probabilistic Prediction, pJ155-J159. Marzban, C., 1998: Scalar measures of performance in rare-event situations. Wea. and Forecasting, 13,

Current Forecast Paradigm

NOGAPS centroid ETA Output Eval. MM5 evaluation Wt. Ensemble Products J2EE Control/ Interface Bean J2EE Control/ Interface Bean J2EE Control/ Interface Bean J2EE Control/ Interface Bean Java Server Pages for each Bean interface Control and Server-side components Stat. tools Meteorology tools IMS & Viz. Tools (XIS) Server Protocols (HTTP, RMI, CORBA..)

Forecaster-in-the-Loop Concept

A New Paradigm (Bob’S)