# Presentation: 549563

## Objective Verification of CPC Outlooks

**Michael Halpert**
**Climate Prediction Center**

## Outline

- Motivation
- Data
- Procedure
- Results
- Future Plans

## Verification at CPC

- Historically, CPC has verified ERF and LRF
- at first order stations

## Forecasts made at 77 (out of 117) stations, 45 correct.

- Heidke Skill Score = 37.7%

## Monitoring Data Sets

_**Temperature**_
- ~5000 stations/day: RFC, HADS, CADB
- 0.5 x 0.5 degree resolution
- 20°- 60°N, 140° - 60°W, Conus only
- Mid – Midnight window
- Daily Max + Min/2
- SD Quality Control check

## Monitoring Temperature

**90 Day Mean/Anomaly**

## Monitoring Data Sets

- Precipitation Station Locations

_**Precipitation**_
- ~8000 stations/day: RFC, HADS, CADB, SNOTEL, Mexican data
- 0.25 x 0.25 deg resolution
- 10°- 60°N, 140° - 60°W, Conus/Mexico
- 12Z – 12Z window
- QC: SD, buddy, Duplicate, Nexrad checks

## Monitoring Precipitation

## 2° x 2° Grid

**20° - 56°N, 130° - 60°W, 232 valid points**

## Temperature Analysis

## Procedure

- Calculate means and tercile limits for all 232 grid boxes based on 1971-2000 base period
- Tercile limits calculated as 0.43 SD for temperature; 33rd and 67th percentile (based on gamma) for precipitation

## Procedure

- Characterize seasonal mean temperature and total precipitation as above, near, or below average.

## Procedure

- Compare verification field to forecast

**DJF Verification Grid**

**DJF Forecast Grid**

## Seasonal OutlookDec 2005 – Feb 2006

## Seasonal OutlookDec 2005 – Feb 2006

**Heidke = 77, Coverage = 73%**

## April – June 2006 Temperature

## April – June 2006 Temperature

## Temperature Skill ScoresGridded vs. Stations ( non-EC)

- Gridded Score – 23.7		Station Score – 24.2

## April – June 2006 Precipitation

**    ****2.6      5.9          43.6**

## April – June 2006 Precipitation

**   ****14.9     39.7        37.5    **

## June 2006 TOfficial, Update, Observations

- OBS

- UPD

- 0.5 Lead

**                      ****Off.    Up.  Change**
**All Stations   ****18.4  33.3****    +14.9 **
**Non-EC:       ****56.6  65.0****     +8.4 **
**% Cov:         32.5  51.3    +18.8     **

## June 2006 TOfficial, Update, Observations

**All Stations 18.8   25.4    +6.6   **
**Non-EC:      48.3   43.1    -5.2**
**% Cov:        38.8   59.1  +20.3       **

- June 2006 TOfficial, Update, Observations

- OBS

- UPD

- 0.5 Lead

## Gridded verification makes tool verification simple 

## JJA 2006 Temperature

## JJA 2006 Temperature

**Official – 60**
**Consolidation – 58.2**

## January – March 1998 Temperature

**Official – 37.3**
**Consolidation – 51.5**

## Temperature Heidke Skill ScoresOfficial vs. Consolidation (non-EC)

**Official – 23.7**
**Consolidation – 27.6**

## Temperature Heidke Skill ScoresOfficial vs. Consolidation (all)

**Official – 11.4**
**Consolidation – 18.4**

## Precipitation Heidke Skill ScoresOfficial vs. Consolidation (non-EC)

- Precipitation Heidke Skill ScoresOfficial vs. Consolidation (non-EC)

**Official – 5.3**
**Consolidation – 12.4**

## Precipitation Heidke Skill ScoresOfficial vs. Consolidation (all)

- Precipitation Heidke Skill ScoresOfficial vs. Consolidation (all)

**Official – 1.4**
**Consolidation – 3.1**

## Future Plans

**Seasonal/monthly**

- Verification of tools

- Ranked Probability Skill Score

-   Conversion of tools to 2x2 grid

## Future Plans

**Extended Range**

- Verification of forecasts

- Development of 5 and 7 day data sets

- Precipitation Complications

- Verification of tools

- RPSS

-   Development of tercile limits