# Presentation: 694565

## Eastern Region Recent Ensemble Developments and Plans

**May 13, 2008**

**4****th**** Ensemble User Workshop**

## Topics

**NFUSE Forecaster Uncertainty Needs Survey**
**Regional High Resolution Ensembles**
**Regional Data Access Team**

## NFUSE Forecaster Uncertainty Needs Survey

**NFUSE Forecaster Uncertainty Needs Survey**

**Survey of NWS operational managers concerning guidance, training, products and services, and forecast system needs related to forecast uncertainty.**
**Distributed to over 400 WFO, RFC, NCEP forecast managers in Fall 2007 – responses from 237.**
**Recommendations made regarding future data, training, products, and AWIPS II requirements.**
**Final report available at: **_**[http://](http://www.nws.noaa.gov/ost/nfuse/NURO_Final_Approved.pdf)**__**[www.nws.noaa.gov/ost/nfuse/NURO_Final_Approved.pdf](http://www.nws.noaa.gov/ost/nfuse/NURO_Final_Approved.pdf)**_

## Selected Key Findings

- Many forecasters use uncertainty guidance...

- Percentage of respondents in each survey class using the specified uncertainty guidance source.

## Selected Key Findings

- Many forecasters use uncertainty guidance, but
-    _**limited data access **_and **ensemble bias/under-dispersion**
- 	are barriers to greater use/acceptance.

- 48-h forecast surface-low track RMSE (km) for extratropical cyclones producing hazardous winter weather over the CONUS
- [compiled by HPC during the 2004-2007 cold seasons].

## Selected Key Findings

- Need for _**high-impact event EPS verification **_(i.e., for heavy rain events, how well does the ensemble perform?)

- Example feature-specific verification using the UK Met Cyclone Database for the ECMWF ensemble prediction system. [Adapted from Watkin and Hewson (2007).]

## Selected Key Findings

- Consensus that forecasters should be involved in the communication of uncertainty forecasts.
- Forecaster views differ as to if and how forecasters should adjust objective guidance.
- Possible adjustment techniques cited in survey responses:
- Forecaster perturbation of key features (jets, shortwaves)
- Selective consensus
- Subjective bias correction on local scale

## Selected Key Findings

- Respondents reported receiving requests for uncertainty information primarily from sophisticated users (e.g., emergency managers), and most often during high-impact events.
**Need to obtain and clarify uncertainty requirements from wide variety of external user groups **
- Such requirements can focus future NWS uncertainty initiatives
- Research
- Training
- Products

## Northeast Regional Ensemble

**Six 12 km local WRF runs by Great Lakes WFOs**
***Vary IC/BC, Physics, Model Core (ARW/NMM)***
**Goal: Probabilistic guidance that adds to what is provided by operational GEFS, SREF, and 12 km NAM**

## Example – Lake Effect Snow

- Means and probabilities in AWIPS.

- Obs

## SUNY Stony Brook Ensemble

- COMET Coop Research Projects exploring hydrologic applications

- 12 member 12 km regional ensemble (Jones et al. 2007)

- QPF Plume for RFC River Forecast Point

- Wind Forecast for NYC

## Regional Data Access Team

- Limited Ensemble Data available to WFOs and RFCs in AWIPS

- Some WFOs view data on web pages, but this is not optimal.

- Only see 10 of 20 GEFS members
- No NAEFS
- No bias corrected output from SREF, GEFS, or NAEFS

## Regional Data Access Team

- Due to necessary AWIPS-2 transition activities, no new datasets to be added to the national baseline until after AWIPS-2 is fielded (2010).

- Regional Team Established to:
- identify operationally relevant data sources,
- prioritize these data sets,
- develop methods/software to make datasets available and useable
- identify/develop improved approaches for monitoring and trouble-shooting dataflows.

## Other Activities

- Experimental Local WFO Products

- Sub-regional ensemble workshop (WFO State College, PA)
- -May 5-6, 2008