Atmospheric Modeling at

RENCI

Brian J. Etherton

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Atmospheric Modeling at RENCI

• Focus of RENCI for C-STAR project is to provide modeling support/development to improve prediction and understanding

• RENCI is producing WRF model output in a production mode.– RAPID REFRESH– DAILY– ENSEMBLE– HURRICANE

WRF forecast of temperature at 6A.M. E.S.T. on January 9, 2010. WRF model is at 1km resolution. Features such as mountains, lakes, and urban areas visible in output.

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Rapid Refresh

• Model specifics– 9km/3km/1km resolution– 12 hour forecast length– RUC IC/BC– Initialized on ‘odd’ hours

• Run time example– 1200 RUC IC (1hr fcst)– 1000 RUC BC– 1315 start– 1430 complete

WRF forecast of radar reflectivity ure at 9 P.M. E.D.T. on October 27, 2010. WRF model is at 1km resolution. Features such as mountains, lakes, and urban areas visible in output.

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Daily

• Model specifics– 9km/3km resolution– 84 hour forecast length– NAM IC/BC– Initialized at 00Z and 12Z

• Run time example– 1200 NAM IC/BC– 1450 start– 1745 complete

WRF forecast of top of the atmosphere brightness temperature at 10 A.M. E.D.T. (1400 UTC) on October 29, 2010. Forecast initialization time was 1200 UTC on October 26, 2010.

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Ensemble

• Model specifics– 9km/3km resolution– 30 hour forecast length– NAM IC/BC– Initialized at 06Z and 18Z

• Run time example– 0600 NAM IC/BC– 0850 start– 1230 complete Ensemble mean forecast of 2-meter

temperature valid at Noon E.D.T. (1600 UTC) on October 20, 2010. Forecasts were initialized at 0600 UTC on October 20, 2010

Ensemble• RENCI is not the

only source of ensemble model data

• 6 WFO (soon 7, with CHS), NCEP, NSSL, and SRNL all contribute

• Total of ~30 members Ensemble member forecasts of temperature and

dewpoint at RDU, valid from 1200 UTC on October 28, 2010 to 1200 UTC on October 29, 2010.

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Ensemble

28 Members at this time – 2 more WFOs to come online by the end of the year.

Hurricane

Forecast of track/intensity of “Earl” for August 30 to September 4, initialized at 1200 UTC on August 30.

• Model specifics– 27km/9km/3km resolution– 132 hour forecast length– GFS IC/BC– Initialized at 00Z and 12Z

• Run time example– 1200 GFS IC/BC– 1620 start– 2030 complete

Earl – prediction versus reality

• RENCI/NCSU WRF forecasts provided non-standard information (such as this ‘simulated satellite’ image)

Forecast valid at: 06Z03SEP2010

Top of Atmosphere Brightness Temperature (C)

Earl Forecasts – The Details

• RENCI/NCSU WRF forecasts provide detailed information as to the extent and duration of tropical storm force and hurricane force winds

Earl Wind Forecasts

• Maximum gust speeds (below) in good agreement with model predicted strongest winds (left)

Track Forecasts from Aug 30

• RENCI/NCSU WRF forecasts predicted a track closer to the North Carolina coast than other operational forecast models.

Average Errors - Track

Forecast Lead Time (Hours)

Aver

age

Erro

r (Ki

lom

eter

s)

• When averaged over 10 cases, RENCI WRF track forecasts (red) are nearly as accurate as operational HWRF and GFS model

• Details from RENCI WRF can be trusted

• Initial condition improvement ongoing

Average Errors - Intensity

Forecast Lead Time (Hours)

Aver

age

Erro

r (Kn

ots)

• When averaged over 10 cases, RENCI WRF intensity forecasts are as accurate as operational HWRF model through 72 hours

• Details from RENCI WRF can be trusted

• Initial condition improvement ongoing

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Output vehicles

• Web Site– www.sensordatabus.org/

wrf• IMAGES• GRIB• GRIB2• NETCDF

• FTP Site– ftp.renci.org

• ALL OF THE ABOVE

• HOPING for ability to ingest into AWIPS (ER on the case!)

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Coming attractions

• BUFR output• 3km Analyses• RhesSYS

Presentation title goes here 17

BUFR Output

• Present ensemble output is 2D surface fields (T, CAPE, etc.)

• Working to get vertical cross sections available

Presentation title goes here 18

BUFR Output

• List of sites is to the right.

• If there are more you want/need let me know.

Presentation title goes here 19

Locally produced analyses (WRFDA)

• Use existing ensemble and MADIS local data sets to produce analyses

• 1200 and 0000 UTC

Initial Conditions – WFO Miami• In Florida during the

summertime, convection often going at initial time

• Convection will generate features (outflow boundaries) which will effect forecasts

• Proper location of convection at initial time essential

Initial Conditions – June 6th 2005

• NAM 12km Tiles– Convection not resolved

Local Analysis and Prediction System (LAPS) – WFO Miami

MIA

EYW

• NAM 12km Tiles– Convection not resolved

Initial Conditions – June 6th 2005

• LAPS 12km Tiles– Convection IS resolved

NAM vs LAPS – 700 hPa RH – 1hr PCP

Precipitation Forecasts

0

0.1

0.2

0 3 6 9 12 15 18

Forecast Hour

Thre

at S

core

LAPS TILE

0

0.1

0.2

0 3 6 9 12 15 18

Forecast Hour

Thre

at S

core

LAPS TILE

06Z Initialization 18Z Initialization

•Gridbox by gridbox (5km x 5km) hourly threat scores•Accounted for wet bias (WRF=2.0mm, VERIFY=0.5mm)•Radar data likely very helpful for 18Z initialization

Presentation title goes here 26

RhesSYS (Hydrology Modeling)

• Where it rains is not the entire story

• Looking to implement RhesSYS (Regional Hydrological and Ecological Simulation System) at RENCI

• Want to know how we can help the hydro

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Final Slide

• My goal is to work with NWS to provide NWP support that is beyond what a single WFO or EMC can provide.

• Let me know what you want!

• Let me know when you want it!

• Let me know if it helped (evaluate!)