2004 Developments in Aviation Forecast Guidance from the RUC

transcript

Stan BenjaminSteve Weygandt NOAA / Forecast Systems Lab

http://ruc.fsl.noaa.gov

Courtesy: ADDS/AWC/NOAA

FPAW Forum – October 2004 – Las Vegas

Convection - 2-12h forecast

Ceiling/visibility

Turbulence

Terminal / surface

3-d RUC weather dataupdated hourly

20km x 50 vertical levelsx 14 variables

Better weather products require improved high-frequencyhigh-resolution models with high-refresh data to feed them

RUC changes Impact on convection, ceiling/vis forecasts for aviation

2004 - 20km RUC implementations completed –

• April – RUC model - vertical advection of moisture better precip and

clouds. More detailed land use/coastline.

• September – RUC analysis – use boundary-layer depth in assimilation of surface/METAR obs better temp/dewpoint/CAPE/convection forecasts

2005- 13km RUC implementation planned • Real-time testing since spring (see

http://ruc.fsl.noaa.gov)

3h CAPE forecast valid 0000 UTC 21 April 2004

Two revisions:1) Better use of METAR obs

using boundary-layer depth (Sept04)

2) Assimilation of GPS precipitable water observations (2005)

Operational RUC Revised RUC

Severe weather reports

13km RUC

Improvements expected from 13km RUC- Improved near-surface forecasts- Improved precipitation forecasts- Better cloud/icing depiction- Improved frontal/turbulence forecasts

New obs assimilated in 13km RUC

- METAR cloud/vis data- GPS precipitable water (~300/hr)- Mesonet surface (temp/wind – 5000/hr)- 915 MHz profilers

20km RUC

Assimilation of METAR cloud, visibility, current weather observations into RUC

Goal: Modify hydrometeor, RH analysis fields to 1) force near match to current ceiling/vis obs when passed through ceiling/vis translation algorithms 2) improve short-range predictions

IFRLIFR

VFR CLR MVFR

To be part of oper 13km RUC - 2005

Cloud ceiling (m)RUC – with and without METAR cloud assimilation

18z Obs17 Nov 2003

Diagnosed ceiling from RUC hydrometeors

Corresponding Ceiling height - meters

IFRLIFR VFR CLR MVFR

METAR Flight Rules

Oper RUC - w/o METAR cloud assim

With METAR cloud assim

17z 27 Jan 04 analysis –After assimilation ofMETAR cloud/ceiling obs

Cloud water mixing ratio (qc),

Background – 1h fcst

17z – 27 Jan 04

MO KY VA MO KY VA

NCAR-RAP CV exp product – Flight Rules

Oper RUC13km RUCw/ c/v assim

Observed –1315z7 Oct 04

GOES visible image

3h fcstValid 14z7 Oct 04

6h precipitation forecastValid 18z Thurs 30 Sept 2004RUC20 (oper) vs. RUC13

RUC CONVECTIVE PROBABILITY FORECAST (RCPF)

• Ensemble-based thunderstorm likelihood product

• 2, 4, and 6-h forecasts every two hours

• In-house testing 2003 and 2004

• AWC evaluation planned for 2005• 2005 – use improved 13km RUC

EVENTUAL GOAL

• Seamless 0-6 h convective guidance product (E-NCWF) • Guidance to forecasters, traffic flow managers, automated decision support systems

• Verification for 26 day period (6-31 Aug 2004)

• RCPFv2004 fcst is a 1-h older than RCPFv2003

RCPFv2004 has similar CSI, much improved bias

RCPFv2003 vs. RCPFv2004

Forecast length

ForecastValid Time

6h Forecast

25 – 49%50 – 74%75 – 100%

Forecasts

09z + 6h

Verification

15z NCWD

10 July 2004

RCPFv2004

POD = .49CSI = .25Bias =1.44

RCPFv2003

POD = .46CSI = .18Bias =2.00

Sample comparison RCPFv2003 and RCPFv2004 products

GOALS in 2004

• Reduce large bias

• Improve spatial coherency, temporal consistency

15z convectionAt fcst

Time...

RCPFv2004

15z + 6h Forecast

21z verif

Sample RCPFv2004 product

25 – 49%50 – 74%75 – 100%

Verification

21z NCWD

23 July 2004

Strength of RCPF- convective initiation

Backbone of improved aviation forecast products for

winds, icing, turbulence, convection, TAFs = weather model forecasts updated at

high frequency with latest observations

Keys to improvement of RUC model aviation forecasts• Higher spatial resolution – better capture fine-scale weather hazards

(13km resolution)• Use new observations to initialize model – force more realism in model initial conditions

(METAR ceil/vis obs, GPS moisture, mesonet)• Improved realism of physical processes in model – clouds, turbulence, land-surface

(revised physics)

Collaboration between FSL, NWS, FAA, NCAR, MIT/LL, NASA, customers

2004 Developments in Aviation Forecast Guidance from the RUC

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