Norwegian Meteorological Institute met.no

TEPS/LAMEPS at met.no

Marit Helene Jensen, Inger-Lise Frogner, Hilde Haakenstad and Ole Vignes

Norwegian Meteorological Institute met.no

TEPS/LAMEPS

• An ensemble prediction system using IFS and HIRLAM

• Running daily since mid Feb. 2005 (quasi operational)

• Focus: Precipitation (large precipitation events of special interest)

• TEPS/LAMEPS is a supplement to EPS from ECMWF:

• LAMEPS has better resolution• TEPS/LAMEPS is designed for our area of

interest• Is valid for day 1 – 3

Norwegian Meteorological Institute met.no

TEPS/LAMEPS – set-up

TEPS/LAMEPS:• TEPS (global model) (~80 km/40 lev.): as EPS,

except:• TEPS is targeted to our area of interest• 20 + 1 members (EPS 50 + 1)

• LAMEPS (regional model, ~20 km / 40 lev.): • HIRLAM 20 + 1 members• Initial perturbations and lateral boundary

conditions from TEPS (6 hourly updates on boundaries)

Norwegian Meteorological Institute met.no

Verificationarea

• Target area SVs

Integration areaHIRLAM

Norwegian Meteorological Institute met.no

Generation of perturbations

Running TEPS to +90h

20 + 1 members12 UTCTEPS is automatically transferred to met.no

TEPS is made ready to run in the Norwegian model environment

TEPS is transferred to Trondheim

Generation of HIRLAM perturbations

LAMEPS running 18 UTC, to +60hResults from LAMEPStransferred back to met.no

Generation ofproducts forusers/customers

00 UTC

30 minutes 2 hours

19 UTC

50 minutes

ECMWF

Norwegian Meteorological Institute met.no

Verification

• 20+1 TEPS/LAMPES/EPS members• Time period 14/2-12/4-2005• Parameter: 24 hours precipitation

(from 06 to 06 UTC)• Forecast lengths

LAMEPS: +36 and +60 hoursTEPS : +42 and +66 hoursEPS : +42 and +66 hours

Norwegian Meteorological Institute met.no

ROC

+36/+42h

NTOT= 81409, NOCC= 778, P_CLI=0.010NTOT= 81409, NOCC= 5040, P_CLI=0.062

Norwegian Meteorological Institute met.no

+60/+66h

NTOT= 81288, NOCC= 5037, P_CLI=0.062 NTOT= 81288, NOCC= 808, P_CLI=0.010

Norwegian Meteorological Institute met.no

Cost/loss

+36/+42h

Norwegian Meteorological Institute met.no

+60/+66h

Norwegian Meteorological Institute met.no

BSS/Area ROC

Norwegian Meteorological Institute met.no

Summary verification

• Small precipitation amounts – TEPS/EPS best

• Medium precipitation amounts (~10 mm/day) - TEPS/EPS best

• Large precipitation amounts (15 mm/day and more) – LAMEPS best

Norwegian Meteorological Institute met.no

Case study: “100 year precipitation” in the middle part of Norway in

August 2003

• 14. – 15. August 2003• Atnadalen: 116,5 mm/24h, 156,2 mm/48h• Sunndalsøra: 102,5 mm/24h, 171,9 mm/48h

Norwegian Meteorological Institute met.no

Observed

14. Aug. 06UTC - 15. Aug. 06UTC

Norwegian Meteorological Institute met.no

Operational HIRLAM 20 km

+42h

Norwegian Meteorological Institute met.no

ECMWFensemble

+42h

Norwegian Meteorological Institute met.no

LAMEPSensemble

+42h

Norwegian Meteorological Institute met.no

Use of LAMEPS

• Forecasting • EU-project Eurorisk• Storm-surge LAMEPS• Input to hydrological models

Norwegian Meteorological Institute met.no

Examples of use of LAMEPS

Area: Selbusjøen 615mohTime T2m dT/dz R6

18+ 0 7.4 -1.3 0.018+ 6 1.0 -0.7 0.018+12 1.7 -0.8 1.5……18+54 3.3 -0.6 1.518+60 5.1 -0.7 0.3

• Ensemble of hydrological models – one time series for each ensemble member as input to the hydrological models (customers)

Norwegian Meteorological Institute met.no

Examples of use cont.

Norwegian Meteorological Institute met.no

Future developments

• Include perturbing of the model physics

• Increase the time resolution of the boundary fields

• Expand system to more parameters: temperature, wind, ….

• Develop probability products• Compute SVs within HIRLAM• Move to higher resolution