Operational implementation of LAPS: a tool for MAP

Operational implementation of LAPS: a tool for MAP POC. P.P. Alberoni1,2, S. Costa1, C. Cacciamani1, V. Levizzani2,3 1

ARPA - Servizio Meteorologico Regionale, Viale Silvani 6, I-40122 Bologna, Italy

2

Institute ISAO-CNR, Via Gobetti 101, I-40129 Bologna, Italy

3

Visiting Scientist at EUMETSAT, Am Kavalleriesand 31 , D-64295 Darmstadt, Germany

Introduction At the end of the Nineties substantial technological improvements deliver on the forecaster desk a large amount of meteorological data to support its activity. Data are both of conventional (e.g. synop, metar, raob, …) and non-conventional (e.g. radar, satellite, sodar, …) type. Most important of all, the increased space and time resolution of the observing systems allow for the description of mesoscale features. Foreseeing the need of a tool to cope with this large amount of information, the NOAA Forecasting System Laboratory (FSL) started the development of the Local Analysis and Prediction System (LAPS) already ten years ago. A complete description of LAPS can be found in Mc Ginley (1989) as regards the overall system; more specific details are given by, among others, Albers (1995), Mc Ginley et al. (1991), Albers et al. (1996), and Birkenheuer (1991). LAPS has recently been ported on the Dec Alpha processor at ARPA-SMR in Bologna, and is now running in a pre-operational setup as analysis scheme (Alberoni et al., 1998) aimed at supporting the implementation of a very short range forecasting system. The porting in Bologna is the first in Europe and a cooperation between ARPA – SMR and FSL has been established.

Operational scheduling The package is running on a hourly basis for research purpose by ARPA – SMR, with the collaboration of ISAO – CNR specifically for satellite data processing. The goal is the production of an effective mesoscale data analysis procedure using different types of data. The domain, centered on Northern Italy, is approximately 1000 x 700 Km2, with a 10 Km grid resolution and 21 isobaric levels from 1100 to 100 hPa. The data currently ingested into LAPS in Bologna are: Ø surface data, both from mesonet and ordinary stations (SYNOP, METAR); Ø upper air soundings; Ø radar 3-D reflectivity and Doppler wind fields; Ø METEOSAT visible and infrared radiances. Every hour the following procedure is performed: Ø Ingestion/analysis process with a 50' or 80' cut-off time; Ø Data from the second analysis cycle is delivered with a maximum delay of 90' from the analysis time.

Support to the POC During MAP SOP the LAPS analyses will be made available at POC in Milano Linate to support the forecasting personnel in their duty for nowcasting and mission-oriented decision processes. The fields include a selection of surface (mslp and wind, potential and equivalent potential temperature, relative humidity, cloud cover), upper level analysis (temperature and humidity at 700 and 850 hPa), and instability indices (lifted index, lifted index times vertical velocity at 600 hPa, positive and negative buoyancy energy, Colorado severe storm index). Cross-sections of the Lago Maggiore target area N-S along the Genova-Ticino transect and the Brenner pass are also provided to support the two main experimental targets. The products are produced in a standard graphic file format (GIF files) and sent hourly to POC. They are organized within HTML Web pages thus providing a simple but effective cross-platform interface, because all that is needed is a web browser. In Figure 1 a snapshot from the main LAPS visualization page is reproduced (left). It includes the hourly analysis section, where all the fields for the hour are included, and the time series section, where the same field covers all the hours. On the right, an example of the cloud cover analysis for 29 June 1999 12 UTC obtained from surface and satellite data is shown. Tests conducted on the cross-sections of the target areas (not included) have shown interesting features in the temperature field, e.g capturing the inversion near the ground.

Fig. 1. Left: the main page for the visualization of LAPS products includes the hourly analysis section, that is all the fields for the same hour, and the time series section, where the same field covers all the hours. Right: example of the cloud cover analysis for 29 June 1999 12 UTC obtained from surface and satellite data.

Conclusion The concept of LAPS analyzed fields and their visualization at the POC have been presented. The output and the visualization of the different products has been conceived having in mind the maximum portability and an easy accessible interface. The MAP SOP will represent a unique opportunity to test LAPS integrated analysis system, due to the high concentration of conventional and special observations. Meanwhile, the tool itself will provide additional support to the campaign.

Acknowledgements One of the authors (PPA) acknowledges support from the European Union through contract ENV4-CT96-0261. VL is grateful for support from: Italian National Research Council (CNR) (Progetto Strategico MAP, Accordo CNR-CONICET, and the Gruppo Nazionale per la Difesa dalle Catastrofi Idrogeologiche); Italian Space Agency (ASI) (contract ARS-96-13). EUMETSAT support and encouragement is gratefully acknowledged.

References Alberoni, P.P., S.Costa, A.Selvini, J.McGinley, and V.Levizzani, 1998: Implementation and test of a mesoscale data assimilation system for Northern Italy, MAP Newsletter, 9, 70-71. Albers,S.C., 1995: The LAPS wind analysis. Weather and Forecasting, 10, 342-352. Albers, S., J.A.McGinley, D.Birkenheuer, and J.R.Smart, 1996: The Local Analysis and Prediction System (LAPS): Analysis of clouds, precipitation, and temperature. Weather and Forecasting, 11, 273-287. Birkenheuer,D., 1991: An algorithm for operational water vapor analysis integration GOES and dual-channel radiometer data on the local scale. J.Appl.Meteor., 30, 834-843. McGinley,J.A., 1989: The Local Analysis and Prediction System. Prepr. 12th Conf. Weather Analysis and Forecasting, Monterey, CA, Amer.Meteor.Soc., 15-20. McGinley,J.A., S.Albers, and P.Stamus, 1991: Validation of the composite convective index as defined by real-time local analysis system. Weather and Forecasting, 6, 337-356.