EXTREME EVENT: HEAVY SNOWFALL ON THE TRENTINO REGION ON 11 MARCH 2004

an extreme event of heavy snowfall occurred in the last 11 march 2004 in many regions of the north Italy. It was one of the most important events of snowfall in the winter season 2003-2004 and it was really unusual for the period. The possibility of snowfall at the lower levels was forecasted two days before but the quantity of the precipitation was generally underestimated by the models. This event caused many problems to the civil protection and to the public above all in the traffic and the increasing avalanche risk

PROPOSAL FOR AN AUTO-UPDATING SNOWFALL MAP OF THE TRENTINE TERRITORY (EASTERN ALPS OF ITALY)

From the early 80s, the “Snow, Avalanches and Meteorology Office of Trento (Italy) Autonomous Province” (“Ufficio Neve,Valanghe e Meteorologia della Provincia Autonoma di Trento”), actually “Ufficio Previsione e Prevenzione” monitors the snowfall conditions and studies avalanches in the same territory; in particular, it manages a network of over 30 manual snow fields, plus about ten automatic measurement stations, added during the last 10 years, between 800 and 2750 meters (Fig. 1). Complete snow-meteorological measurements are daily performed (AINEVA-CAI Model 1) while automatic stations also measure the snow cover thickness, as well as classical meteorological parameters

Analysis of recent meteorological configurations responsible for substantial snowfalls in the Trentine sector of the Adige valley bottom (eastern italian Alps).

Aim of this presentation is to analyse the synoptic conditions favourable to snowfall with more than 10 cm fresh snow cover in the bottom of the Trentine sector of the Adige Valley. Following the abundant and reiterated snowfalls in the study area during the 2005-2006 winter season and the many discomforts to the population and mainly to the road traffic, an accurate study of such events resulted necessary for a reliable forecast. The valley orientation in a NNE-SSW direction lets the Mediterranean warm-humid air masses to get in as far as the main headwater divide (Brenner Pass) and to make its climate relatively mild. Moreover, such humid air inflows bring mean annual precipitation of about 800-1000 mm that gradually decreses from the lower valley mouth to the main divide. The precipitation regime consists of rainfalls in spring and autumn whereas a strong absolute minimum occurs between December and Febraury when snowfalls are more likely on the valley floor. In fact, the vally is annually subjected to warm advection snowfalls, though infrequent and scarce, between November and mid April. The study area is about 80 km long with elevation ranging from 130 and 230 m a.s.l. All the snowfall events observed from 1980 to 2006 were analysed by using the data of the Civil Protection Authority of Trento Province, i.e. Trento Roncafort (194 n a.s.l.), Trento Laste (312 m a.s.l.), Rovereto (203 m a.s.l.) and Ala (197 m a.s.l.) meteo stations. Through the study and analysis of ground and at the 500 hPa geopotential meteo maps, satellite images, thermodynamic diagrams of the nearest sounding stations and the data of the nivometeorological stations, the synoptic types that characterised the snowfalls were studied and classified and a clusterisation was made. For each of the synoptic types defined the conditions for a quantification of the mean characteristic meteo parameters were anlysed in order to obtain a reliable forecast of intense snowfalls on the valley bottom

PROPOSAL FOR AN AUTO-UPDATING SNOWFALL MAP OF THE TRENTINE TERRITORY (EASTERN ALPS OF ITALY)

From the early 80s, the “Snow, Avalanches and Meteorology Office of Trento (Italy) Autonomous Province” (“Ufficio Neve,Valanghe e Meteorologia della Provincia Autonoma di Trento”), actually “Ufficio Previsione e Prevenzione” monitors the snowfall conditions and studies avalanches in the same territory; in particular, it manages a network of over 30 manual snow fields, plus about ten automatic measurement stations, added during the last 10 years, between 800 and 2750 meters (Fig. 1). Complete snow-meteorological measurements are daily performed (AINEVA-CAI Model 1) while automatic stations also measure the snow cover thickness, as well as classical meteorological parameters

Proposal for an auto-updating snowfall map of the Trentine territory (Eastern Alps of Italy),

From the early 80s, the “Snow, Avalanches and Meteorology Office of Trento (Italy) Autonomous Province” (“Ufficio Neve,Valanghe e Meteorologia della Provincia Autonoma di Trento”), actually “Ufficio Previsione e Prevenzione” monitors the snowfall conditions and studies avalanches in the same territory; in particular, it manages a network of over 30 manual snow fields, plus about ten automatic measurement stations, added during the last 10 years, between 800 and 2750 meters (Fig. 1). Complete snow-meteorological measurements are daily performed (AINEVA-CAI Model 1) while automatic stations also measure the snow cover thickness, as well as classical meteorological parameters

TENDENZE TERMOMETRICHE TRENTENNALI

L’analisi dei trend termometrici relativi alle stazioni è in fase di avanzato sviluppo, risulta tuttavia evidente che, come per l’intera costa adriatica (Bisci et al 2001) sembrerebbe evidente un segnale opposto a quello presente a scala regionale, con un lievissimo raffreddamento a quote collinari seguito da un altrettanto lieve riscaldamento, specie oltre i 1000 metri; dall’analisi dei dati standardizzati (fig. 7) è evidente una notevole alternanza di anni con temperature superiori ed inferiori alle medie ed una tendenza seppur infinitesima ad un decremento dei valori stessi. E’ altresì evidente una notevole variabilità intrannuale nel decennio ‘71-’81, con una successiva tendenza al calo di tale variabilità. In generale gli anni più caldi sono risultati essere il 1982 ed il ‘90 (anche se dall’esame dei dati relativi all’ultimo decennio gli anni compresi tra il ’96 ed il ‘99 si sono rivelati ancora più caldi, specie in montagna), mentre anni particolarmente rigidi si sono avuti nel periodo 1976-1980

Inverno 2005 :le nevicate eccezionali sull’ italia centrale - analisi meteo-climatica e nivologica dell’evento

Scopo del presente studio era quello di analizzare le condizioni meteorologiche e i relativi fenomeni che hanno caratterizzato l’inverno scorso in Italia centrale. In quest’area, l’inverno scorso è risultato essere uno dei più nevosi e freddi dell’ultimo secolo, ed in particolare nelle zone collinose e nelle pianure, con nevicate diffuse che hanno interessato i due versanti della penisola italiana, arrivando ad interessare città come Roma e Napoli. Il persistere di un indice NAO negativo per oltre due mesi, da gennaio a marzo, assieme a processi di stratworming molto intensi hanno determinato tali anomalie meteoclimatiche. Sulla base dell’analisi delle condizioni sinottiche e nivometriche sono stati determinati i tipi di circolazione che possono causare nevicate sul versante tirrenico della penisola, solitamente caratterizzato da clima mite e rari fenomeni nevo

Analysis of spatial and temporal distribution of precipitation in Trentino (Italian Eastern Alps): Preliminary report

The records of 92 pluviometric stations located in the Trentino Province (Italian Eastern Alps) were analyzed in order to find significant features in their spatial and temporal distribution. Differentiation of climatic regimes was detected, as well as the influence of many topographic-geographic parameters. Analyses of the data from the 20 stations with the best continuity of records indicate some periodic trends, with a major influence of those having a wavelength of ca. 26.7, 36.9 and 13.5 years. Also non strictly periodic Mediterranean oscillations influences the precipitation in the study area