weatherVIC Systems - Analyzing Cold Fronts

Project Overview

Portable weather station installed on top of a roof

A cold front is defined as the leading edge of a cooler, drier mass of air. The air with greater density wedges under the less dense and warmer air, typically causing the formation of a narrow line of showers and thunderstorms when enough moisture is present.

Purdue University's Front Intercept Team (PUFIT) recently began work on a project to better understand the effects of the passage of cold fronts. The main objective of this student group project was to collect data through a series of weather instruments placed in strategic locations throughout Indiana and Ohio.

The project sought to prove or disprove a list of hypotheses created by the team. These hypotheses included:

• Surface temperature gradients and pressure gradients being directly proportional to surface wind direction and speed with the passage of a cold front

• The strength of potential temperature and wind direction and speed leading to frontogenesis or frontolysis

• The classification of inactive/active cold fronts.

System Description

weatherPACK

The PUFIT team selected the following locations to set up temporary weather stations: Crown Point, Ind.; Muncie, Ind.; Indianapolis, Ind.; Vincennes, Ind.; and Dayton, Ohio. At each of these sites, a NexSens weatherVIC system was selected to simultaneously measure the weather parameters in question. weatherVIC is a PC-based portable weather station system consisting of a Vaisala WXT520 multi-parameter weather sensor, weatherVIC software, 100-foot PC cable, and AC adapter.

Using a laptop computer and NexSens weatherVIC software, the team collected data over a three-week period from Oct. 8 to Oct. 30, 2007. The parameters recorded were wind direction, wind speed, station pressure, air temperature, relative humidity, and total rainfall. Weather parameters at each site were recorded every 10 minutes over the three-week period, resulting in a minimum of 2,782 data points per location.

At the end of the study, the weather data was brought back to Purdue University for further analysis, which included plotting the time series of weather data parameters collected. With this information, PUFIT aims to gain insight into cold frontal passage and evaluate their hypotheses.