Source: Hans Schmitz, Purdue Extension Educator – Posey County
With the cool temperatures soon to be behind us, now is the time to be checking plants for any sustained frost damage. When anticipating cold temperatures, many resources exist to evaluate the amount and area of cold expected. Weather and climate resources may be difficult to interpret once found, however. A lot of tabular data exists that may look better graphically, or a lot of graphics may have too much overlaid information to interpret easily. The Indiana State Climate Office (IN-SCO) has a new web site, found at ag.purdue.edu/Indiana-state-climate. Our state climatologist, Dr. Beth Hall, now has over a year of experience in her position and continues to improve weather and climate monitoring resources in Indiana. Most of these resources can be found at the web site.
Perhaps the most important resource that the IN-SCO controls is the Purdue Mesonet. A mesonet is a mesoscale network of weather stations. The mesoscale is a relatively small scale, meteorologically speaking, with multiple stations covering a defined area, anywhere from a few stations per state, to a station per county, to even multiple stations per county. The Purdue Mesonet contains nine Purdue farm-based stations around the state supported by the IN-SCO. In addition, the National Weather Service (NWS) maintains 49 Automated Surface Observing Stations, usually located at airports around the state. The Indiana Water Balance Network (IWBN), maintained by the Indiana Geological and Water Survey at Indiana University, has 13 sites around the state with more on the way. These network stations are all installed and maintained to National Weather Service specifications, which separates them from the backyard weather station that can upload information to private, online weather services. Data from the mesonets are maintained separately, but NWS and Purdue farm data are accessible through the IN-SCO web site. The advantage of the Purdue farm and IWBN mesonet data is the availability of variables such as wind, soil temperature, humidity, and solar radiation, variables less common from other weather station networks.
In addition to near real-time weather data provided by the Purdue Mesonet, the IN-SCO provides regularly updated maps of the state for recent time periods depicting rainfall and temperature amounts, averages, and deviations from the climatological normal. In addition, a tools tab leads to Midwest Regional Climate Center products focused around drought, agriculture, winter, or the Great Lakes. Using this tab also provides some projects the IN-SCO has developed recently. For instance, after a period of more than seven days above 35 degrees Fahrenheit, the Evansville Museum station has never recorded a cold snap with a resultant temperature below 18 degrees. The average first fall freeze in Indianapolis occurs on November 3rd, although the trend line first freeze is predicting (with very low confidence) closer to November 8th. Since 1950, Indiana has experienced four F5/EF5 tornadoes, the strongest tornado that exists. All four occurred in 1974.
If anyone would be looking for specific weather or climate data and cannot find it readily, the site ( ag.purdue.edu/Indiana-state-climate) has a link to request data from the state climate office. These requests, if possible, should be restricted to weather and climate data requests.