Date of this Version
The incidence of both drought and flooding on the Vermont landscape within the same calendar year is not an uncommon occurrence. The year 1998 was no exception, in that the ice storm of January and statewide flooding of June/July finally gave way to drought conditions as the year drew to a close. These dry conditions continued into late June/early July 1999, when a series of convective and frontal systems brought steady rainfall amounts that were helpful in reducing the surface moisture deficits. Hydrologic deficits, however, still existed in mid-July.
With the exception of the most severe events, which can span entire years (e.g., 1961–69, 1980–81, 1988–89 and 1995), droughts in Vermont tend to be a summer phenomenon. When they occur during the cooler time of the year (winter and spring), their impacts, intensity, and other characteristics are somewhat different from droughts that occur during the warmer months. In a climate that is best described as changeable, it is sometimes challenging to interpret climate signals from one season to the next. The dry conditions that have plagued the state since October 1998 have alternated with periods of above-average precipitation receipt. As such, the intensity and occurrence of drought among the state’s three climatic divisions (Northeastern = 1; Western = 2; and Southeastern =3), as shown in Figure 1, have varied over the period of interest. The quest for determining the drought signal is even further complicated by the fact that the monthly time scale may be inappropriate for adequately describing the nature of dry conditions across Vermont during the cooler time of the year.