Growing season moisture deficit is evaluated for the northeastern United St
ates for the period 1895 through 1996. Moisture deficit values are calculat
ed using the Thornthwaite/Mather water budget analysis technique. This tech
nique allows for the estimation of soil moisture parameters using only mean
monthly temperature and monthly precipitation values. Thus, soil moisture
estimates can be derived for periods extending back to the nineteenth centu
ry with the use of climate division data. For the northeastern United State
s taken as a whole, growing season moisture deficit values show no evidence
of a consistent long-term trend over the period 1895 through 1996. However
, the entire region has been subject to decadal-scale variations in moistur
e deficit, the most pronounced being an anomalous moist period that extende
d from the late 1960s through the 1980s. A regionalization of growing seaso
n moisture deficit indicates the existence of 3 spatially distinct regions
across the northeastern United States. One region extends along the Atlanti
c Coast from the Chesapeake Bay, north to the coast of Massachusetts and in
land to the higher terrain of the Catskill and Pocono Mountains. A second r
egion includes most of northern New England and northeastern New York, whil
e a third region encompasses southwestern New York, western Pennsylvania an
d West Virginia. Each region has diverse time series of moisture deficit va
lues for the period of record. Severe moisture deficit growing seasons are
more strongly associated with negative precipitation anomalies than with po
sitive temperature anomalies in the Northeast. The negative precipitation a
nomalies are associated with a decrease in both the frequency and intensity
of precipitation, which occurs in conjunction with a decrease in the frequ
ency of convective rainfall events. Consistent upper-tropospheric flow patt
erns are associated with the driest and wettest growing seasons.