Three extreme precipitation events with peak observed rainfall of grea
ter than 700 mm over the South Island of New Zealand were simulated us
ing the DAR hydrostatic mesoscale model nested within the ECMWF analys
es. The ECMWF analyses for two of the events showed a low-level jet wi
th mixing ratios greater than 12 g kg(-1) crossing tbe South Island of
New Zealand during the heavy precipitation near a cold front. The thi
rd case, which had smaller mixing ratios, occurred as a tow-level jet
and crossed the South Island while a low redeveloped downstream. Three
different orographies were used with the 30-km horizontal resolution
model runs, with progressively increased terrain heights. The highest
orography was created by artificially inserting the effective barrier
of the Southern Alps to northwesterly how in the model grid. Orography
had a strong influence on the amount of precipitation: the peak preci
pitation was related to orographic slope while the area-averaged preci
pitation was related to the maximum orographic elevation. The model su
ccessfully simulated nearly half the peak observed precipitation and o
ver half the area-averaged precipitation (determined by hydrological m
eans) in two of the cases and much less in the third case. Refining th
e horizontal resolution from 30 to 15 km also increased the peak preci
pitation amounts. However, the area-averaged precipitation in the 15-k
m runs was not significantly larger than in the 30-km runs, suggesting
more concentrated precipitation over a smaller area. All simulations,
except the artificial barrier orography case, produced a mountain wav
e consistent with linear theory, in spite of the nonsteady flow, irreg
ular orography, and the large amount of diabatic heating present. The
amplitude of the mountain wave increased with mountain height and reso
lution. The absence of a mountain wave in the run with the artificial
barrier orography indicates unrealistic flow for that configuration.