A slow moving trough is forecast to move onto the northeast of Northland later
today, bringing outbreaks of rain to the area. Some heavy falls are possible in
the east north of Whangarei by this evening.
Meanwhile, a low is expected to deepen over the north Tasman Sea and
move slowly south towards northern New Zealand on Sunday and Monday.
The low is expected to bring a strengthening northeast flow and even
heavier rain to Northland during Sunday, and to Coromandel Peninsula
and Bay of Plenty from late Sunday morning or afternoon through to
Monday morning or possibly longer. Heavy rain is expected to develop
in Gisborne and the ranges of Hawkes Bay during Sunday afternoon as a
strong to gale easterly flow spreads over central and southern parts
of the North Island. Rain should ease in the Hawkes Bay ranges by
Monday night, although moderate to heavy falls are likely to continue
in the Gisborne ranges through to Tuesday morning and possibly even
into Wednesday, depending on how slowly the low departs to the east.
Rainfall amounts in all these areas are likely to exceed 100mm about
the hills and ranges, with 200mm or possibly more in the ranges of
Coromandel Peninsula and Gisborne over several days. People in these
areas are advised to look out for rapidly rising rivers and streams,
and be prepared for local surface flooding and slips.
FOR THE LATEST WEATHER AND FORECAST CHARTS PLEASE GO TO
MORE DETAILED INFORMATION FOR EMERGENCY MANAGERS AND TECHNICAL USERS FOLLOWS:
HEAVY RAIN WARNING
AREA/S AFFECTED: NORTHLAND COROMANDEL PENINSULA BAY OF PLENTY GISBORNE AND THE
HILLS AND RANGES OF HAWKES BAY
Rain is expected to return to northeastern parts of Northland by this
evening,with possible heavy falls in the east north of Whangarei.
However, the heaviest and most widespread rain is expected during
Sunday morning and afternoon in a strengthening northeast flow. In
the 24 hours from 6pm Saturday to 6pm Sunday,expect 100 to 120mm of
rain about the eastern hills north of Whangarei, with 50 to 80mm
possible elsewhere. The heaviest falls are expected Sunday morning,
when rates could reach 20mm per hour about the eastern hills.
COROMANDEL PENINSULA AND BAY OF PLENTY WEST OF TE PUKE, INCLUDING THE
Heavy rain is expected to develop late Sunday morning or afternoon in
a strengthening east to northeast flow. In the 24 to 30 hours from
about 9am Sunday in Coromandel Peninsula and midday further south,
expect 120 to 170mm of rain near the ranges, with 60 to 90mm at lower
levels. Note that heavy rain could continue through to Tuesday in a
strong to gale easterly flow.
BAY OF PLENTY EAST OF TE PUKE
Heavy rain is expected to develop early Sunday afternoon, but should
become confined to the extreme eastern ranges east of Opotiki by
Sunday night. In the 12 hours from midday to midnight Sunday, expect
50 to 80mm of rain, especially in the eastern ranges, where a further
100mm is possible through Monday and early Tuesday.
Heavy rain is expected to develop Sunday afternoon, as a strong to
gale easterly flow develops over the area. In the 36 hours from 3pm
Sunday to 3am Tuesday,expect 100 to 150mm of rain, with 200mm likely
about the ranges north of Ruatoria. The heaviest falls are expected
overnight Sunday and Monday morning,when rates could reach 25mm per
hour about the ranges. Note, further moderate to heavy rain is
possible about the ranges through the remainder of Tuesday and even
Wednesday in a strong southeast flow.
THE HILLS AND RANGES OF HAWKES BAY
Heavy rain is expected to develop Sunday afternoon and continue
through to Monday afternoon before easing Monday evening. In the 24
hours from 3pm Sunday to 3pm Monday, expect 100 to 120mm of rain.
Heaviest falls expected overnight Sunday or Monday morning, when
rates could reach 15 to 20mm per hour.
NEXT SEVERE WEATHER WARNING WILL BE ISSUED AT OR BEFORE
9:00pm Saturday 27-Jun-2009
Forecast prepared by: Andy Downs
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