surf zone forecast
National Weather Service Honolulu HI
700 PM HST Fri Nov 21 2008
Hiz005>011-221900-
Oahu-
700 PM HST Fri Nov 21 2008
Surf along north facing shores will increase to 7 to 9 feet through
Saturday.
Surf along west facing shores will increase to 4 to 6 feet through
Saturday.
Surf along east facing shores will be 2 to 4 feet through Saturday.
Surf along south facing shores will be 1 to 3 feet through Saturday.
Outlook through Thursday Nov 27:
the incoming northwest swell will decrease and become more north
northeast on Sunday and Monday. A new moderate swell from the
northwest will arrive Monday and peak on Tuesday.
Surf heights are forecast heights of the face or front of waves. The
surf forecast is based on the significant wave height in the zone of
maximum refraction. Some waves may be more than twice as high as the
significant wave height. Expect to encounter rip currents in or near
any surf zone.
&&
Collaborative nearshore swell and wind forecast for Oahu
NWS/ncddc Honolulu HI
300 PM HST Fri Nov 21 2008
This collaborative forecast will be updated Monday through Friday at
300 PM when pat Caldwell is available. When pat Caldwell is not
available...the latest collaborative forecast will remain posted for
4 days.
Forecast swl dmnt dmnt h h hgt wind wind spd
date hgt dir pd 1/3 1/10 tend prob spd dir tend
1 PM 3 N 11 4 6 down 7-10 se same
11/21 2 ENE 9 2 4 down
2 S 14 2 4 down
Sat 5 NW 12 8 10 same high 11-16 se up
11/22 2 N 9 2 4 down low
5 ESE 6 2 2 up low
Sun 3 N 10 4 6 up low 17-21 E up
11/23 6 E 7 2 4 up low
Mon 3 N 10 4 6 same low 17-21 E same
11/24 7 E 8 4 6 up low
2 WNW 17 2 4 up low
Tue 4 NW 15 6 8 same low 17-21 E same
11/25 7 E 8 4 6 same low
Wed 4 NW 14 6 8 down low 17-21 E same
11/26 7 E 8 4 6 same low
Legend:
swl hgt open ocean swell height measured from trough to crest
in feet located 20 nautical miles offshore
dmnt dir dominant direction typically +/-10 degrees in 16 Compass
points
dmnt pd dominant period in seconds
h1/3 significant wave height in the surf zone
h1/10 average height of the highest one-tenth waves in the surf
zone
hgt tend height tendency of swell (valid values: up/down/same)
prob probability of occurrence (valid values: high/Med/low)
wind spd open water wind speed measured in knots located
20 nautical miles offshore
wind dir wind direction in 16 Compass points
spd tend wind speed tendency (valid values: up/down/same)
Surf heights will vary between different beaches and at the same
beach at different break areas.
Discussion:
summary...
mostly below seasonal average surf for North Shores into mid week.
Detailed...
mid Friday on northern shores has small surf from 350-010 degrees
with 9-12 second periods. This episode is declining. A new event is
expected around Sundown Friday evening.
A gale low pressure formed about 1500 nm NW of the islands on late
Tuesday...with about 18 hours of fetch in the 315-325 degree band
reaching to within 800 nm of Oahu Wednesday morning. The wind speeds
dropped rapidly Wednesday afternoon.
Buoy 51001 began showing low magnitude energy from this source late
Friday morning. Local surf should pick up after Sundown today...peak
in the moderate category on Saturday from 315-325 degrees...then
drop to small heights by early Sunday.
Near gales associated with a broad...stationary low pressure system
se of Kodiak...Alaska hovered over a fetch in the 000-010 degree
band about 2000 nm away on Wednesday through Thursday. A small
episode is expected locally...building Sunday and dropping Tuesday.
The jet stream is shifting into a zonal pattern from the Kuril
Islands eastward to the longitudes of Hawaii...sending back to back
gales rapidly eastward...and leading to overlapping...mostly small
episodes with peak moments to the moderate category next week into
the Holiday.
The first system had severe gales east of hokkaido...Japan late
Wednesday...with the head of the fetch about 2500 nm away late
Thursday. The
system tracked toward the Aleutians...aiming swell mostly well north
of Hawaii on Friday.
A small...long-period episode from 300-315 degrees is due late
Monday...peaking on Tuesday in the upper-end small category.
Models show several gale areas along the zonal band between 40-50n
latitude from the Kurils to the dateline...which should coincide
with new arrivals late Tuesday into Wednesday...of at least similar
magnitude...perhaps a notch higher.
Mid Friday on Eastern Shores has small breakers from leftover trades
from about a day ago. See the latest NWS state weather discussion
forecast for explanations of the unsettled weather and winds for the
weekend.
Fresh trades from 70-100 degrees are expected on Sunday...holding
into mid week...with a return to moderate windswell by Monday.
Mid Friday on Southern Shores is tiny to occasionally small from a
weak southern hemisphere source. Other than chop from the south
component to the local wind over the weekend...no significant surf
is expected.
Into the long range...no surf expected from southern hemisphere
sources. From the North Pacific...a moderate NW episode is expected
on Thursday holding into Friday. Models suggest a winter Mode
setting up in the North Pacific...bringing above average seasonal
surf starting roughly 11/28 out about a week. An alternating pattern
of highs and lows passing by immediately north of the state should
lead to quasi-daily wind changes from around the Compass starting
late next week out about a week. Long range estimates are subject to
radical rehashing.
This collaborative forecast will be resumed on Monday...November 24.
This forecast was produced through the collaborative efforts of
NWS and ncddc. Please send suggestions to W-hfo.Webmaster@noaa.Gov
or call the warning coordination meteorologist at 808-973-5275.
Additional resources:
see /in lowercase/ http://www.Prh.NOAA.Gov/hnl/pages/marine.Php
$$
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