PAT CALDWELL
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SwellCaldWell Updated 3 PM Monday, February 17, 2025
DATE |
SWELL HGT |
SWELL DIR |
SWELL PER |
SURF H1/3 |
SURF H1/10 |
TREND |
PROB |
WIND SPD |
WIND DIR |
TREND |
1 PM |
5 |
NW |
20 |
10 |
15 |
UP |
11-16 |
NNW |
UP |
|
02/17 |
2.5 |
NNW |
10 |
2 |
4 |
DOWN |
|
|
|
|
|
2.5 |
W |
9 |
2 |
3 |
DOWN |
|
|
|
|
TUE |
9 |
WNW |
16 |
15 |
20 |
SAME |
LOW |
8-12 |
E |
SAME |
02/18 |
|
|
|
|
|
|
|
|
|
|
WED |
8 |
WNW |
15 |
14 |
18 |
DOWN |
LOW |
8-12 |
E |
SAME |
02/19 |
|
|
|
|
|
|
|
|
|
|
THU |
7 |
NW |
14 |
10 |
14 |
DOWN |
LOW |
8-12 |
E |
SAME |
02/20 |
|
|
|
|
|
|
|
|
|
|
FRI |
5.5 |
NW |
14 |
7 |
11 |
DOWN |
LOW |
8-12 |
E |
SAME |
02/21 |
|
|
|
|
|
|
|
|
|
|
SAT |
3.5 |
NW |
13 |
5 |
7 |
DOWN |
LOW |
5-10 |
E |
DOWN |
02/22 |
|
|
|
|
|
|
|
|
|
|
Table Definitions given after Discussion
Summary
Active midwinter pattern.
Discussion
Midday Monday 02/17 on northern shores has rising surf above the seasonal average from 310-320 degrees of 16-22s intervals. Heights are predicted to remain elevated on Tuesday.
On this day, 02/17, in the historical H1/10 visual surf observation Goddard-Caldwell database (starting 9/1968) for the north shore of Oahu, the average is 8.0 Hs, (16’ peak face, Oahu Surf Climatology) and the largest surf on this date was 35 Hs (sets 70’ peak face top spots) in 1983—middle of a strong El Nino winter.
Moon’s view
- NWPAC to central NPAC winter mode dominated by cyclonic circulation.
Kurils low hurricane force low 2/13-16—two parts, 310-320 and 295-310 degrees
- Backstory:
- Part 1—310-320 degrees. A low deepened to ~950 mb off the Kurils Thursday 2/13. It occluded right away, coinciding with maximum strength (hurricane force), broadening of the gyre, and stalling of the track.
- The center was nearly stationary for 3 days into Saturday with the 310-320 degree fetch slowly weakening.
- Sunday saw the 310-320 degree fetch stretch east to the Date Line, at which point the aim became more west to east—NE of Hawaii. This fetch is fading 2/17.
- Pulse status:
- NOAA NW Hawaii buoy 51001 ramped up sharply Sunday night in the 16-21s band. Deep water swell to 10’.
- PacIOOS/CDIP Hanalei buoy to 7’ swell by 1PM 2/17, while Waimea around 5’. Just goes to show you how much more a swell jacks up upon breaking with the longer period energy. Cams showing above average surf. Sets are inconsistent given the long travel and the sharp focus in the long period bands.
- Prognosis:
- The 310-320 degree energy should peak on Tuesday then slowly drop into
- Part 2 Kurils system 2/14-16—295-310 degree energy
- The broad gyre aforementioned began to focus dominant strength over the 295-310 degree band starting Friday 2/14 hugging Japan stretching eastward. Seas grew over 30’
- A captured fetch was set up with the fetch reaching the Date Line Sunday about 1200 nm away.
- The pattern weakened sharply 2/17.
- This more WNW energy should overlap the aforementioned.
- Some Kauai/Niihau shadow issue down-swell islands.
- It should be filled in on Tuesday and hold about the same on Wednesday.
- Slow downward trend into Saturday.
Midday Monday 02/17 on the east side has breakers way below the trade wind swell average. Similar surf on Tuesday.
Windward wind-head concerns —
- Hovering just below the desired threshold this week.
East side surfer interests—
- Whole lotta nada, Country swells placing east side mostly in shadow.
Midday Friday 02/17 on southern shores has tiny to small breakers, highest on W-exposures. More of the same on Tuesday with W-exposures nosing up.
On this day, 02/17, in the historical H1/10 visual surf observation Goddard-Caldwell database (starting 1972) for the south shore of Oahu, the average is 1.4 Hs, (~3’ peak face) and the largest surf on this date was 5 Hs (10’ peak face) in 1999 from S under 10 knot E winds— rare winter, above average southern hemi.
Moon’s view:
- Some systems hugging Antarctica SE of New Zealand— low odds.
Antarctic low 2/13-15
- A fetch stretched NE from the ice sheet aiming highest at the Americas with mostly middle gales. There may be some tiny to small breakers locally within 2/21-23 from 180 degrees.
Into the long range, let’s see what Wooly Worm is up. Lunch time, I hear lots of noise in the kitchen. There’s Wooly with a big pot of stew. Good sign plenty more winter goodies to come. Models show next WNW/NW rising above average Sunday 2/23 with new events spaced about 3 days apart right out to the end of Feb and start of March.
The next SwellCaldWell forecast will be issued Wednesday, February 19.
Climatology update (February 4, 2025) to include through January 2025:
Summary (click below for details of each)
North shore, month of January 2025: Above average for XL days (sub giant) in January, nsstat01 otherwise near to below average. For the start of the 24/25 season, looking good, above average for Xl to giant, nmstat09_01.
South shore, month of January 2025: Minimal from southern hemi but near average from west or local konas, ssstat01.
Wind-heads: January 2025: Fresh+ trades days wayyyyy below average, wwstat01. So much for the positive correlation between enhanced fresh trades and La Nina winter months in Hawaii. Southerly konas average, with post-frontal N-component winds above average.
Climate Fun 1.
Monthly Stats
North Shore Oahu (1968-present):
January: nsstat01
February: nsstat02
March: nsstat03
April: nsstat04
May: nsstat05
June: nsstat06
July: nsstat07
August: nsstat08
September: nsstat09
October: nsstat10
November: nsstat11
December: nsstat12
South Shore Oahu (1972-present):
January: ssstat01
February: ssstat02
March: ssstat03
April: ssstat04
May: ssstat05
June:ssstat06
July: ssstat07
August: ssstat08
*Picts surf forecaster validation duties Big Wednesday 8/18/21
(photos Shredsniper.com, Mike Carroll)
September: ssstat09
October: ssstat10
November: ssstat11
December: ssstat12
Wind (1988-present, PC’s best guess):
January: wwstat01
February: wwstat02
March: wwstat03
April: wwstat04
May: wwstat05
June: wwstat06
July: wwstat07
August: wwstat08
September: wwstat09
October: wwstat10
November: wwstat11
December: wwstat12
Seasonal Stats
North Shore Oahu, 1968/69-2023/24; (full season, September to June): nmstat09_06
North Shore Oahu, 2024 new season (Sept-DEC): nmstat09_01
South Shore Oahu, 1972-2024 (March thru November): smstat03_11
Helpful links,
Educational outreach: Waves 101– Why Surf Varies Time/Place
Table Definitions
DATE |
Represents daylight hours in zones of high refraction (biggest surf spots |
SWELL HGT |
Deep water swell (H1/3) height (feet) corresponding to a nominal (~3 mile) location |
SWELL DIR |
Deep water swell direction (from) centered on 16 point compass bands. |
SWELL PER |
Deep water swell period (seconds). |
SURF H1/3 |
Breaker H1/3 (defined above) height (feet, peak face) during most active envelopes. H1/3 |
SURF H1/10 |
Average of highest 1/10th of all breakers (feet, peak face) during active envelopes; |
PEAK FACE |
Trough to crest height (feet) on shoreward side of breaker at moment and location along |
Ocn H1/100 Cleanup or Sneaker set |
Waves arrive within a range of sizes. Surf zone enthusiasts emphasize the smaller percent |
TREND |
Breaker height (wind speed) tendency during daylight |
WIND SPD |
Wind speed (knots) for nominal coastal location on the windward side relative to |
WIND DIR |
Wind direction (from) centered on 16 point compass bands. LV refers to light and variable. |