1. PPJ Topics: Weather, ITCZ, and Passage Making
Sylvia Seaberg & Tom Condy - SV Cinnabar
Pacific Puddle Jump Seminar
2018/2/7 La Paz, BCS, Mexico

2. Introduction
Objective: Share some ideas learned from our two PPJs in 2016, 2017 on two different bluewater cruising sloops to provide helpful info for our fellow PPJ cruisers.
Weather Considerations
ITCZ Considerations
Passage Considerations (separate slide deck)
Disclaimer – we are not authorities; use info at your own risk.

3. Weather – Can be Perplexing!

4. Favorite Weather Resources
Saildocs server provides compact weather docs over sat phone, SSB, internet/web, etc. via .
Free to anyone (community service)
But supported by SailMail members ($270 /yr)
Just send an to
Typical WX briefing request – simple!:
Gets 2 grib forecasts, spot forecast, fleet code, 2 text forecasts, and Met Bob’s weekly weathergram.
WeFAXs over SSB Radio (not covered here)
send GFS:10S,20S,158W,140W|1,1|0,6..168|PRMSL,WIND,WAVES,RAIN,GUST
send GFS:04N,50S,146E,096W|5,5|0,6..168|PRMSL,WIND,HGT500,WAVES,RAIN
send Spot:16.32S,151.4W|5,6|PRMSL,WIND,WAVES,RAIN,GUST
send fleet.nadi
send nadi.sopac
send fr.poly.en
send nz.wgrm
*send fr.poly.long.en
*send fr.poly

5. Grib files – Get both large & small areas
Viewfax app – free grib file retriever, viewer. Get surface mb, 500 mb, winds, waves, rain,

6. Grib Files - Great, but…
Overall, gribs are enormously good for the main picture; better when used together with other products
However, gribs often:
Miss localized phenomena (e.g. squalls, shifts)
Underestimate wind strength
Aren’t the best with slow moving, amorphous, tropical air masses about the equatorial regions (i.e. ICTZ, SPTZ).
Are pretty good up to about 5 days out
Remember to heed the usual precautions (of computer model use)

7. NWS Spot Forecast Text forecast Specific lan/lon point Grib-based
Data extracted from file gfs z.grb dated 2017/11/10 16:55:14
Data extracted from file ww z.grb dated 2017/11/10 16:42:52
request code: Spot:16.32S,151.4W|5,6|PRMSL,WIND,WAVES,RAIN,GUST
Forecast for 16°19S 151°24W (see notes below)
Date Time PRESS WIND DIR WAVES DIR PER RAIN GUST
utc hPa kts deg mtrs deg sec mm/h kts : : : : : : : : : : : : : : : : : : : :
Refer to notice & warnings sent 2017/10/29 08:41:21, for another copy send a (blank) to:
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Text forecast
Specific lan/lon point
Grib-based
Easy, quick means to your local 5-day forecast

8. Fleet Code Fiji Met Svc Compact Text coded WX via email
Use ‘physplot.exe’ viewer (free) from pangolin.co.nz
Current/synoptic condx: crude wx map but w/SPCZ, ITCZ

9. Fiji Met Svc – Marine WX Bulletin
URL:
Date: 29 Oct :41:
Last-Modified: 29 Oct :03:
MARINE WEATHER BULLETIN FOR ISLANDS AREA
EQUATOR TO 25S BETWEEN 160E AND 120W.
ISSUED BY FIJI METEOROLOGICAL SERVICE EQUATOR to 25S between 160E and 120W
issued by Fiji Meteorological Service Oct UTC.
PART 1 : WARNINGS NIL.
PARTS 2 AND 3 : SYNOPSIS AND FORECAST VALID UNTIL Oct UTC.
TROUGH T1 03S 160E 08S 170E 15S 175E 20S 177E 25S 179E SLOW MOVING.
POOR VISIBILITY IN OCCASIONAL SHOWERS, HEAVY AT TIMES AND FEW
THUNDERSTORMS WITHIN 210 NAUTICAL MILES OF T1.
TROUGH T2 11S 177E 16S 176W 20S 169W SLOW MOVING. POOR VISIBILITY IN
OCCASIONAL SHOWERS AND FEW THUNDERSTORMS WITHIN 180 NAUTICAL MILES OF
T2.
WEAK TROUGH T3 14S 171W 09S 165W 05S 159W SLOW MOVING. POOR
VISIBILITY IN OCCASIONAL SHOWERS, HEAVY AT TIMES AND ISOLATED
THUNDERSTORMS WITHIN 150 NAUTICAL MILES OF T3.
WEAK TROUGH T4 11S 157W 09S 147W 12S 140W 15S 135W 25S 123W SLOW
MOVING. POOR VISIBILITY IN SOME SHOWERS WITHIN 150 NAUTICAL MILES OF
T4.
STATIONARY FRONT SF 15S 157W 20S 148W 25S 140W. POOR VISIBILITY IN
SOME SHOWERS WITHIN 150 NAUTICAL MILES OF SF.
IN THE AREA SOUTH OF 20S AND BETWEEN 175W AND 145W, EXPECT EASTERLY
WINDS 20 TO 25 KNOTS, ROUGH SEAS. MODERATE SOUTHERLY SWELLS.
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Synopsis and forecast
Coverage area spans Fiji , Tonga, Samoa, Cooks, Fr Poly:
Equator S 160E W

10. French Met– Marine WX Bulletin
URL:
Date: 06 Feb :14:
French Polynesian Weather in Broken English
EXPERIMENTAL USE ONLY
This is an experimental translation of French Polynesian Weather forecasts.
Words in UPPER CASE are original French. Words in lower case are all translated.
You can find the original text here:
bulletin marine from 06/02/2018 to 02:00 UTC valid until 07/02/2018 to 02:00 UTC.
A : no warning current/during nor provided.
B : .
C : .
D :
situation general from 05/02/2018 to 1200UTC : - high pressure 1023 mbar center by/through 37S 141W nearly stationary.- area low pressure with a first minimum to 1001 mbar center by/through 22S and 153W, maintaining a time disturbed from north-west TUAMOTU until towards the SOCIÉTÉ and the north AUSTRALES.
A35EST MARQUISES : UA HUKA - HIVA OA
north-east 11/16KT coming tuesday morning to sector east, sea moderate.
A40OUEST MARQUISES : EIAO - NUKU HIVA
north to north-east 11/16KT locally 17/21KT, gusts 25KT.sea moderate.
B35
north-east TUAMOTU : PUKAPUKA
north north-east 11/16KT coming tuesday morning to sector east on half north area , sea moderate, showers isolated.
B40
north TUAMOTU : NAPUKA - TAKAROA
north 11/16KT, sea moderate, showers isolated, squalls on the south from the area.
. . .
Synopsis and forecast
Coverage area spans all 5 island groups of French Poly
Translation by SV Sarana

11. (Cont’d) French Met– Marine WX Bulletin
. . .
TAHITI / west TUAMOTU : TAHITI - FAKARAVA - ANAA
north north-east 11/16KT locally 17/21KT, gusts 35KT underneath squalls, sea moderate to locally rough, rain, showers and squalls locally stormy.
C50
ILES underneath the wind : MAIAO - HUAHINE - RAIATEA - MAUPITI
on the quarter south-west from the area : low pressure 04/08KT coming to sector north-east monday evening, sea slight. elsewhere north north-west 11/16KT, gusts 30/35KT underneath squalls, sea moderate to locally rough, showers and squalls locally stormy.
D30
GAMBIER : MANGAREVA - TEMOE
east north-east 07/10KT, gusts 25/30KT underneath squalls, sea slight to moderate, showers isolated.
...
east RAPA : MAROTIRI
sector east 17/21KT easing monday evening 11/16KT, gusts 25/30KT. sea moderate.
E40
HOULES MARQUISES : swell long from north-west 1M increasing 1.5M tuesday morning.
TUAMOTU : swell long from south 1M on the half east of TUAMOTU. elsewhere, swell long from north-west from 1M increasing 1.5/2M tuesday morning.
GAMBIER : swell long from south 1M.
SOCIETE : sea from wind north-west 1.50/2M. swell long from north-west 1 M increasing 1.5/ M tuesday morning.
AUSTRALES : sea from wind easterly 2M/2M50.
RAPA : sea from wind easterly from 1.5M.
Broken English provided for free by Eric from
Contact me through my website if you locate severe errors. Please include the section of original text for debugging.
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(cont’d)
Short and long forecast versions

12. Weather Routing Benefits: Downsides:
Potentially safer, faster, more comfortable passages and better seamanship if weather conditions are anticipated
With pro service:
Expertise supplements one’s own analysis
Uses powerful routing software (SW) for you
‘Extra crewmember’
Downsides:
Costs, comms, hassles, info/forecasts not always correct
Via applications – Expedition SW, Open CPN, other, etc.
Via web services – Predict Wind, Squid, etc.
Via weather router services – Professional meteorologists

13. Pro Weather Router Services
We’ve had good experiences
Used occasionally on long and/or complex passages
Found the fee “menu” is very reasonable
Did not use on either PPJ trips
Plan to use for Tonga – New Zealand passage
Here are the two recommended routers with excellent track records that I have used:
commandersweather.com/ - Ken Campbell based in New Hampshire
- Rick Schema based in Hawaii.
Ask for staff with direct experience in your area of interest

14. Routing – Expedition Software (SW)
With gribs, generates optimal routes
Isochrones
All-in-one overlay of weather, track, routes, &charts is extremely helpful

15. Routing – Expedition SW Result - Table
Result – tabular output
Waypoints
TWS, TWA
BSP
Headings
Motor, Sail times
ETA, Duration

16. Routing – Expedition SW
Geo-ref’d images overlay
Satellite photos
WX faxes
Streamline analysis, etc
Open CPN is gaining similar
Expedition SW is very expensive ($1200), but includes updates for life. Racing oriented – used by worlds top teams. Healthy learning curve. Powerful but quirky GUI.

17. ITCZ Definition - Inter-Tropical Convergence Zone
A broad area of low atmospheric pressure located in the equatorial region where the NE and SE tradewinds converge, extending between 10 N and 10 S latitude. The hot, humid air becomes buoyant, rises and cools, forming clouds, frequent heavy thunderstorms, and the doldrums.

18. ITCZ Observations Crossing - conventional wisdom says:
Cross zone quickly (orthogonally) at “narrow” location; nominally aim for around 130 W lon
1st trip – Heavy squalls/rain/wind/waves for many days – rather miserable. Crossed ~128 W (diagonally - oops)
2nd trip – Moderate condx and tolerable. Crossed ~ 128 W
Both trips - doldrums at times motored off/on (3-4 days total). Bring sufficient fuel.
Both trips – squally wx both above and below equator
Some sailors reported all nice wx, others worse wx
It’s a gamble!
1st Trip – 3AM, wind increased to 34 kts, clocked around through 270 deg, big challenge to avoid accidental jib.

19. ITCZ - Sources - NHC High Seas Synopsis & Forecast
< edit: abbreviated – for seminar>
URL:
FZPN03 KNHC HSFEP2
HIGH SEAS FORECAST
NWS NATIONAL HURRICANE CENTER MIAMI FL
0430 UTC TUE FEB
SUPERSEDED BY NEXT ISSUANCE IN 6 HOURS
SEAS GIVEN AS SIGNIFICANT WAVE HEIGHT...WHICH IS THE AVERAGE
HEIGHT OF THE HIGHEST 1/3 OF THE WAVES. INDIVIDUAL WAVES MAY BE
MORE THAN TWICE THE SIGNIFICANT WAVE HEIGHT.
SECURITE
E PACIFIC FROM THE EQUATOR TO 30N E OF 140W AND 03.4S TO THE
EQUATOR E OF 120W
SYNOPSIS VALID 0000 UTC TUE FEB 06.
24 HOUR FORECAST VALID 0000 UTC WED FEB 07.
48 HOUR FORECAST VALID 0000 UTC THU FEB 08.
INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
TROUGH FROM 08N73W TO 06N77W TO 07N85W TO 06N90W. ITCZ CONTINUES
FROM 06N90W TO 05N100W TO 07N109W TO 06N116W TO 09N125W. ITCZ
RESUMES FROM 10N128W TO 09N136W TO BEYOND 08.5N140W. SCATTERED
MODERATE FROM 07N TO 10N BETWEEN 135W AND 140W.
One of the few products to DEFINE loc. of ITCZ
FZPN03.K - NHC HIGH SEAS FORECAST EQ-30N, E of 140W
to: Send FZPN03.KNHC

20. ITCZ – Sources Streamline Analysis
NWS Hawaii (HNL)
Wind flows – good for light air tropic areas
37 KB size
Link to image

21. ITCZ - Sources - NOAA Tropical FB
Curr Sfc Fcst FAX 20S-30N, E of 145W; size 28KB
FTPmail to:
open
cd fax
get PYFA90.TIF
quit

22. ITCZ – Sources US Navy (FNMOC) Precipitation
Excellent – 40KB size
Prev 6 hr precip from NAVGEM WX model from the USN
SV “All Day” Vlad had a small BW image of this working in PPJ Yahoo Group.
Saildocs errors on the URL format.

23. Final Thoughts
S. Hemi Weather – is upside down! It takes effort to comprehend. Corenman’s Letters From The SoPac is a great overview. (Latitude 38)
Fr Poly Weather – is more volatile than advertised; often cloudy/squally. The tropic atmosphere seems very dynamic.
Satphone/GO!/Iridium – Not carried on either passage (ours broke). Valuable tool; looking to re-aquire soon.
Light and Lumpy Condx – Have a solution for boom slam and sail slatting. We use a preventer, reefing, secured eqpt.
Boat setup – Have solutions for ventilation, sun shade, rain/wet, bug screens.

24. Conclusion – Buen Viaje! Bon Voyage!
Wherever you go, no matter what the weather, always bring your own sunshine – Antiony J. D’Angelo

25. Extra Slides

26. 2 PPJs Passages - Stats - Route Dist. ~2700 nm
Cinnabar /4-4/21
Crew: pers
Time: days
Avg BSP: kts
Avg Dist/Day: nm
Longest Day: nm
Smallest Day: nm
Eng Time: hrs
Genset Time: hrs
Approx Fuel: gals
Shindig /24 – 4/11
4 pers
19.2 days
5.8 kts
153 nm
163 nm
102 nm
88.9 hrs
25.0 hrs
121 gals
Cinnabar is a Schumacher 52, disp 15 tonnes; Shindig is an Oyster 485, disp 20 tonnes

27. Route vs Actual Tracks
Shindig
Cinnabar

28. FNMOC - E Trop Pac 6-hr Precip
Vlad’s small-size (9KB), B&W image version from 2016.

29. NWS WeFax Symbols