Received: from zonker-fddi.hpl.hp.com by opus.hpl.hp.com with SMTP (1.37.109.8/15.5+ECS 3.3+HPL1.1) id AA12428; Thu, 3 Aug 1995 18:50:42 -0700 Return-Path: <poulton@zonker.hpl.hp.com-DeleteThis> Received: by zonker.hpl.hp.com (1.37.109.8/15.5+ECS 3.3+HPL1.1) id AA02006; Thu, 3 Aug 1995 18:50:35 -0700 Date: Thu, 3 Aug 1995 18:50:35 -0700 From: Ken Poulton <poulton@zonker.hpl.hp.com-DeleteThis> Message-Id: <9508040150.AA02006@zonker.hpl.hp.com-DeleteThis> To: wind_talk@opus.hpl.hp.com-DeleteThis Subject: Re: suscribe
$r $wx/winds*
windspeed.info --- SF Bay Area wind/weather information by e-mail.
$Header: windspeed.info,v 1.16 95/06/21 00:23:50 poulton Exp $
=== Windspeed mailing lists ===
Lists maintained by listserv@jr.hpl.hp.com-DeleteThis:
wind_afternoon Automatic hourly wind reports from noon to 6 pm daily.
wind_thresh Automatic wind reports when the wind is over
15 knots (during daylight hours).
wind_24 Automatic wind reports every hour.
wind_talk Discussion other than current wind reports.
To unsubscribe: send e-mail to listserv@jr.hpl.hp.com-DeleteThis with the contents
unsubscribe <list_name>
To subscribe: send mail with the contents
subscribe <list_name> <your_first_name> <your_last_name>
To switch to a once-a-day digest for wind_talk, send
set wind_talk mail digest
To switch back to separate messages for wind_talk, send
set wind_talk mail ack
For more info about these mailings, the data and listserv, send this:
info <list_name>
You can also get windspeed reports on demand - simply send a message
to windreport@jr.hpl.hp.com-DeleteThis (the contents don't matter). But please
do not poll this hourly; it loads the machine too much and can cause
all the wind reports to stop.
For web browser access to the wind_* lists and more, see
http://www.crc.ricoh.com/~jackg/windsurf.html
=== Policy on what should be posted ===
For wind_thresh, wind_afternoon and wind_24:
I (poulton@hplabs.hpl.hp.com-DeleteThis) post hourly reports from Northern
California airports.
Other *current* wind reports (e.g., from windtalkers) are okay.
Send these to "windspeed@jr.hpl.hp.com-DeleteThis" and they will go to all four
lists.
Anything else that should be announced to Bay Area windsurfers in
general, e.g., cleanup days, sewage spills, threats to windsurfing
access locations. Please also post these to rec.windsurfing if
possible.
For wind_talk:
Sailing reports.
Equipment reports - failures, reviews.
Equipment for sale.
Whatever else you want to say, hopefully windsurfing-related.
When you *reply* to a message, remember that most mailers will reply to
the whole mailing list rather than just the original author. If that
is your intent, fine, but when sending a personal message, please
remember to address the message manually.
=== How to post messages ===
To post to wind_talk, send e-mail to wind_talk@jr.hpl.hp.com.-DeleteThis
=== About the data ===
The windspeed data is now reported in knots. It was formerly converted
to mph, but that conflicted with the SFO phone, etc, so everything
(except the Bay Area forecast) is now in knots. Pre-June92 data files I
have stored are in mph, but all are marked with mph or knots.
You can get windspeed reports on demand - simply send a message
to windreport@jr.hpl.hp.com-DeleteThis (the contents don't matter). The standard
report will come by return e-mail. Please don't set this up for regular
polling because that will load my workstation unduly. Problems to
windspeed-request@jr.hpl.hp.com.-DeleteThis
=== Multiple mailings ===
Sometimes we get two mailings per hour. The reason is as follows.
The primary network data source that supplies all the current readings
(don't ask where) has gotten reaaal slow of late. It appears that the
network connection to that whole subnet is very heavily loaded (like,
20-50% of the packets fail on a ping). This causes my data retrieval
script to fail fairly often. It retries, but the result is that data
from this source is often 15-30 minutes after the hour.
I also have a secondary source, but the data there is much sparser and
watered down for use by the public. In particular, the wind direction
is reduced to w, nw, n, etc. I dislike using this source for SFO because
there is a big windsurfing difference between 270 and 290.
My compromise is to mail with the secondary data (for SFO only) if the
primary source does not come through by 14 minutes past the hour. In
this case, the secondary-source SFO data shows up at the very end of the
message, with time nn59 and a direction ending in "4" (indicating a
resolution of 45 degrees in the direction). When the secondary source
does come through, we get a second mailing with the real data.
=== Reporting locations ===
NWS and the FAA maintain separate weather operations at SFO. The FAA
operates the 877-3585 "AFIS" recording, while NWS does the reports
we get by network. They share the temperature and dewpt instruments, but
for wind the NWS has one instrument near the intersection of the two main
runway pairs, while FAA has 6 instruments around the runways. One
other important difference is that FAA reports magnetic directions,
while NWS reports true directions. To convert, add 17 degrees
(rounded to 20, generally) to the FAA (phone) report to get true readings.
The terminal forecasts use true directions as well.
The "SOSF" data in the network reports comes from South SF on San Bruno
Mountain. I was told it is at 810 feet elevation (the ridge peak is at
1000-1200 feet) and at the nearer end of the ridge. It seems to read
2-3 knots higher than the meters at the airport.
There are broadcasts on 118.45 MHz every 30 seconds called "Shoreline
Departure". This is apparently from the SOSF instrument. It requires
an aircraft-band scanner to receive. The $20 Radio Shack aircraft radio
can just barely get this from Coyote and 3rd Ave. Real (digital)
scanners cost $60 (AC-powered) to ~$200-300 (walkie-talkie size); they
can get this signal from at least as far south as Palo Alto.
San_Luis_O is San Luis Obispo down the coast, not San Luis Resevoir.
Travis_AFB is about 20 miles NW of Rio Vista and seems to have similar
conditions to Rio.
The Dread ASCII Graphics Map of the California Coast
With Apologies to NOAA map MSC-9.
'#' marks the points used to mark coastal forecast region boundries.
---------------- CA - OR border --------------------
# Pt St George Crescent City 41.8 deg lat
+
+ Eureka 40.8
+ Cape Mendocino 40.4
+
+ Pt Cabrillo Ft Bragg 39.4
# Pt Arena 38.9
+ Bodega Bay Santa Rosa 38.4
+ Pt Reys 38.0
+ GG SF 37.7
+ Pillar Pt Half Moon Bay 37.5
+ San Jose 37.4
+ Pigeon Pt 37.2
+ Santa Cruz 37.0
# Pt Pinos Monterey 36.6
+ Pt Sur 36.4
+
+ Pt Piedras Blancas 35.6
+ San Luis Obispo 35.3
# Pt Sal Santa Maria 34.9
+ Pt Conception Santa Barbara 34.5
+++++++++
+ LA, etc 33.8
+
------ CA - Mex border 32.5
=== Examples of decoding the "cryptic comments" ===
SKY /CRYPTIC COMMENTS
heights/100ft
-----------------------------------
clr
Clear
clr /st w-n mdt cu e-se
Clear, stratus west to north, moderate cumulus east to southeast
5 sct /fbnk w-n
Scattered clouds at 500 feet, fogbank west to north
30 sct
Scattered clouds at 3000 feet
30 -sct
Thin scattered clouds at 3000 feet
clr /h alqds
Clear, haze all quadrants
7 sct 12 bkn
Scattered clouds at 700 feet, broken clouds at 1200
clr /cu tcu omtns ne-e
Clear, cumulus and towering cumulus over mountains northeast to east
clr / k nw
Clear, smoke northwest
35 sct 250 sct /mdt cu dsnt ne=
Scattered clouds 3,500 feet, scattered 25,000, moderate
cumulus distant northeast
15 -sct 40 -sct 120 -sct /k15 -sct cbs dsnt ne-e mdt cu dsnt s sw ag fire 3w few ac ne-s
1,500 thin scattered, 4,000 thin scattered, 12,000 thin scattered,
smoke tops 1,500 feet, thin scattered cumulonimbus distant
northeast through east, moderate cumulus distant south to southwest
agricultural fire 3W?, few altocumulus northeast through south
=== Common wind patterns ===
A common pattern for good summer days is to have 5-10 knots W to NW
during the night and morning, often with a lull around noon where the
wind drops and shifts to N to NE. In the next two hours the wind will
swing around to NW and pick up to 15 to 20 knots between 2 and 6 pm.
If the sky is clear or low clouds are clearing, a good morning breeze
(NW 8-10 knots) usually means a good afternoon wind.
When the marine clouds come far into the bay (e.g., morning overcast
over the whole bay), SFO may remain under the clouds and have fairly
mild wind readings (~~15 knots) all afternoon, but Coyote and 3rd can be
cranking if they are beyond the clouds. This is most easily seen from
the multi-city "sky" sections: if SFO is reporting *low* clouds (e.g, "9
sct" or "8 bkn") then it is under the marine clouds. If Hayward is
clear, then the cloud line is somewhere over the Bay, and Coyote and 3rd
are probably blowing hard. The clouds run in a stream only a couple of
miles wide from SFO to Hayward; about the time the clouds get to Hayward
the wind at Coyote and 3rd will shut off.
When we get very thick marine layers, we will often get fog coming over
the hills way down the peninsula. This often causes a west wind over
much of the Peninsula, but may cut off Coyote (wrong direction for the
NW-facing San Bruno gap, plus the wind is more diffused). This will
generally show up as a SFO wind direction less than 290. Sometimes
Oyster Point and Flying Tigers will blow in this case, and the winds can
be higher than those recorded at SFO. 3rd Ave can also have
significantly steadier winds. If the fog is coming over the hills as
far south as Woodside, then Palo Alto is a good bet. Wind on the water
is generally 2-5 knots more than that recorded at the Palo Alto airport.
Depending on where the fog line is, other good locations may be Crissy
or Berkeley. If the fog/clouds are coming well inland each night, Rio
Vista and San Luis Res are generally good. These locations tend to
crank up late in the afternoon (4 to 6 pm), blow all night and subside
sometime mid-morning. They fairly often get over 25 knots.
=== Tides and Hazards ===
These discussions use location-adjusted tide values.
For sailing at Palo Alto, we used to need a tide level of at least 4 feet.
With the new dock, 2.5 feet seems to be okay if you stay in the little harbor
channel until you pass the downwind point. The "deep"-water channel runs
right next to the white poles; everything else near the shore is mud
flats at +1 to +2 feet. Hazards: there seems to be something hard at
about +6.0 near the downwind point several hundred yards out.
For 3rd Ave, +3 feet is the limit for the old launch by the blue tanks
(using the SM-adjusted tides, a little over +2 feet for GG height). At
the new launch (fenced lot) +2.5 feet is fine. +2.0 feet is still okay
for launching but is beginning to make hazards of the 4 sandbars between
the launch and the channel. The bars are: 1) along the edge of the
channel, from the channel marker south - 0 ft near the marker, +1.5 ft
near the bridge; 2) about halfway from the old launch to the channel
marker - +1 ft; 3) two bars very near the new launch, maybe 0 feet.
For Coyote Point, 0 feet is fine (you have to walk out 100 yards, but
the mud is less than 6 inches deep). There was a recent report of a
sandbar at about -1 feet just outside the swim area, however. There is
also now a post broken off at about +1 ft, situated halfway between the
two remaining posts on the side of the swimming area next to the launch
beach. Another sailor reported a 1" pipe at a 45 degree angle, top at
about +2.5 ft, about 3/4 of the way along the swim area and maybe 50 yards
upwind from the poles (just downwind of a beam reach from the upwind
corner of the swim area).
At Crown Sterling, 1 foot is enough to launch, but you need 2.5 feet to
be clear of the sandbars. The main one lies across a line between the
Crown Sterling launch and the pole in the water just south of the runway
piers (this line is nearly directly across the usual wind). It sits
about two thirds of the way from the shore to the pole, running roughly
parallel to the wind direction, maybe half a mile long. The upwind end
is at 0.0 feet, the downwind end is at +0.4 feet. There is another at
around -0.5 ft around 100 feet upwind of the pole and another downwind
of the pole (may be continuous). There is some other kind of
obstruction at -1 to 0 ft further out along the same line. Near the
shore, there is a pole with its top at +1.0 ft; it is 125 yards north of
the hotel and 30 yards from the shore.
Mariott's requires at least +5 feet (SM-adjusted, or +4 GG) to launch.
Haskins Ave requires about +3 feet to launch.
Michael's Beach needs about 0 feet to launch.
In all the above locations, remember that there are often big rocks
sitting on the bottom in otherwise just-barely-passable water. (Kirk
broke an ankle that way.)
Oyster Point, Candlestick, Crissy field and Berkeley seem to have no
problems at low tides.
Point Isabel is also pretty much always sailable. One must always pay
attention to the submerged rocks near the access point, no matter what
the tide level is. Also, the water can get pretty shallow near the
opposite shore---the new housing development in Richmond.
At Powerlines (Sherman Island) some of the levee riprap at the launch
openings goes under water at high tides, creating hazards if you sail too
close (I broke a finbox this way).
At San Luis forebay, 219 feet is the danger level (it's pumped, not tidal).
=== Site-specific etiquette ===
Fisherman at some locations have had their lines broken by too-close
windsurfers. They asked that we not sail within 100 yards of any
fishing areas - a reasonable request. The fishing areas I know of at
sailing sites would include the pier at Candlestick, the pier at Oyster
Pt, the point between Oyster Pt and Tigers and the point just north of
the main beach at Coyote.
=== Mailing list additions and deletions ===
Send requests for mailing list additions and deletions to
listserv@jr.hpl.hp.com.-DeleteThis (From HPdesk, use
"'listserv'/hp1900/um(listserv@jr.hpl.hp.com-DeleteThis)") The legal commands are
given below.
Everything appearing in [] below is optional; everything appearing
in <> is mandatory.
Recognized requests are:
help [request]
--------------
Without arguments, this file. Otherwise get specific information on the
selected topic.
subscribe <list> <your name>
----------------------------
The only way to subscribe to a list.
unsubscribe <list> (or: signoff <list>)
---------------------------------------
Remove yourself from the specified list.
which
-----
Get a listing of discussion lists to which you have subscribed.
set <list> [<option> <value>]
-----------------------------
Without the optional arguments, get a list of all current settings for
the specified list. Otherwise change the option to the new value for that
list.
recipients <list> (or: review <list>)
-------------------------------------
Get a list of all people subscribed in the specified list.
information <list>
------------------
Get information about the specified list.
statistics <list> [subscriber email address(es)]
------------------------------------------------
Get a list of subscribers along with the number of messages each one
of them has sent to the specified list. If the optional email addresses
are given, then statistics will be collected for these users only.
lists
-----
Get a list of discussion lists that are served by this server.
index [archive | path-to-archive] [/password]
---------------------------------------------
Get a list of files in the selected archive, or the master archive if
no archive was specified.
get <archive | path-to-archive> <file> [/password] [parts]
----------------------------------------------------------
Get the requested file from the specified archive. Certain subparts may
be obtained by specifying them as optional arguments.
=== Files Available ===
You can get various files from the listserv by sending a message to
listserv@jr.hpl.hp.com-DeleteThis with the message "get wind_talk <file>" where
<file> is one of these:
file contents
---- -----------------
SFBA A description of the SF Boardsailing Association
safety_guide The SFBA safety guide
SF_info Kirk Lindstrom's FAQ for SF Bay sailing
archive The whole wind_talk archive. 2 MB in 32 chunks of 66 KB.
windspeed.info This information file - wind_* FAQ, plus misc SF Bay info
=== People ===
I sail mostly Coyote Point and 3rd Avenue; I wear a yellow helmet
and a blue PFD; my Previa has Gorge Racks and license "KEN KATI".
If you see me, say hi!
=== Other Electronic Windsurfing Forums ===
There is another windsurfing mailing list called windsurfing@fly.com-DeleteThis;
this has a world-wide focus and readership. Send the message "help" to
windsurfing-request@fly.com.-DeleteThis
For those with access to Usenet (network news), there is a newsgroup
rec.windsurfing, also with global focus and readership.
=== Other Windsurf Weather Reporting Services ===
There are three commerical services providing windsurfing reports now.
Windsight is the major wind report provider in the Gorge; they have made
a big investment in wind sensors in the Bay Area in the last year. You
get an account and call an 800 number to get information; they bill your
account by the time on the phone. Call 1-800-934-2278 for account info.
Call of the Wind is a new service that operates via pagers. 1-800-WINDCALL
Pacific Bell is operating a new windsurfing information service.
To get it, you have to subscribe to their Message Center service.
For all of the above services, sensor location is a big issue. At locations
such as Coyote, 3rd Ave and Crissy, the previaling wind pattern has an
offshore windline, leading to very different conditions on the water vs.
on the beach.
=== Acknowledgements ===
Much of this data is provided by the University of Michigan "Weather
Underground" project, a National Science Foundation funded effort to
provide weather and environmental information for educational and
research purposes. Redistribution of this data for non-commercial
purposes is permitted, provided that the University of Michigan Weather
Underground project is credited as the data source. Commercial users
who wish to redistribute the data should contact us via email at
sdm@madlab.sprl.umich.edu-DeleteThis to make arrangements, or contact our data
provider, Alden Electronics (508-366-8851) to acquire their own data
feed.
For more information about the Unidata project, contact
support@unidata.ucar.edu.-DeleteThis For more information about the Weather
Underground, contact sdm@madlab.sprl.umich.edu.-DeleteThis
This archive was generated by hypermail 2b29 : Mon Dec 10 2001 - 02:29:47 PST