WX Beta Testers

EPAC zonesEPAC Beta Testers FAQs

Thanks for being part of the trial phase of  the new East Pacific Coastal Forecasts from NOAA!  Your feedback will be sent to NOAA forecasters and will help improve this important service.

The following will help you get a sense of what the EPAC team has been working on to get to the trial phase of the program, and what has to be done before the product becomes official December 1, 2014. Part of the process involves cruisers such as yourselves. Your help in evaluating the forecasts, the zones, special areas and conditions you experience are invaluable, our friends at NOAA say.

The answers to each question come from correspondence with NOAA forecasters, so you’ll notice that it is very conversational, and sometimes uses technical jargon. If there is anything that you don’t understand, use the Comment Box at the bottom and we’ll try to get an answer as quickly as we can.

 

 General Questions

1.  Where does the information come from?

These experimental text forecasts are being generated off NOAA’s 10km by 10km gridded database [GRIBs]… based on the latest global computer model runs (GFS, ECMWF, UKMET, NAM, etc.).

2.  Will a real person be evaluating the forecasts?

Yes and No. The text forecasts will be running automatically on a “cron” [automatic updates generated by computer], every 6 hours for now, during the experimental phase.  Forecasters will not be Quality Controlling [QC’ing] the data on a routine basis until closer to the planned official implementation date of Dec. 1st.

That being said, please keep in mind that the forecasters ARE constantly examining current observations, satellite, radar, and evaluating the latest global model to construct and update the gridded database.  We are even in the process of taking those forecaster value-added winds to run our own local wave model so that the 2 parameters  (winds and waves) are completely coordinated. 

3. What about wave information?

Partitioned wave data will fall out of that local wave model giving us a better picture of all wave groups (wave height, direction and period per wave group) which will one day soon also be included in the text forecasts. Please note that the text formatters (software) that we use to then generate the text products which you would receive during the trial period are not 100% perfect.  Thus the caveat that the output will not be always QC’d should be applied until Dec 1.

 4. There are a bunch of new forecast zones that are somewhat unfamiliar. Can you explain how they were created?

Our East Pacific Offshore Waters Forecast zones start at the Mexico/California border and out to 250 NM,  all the way to Ecuador. The zones are based on climatology, political boundaries, jump points, etc.

We utilized the Quickscat scatterometer / satellite climatology database when configuring the actual zones, as well as when configuring the “local effect” areas which will subdivide said zone, along with sailing routes/points, etc. These local effect areas help to break up a large zone into pieces so that we can better capture localized wind and sea effects for a particular area.

 5. Can you please explain how these “local effect areas” are represented in the new zones?

Currently we have the following local effect areas  (click to see map here):

PMZ013 within 60 nm of shore, PMZ015 within 60 nm of shore, PMZ023 (old PMZ021 with addition of central Gulf of CA zone) near Cabo Corrientes,  PMZ027 (old PMZ025) Gulf of Tehuantepec, PMZ113 Gulf of Papagayo, PMZ115 near the Azuero Peninsula, and PMZ117 Gulf of Panama.  The local effect areas themselves need to be “large” enough / cover enough area within a particular zone to trigger the special wording.  That being said we would gladly take feedback on such areas as well.

5.a The new zones are very large. How will NOAA forecasters deal with small areas that produce dangerous winds, like the Tehuantepec, or the Chubascos of the Northern Sea of Cortez?

We are subdividing some of the zones into smaller areas which will be included *if* certain criteria are met.  For example, the zone that contains the Gulf of Tehuantepec will have a special “local effect area” so that if a Gale is to occur there it will be broken out into more detail separately (GULF OF TEHUANTEPEC… ), with the remainder of the zone labeled as ELSEWHERE… This will capture special areas quite nicely (e.g. Gulf of Papagayo, near Cabo Corrientes, Gulf of Panama, etc.).

6.  How does it compare or differ from existing NOAA products and the weathergrams of Bob McDavitt, Baja Geary’s Sonrisa Forecasts, SolMate Santiago’s SailMail offerings?

7.  How will the final product differ from the experimental one?

During the period from May 1 to Dec 1 we will be working to adjust our workflow and deadlines for current products for the forecasters that would be issuing the Pacific Offshore Waters Forecasts once they would become official Dec 1. Until that point, the text output will be generated automatically on the crons that I mentioned and they will not be QC’d on a routine basis until Dec 1, at which point they will ALWAYS be QC’d prior to transmission.   A synopsis section describing weather conditions during the next 5 days will be provided when forecasters start issuing the final product.

Once the proposed/experimental Offshore Waters Forecasts become official, we will have a Marine Weather Discussion to accompany the forecast product.  In the meantime we will talk about the Gulf of California and other Gulfs in the tropical weather discussion products most of the time.  If the weather is benign then unfortunately the forecaster on duty may not make any mention of these particular areas.

8. And when the product becomes “official”?  What can we expect in terms of weather discussion?

We do plan on either 1) adding a new Marine Weather Discussion to cover all of the zones out to five days, regardless of wind speed and wave heights (no criteria, all weather will be discussed regardless) -or- 2) by updating / upgrading the format of our current Tropical Weather Discussion to do the same.  Either way, yes, there will be a detailed discussion out to 5 days for the zones regardless of criteria.

 9. What kind of feedback from sailors will help NOAA in the development of the EPAC Offshore Forecast?

“Yes indeed, I could not agree more about the role of social engagement in weather forecasting.  Having help from cruisers and all of their feedback is priceless.” – Jeffrey Lewitsky

Regarding observations, with no buoys at all in those zones we would gladly welcome any.  Currently we get the occasional ship observation and also satellite altimeter passes, but compared to our Atlantic waters we have maybe 5% of the observations coming in for the Pacific that we do in the Atlantic. (See more below)

 

QUESTIONS ABOUT USING THE EXPERIMENTAL FORECASTS

 1.  How can they be used safely during its experimental phase?

Please understand the limitations by reading the above explanations. If you have any questions, please post them at the Southbound Net website.  So far, forecasters at the National Hurricane Center of NOAA are simply labeling them “experimental.” That being said, you should consider the forecasts as just another set of information when making your passage plans.

2.  How do I get the forecasts?

There are two ways, depending on whether you have access to the Internet, or not.   If yes,  you can go to this URL for the Mexico forecasts:

http://www.nhc.noaa.gov/experimental/epoffshores/data/WRKOFFPZ7

For Central America to Ecuador, point your browser here:

http://www.nhc.noaa.gov/experimental/epoffshores/data/WRKOFFPZ8

If you are restricted to High Frequency Radio, you can request the forecasts through Saildocs. Here is how you do it:

 

To request current forecast for Pacific Mexico, send email to query@saildocs.com
with this in the body of the message: send OFFPZ7
For Central America-Ecuador send this: send OFFPZ8
For multiple days of forecasts:
(this will subscribe you for 5 days)
sub OFFPZ7 days=5
If you want to get the latest every time
you check your mail, do this:
 sub OFFPZ7 interval=1

Note:  if you do have Internet, you can also use your normal email program or webmail to request documents from Saildocs using the same method.

3.  What  does the “header” mean at the top of the forecast?

Below is a typical “header” you will find at the top of each forecast.

URL:  http://www.nhc.noaa.gov/experimental/epoffshores/data/WRKOFFPZ7

Date: 30 Mar 2014 10:06:19                                          10:06:19 Time sent  (Pacific Time)
Last-Modified: 30 Mar 2014 09:01:03                       09:01:03 -0000 Time forecast created
Expires: 30 Mar 2014 10:11:19 -0000                         (After this time you should get a fresher forecast
TEST01 KNHC 300900                                                  Test identifier – ignore
OFFPZ7                                                                               OFFPZ7   This is the Mexico forecast.

(OFFPZ8   would be for Central American to Ecuador)

230 AM PDT SUN MAR 30 2014                                   First  forecast of the day (there are four updates/day)

4.  We got your forecast in the zone we were traveling in and it was wrong.  Is there anything we should do to report this anomaly?

“Absolutely!   Please advise the participants that any weather data is helpful, and not to worry if they don’t have a working instrument such as a barometer or anemometer, the rest of their observation will make it to us even if it’s only vessel name plotted at their position. “ – Forecaster Martin

If you have the Airmail program, you can submit weather and position reports by configuring the program to submit them whenever you use it to send regular email. For more information on submitting WX reports see here and here.

5. Add another important question here by submitting it in the Comment Box below.

6. Or add another one here the same way.

 

New NOAA Zones and Comparisons

Below are the 14 new zones . They are precisely defined by coordinates, and their boundaries are influenced by climatology, political boundaries (Mexican States and countries), and common cruiser jump points. Contrast these to the ones many cruisers are currently familiar with, which focus on popular passage routes (“Northern Crossing”,  “Mazatlan to Banderas Bay”, etc.) and promontory points with enhanced winds.

 

A comparison of the new zones and old are tabled on next page.

 ZONE  LON LAT  LOCATION  COMPARABLE 1:  SOLMATE SANTIAGO COMPARABLE 2:  SONRISA
PMZ011 -117.749 30.187 EAST PACIFIC WITHIN 250 NM OF THEUS MEXICO BORDER TO PUNTA EUGENIA ENSENADA – CEDROS Spot forecasts at Ensenada, San Quintin
PMZ013 -114.953 23.405 EAST PACIFIC WITHIN 250 NM OF
PUNTA EUGENIA TO CABO SAN LAZARO
CEDROS – SAN LAZARO Spots:  Turtle Bay, Abreojos,
PMZ015 -114.953 23.405 EAST PACIFIC WITHIN 250 NM OF CABOSAN LAZARO TO CABO SAN LUCAS SAN LAZARO – CABO FALSO Spots:  Mag Bay,  Cabo Falso
PMZ017 -113.466  29.931 NORTHERN GULF OF CALIFORNIA SEA OF CORTEZ NORTHERN HALF (north of 27N) Northern Sea:Baja Side, Center, Guaymas 
PMZ019 -110.194 25.945 CENTRAL GULF OF CALIFORNIA
PMZ021 -110.194 25.945 SOUTHERN GULF OF CALIFORNIA SEA OF CORTEZ SOUTHERN HALF (south of 27N) Southern Sea: East Cape,  Center, Mazatlan
  MAZATLAN TO BAHIA BANDERAS Spot: Mazatlan, Puerto Vallarta
PMZ023 -106.744 19.902 ENTRANCE TO THE GULF OF CALIFORNIA INCLUDING CABO CORRIENTES CABO CORRIENTES TO MANZANILLO Spot : Cabo Corrientes (promontory forecast)
PMZ025 -102.52 15.897 EASTERN PACIFIC WITHIN 250 NM OF
MEXICO MICHOACHAN AND GUERRERO
MANZANILLO TO BAHIAS DE HUATULCO Spot: Manzanillo, Zijuatanejo
PMZ027 -97.381 13.898 EASTERN PACIFIC WITHIN 250 NM OFMEXICO OAXACA AND CHIAPASINCLUDING GULF OF TEHUANTEPEC TEHUANTEPEC
 
PMZ111 -91.813 12.042 EASTERN PACIFIC WITHIN 250 NM OFGUATEMALA AND EL SALVADOR
PMZ113 -88.672 10.329 EASTERN PACIFIC WITHIN 250 NM OFNICARAGUA AND NORTH COSTA RICA
INCL.  THE GULFS OF FONSECA AND PAPAGAYO
PMZ115 -84.389 6.574 EASTERN PACIFIC WITHIN 250 NM OFCOSTA RICA AND WEST PANAMA
PMZ117 -80.249 -0.85 EASTERN PACIFIC WITHIN 250 NM OFECUADOR INCLUDING GULF OF GUAYAQUIL

 

 

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