NWS prediction doesn't even agree with itself! - SailNet Community

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  #1  
Old 02-23-2012
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NWS prediction doesn't even agree with itself!

I've often noticed that the NWS Marine prediction contradicts itself. I've posted todays forecast for the SF Coastal waters below. Notice that the high winds discussed in the synopsis are not reflected in the daily forecast.

Synopsis...GULF OF THE FARALLONES...AND CORDELL BANK NATIONAL MARINE SANCTUARIES...STRONG AND GUSTY NORTHWEST WINDS WILL CONTINUE OVER THE COASTAL WATERS TODAY AS STRONG HIGH PRESSURE REMAINS OVER THE EASTERN PACIFIC. GALE FORCE WINDS WILL BE POSSIBLE OVER THE OUTER WATERS AND OCCASIONAL GALE FORCE GUSTS WILL BE POSSIBLE OVER THE INNER WATERS. WINDS WILL GRADUALLY DECREASE TONIGHT AS HIGH PRESSURE WEAKENS.

Today: NW wind 8 to 11 kt. Sunny. Mixed swell...WNW 11 ft at 14 seconds and SSW 1 ft at 16 seconds. Wind waves around 2 ft.
Tonight: NW wind 6 to 11 kt becoming variable and less than 5 kt after midnight. Clear. Mixed swell...WNW 11 ft at 13 seconds and SW 1 ft at 15 seconds. Wind waves 1 to 2 ft.

11 Knots is not "strong" wind in the SF bay, much less offshore! Just checked the actual wind speeds offshore, and they are already in the mid 20's.
The Accu Weather model I use because I find it more accurate agrees with the NWS synopsis. I know wind is difficult to predict (especially in Winter). However I would expect a prediction to agree with itself! Unfortunately, I think most people are likely to skip the wordy synopsis, and look at the daily prediction. Today, they would be in for a surprise!
Have others noticed this discrepancy elsewhere?

Last edited by L124C; 02-23-2012 at 02:38 PM.
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Old 02-23-2012
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Two of my favorite acronyms:

NOAA = Not Overly Accurate Administration

and (in the voice of Porky Pig?)

NWS = Not Weally Sure
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Old 02-23-2012
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A long deceased friend and former Conch from the lower Florida Keys once said to me "If I fished by NOAA Weather I would have either starved to death or drowned." He was a commercial shrimper for the better part of 30 years, then became a charter fishing captain for another 30 years before passing away. I'll never forget his statement till the day I die.

Cheers,

Gary
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Old 02-23-2012
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PBzeer has a spectacular aura about PBzeer has a spectacular aura about PBzeer has a spectacular aura about
National Data Buoy Center

When offshore, I check the forecast to the buoy data, which is actual conditions, not forecasted ones.
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Old 02-24-2012
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NOAA weather radio accuracy is questionable at times..
Last May crossing Florida Bay enroute to Key West:

"Wind SE 5 to 10 knots, seas 2-3 feet"
Actual? Winds S 15 gusting about 20 beating into 6-8 ft seas..Coast Guard station in Key West came on 16 asking vessels to report actual conditions..guy comes on and says.."well, it ain't 2 feet"
That said it was sunny and warm and despite our bash fest it was still a fun trip. :-)
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Old 02-24-2012
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Quote:
Originally Posted by travlineasy View Post
A long deceased friend and former Conch from the lower Florida Keys once said to me "If I fished by NOAA Weather I would have either starved to death or drowned." ---
Gary
Gary - You and I must have hung out with the same type of fishermen at one time or another. The shrimpers I knew were in Georgia but the attitude was the same.
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Old 02-24-2012
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Besides the National Data Buoy Center which PBzeer linked to NOAA does have a lot of other products that give you a much wider view of conditions. It is really up to you to check as many sources as you can and not just rely on one encapsulated statement.
I give you NOAA (not always accurate) marine weather fax charts: Radiofax Charts - Pt. Reyes, CA
Check the wind strength and wave heights of the entire ocean before heading out and while afloat if you have the internet connection.
Local weather is just that. Local and it will not always be accurate. The big picture helps explain why a local forecast may be made that is not, so much.
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Old 02-24-2012
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Quote:
Originally Posted by PBzeer View Post
National Data Buoy Center

When offshore, I check the forecast to the buoy data, which is actual conditions, not forecasted ones.
Well...If you are offshore, you ARE a weather station! What ever will happen, WILL HAPPEN, and you will be the first to know with 100% accuracy! Obviously, the point of a forecast is to anticipate conditions you may face BEFORE you are in them. The point of my OP was not that the NWS is not very accurate, but that it doesn't even agree with itself. Which is very scary! Maybe they are hedging their bets. At least half of the forecast will be correct!
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Old 02-24-2012
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I think that you are looking at this a bit in the wrong way.
No one, not even NOAA with all its buoys, satellites and other weather stations can predict local weather as well as you can on the ground or the surface of the water. From your synopsis they said: "GALE FORCE GUSTS WILL BE POSSIBLE OVER THE INNER WATERS" which means wind up to about 39 knots. They will never know how the weather will play out until it does but they only PREDICT what will happen in you local area. Basically, they got it right. You just need to know enough to read it all and figure out for yourself if there is a threat of bad weather you are willing to deal with, or not. The problem is that the more you read the more possible threats you might find and you might never leave the dock if you believed everything they forecast for your area. That is why looking at the broader weather picture is more then helpful.
Keep in mind that most NOAA forecasts, either weather fax or even live buoy data give you the "highest 1/3 of the waves" which means that 2/3 of the waves could easily be higher then their forecast shows.
Local conditions. Yes, you are your own weather station.
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Old 02-25-2012
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Quote:
Originally Posted by CalebD View Post
I think that you are looking at this a bit in the wrong way.
No one, not even NOAA with all its buoys, satellites and other weather stations can predict local weather as well as you can on the ground or the surface of the water. From your synopsis they said: "GALE FORCE GUSTS WILL BE POSSIBLE OVER THE INNER WATERS" which means wind up to about 39 knots. They will never know how the weather will play out until it does but they only PREDICT what will happen in you local area. Basically, they got it right. You just need to know enough to read it all and figure out for yourself if there is a threat of bad weather you are willing to deal with, or not. The problem is that the more you read the more possible threats you might find and you might never leave the dock if you believed everything they forecast for your area. That is why looking at the broader weather picture is more then helpful.
Keep in mind that most NOAA forecasts, either weather fax or even live buoy data give you the "highest 1/3 of the waves" which means that 2/3 of the waves could easily be higher then their forecast shows.
Local conditions. Yes, you are your own weather station.
Huh? If you are "on the ground or water", you are experiencing the weather and not predicting it (other than in a very immediate sense).
It was not "my" Synopsis, the NWS's produced it. How did they "get it right" if the actual conditions (buoys) agreed with the synopsis ("strong and gusty winds"), but not the daily forecast ("8 to 11 kts")? If you don't think the synopsis should be reflected in the forecast, please explain why. If you think the synopsis was reflected in the forecast please explain how. They seem completely unrelated to me! As I see it, the synopsis is a discussion of the conditions on which the NWS is basing their prediction. Seems like they should be related!

Oddly, the definition of synopsis is:
1: a condensed statement or outline (as of a narrative or treatise) : abstract
They way the NWS uses it, the synopsis expands the discussion, while the daily forecast condenses it. Anyway, I think they should at least agree!

Last edited by L124C; 02-25-2012 at 03:21 AM.
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