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Old 07-03-2015, 11:22   #1
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GRIB Data Anomalies

Downlaoding GRIBs while waiting for a weather window to hop around the corner to the San Blas. Got the attached GRIB this AM which shows winds of over 100 knots across the area, but just for one time period. Pretty obviously an anomaly (either in the raw data, which I haven't checked, or of the viewer), but don't think I'll go then just in case! ;-)

First time I've run across this. Anyone else encounter this type of error with GRIB data/viewers?
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Old 07-03-2015, 12:59   #2
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Re: GRIB Data Anomalies

I don't see 100kt arrows anywhere? Those orange darts are wave direction. BTW, what model is this? There haven't been any due E winds here for weeks, and no forecast for anything more East than 30* or so.

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Old 07-03-2015, 13:27   #3
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Re: GRIB Data Anomalies

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Originally Posted by colemj View Post
I don't see 100kt arrows anywhere? Those orange darts are wave direction. BTW, what model is this? There haven't been any due E winds here for weeks, and no forecast for anything more East than 30* or so.

Mark
If you look closely, the wind barbs are 2 flags (50 knots each) or 2 flags and a short (105 kts). Small display in upper right of screen shows forecast condition a cross hairs (102 kts).

Darts represent waves and are of normal height and direction for prevailing conditions (not for the 100 kts wind or direction). Just the wind is really whacky.

This was from GFS and everything else in that GRIB file is normal for current conditions except this one frame.

Good news is that the normal GFS forecast shows winds abating and backing starting on Tuesday.

Normal display for Tuesday 1600 below. Crosshairs are just N of Porvenir.
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Old 07-03-2015, 13:31   #4
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Re: GRIB Data Anomalies

Very gusty in Buenaventura today. Still nasty around the San Blas?
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Old 07-03-2015, 13:44   #5
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Re: GRIB Data Anomalies

OK, maybe I see that. I just thought they were 20kt arrows.

I am looking at the same GFS model in zyGrib, and it doesn't show that - completely different wind strength and direction. I suspect it is a PocketGrib issue?

Winds aren't the problem here (20-25kts) - but the waves are the largest I have seen in 3 years. Even Tue-Wed will be 12-14'.

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Old 07-03-2015, 14:13   #6
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Re: GRIB Data Anomalies

Yeah, probably just a software issue or damaged data due to flaky internet here (never assumed it was valid).

Where are you getting wave height forecasts?
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Old 07-03-2015, 14:17   #7
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Re: GRIB Data Anomalies

can you post the grib file here, so we can try your file with different viewers?

Dirk
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Old 07-03-2015, 14:54   #8
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Re: GRIB Data Anomalies

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Originally Posted by belizesailor View Post
Where are you getting wave height forecasts?
I'm using the FNMOC-WWW3 wave height model, along with Chris Parker's forecasts.

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Old 07-03-2015, 15:30   #9
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Re: GRIB Data Anomalies

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Originally Posted by colemj View Post
I'm using the FNMOC-WWW3 wave height model, along with Chris Parker's forecasts.

Mark
I looked at WWW3 a few days ago, but will take another look.

I discussed NOAAs forecast of winds laying down early next week with Chris Parker and he did not agree with their forecast. Be interesting go see how it works out.

Just looking at RadioFax charts....Wow, I've never seen all the big wind features cranking at once in the region (Tehuantepecer, Papagayo, Colombian Low...)...27' max seas off Mexico! Yeeha!
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Old 07-03-2015, 15:31   #10
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Re: GRIB Data Anomalies

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Originally Posted by LeaseOnLife View Post
can you post the grib file here, so we can try your file with different viewers?

Dirk
Will give it a shot.

Update: nope. Mobile app only supports images. If you want it then PM me and I will email. The data browser view on PocketGrib shows the high winds too, but normal prevailing patterns immediately before and after so I suspect its corrupted data.
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Old 04-04-2015, 20:40   #11
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Re: GRIB Data Anomalies

We had 100 knot forecasted winds off coast of Baja a couple weeks ago. Just for one time period. Wasn't sure it would be anomaly so teleported home.


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