Accumulation tool broken across models
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Ive noticed for some time, even after recent changes, that the accumulation tool does not work properly. Across models, the accumulation calculation is not correct based on the underlying data.
It seems the tool is simply integrating the rain rate over a different time period than the slider is set. For example, for a rain event that lasts 4 days, the accumulation should be maximum when the 4 day slider is moved to capture the whole event. But I find the accumulation calculation is higher when the slider is advanced to capture time before it starts raining but misses the tail end of the event.
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@userJeff Could you please provide some examples with screenshots?
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@Suty thank you for reading this. Its hard to capture this in screenshots just due to the detailed nature of rainfall integration. But here are three screenshots that suggest the narrative.
The first screenshot is the rain/thunder layer at 6pm Tuesday showing the storm system just about to strike the coast of northern California. This layer suggests the start of substantial rainfall is after 6 pm Tuesday with little rain before that.
The next screenshot zoomed in closer on Eureka, CA as an example shows the 4 day accumulation starting at 6pm Tuesday. The 4 day accumulation over this interval is displayed as about 6.3 inches.
The third screenshot with the picker over the same location shows the 4 day accumulation but starting 10 hours earlier at 8 am. The 4 day accumulation over this earlier interval is displayed as about 7.6 inches. Its strange there is over an inch of additional precipitation when the rain/thunder layer shows little activity over these 10 hours. If anything this time interval should show less rain as its missing the end of the storm that lingers into Saturday.
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The forecast changed slightly since I last posted but another easy screenshot I can do to show something is off is the hourly forecast for Tuesday
If adding up the hourly precip between 8 am and 6 pm there is well under 1 inch of precip over this interval, only about 1/4 inch.
