When to interpolate

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Ronald Miller, modified 6 Years ago.

When to interpolate

Youngling Posts: 6 Join Date: 9/24/12 Recent Posts

I'm sure that there is work being done to Forecast Builder to accomodate NBM3.1 when it arrives this fall. We have a suggestion that's kinda been bugging us during the SuperBlend era of FB. Namely, why are grids interpolated to hourly at Step 2 & 3? Instead, it seems to us that it would be better for Steps 2 & 3 to just populate the NBM grids directly, which are generally 3-hrly TC1 grids after 36 hours. This would make it easier for forecasters to look over the T, Sky, SnowLevel, MaxTwAloft, etc, grids, make any needed edits. Then FB would interpolate these to hourly when it's doing it's integrity checks before Step 4. As it is now, forecasters are constantly having to re-interpolate manually if they make any edits.

Ron

Nicholas Langlieb, modified 6 Years ago.

RE: When to interpolate

Youngling Posts: 5 Join Date: 1/20/15 Recent Posts

Hi Ron,

In the current latest_stable version there is a config item, interpolateOnPopulate. If you set this to False then the interpolation will not occur until the consistency checks in step 4. This is for the following grids:

Wind

WindGust

Sky

PoP

SnowLevel

MaxTwAloft

ProbRefreezeSleet

ProbIcePresent

This does not apply to the ForecastBuilderCRON in which all grids will be interpolated. Hopefully this will help out with the issue you have brought up.

-Nick

Ronald Miller, modified 6 Years ago.

RE: When to interpolate

Youngling Posts: 6 Join Date: 9/24/12 Recent Posts

Nick, you're right. That's what I was looking for. But I would also like to see it in the FB Cron. Is there are reason that my Config setting doesn't apply to the cron script? To my way of looking at it, the cron script just replaces/forces Steps 2 & 3, so the same rationale would apply (i.e. allow the forecasters to review/edit the grids populated via cron before they run Steps 4-6).

Ron

Andy Just, modified 6 Years ago.

RE: When to interpolate

Youngling Posts: 89 Join Date: 6/2/15 Recent Posts

Ron,

The interpolate is forced in the CRON procedure so it can produce the precipitation type probabilities, SnowAmt and IceAccum. Additionally, we have had a growing number of requests to have the CRON procedure produce the Wx grids, which would also require the interpolate. Essentially, we would make the CRON procedure an approach to giving a complete first start to the entire forecast.