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September Discusssion--winter bound or bust


moneypitmike

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One hell of a cold shot on the GFS op later in the period for the Plains. Wow.

 

 

 

Reminds me a bit of the Oct 2009 cold that set the stage for the back to back snow events on 10/16 and 10/18 that year. Not uncommon to get some big cold in October during developing El Ninos.

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Reminds me a bit of the Oct 2009 cold that set the stage for the back to back snow events on 10/16 and 10/18 that year. Not uncommon to get some big cold in October during developing El Ninos.

 

U got 2 get it frosty so u can snuggle when u watch Hocus Pocus on ABC Family

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That's one of the reasons why I hate how the NWS puts out those deterministic rain forecasts so far out. Yesterday afternoon OKX had like 1.3" for New Haven. While that's certainly possible - I'd say a reasonable range of possible QPF was 0.25"-1.75". Not sure how a super low confidence 1.3" does anyone any good.

 

It may take some time, but the trend has been established that probabilistic QPF is something customers and forecaster alike want to see. Many WFOs already develop these products, and I know we got some really intensive training two years ago about how it could be done in the grids without a huge learning curve.

 

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It may take some time, but the trend has been established that probabilistic QPF is something customers and forecaster alike want to see. Many WFOs already develop these products, and I know we got some really intensive training two years ago about how it could be done in the grids without a huge learning curve.

 

 

I agree with ranges, but not probabilistic QPF. So what does a 50% chance of 1", 67% chance of 0.75", 75% of 0.25", 95% of 0.10" mean??? What's the forecast? Give a range of 0.75-1.25" that you're  confident in.

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I agree with ranges, but not probabilistic QPF. So what does a 50% chance of 1", 67% chance of 0.75", 75% of 0.25", 95% of 0.10" mean??? What's the forecast? Give a range of 0.75-1.25" that you're  confident in.

 

I don't think we're ever going to satisfy everyone, and I know a lot of the general public would struggle with probabilities. At the same time, many of our key decision makers go based of confidence levels (i.e. plans get put into action once the chance of 1" of rain reaches 50%).

 

It's definitely one of the more interesting talking points within the NWS.

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It may take some time, but the trend has been established that probabilistic QPF is something customers and forecaster alike want to see. Many WFOs already develop these products, and I know we got some really intensive training two years ago about how it could be done in the grids without a huge learning curve.

 

 

 

I agree with ranges, but not probabilistic QPF. So what does a 50% chance of 1", 67% chance of 0.75", 75% of 0.25", 95% of 0.10" mean??? What's the forecast? Give a range of 0.75-1.25" that you're  confident in.

 

 

I don't think we're ever going to satisfy everyone, and I know a lot of the general public would struggle with probabilities. At the same time, many of our key decision makers go based of confidence levels (i.e. plans get put into action once the chance of 1" of rain reaches 50%).

 

It's definitely one of the more interesting talking points within the NWS.

 

Yeah there's no easy answer. I wish probabilistic forecasts were easy to understand for the public... we get forced into deterministic forecasts all the time regardless of certainty.

 

When I see the specific QPF forecasts to a tenth of an inch 48 hours out from the NWS I just laugh. I definitely wouldn't put that forecast out on TV (mostly because we don't have to... the public isn't clamoring for a rain forecast like a snow forecast) so I feel bad that they're forced to do it. I'd rather see ranges that are adjustable based on confidence. 

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Yeah there's no easy answer. I wish probabilistic forecasts were easy to understand for the public... we get forced into deterministic forecasts all the time regardless of certainty.

 

When I see the specific QPF forecasts to a tenth of an inch 48 hours out from the NWS I just laugh. I definitely wouldn't put that forecast out on TV (mostly because we don't have to... the public isn't clamoring for a rain forecast like a snow forecast) so I feel bad that they're forced to do it. I'd rather see ranges that are adjustable based on confidence. 

 

Some offices go even further than what you usually see online. And it has it merits too. I know BOX liked (likes?) to put as much data as is available into the grids. That way when the next forecaster blends in new data with the old it time lags things like QPF, which in theory should result in a more accurate forecast.

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Some offices go even further than what you usually see online. And it has it merits too. I know BOX liked (likes?) to put as much data as is available into the grids. That way when the next forecaster blends in new data with the old it time lags things like QPF, which in theory should result in a more accurate forecast.

 

I feel like there's a big difference between what you're working with in the grids and what you put out to the public though. Even if in order to popular grids you have a specific forecast for a point... shouldn't what you release to the public be more representative of the certainty? 

 

For example the 1.3" of rain in New Haven yesterday I probably would have felt more comfortable with a very wide range given the spread in guidance. Not sure if a specific total has much of a use to the end user if the number is quite uncertain. 

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I feel like there's a big difference between what you're working with in the grids and what you put out to the public though. Even if in order to popular grids you have a specific forecast for a point... shouldn't what you release to the public be more representative of the certainty? 

 

For example the 1.3" of rain in New Haven yesterday I probably would have felt more comfortable with a very wide range given the spread in guidance. Not sure if a specific total has much of a use to the end user if the number is quite uncertain. 

 

Well and that was some of the training that I mentioned. I wish I could remember the specifics now, but it basically generated a probability of outcomes based on our deterministic number. Like if we forecast 0.25" how often does it reach 0.50" or how often do we only get 0.10".

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Well and that was some of the training that I mentioned. I wish I could remember the specifics now, but it basically generated a probability of outcomes based on our deterministic number. Like if we forecast 0.25" how often does it reach 0.50" or how often do we only get 0.10".

 

That's pretty cool - makes sense. 

 

I wish there were easier ways to convey uncertainty to the public. It's really really really tough to do. 

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It's probably going to rain is probably enough probalistic for John Q

 

It's very true, but we also have other users that require more than that. I think know eventually we'll transition more away from the forecasting and more towards creating these somewhat redundant products that can be digested by all users.

 

John Q says, "how much?", DOT says, "when does it start and stop?", and EMs say, "what's the likelihood we reach X amount?"

It can't all be done with one product, and as things currently stand we don't have the time to provide all that information. That's why we're transitioning towards establishing better methods for populating the long term grids, that required less collaboration and less editing by hand. Saves valuable time for providing the decision support services that users are craving nowadays.

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Yeah there's no easy answer. I wish probabilistic forecasts were easy to understand for the public... we get forced into deterministic forecasts all the time regardless of certainty.

 

When I see the specific QPF forecasts to a tenth of an inch 48 hours out from the NWS I just laugh. I definitely wouldn't put that forecast out on TV (mostly because we don't have to... the public isn't clamoring for a rain forecast like a snow forecast) so I feel bad that they're forced to do it. I'd rather see ranges that are adjustable based on confidence. 

 

I agree.

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I like the idea of ranges too. Total of 1-1.5" or something like that makes sense to the public and at least conveys uncertainty. You can cover heavy rain chances in FFW such as rainfall up to 6" expected, as you lay out the discussion and reasoning of the watch. I know our clients are interested in probability forecasts too , but I think it will cause a lot more problems then actual help.

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Well not much else to say...it's official

 

It was another drier-than-normal week across the Northeast and Mid-Atlantic. Cooler-than-normal temperatures helped keep evapotranspiration down, but hydrological impacts were mounting in southern New England from the lack of rain. Streams were low from Connecticut to eastern Massachusetts, with soils drying and pastures and rangeland suffering. In Manchester, Connecticut, the Water and Sewer Department has issued a water conservation alert because its reservoir was below 80 percent of capacity; a ban on outdoor watering and other outdoor water uses took effect in Ipswich, Massachusetts as the rainfall deficit continued to build; and level 5 drought conditions were declared in Danvers, Massachusetts, due to low flow in the Ipswich River and the rapid depletion of the city’s reservoir. September 22 reports from the U.S. Department of Agriculture (USDA) indicated that 26% of the topsoil and 20% of the subsoil in New England was short to very short of moisture (dry to very dry), and 12% of the pastures were rated in poor to very poor condition. D1 (moderate drought) was added to the southern New England states

 

U.S. Drought Monitor Northeast

20140923_northeast_none.png

Intensity:

  • d0.pngD0 - Abnormally Dry
  • d1.pngD1 - Moderate Drought
  • d2.pngD2 - Severe Drought
  • d3.pngD3 - Extreme Drought
  • d4.pngD4 - Exceptional Drought

 

Download:    png-24x24.png pdf-24x24.png jpg-24x24.png
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Is First CT Lake, NH really abnormally dry?  Its really hard to go drought in the north country mountains...especially after a decently wet summer.  So I find that hard to believe...

 

 

You are looking at a D0 on there...which is basically nothing. But it has been dry the past 60 days or so.

 

We are pretty unfamiliar with any type of drought around here when you compare it to other regions of the U.S. We haven't had any type of serious drought since the 1960s...and even those were not unmanagable.

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You are looking at a D0 on there...which is basically nothing. But it has been dry the past 60 days or so.

 

We are pretty unfamiliar with any type of drought around here when you compare it to other regions of the U.S. We haven't had any type of serious drought since the 1960s...and even those were not unmanagable.

Though it got very close for NYC in summer, 1966, when their supply reservoirs were down under 20% and getting toward the levels where pumping became problematic. The came 5.5" on 9/21/66.

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