NNE Summer 2016

[Lava Rock]

Wow, it's pouring out.  The radar suggests it's going to continue raining hard for another hour or so.

Which brings me to the NWS Point & Click forecast and several questions:  First, here's the current P&C for my neck of the woods in Orwell:

Showers likely, mainly before 11am. Cloudy through mid morning, then gradual clearing, with a high near 86. Light and variable wind becoming southwest around 5 mph in the afternoon. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible. Now I get that precip amounts could be higher in thunderstorms, and a P&C usually captures that possibility with a caveat after the forecast precipitation totals.  But this morning, there is already 0.62 inches in the gauge, and the radar suggests another quarter inch is quite likely.  Quite a big difference from the forecast precipitation totals in the P&C (and the AFD, for that matter).

Thus, my first question: what happens to get such a disconnect between the P&C and the actual weather?  This summer, in my neck of the woods, the disconnect has been weighted toward precipitation totals that have come in much less than forecast, so much so that I've taken to lowering my expected total by half.  For instance, if the P&C calls for 0.25-0.50 rain in the afternoon, followed by 0.50-0.75 rain in the evening, the low end would be a total of 0.75 inches, which means that I expect to get only about 0.35-0.40 inches.  This morning offers the rare case of weather that over-performs when compared with the P&C.

Second question: is anyone else experiencing this, with fairly consistent under/over performance?  Maybe this is a My Backyard Situation only and nobody else is seeing this pattern.

Third question: Is there a way to see archived P&Cs? For instance, I'm pretty sure yesterday's P&C called for 50% showers in the afternoon (it cleared out with nothing remotely nearby), and 10% showers overnight (it was cloudy, with any rain on the radar well to the south), but I'd rather not rely on my memory if I'm going to be critical of the P&C.

 

 

For the most part precip totals have been well under forecast most of the summer here.

[wxeyeNH]

Rain over.  Really happy.  Many of the heavy echoes went right over me.    Total .62"!

[dendrite]

0.23" through the tipper. A respectable finale. I've been letting the lawn grow out so it's looking lush. The lower sun angle helps as well. 

[powderfreak]

5 hours ago, ApacheTrout said:

Wow, it's pouring out.  The radar suggests it's going to continue raining hard for another hour or so.

Which brings me to the NWS Point & Click forecast and several questions:  First, here's the current P&C for my neck of the woods in Orwell:

Showers likely, mainly before 11am. Cloudy through mid morning, then gradual clearing, with a high near 86. Light and variable wind becoming southwest around 5 mph in the afternoon. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

Now I get that precip amounts could be higher in thunderstorms, and a P&C usually captures that possibility with a caveat after the forecast precipitation totals.  But this morning, there is already 0.62 inches in the gauge, and the radar suggests another quarter inch is quite likely.  Quite a big difference from the forecast precipitation totals in the P&C (and the AFD, for that matter).

Thus, my first question: what happens to get such a disconnect between the P&C and the actual weather?  This summer, in my neck of the woods, the disconnect has been weighted toward precipitation totals that have come in much less than forecast, so much so that I've taken to lowering my expected total by half.  For instance, if the P&C calls for 0.25-0.50 rain in the afternoon, followed by 0.50-0.75 rain in the evening, the low end would be a total of 0.75 inches, which means that I expect to get only about 0.35-0.40 inches.  This morning offers the rare case of weather that over-performs when compared with the P&C.

Second question: is anyone else experiencing this, with fairly consistent under/over performance?  Maybe this is a My Backyard Situation only and nobody else is seeing this pattern.

Third question: Is there a way to see archived P&Cs? For instance, I'm pretty sure yesterday's P&C called for 50% showers in the afternoon (it cleared out with nothing remotely nearby), and 10% showers overnight (it was cloudy, with any rain on the radar well to the south), but I'd rather not rely on my memory if I'm going to be critical of the P&C.

 

 

I wouldn't look too much into the precip amounts...it's just a smoothed mean which during convective season it's much more hit or miss than just widespread 0.25-0.5" that the grids will show.  One spot could get zero while someone else has over an inch...but there's no way to accurately show that so the grids just show a smoothed mean I think.

[powderfreak]

BTV NWS is ready for winter...

Temperatures will be
above normal to start...but trend below normal by late next
week...with even the 0C 850mb isotherm progged to make an
appearance off both the latest 00z ECMWF/GFS. Some people are
excited about the arrival of cooler weather and are looking
forward to the upcoming winter months already.

[wxeyeNH]

Just after the rain ended I took the drone up for a quick look around.  Here's a 2 minute video of flying over the low clouds.   Interesting to see how the low Cu don't form over Newfound Lake.  

 

[ApacheTrout]

22 minutes ago, powderfreak said:

BTV NWS is ready for winter...

Temperatures will be
above normal to start...but trend below normal by late next
week...with even the 0C 850mb isotherm progged to make an
appearance off both the latest 00z ECMWF/GFS. Some people are
excited about the arrival of cooler weather and are looking
forward to the upcoming winter months already.

That paragraph made me smile and think that someone's been following the DIT discussion. 

[tamarack]

5 hours ago, dendrite said:

0.23" through the tipper. A respectable finale. I've been letting the lawn grow out so it's looking lush. The lower sun angle helps as well. 

Just clouds in Augusta.  Doubt the home front did any better.

[eekuasepinniW]

.41

[ApacheTrout]

3 hours ago, powderfreak said:

I wouldn't look too much into the precip amounts...it's just a smoothed mean which during convective season it's much more hit or miss than just widespread 0.25-0.5" that the grids will show.  One spot could get zero while someone else has over an inch...but there's no way to accurately show that so the grids just show a smoothed mean I think.

That doesn't make sense to me.  I thought the precipitation totals were based on the precipitable water, not blended to mix with areas that don't receive rain.

Maybe I'm misunderstand the forecast language.  In this morning's P&C, a sixty percent chance of showers with new precipitation amounts of less than 0.10 inch  says to me that there's a 60% chance that an area will receive precipitation, and that if it rains in your area, it really won't be that much.

Now in the case of this morning's rain, I fell in the area that received rain, so I'd expect to see little rain.  Yet I ended up with 0.92 inches.  To me, that suggests the forecast rain amount was off quite a bit.

I don't expect every precip forecast to work out, and just being off a bit doesn't mean the forecast was incorrect, as just being off 2 miles can mean you missed rain completely, or you got rain but were on the edge of a substantial amount.  It just seems to me that this summer, the precip totals have been fairly consistently off from the forecasted amounts.  At least in my neck of the woods. 

 

 

 

[dendrite]

90 at CON again. What an lol heat wave.

The last 3 days of highs...

CON 90/90/90

MHT 89/86/89

ASH 88/86/89

LCI 86/83/85

1P1 85/84/84

me 84/83/82

[OceanStWx]

10 hours ago, powderfreak said:

I wouldn't look too much into the precip amounts...it's just a smoothed mean which during convective season it's much more hit or miss than just widespread 0.25-0.5" that the grids will show.  One spot could get zero while someone else has over an inch...but there's no way to accurately show that so the grids just show a smoothed mean I think.

Yeah, QPF is going to blow on a P&C level. There is basically no way to get it right at that kind of resolution.

I think most of the time a forecaster's QPF grid is an average across areas. But QPF by its very nature is usually more hit and miss than an average, especially in convection. Now I could put 1" for one town, and 0" for the one next door, but what if the storm hits slightly east and the next door town gets 1" and the other town gets nothing? Then it's a really poor forecast, versus an average that gave each town something, but maybe not the absolutely correct total.

Now this case from the post you quoted could also be a matter of more frequent grid updates being needed.

In the end, the P&C is kind of a black box for us. It says things like "amounts between a quarter and a half inch" when the grid scale is such that we should have a smaller range than that.

[eekuasepinniW]

How is it possible that LCI was made even worse at measuring precip after the upgrade?

Me | LCI

June:  0.00 | 2.72
July: 0.15  | 3.39

At least August seems better:
Aug:  2.33 | 2.78

May was impressive:
May:  2.19 | 2.19

[powderfreak]

Ginx posted this in an animation in the other thread, but thought it should be posted here too.  This is the firstl 0C cold shot I've seen modeled this season.

 

[powderfreak]

Some decent storms in N.VT this afternoon.  Training the same areas too so someone is getting a lot of rain.

[eekuasepinniW]

That's enough out of you.

[powderfreak]

7 minutes ago, eekuasepinniW said:

That's enough out of you.

Ha, only inflow breezes here to the south.  Quite gusty though in the direction of the storm...radar estimates of 1-2" for a narrow band too.

[wxeyeNH]

PF,  the rich get richer.  How much rain has Northern Vermont gotten this summer,  40" 50" 60" 70"?  HRRR wants to get convection down to Central NH later this evening but not much upstream at the moment.  

Looks like TD8 and TD9 should anything develop will be wide right turns well south of us.  Wave coming off Africa is suppose to develop and move across the Atlantic in the next 10 days.  Got to get some tropical moisture up here without resulting damage.  Drought will definitely worsen over the next week.  I actually did pretty good this month, 3.44" assuming no more rain before month ends.

 

[powderfreak]

44 minutes ago, wxeyeNH said:

PF,  the rich get richer.  How much rain has Northern Vermont gotten this summer,  40" 50" 60" 70"?  HRRR wants to get convection down to Central NH later this evening but not much upstream at the moment.  

Looks like TD8 and TD9 should anything develop will be wide right turns well south of us.  Wave coming off Africa is suppose to develop and move across the Atlantic in the next 10 days.  Got to get some tropical moisture up here without resulting damage.  Drought will definitely worsen over the next week.  I actually did pretty good this month, 3.44" assuming no more rain before month ends.

 

Haha it's all convective and scattered.  I'm not getting anything but PWS near St Albans, VT (Champlain Valley north of BTV) have had 2.2" and 2.5" in the past 2 hours.   

It's been about an average rain season so far, just seems like it's been very wet with how dry some areas have been running.  But you get a lot of these types of days where some get zero and others get 1"- 2".

[ice1972]

Staying south of Jeffersonville at Smuggs and the rain train has been tremendous....KCXX radar has been interesting cuz you have to switch to Tilt 2 or 3 to see it....I'm guessing Tilt 1 is too flat to get through the mountains?

Anyway tremendous rain

[mreaves]

4 hours ago, wxeyeNH said:

PF,  the rich get richer.  How much rain has Northern Vermont gotten this summer,  40" 50" 60" 70"?  HRRR wants to get convection down to Central NH later this evening but not much upstream at the moment.  

Looks like TD8 and TD9 should anything develop will be wide right turns well south of us.  Wave coming off Africa is suppose to develop and move across the Atlantic in the next 10 days.  Got to get some tropical moisture up here without resulting damage.  Drought will definitely worsen over the next week.  I actually did pretty good this month, 3.44" assuming no more rain before month ends.

 

Maybe I'm not north enough, I'm still under water usage warning. ☹️

[eyewall]

On 8/27/2016 at 9:01 PM, powderfreak said:

Ginx posted this in an animation in the other thread, but thought it should be posted here too.  This is the firstl 0C cold shot I've seen modeled this season.

 

Bring it! Anyway I did notice while doing the race to the top of Vermont on Mt. Mansfield yesterday that some trees are fading or showing hints of yellow. I am wondering how the conditions this year will impact foliage.

[powderfreak]

13 hours ago, ice1972 said:

Staying south of Jeffersonville at Smuggs and the rain train has been tremendous....KCXX radar has been interesting cuz you have to switch to Tilt 2 or 3 to see it....I'm guessing Tilt 1 is too flat to get through the mountains?

Anyway tremendous rain

Yesterday was all or nothing.

You can see the Stowe Village 0.00" in southern Lamoille County, while 10-15 miles north there was a ban of 1.5-2.5" that rolled though.

Those differences make for widely variable summer totals haha.  A shut-out vs 2" is tough  ground to make up.

Crazy that 5 stations had over 2" (which is tough to do) and 9 or 10 over 1.5"....then the other 40 stations had like nothing in the CoCoRAHS reports.

[backedgeapproaching]

Max min of the warm season last night here at 69.1F for the low.

[wxeyeNH]

Just looked at the 12Z Euro and GFS for rain chances over the next 10 days.  Except for (yawn)  N VT the models show no rain to perhaps .25" over the remainder of New England for over 200 hours out. . Midweek fropa passing is the only chance.  

[powderfreak]

Missed 1"+ by like 10 miles and 2" by like 15 miles.

Max rain yesterday was Sutton, VT COOP with 3.08".  

Interesting as the models had nothing remotely close to the swath of 1-3" rains yesterday evening.

[Lava Rock]

Just looked at the 12Z Euro and GFS for rain chances over the next 10 days.  Except for (yawn)  N VT the models show no rain to perhaps .25" over the remainder of New England for over 200 hours out. . Midweek fropa passing is the only chance.  

What else is new. Was surprised to pick up 0.04" last night. Lawn actually looks decent.

[borderwx]

23 hours ago, eyewall said:

Bring it! Anyway I did notice while doing the race to the top of Vermont on Mt. Mansfield yesterday that some trees are fading or showing hints of yellow. I am wondering how the conditions this year will impact foliage.

Bike or Run?  It was surprisingly hot, woke up to showers and low 60's here and thought the top would be same. The sun really is hot

Needing the porch light now for dinners, that hot sun is really starting to make progress south down the range.

[eyewall]

2 hours ago, borderwx said:

Bike or Run?  It was surprisingly hot, woke up to showers and low 60's here and thought the top would be same. The sun really is hot

Needing the porch light now for dinners, that hot sun is really starting to make progress south down the range.

I did the run. The bike looked harder (although much more fun for them going back down). Either way I definitely pushed myself and did a time of 1:22:58 (I am definitely not in the elite class LOL).

 

[J.Spin]

16 hours ago, powderfreak said:

Missed 1"+ by like 10 miles and 2" by like 15 miles.

Max rain yesterday was Sutton, VT COOP with 3.08".  

Interesting as the models had nothing remotely close to the swath of 1-3" rains yesterday evening.

 

Boy, that really was quite the tight gradient of effects from those storms.  I was riding the Hardy’s Haul/Kimmer’s loop up above the The Matterhorn when that was starting up – there was a lot of rumbling and it looked quite ominous toward Smuggler’s Notch and northward, and I figured we were going to be in for it pretty quickly.  Fortunately that heavy rain stayed to the north and the trails stayed dry, but that was an impressive cut off of precipitation.