Substantial drought relief rains en-route?

[Ginx snewx]

Models pointing towards a 1-3 type heavy rain threat beginning Sunday the 22nd. Hopefully they got it right.

[It's Always Sunny]

Models pointing towards a 1-3 type heavy rain threat beginning Sunday the 22nd. Hopefully they got it right.

Depends on when it phases to see how much moisture we'll get.

[CT Rain]

Fire up the spotlight

[Damage In Tolland]

Dry begets dry?

[Ginx snewx]

Fire up the spotlight

There is a great paper on oro enhanced rains from SE winds in NCT CMA, have to find it. I think it was on the Box homepage, seems to be that kind of setup.

[Ginx snewx]

There is a great paper on oro enhanced rains from SE winds in NCT CMA, have to find it. I think it was on the Box homepage, seems to be that kind of setup.

yea here it is

http://www.erh.noaa.gov/box/orographic_rainfall.htm

[CoastalWx]

There is a great paper on oro enhanced rains from SE winds in NCT CMA, have to find it. I think it was on the Box homepage, seems to be that kind of setup.

The only issue I have with that is yeah it's oro enhanced, but the natural QG forcing is always going to be further west in a set up like that. So climo doesn't just favor that area because of orographic lifting...it's also from stronger LLJ, stronger isentropic lift, and don't forget PVA and jet dynamics.

[NorEaster27]

inches upon inches of rain

[Ginx snewx]

These events were characterized by southeasterly flow of 35-45 kts at 1000 mb. At 850 mb and 700 mb, the inflow was southerly, but with a noticeable variation in speeds, ranging from as little as 30 kts to as much as 70 kts. This range of speeds at 850-700 mb played an important role in the magnitude of the observed rainfall maxima. Even with significant theta-E and dew point advection, when the 850-700 mb inflow exceeded 50 kts, the observed rainfall maxima were much less than those associated with inflow speeds at 850-700 mb below 50 kts.

[Ginx snewx]

The only issue I have with that is yeah it's oro enhanced, but the natural QG forcing is always going to be further west in a set up like that. So climo doesn't just favor that area because of orographic lifting...it's also from stronger LLJ, stronger isentropic lift, and don't forget PVA and jet dynamics.

agree just something to look for precip maxes if this pans out. Hopefully it does.

[Typhoon Tip]

BIrving already posted the 00z Euro operational chart back on page 41 of that now absurdly long thread...haha. I was wondering if this may take place.

It is not uncommon to have comparatively frightening upper level features under perform in the surface evolutions at this time of year. The horizontal thermal gradients at this time of year, thanks in greater part to the sun, are neutralized to a greater degree. Dynamics aloft don’t parlay cyclogenesis to the surface as proficiently as they do in the winter. This 00z Euro operational run really underscores the loss of ambient baroclinicity that happens at this time of year; such that a fierce looking dynamical system aloft spins up a low the attenuates much faster than one might immediately expect for a 4-contoured mid level closure …

Re this dry begets dry thing..

I have discussed this before, but it is a hypothesis I currently subscribe to… This whole adage in weather of “dry begets dry”, I think more a function of statistics – namely, frequency - over anything phsyical in the field; though physics does play at least some minimal role.

Think about it. How often does a +3 SD rain event take place ? Answer, rarely, as that is a respectively large standard deviation, which means it is by definition a relatively rare event. Well, if a given region is in a -4SD precipitation anomaly – meaning, quite droughty and uber dry – that means the region would need at a minimum a +4SD event to counter-balance that dryness. Or, a series of events that summate to that amt, while not having so much temporal distance between them that intervening drying cancels out the benefit of each individual event.

Now ask, how often is a +4 SD rain event going to happen ? How often is a series of event summing to that proportion accountable ?? Rare in both cases…

Conclusion: I don't believe there is anything particularly special in the physics of a drought that actually serves onto the drought – which is what “dry begets dry” seems to dance around as an intended meaning. It may purely be a function of once random chance has gotten a region into a dry funk, it is just statistically hard to get that region back to normal.

That all said … yes, there are some truths to land-moisture deficits helping to accentuate a moisture sink. But if we think of it in terms of scaling the equation of environmental influencers, I bet those physical processes are not as determinant as the shear variability (statistical) side of the argument.

That’s my theory and I am sticking to it

[ski MRG]

With a little luck maybe we can see this morph into a blue bomb for the high terrain.

[Damage In Tolland]

With a little luck maybe we can see this morph into a blue bomb for the high terrain.

:weenie:

[ChrisM]

With a little luck maybe we can see this morph into a blue bomb for the high terrain.

Maybe above 4500' lol

[CoastalWx]

agree just something to look for precip maxes if this pans out. Hopefully it does.

Yeah, I hear ya. There's also a nice land/sea coastal convergence zone that adds to precip totals across eastern areas, esp near BOS and just south. That's more on NE flow.

[CoastalWx]

BIrving already posted the 00z Euro operational chart back on page 41 of that now absurdly long thread...haha. I was wondering if this may take place.

It is not uncommon to have comparatively frightening upper level features under perform in the surface evolutions at this time of year. The horizontal thermal gradients at this time of year, thanks in greater part to the sun, are neutralized to a greater degree. Dynamics aloft don’t parlay cyclogenesis to the surface as proficiently as they do in the winter. This 00z Euro operational run really underscores the loss of ambient baroclinicity that happens at this time of year; such that a fierce looking dynamical system aloft spins up a low the attenuates much faster than one might immediately expect for a 4-contoured mid level closure …

Re this dry begets dry thing..

I have discussed this before, but it is a hypothesis I currently subscribe to… This whole adage in weather of “dry begets dry”, I think more a function of statistics – namely, frequency - over anything phsyical in the field; though physics does play at least some minimal role.

Think about it. How often does a +3 SD rain event take place ? Answer, rarely, as that is a respectively large standard deviation, which means it is by definition a relatively rare event. Well, if a given region is in a -4SD precipitation anomaly – meaning, quite droughty and uber dry – that means the region would need at a minimum a +4SD event to counter-balance that dryness. Or, a series of events that summate to that amt, while not having so much temporal distance between them that intervening drying cancels out the benefit of each individual event.

Now ask, how often is a +4 SD rain event going to happen ? How often is a series of event summing to that proportion accountable ?? Rare in both cases…

Conclusion: I don't believe there is anything particularly special in the physics of a drought that actually serves onto the drought – which is what “dry begets dry” seems to dance around as an intended meaning. It may purely be a function of once random chance has gotten a region into a dry funk, it is just statistically hard to get that region back to normal.

That all said … yes, there are some truths to land-moisture deficits helping to accentuate a moisture sink. But if we think of it in terms of scaling the equation of environmental influencers, I bet those physical processes are not as determinant as the shear variability (statistical) side of the argument.

That’s my theory and I am sticking to it

Yeah just because the heaviest axis might be west has nothing to do with dry begets dry..lol.

I do believe in the feedback process to a point on influencing ridging in areas like the Plains and what not, especially Spring and Summer.

[Chrisrotary12]

I was wondering when this thread was going to pop up. Models have been showing this system for a few days now. Much needed rain on the way.

[SpartyOn]

BIrving already posted the 00z Euro operational chart back on page 41 of that now absurdly long thread...haha. I was wondering if this may take place.

It is not uncommon to have comparatively frightening upper level features under perform in the surface evolutions at this time of year. The horizontal thermal gradients at this time of year, thanks in greater part to the sun, are neutralized to a greater degree. Dynamics aloft don’t parlay cyclogenesis to the surface as proficiently as they do in the winter. This 00z Euro operational run really underscores the loss of ambient baroclinicity that happens at this time of year; such that a fierce looking dynamical system aloft spins up a low the attenuates much faster than one might immediately expect for a 4-contoured mid level closure …

Re this dry begets dry thing..

I have discussed this before, but it is a hypothesis I currently subscribe to… This whole adage in weather of “dry begets dry”, I think more a function of statistics – namely, frequency - over anything phsyical in the field; though physics does play at least some minimal role.

Think about it. How often does a +3 SD rain event take place ? Answer, rarely, as that is a respectively large standard deviation, which means it is by definition a relatively rare event. Well, if a given region is in a -4SD precipitation anomaly – meaning, quite droughty and uber dry – that means the region would need at a minimum a +4SD event to counter-balance that dryness. Or, a series of events that summate to that amt, while not having so much temporal distance between them that intervening drying cancels out the benefit of each individual event.

Now ask, how often is a +4 SD rain event going to happen ? How often is a series of event summing to that proportion accountable ?? Rare in both cases…

Conclusion: I don't believe there is anything particularly special in the physics of a drought that actually serves onto the drought – which is what “dry begets dry” seems to dance around as an intended meaning. It may purely be a function of once random chance has gotten a region into a dry funk, it is just statistically hard to get that region back to normal.

That all said … yes, there are some truths to land-moisture deficits helping to accentuate a moisture sink. But if we think of it in terms of scaling the equation of environmental influencers, I bet those physical processes are not as determinant as the shear variability (statistical) side of the argument.

That’s my theory and I am sticking to it

Solid write up FTW

[Tropopause_Fold]

having the upper level low dig so far south produces a nice tap to the tropics/sub-tropics...something we haven't seen recently (obviously)

[Ginx snewx]

having the upper level low dig so far south produces a nice tap to the tropics/sub-tropics...something we haven't seen recently (obviously)

Nice graphic, man NOGAPS and GEM are soakers too.

[CoastalWx]

GFS really blasts the front through here Saturday Night.

[CoastalWx]

Phil's area FTW?

[CoastalWx]

GFS not buying west solution for now.

[Tropopause_Fold]

hvy hvy rain on the GFS

[CoastalWx]

Wow inches from ORH east.

[Damage In Tolland]

Toss it folks

[Tropopause_Fold]

Toss it folks

you could not be more predictable

[CoastalWx]

You can see models are still playign around with things, but the GFS goes nuts with that nrn stream s/w. Will be interesting to see what th euro does.

[Damage In Tolland]

you could not be more predictable

Like the wx?

[Tropopause_Fold]

Like the wx?

forest fire thread cancel