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NE Tropical Thread


free_man

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This is true. There's a kind of growing thump about comparing Cat 1's at this latitude with Nor'easters, but it's not sound.

Meteorologically that makes no sense. In a Nor'easter, boundary layer inhibition prevents the vast majority of wind momentum from getting to the surface. In strong Nor'easters, with 50+mph winds fire hosing Logan, the wind may be NNE at ORH west of the inevitable coastal boundary that demarcates the interface between the better mixed air and the inland damming. At considerably less velocity at that.

In tropical systems, everyone is well mixed, period. Frictional effects do dwindle the wind, and there is some Ekman boundary layer/compression effecting air flow, but you can mix tremendous gust down right to your roof-tops and driveways given any convective activity at all. The two are not the same.

Nor'easter is a cardio infarction

Trop Cyclone is a accute tachycardia

both will kill but a different way -

its easy, leaves on trees vs no leaves.

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Yes...this is a big point forgotten on many (and shouldn't be).

Its not uncommon to get 50-60mph winds in winter on CAA events, but theres no leaves on the trees and usually the upper part of the soil is frozen (or getting there) which further inhibits the chances of uprooted trees...in tropical systems, we have foliage on the trees for the most part and the ground is warmer and often soft/saturated. Coming from the opposite direction as most winter events is also a little extra boost.

Thus, a 45mph wind from the south in a tropical system is going to be a lot more damaging than a 60mph wind from the northwest in winter.

yeah key point.

that's why a bunch of non-severe tstorms take down limbs and trees around here in the summer...yet we'll have multiple episodes each winter with gusts 55-65 and hardly have any issues.

even last year during irene...the S wind was gusting to like 40 mph at 8AM and there were already power outages and trees down. i remember before i came to pick you up, driving around and seeing some trees and power lines down and it was barely what I would consider "windy"

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You might inject lower theta-e air as well from downsloping.

Odd that BI was termed a tornado with no air/ ground investigation. Irene produced some areas in ECT that were described and I saw which were very similar in nature to BID. I watched rotation my self. Many folks in Sterling the next town over reported that the damage on their properties was lying in a circular motion yet it was ignored.

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its easy, leaves on trees vs no leaves.

What -

I'm talking about the Meteorological differences between well mixed barotropic air, versus boundary layer inhibition in a baroclinic environment, and your giving me leaf discussion?

ahaha, Just kidding. Yeah, it's true that having less foliage is better. Heck, just as the oaks last October. zomb!

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What -

I'm talking about the Meteorological differences between well mixed barotropic air, versus boundary layer inhibition in a baroclinic environment, and your giving me leaf discussion?

ahaha, Just kidding. Yeah, it's true that having less foliage is better. Heck, just as the oaks last October. zomb!

Its def easier to mix down a LLJ in the tropical systems...no doubt about that. That's why when we have an 80 kt LLJ in a tropical system, we are expecting hurricane force (or close to it) gusts...but do not quite expect that when we see a roaring southerly LLJ in late November or something. We end up maxing out at 50-60.

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Its def easier to mix down a LLJ in the tropical systems...no doubt about that. That's why when we have an 80 kt LLJ in a tropical system, we are expecting hurricane force (or close to it) gusts...but do not quite expect that when we see a roaring southerly LLJ in late November or something. We end up maxing out at 50-60.

Superstorm 93

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Its def easier to mix down a LLJ in the tropical systems...no doubt about that. That's why when we have an 80 kt LLJ in a tropical system, we are expecting hurricane force (or close to it) gusts...but do not quite expect that when we see a roaring southerly LLJ in late November or something. We end up maxing out at 50-60.

The thing is though, the ability to mix down in the CCB is almost lesser necessary if there is a huge llv p-g f

I think there was one Nor'easter with 974mb depth parked over the LI S back in the 1960s sometime, that generated 70mph wind considerably inland, with power outages and thundersnow. It's in the Kocin book - I'll look it up later. But yeah, the 1978 Feb storm had some good wind gusts inland, as did 1992 December. Man, I remember Fox Tower shaking from titanic blasts dude. So yes it can happen, but just not as easily as a straight up/down transfer scenario -

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Let's just pray the GGEM has a clue..Seems like all met concensus is Euro is too far west

I'm curious if they edge the current motion slightly N of 270 at the 5pm - seems the llv center axis has shifted slightly N of the convective mass during the mid day, and is more W by WNW ... maybe 280, but eyes can be deceived.

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The thing is though, the ability to mix down in the CCB is almost lesser necessary if there is a huge llv p-g f

I think there was one Nor'easter with 974mb depth parked over the LI S back in the 1960s sometime, that generated 70mph wind considerably inland, with power outages and thundersnow. It's in the Kocin book - I'll look it up later. But yeah, the 1978 Feb storm had some good wind gusts inland, as did 1992 December. Man, I remember Fox Tower shaking from titanic blasts dude. So yes it can happen, but just not as easily as a straight up/down transfer scenario -

Well yeah...that's one reason why we get better wind storms in the winter anyway is the PG at the sfc is often so great in those storms. We also get better LLJs in general in the winter...so we aren't required to mix down as much of the LLJ to get decent sfc winds...we can rip a 75 knot LLJ on CAA and mix down 60-70% of that and see some impressive winds.

Some of these TSs that affect us barely have a 45 knot LLJ, like Earl, lol. So even mixing down almost all of that will produce winds worse than the other example in winter.

Last year on the Cape, we had about a 70-75 kt LLJ during Irene and we were able to mix down a good 85-90% of that at the peak.

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Well yeah...that's one reason why we get better wind storms in the winter anyway is the PG at the sfc is often so great in those storms. We also get better LLJs in general in the winter...so we aren't required to mix down as much of the LLJ to get decent sfc winds...we can rip a 75 knot LLJ on CAA and mix down 60-70% of that and see some impressive winds.

Some of these TSs that affect us barely have a 45 knot LLJ, like Earl, lol. So even mixing down almost all of that will produce winds worse than the other example in winter.

Last year on the Cape, we had about a 70-75 kt LLJ during Irene and we were able to mix down a good 85-90% of that at the peak.

Was the top of Blue Hill complete denuded by 1938 - hahaha. Man, can you imagine being up there in something like that... ?

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Isaac is official to public:

an Air Force Reserve hurricane hunter aircraft investigating the depression reported 44-kt flight-level winds at 1000 ft to the northeast of the center...as well as bias-corrected SFMR surface winds estimates of 35 kt. The minimum central pressure was near 1005 mb. Based on these data...the depression is upgraded to Tropical Storm Isaac. Despite the upgrade...the cyclone remains somewhat disorganized...with the low-level center partly exposed to the north of the main convective mass.

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LOCATION...15.4N 53.9W

ABOUT 500 MI...810 KM E OF GUADELOUPE

MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H

PRESENT MOVEMENT...W OR 275 DEGREES AT 17 MPH...28 KM/H

MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES

they did edge it north as thought, but only 5 degrees. Looks like they are going with the straight up clustered mean -

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Eh, "THE LOW-LEVEL CENTER HAS NUDGED NORTHWARD DURING THE AFTERNOON...BUT THE LONGER TERM MOTION IS 275/15." The longer term motion is a mean there, so it may actually be moving slight N of even 275. It really looks 280 to my eyes for the last 3 hours.

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Looks like they are confirming both the NE shear, and the SAL entraining mentioned yesterday, too.

How about 96L though? That thing's got a nice hefty circulation area. That one doesn't have near the SAL issues and is better aloft. Could we get two CV 'canes at once? Been a long time since we've seen that.

I think - Will?

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Looks like they are confirming both the NE shear, and the SAL entraining mentioned yesterday, too.

How about 96L though? That thing's got a nice hefty circulation area. That one doesn't have near the SAL issues and is better aloft. Could we get two CV 'canes at once? Been a long time since we've seen that.

I think - Will?

Joyce... might have better chance of east coast impact from this far out... (paging CTBlizz)

Anyone know how close do these have to be to see Fujiwhara effect?

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Joyce... might have better chance of east coast impact from this far out... (paging CTBlizz)

Anyone know how close do these have to be to see Fujiwhara effect?

Usually around 1,500 N Miles ...but not in every case. Size matters. A large cyclone with a huge circumvallate might snare a TC into orbit form a longer distance, where as two even powerful systems might mutually resist such that a closer situation - in all cases that I have seen the pressure fields become entangled, with the outer measured gradient enclosing both. It's tough to get a really obvious F effect going, because the outflow from one storm might impinge on the other and cause it's destruction.

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Usually around 1,500 N Miles ...but not in every case. Size matters. A large cyclone with a huge circumvallate might snare a TC into orbit form a longer distance, where as two even powerful systems might mutually resist such that a closer situation - in all cases that I have seen the pressure fields become entangled, with the outer measured gradient enclosing both. It's tough to get a really obvious F effect going, because the outflow from one storm might impinge on the other and cause it's destruction.

thanks

in any case, rough estimate is that these systems are barely in range, but certainly far too weak at this point

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