2021 Tropical Season

the 12k and 3k NAM both seem to be a bit NW with the heaviest of the rainfall totals

ugh

SoulSingMG wrote:Holy crap.

WOWWW, even the south did not get past red yikes. This is potentially going to be devastating to flood prone areas and the news just said power outages are likely for coastal areas and parts of NJ. It is all about where this sets up which is going to be a nowcast.

Here is a closer up image, wow, I have never seen this, not that i remember anyways.




tornado threat...

so ray (rb) I saw 18z GFS, the system that is now a depression goes NW and then north I see the HP, if the HP were 500 miles more west would been a direct hit on us, are you thinking the HP is much further west than shown?

jmanley32 wrote:so ray (rb) I saw 18z GFS, the system that is now a depression goes NW and then north I see the HP, if the HP were 500 miles more west would been a direct hit on us, are you thinking the HP is much further west than shown?

Kind of lol it’s a very complex evolution that would have to occur in order for it to be a threat to us, but just because it’s complex, it doesn’t mean that it can’t/won’t happen.

Basically, I’m banking on the Atlantic ridge being undermodeled for two reasons:

1. The anomalously warm ocean waters should lead to its enhancement
2. The depression should readily achieve Major hurricane status, so that will work to add additional latent heat into the ridge and help to further build its western flank. This would start to lead to a positive feedback loop in tandem with (1). As the ridge builds westward in response to the hurricane moving westward, it should continue to steer the hurricane westward, thereby allowing the ridge to continue to build westward.

However, that’s the “easier” part of the forecast. The complexity comes in with how the pattern sets up over the eastern CONUS, and how the trough behaves. Basically, if you watch the entire loop of the hemispheric H5 anomalies, you’ll notice that there is discontinuous retrogression occurring. For example, the time-mean trough starts over Newfoundland, then shifts westward to be over the Northeast, then shifts westward to be over the Great Lakes. This fits the logical progression of the remnant Atlantic blocking, but it’s contained within an overall hemispheric and global pattern that supports ridging in the eastern CONUS.

This is where it gets tricky fast. How does that retrograding trough behave? Does it cut off and drift southward over east-central CONUS and allow the ridging to build over the top of it (anti-cyclonic wave break) and eventually link up with the Atlantic ridging building westward, as the trough/cutoff low decays? Or, do we see a decrease in the amplitude of the trough as the lead time decreases, and then see the main trough split, with one piece ejecting northeastward through northern New England/southern Canada, and the other slip back in response to additional energy being allowed to slip in the backside and continue the retrogression of the mean trough toward the central CONUS?

I can’t really offer concrete opinion on the evolutions that would follow yet, but my concern is with the second evolution IF it evolved that way. Because with the trough split, it should allow heights to build faster to the northwest of the hurricane, thereby increasing the time of westward movement (ala today’s 12z GEM). However, with that second piece hanging back, it would still allow for a window to come almost due north (similarly to Henri, though without the retrograde).

If the first option evolved, then it would be more of a threat for the Southeast.

This is all very preliminary musing on my end, though, as I’ve not yet had a real chance to sit and analyze. Thursday or Friday should offer me that opportunity, though I will try to dabble before then.

weatherwatchermom wrote:RB what is your take on tomorrows storm all quiet on here

I’ve not followed it closely, so I can’t really offer too much other than what’s already been highlighted by our comrades haha looks like it’s a lose-lose no matter where you are: North of about 195 you get several inches of rain, and south of there you get less rain but an enhanced threat of severe thunderstorms.

Maybe somebody else can be a bit more specific for ya….?

rb924119 wrote:

jmanley32 wrote:so ray (rb) I saw 18z GFS, the system that is now a depression goes NW and then north I see the HP, if the HP were 500 miles more west would been a direct hit on us, are you thinking the HP is much further west than shown?

Kind of lol it’s a very complex evolution that would have to occur in order for it to be a threat to us, but just because it’s complex, it doesn’t mean that it can’t/won’t happen.

Basically, I’m banking on the Atlantic ridge being undermodeled for two reasons:

1. The anomalously warm ocean waters should lead to its enhancement
2. The depression should readily achieve Major hurricane status, so that will work to add additional latent heat into the ridge and help to further build its western flank. This would start to lead to a positive feedback loop in tandem with (1). As the ridge builds westward in response to the hurricane moving westward, it should continue to steer the hurricane westward, thereby allowing the ridge to continue to build westward.

However, that’s the “easier” part of the forecast. The complexity comes in with how the pattern sets up over the eastern CONUS, and how the trough behaves. Basically, if you watch the entire loop of the hemispheric H5 anomalies, you’ll notice that there is discontinuous retrogression occurring. For example, the time-mean trough starts over Newfoundland, then shifts westward to be over the Northeast, then shifts westward to be over the Great Lakes. This fits the logical progression of the remnant Atlantic blocking, but it’s contained within an overall hemispheric and global pattern that supports ridging in the eastern CONUS.

This is where it gets tricky fast. How does that retrograding trough behave? Does it cut off and drift southward over east-central CONUS and allow the ridging to build over the top of it (anti-cyclonic wave break) and eventually link up with the Atlantic ridging building westward, as the trough/cutoff low decays? Or, do we see a decrease in the amplitude of the trough as the lead time decreases, and then see the main trough split, with one piece ejecting northeastward through northern New England/southern Canada, and the other slip back in response to additional energy being allowed to slip in the backside and continue the retrogression of the mean trough toward the central CONUS?

I can’t really offer concrete opinion on the evolutions that would follow yet, but my concern is with the second evolution IF it evolved that way. Because with the trough split, it should allow heights to build faster to the northwest of the hurricane, thereby increasing the time of westward movement (ala today’s 12z GEM). However, with that second piece hanging back, it would still allow for a window to come almost due north (similarly to Henri, though without the retrograde).

If the first option evolved, then it would be more of a threat for the Southeast.

This is all very preliminary musing on my end, though, as I’ve not yet had a real chance to sit and analyze. Thursday or Friday should offer me that opportunity, though I will try to dabble before then.

interesting what little of that I understood, I see what CMC is doing, so are you thinking the storm stays further west than NW or NNW like the CMC? Will be interesting to follow the evolution you are discussing. Wouldn't that be the bees knees, hurricane henri, remnants of ida and a week later potential major hurricane threatening the EC may be even the area can the tropics get any more active?

jmanley32 wrote:

rb924119 wrote:

jmanley32 wrote:so ray (rb) I saw 18z GFS, the system that is now a depression goes NW and then north I see the HP, if the HP were 500 miles more west would been a direct hit on us, are you thinking the HP is much further west than shown?

Kind of lol it’s a very complex evolution that would have to occur in order for it to be a threat to us, but just because it’s complex, it doesn’t mean that it can’t/won’t happen.

Basically, I’m banking on the Atlantic ridge being undermodeled for two reasons:

1. The anomalously warm ocean waters should lead to its enhancement
2. The depression should readily achieve Major hurricane status, so that will work to add additional latent heat into the ridge and help to further build its western flank. This would start to lead to a positive feedback loop in tandem with (1). As the ridge builds westward in response to the hurricane moving westward, it should continue to steer the hurricane westward, thereby allowing the ridge to continue to build westward.

However, that’s the “easier” part of the forecast. The complexity comes in with how the pattern sets up over the eastern CONUS, and how the trough behaves. Basically, if you watch the entire loop of the hemispheric H5 anomalies, you’ll notice that there is discontinuous retrogression occurring. For example, the time-mean trough starts over Newfoundland, then shifts westward to be over the Northeast, then shifts westward to be over the Great Lakes. This fits the logical progression of the remnant Atlantic blocking, but it’s contained within an overall hemispheric and global pattern that supports ridging in the eastern CONUS.

This is where it gets tricky fast. How does that retrograding trough behave? Does it cut off and drift southward over east-central CONUS and allow the ridging to build over the top of it (anti-cyclonic wave break) and eventually link up with the Atlantic ridging building westward, as the trough/cutoff low decays? Or, do we see a decrease in the amplitude of the trough as the lead time decreases, and then see the main trough split, with one piece ejecting northeastward through northern New England/southern Canada, and the other slip back in response to additional energy being allowed to slip in the backside and continue the retrogression of the mean trough toward the central CONUS?

I can’t really offer concrete opinion on the evolutions that would follow yet, but my concern is with the second evolution IF it evolved that way. Because with the trough split, it should allow heights to build faster to the northwest of the hurricane, thereby increasing the time of westward movement (ala today’s 12z GEM). However, with that second piece hanging back, it would still allow for a window to come almost due north (similarly to Henri, though without the retrograde).

If the first option evolved, then it would be more of a threat for the Southeast.

This is all very preliminary musing on my end, though, as I’ve not yet had a real chance to sit and analyze. Thursday or Friday should offer me that opportunity, though I will try to dabble before then.

interesting what little of that I understood, I see what CMC is doing, so are you thinking the storm stays further west than NW or NNW like the CMC?  Will be interesting to follow the evolution you are discussing. Wouldn't that be the bees knees, hurricane henri, remnants of ida and a week later potential major hurricane threatening the EC may be even the area can the tropics get any more active?

There’s obviously a third option, which is climatologically favored but last on my current list of possible outcomes, and that is the trough stays coherent over the eastern CONUS and the hurricane is lofted wide-right of land entirely haha but at the minimum, I do think we see interaction with at least some part of the North American continent, even if it’s eastern Nova Scotia lmaooo

But I’ll have a more definitive opinion over the next couple of days aha again, this is all high-level conjecture from me at this point.

We went into storm mode for Henri and this rain/ svr wx event w/ ida looks far worse and no storm mode?

The rain tomorrow looks to really train over PA before coming east giving them the majority of the epic flooding, 3km has some spots seeing 10-15 inches...Any shift east of the system will bring the heaviest access into the area, nws even says in their briefing that the setup of the main area is still shifting.

DAYUMMM RGEM!!!

The overnight model runs shifted the heaviest axis of rain to our north and northwest. That said, it's still going to pour buckets at some point for everyone. But, the threat of severe flooding for NYC Metro is minimized slightly due to the latest shift.

NAM:



GFS:



We've dealt with 2-3" rainstorms plenty of times. It is when it gets to be 4-8"+ of rain - which is what parts of NY state will get - is when it becomes a big issue for NJ. We have saturated grounds though, so still be on the lookout for localized flooding. The areas of NJ that will be an issue is in the northern part, especially NW NJ.

You can tell from the current radar where all the heaviest rain is destined to go. All that heavy 'stuff' in PA is headed to CP land N&W of NYC.

Yeah I dunno frank the WPC still has the area under rare high flash flooding and a 3-6 to 6-10 inch rainfall. their axis of heaviest rain hasnt shifted much but includes area you are talking about, models have been back and forth on this for days, and I think the rain we see is when the part wraps in more from the soyuth with the potential for svr wx too. We will see what happens. Even NWS upped their totals from 3-45 to 3-6 with higher totals likely. And we are already getting pre-heaviest rainfall now some in quite heavy downpours.

Next we are looking at larry, let me tell you all my family members that have a storm named after them have been BAD, this is larry my father already slated to become a major cane, will be interesting to see how close he gets to the EC, models are showing pretty close and rb's analysis is interesting to say the least. We track!

New 12z HRRR bumped north

aiannone wrote:New 12z HRRR bumped north

Interestingly while the extended duration precip goes north, it has NJ getting absolutely hammered from around 7pm to 11 pm such that for most of us we make up the difference.

Zhukov1945 wrote:

aiannone wrote:New 12z HRRR bumped north

Interestingly while the extended duration precip goes north, it has NJ getting absolutely hammered from around 7pm to 11 pm such that for most of us we make up the difference.

Thats exactly what I was talking about, although areas north see that huge area of rain I think we see what is shown in your map which will be fierce and intense moreso than a streadier longer duration rain north, again we will see. I am also concerned a bit about the tornado risk and svr storm risk, they pushed the slight and enhanced areas slightly north from yesterday, I think tornado watches go up at some point for some areas later. Either the models or right or they are wrong at this point 50/50.

aiannone wrote:New 12z HRRR bumped north

no denying models have bumped north but it def wont take much of a shift to change things, I think we just have to wait and see. Any serious totals will be localized, though NWS said could be likely. They may change their tune as well as WPC if they agree with the SR models.

A couple things to consider:

-The heaviest rain in NE NJ/NYC falls faster than some of the higher totals to the northwest and since our FFG is much more nail-biting in the NYC metro than say NEPA, big problems could occur even if we get “only” 3-4 inches in the area but it falls in shorter time (that’s looking like later this evening).

-Careful what we wish for; the further north the warm front goes and “less” rain we get, the greater the tornado risk becomes toward NNJ/NYC metro. The spin-up risk over SNJ is eye-popping to say the least.

13Z HRRR even more aggressive for NJ - just absolutely insane heavy rain for 5-7 hours starting around 5 pm. Dumps about 10" on Hunterdon county.

This looks pretty bad (WPC rain map) as it stands, 3-6 with embedded 6-10...I agree with soul, either way we have issues its either super heavy rain (which I think we experience either way to some extent) and a potential increase in tornado threat if any more trends north.

rb924119 wrote:

jmanley32 wrote:so ray (rb) I saw 18z GFS, the system that is now a depression goes NW and then north I see the HP, if the HP were 500 miles more west would been a direct hit on us, are you thinking the HP is much further west than shown?

Kind of lol it’s a very complex evolution that would have to occur in order for it to be a threat to us, but just because it’s complex, it doesn’t mean that it can’t/won’t happen.

Basically, I’m banking on the Atlantic ridge being undermodeled for two reasons:

1. The anomalously warm ocean waters should lead to its enhancement
2. The depression should readily achieve Major hurricane status, so that will work to add additional latent heat into the ridge and help to further build its western flank. This would start to lead to a positive feedback loop in tandem with (1). As the ridge builds westward in response to the hurricane moving westward, it should continue to steer the hurricane westward, thereby allowing the ridge to continue to build westward.

However, that’s the “easier” part of the forecast. The complexity comes in with how the pattern sets up over the eastern CONUS, and how the trough behaves. Basically, if you watch the entire loop of the hemispheric H5 anomalies, you’ll notice that there is discontinuous retrogression occurring. For example, the time-mean trough starts over Newfoundland, then shifts westward to be over the Northeast, then shifts westward to be over the Great Lakes. This fits the logical progression of the remnant Atlantic blocking, but it’s contained within an overall hemispheric and global pattern that supports ridging in the eastern CONUS.

This is where it gets tricky fast. How does that retrograding trough behave? Does it cut off and drift southward over east-central CONUS and allow the ridging to build over the top of it (anti-cyclonic wave break) and eventually link up with the Atlantic ridging building westward, as the trough/cutoff low decays? Or, do we see a decrease in the amplitude of the trough as the lead time decreases, and then see the main trough split, with one piece ejecting northeastward through northern New England/southern Canada, and the other slip back in response to additional energy being allowed to slip in the backside and continue the retrogression of the mean trough toward the central CONUS?

I can’t really offer concrete opinion on the evolutions that would follow yet, but my concern is with the second evolution IF it evolved that way. Because with the trough split, it should allow heights to build faster to the northwest of the hurricane, thereby increasing the time of westward movement (ala today’s 12z GEM). However, with that second piece hanging back, it would still allow for a window to come almost due north (similarly to Henri, though without the retrograde).

If the first option evolved, then it would be more of a threat for the Southeast.

This is all very preliminary musing on my end, though, as I’ve not yet had a real chance to sit and analyze. Thursday or Friday should offer me that opportunity, though I will try to dabble before then.

Hey Ray I have to throw my two cents into the ring here. With Larry forecast to gain intensity rather quickly, even up to a major By the end of the week the altitude at which will influence Larry's motion begin to increase. Looking at 300mb there is a very distinct northerly vector by the time Larry reaches approx 45-50W Long; whereas, beneath that at 500mb the vecotor still seems to be westerly. Also good ol' Coriolis forces come into play the stronger he gets too.

Combined with the timing of the various troughs propagating NA into the Atlantic just something else to factor when looking at "Larry Balls". Sorry Larry Balls was the nick name to a guy I used to hang out with back in my high school days. I digress