2021 Tropical Season

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.

sroc4 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.

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  

SoulSingMG wrote:

Zhukov1945 wrote:
16Z HRRR continues to bring some massive rain later in the day

jmanley32 wrote:My sister is at the beach in delaware with the family. Says it is a very nice day, does not seem at all concerned.

jmanley32 wrote:

Zhukov1945 wrote:
16Z HRRR continues to bring some massive rain later in the day

your avatar is huge too, i cannot see what you write on the left, Frank can you find out why this is happening for a few individuals?  Looks like HRRR is shifting the heaviest rain back south. At this point who knows

Zhukov1945 wrote:

jmanley32 wrote:

Zhukov1945 wrote:
16Z HRRR continues to bring some massive rain later in the day

your avatar is huge too, i cannot see what you write on the left, Frank can you find out why this is happening for a few individuals?  Looks like HRRR is shifting the heaviest rain back south. At this point who knows

Changed it and hopefully it fixed the issue.  Latest HRRR still likes that intense band over Hunterdon headed NE, been consistent with that all day

jmanley32 wrote:So whats the story with Larry rb? Or maybe we should give it the weekend to recover, today was hell on earth. I do not even want to talk about it.  I will never forget this storm. ranks up there with Sandy for me. MAYBE HIGHER.

Joe Snow wrote:

jmanley32 wrote:So whats the story with Larry rb? Or maybe we should give it the weekend to recover, today was hell on earth. I do not even want to talk about it.  I will never forget this storm. ranks up there with Sandy for me. MAYBE HIGHER.

I do think we are going to get another cane this way.