2021 Tropical Season

I don’t get it. What does the NHC see that would warrant a shift west with the cone?

nutleyblizzard wrote:I don’t get it. What does the NHC see that would warrant a shift west with the cone?

pfffff who knows, maybe they are go by recon data and not the models.

look at arw, clearly they are taking that into acct lol, i doubt it. but arw has landfall in central jrsy coast.

doesnt make sense cape hjas a hurricane watch and fairfield county to NYC does not. the main path is much closetr to nyc than cape cod. who knows what they are thinking period. i wonder if local NWS also has input on hurricane watch warnings etc, you know upton always cautious.

EMS just went off on my phone storm surge warning for NYC area. I think we def go to hurricane warnings between now and tomorrow unless theres some drastic change. NHC is seeing rb's track closer and closer.  I also noted that now the area is in 80-90% chance of TS winds 39+ mph and 50 kt 50%, thats a big increase from. wow literally never seen this b4, the TV froze on a EMS alert you cannot change the channel. was displaying on it for bout 10 min.

wow....NYZ079-211000-
/O.CON.KOKX.SS.W.1008.000000T0000Z-000000T0000Z/
1135 PM EDT FRI AUG 20 2021
Northeast Suffolk-

...HURRICANE WARNING REMAINS IN EFFECT...
...STORM SURGE WARNING REMAINS IN EFFECT...

* LOCATIONS AFFECTED
- Wading River
- Mattituck
- Orient

* WIND
- LATEST LOCAL FORECAST: Equivalent Strong Tropical Storm force
wind
- Peak Wind Forecast: 50-65 mph with gusts to 80 mph
- Window for Tropical Storm force winds: early Sunday morning
until early Monday morning

GFS ticks east, also weaker

Updated TS warning, winds upped a lot and potential for 74-110 mph

A Storm Surge Warning means there is a danger of life-threatening
inundation, from rising water moving inland from the coastline,
somewhere within this area within the next 36 hours

A Tropical Storm Warning means tropical storm-force winds are
expected somewhere within this area within the next 36 hours

* LOCATIONS AFFECTED
- Riverdale
- Fordham
- Co-Op City

* WIND
- LATEST LOCAL FORECAST: Tropical storm force winds remain
possible
- Peak Wind Forecast: 25-35 mph with gusts to 45 mph

- THREAT TO LIFE AND PROPERTY THAT INCLUDES TYPICAL FORECAST
UNCERTAINTY IN TRACK, SIZE AND INTENSITY: Potential for wind 74
to 110 mph
- The wind threat has increased from the previous assessment.
- PLAN: Plan for life-threatening wind of equivalent CAT 1 or
2 hurricane force.

Sanchize06 wrote:GFS ticks east, also weaker

lol whatever screw the models, they are no help. lol, im just go watch this thing real time. NHC has fringe effects coming in tomorow night now.

I was thinking about it, the models are taking the current weaker data which would bring it more east. but the NHC said he is strengthening, maybe they are banking on the intensification and a more westward turn that will be reflected in the models tomorrow? Does that make sense? Cuz recon is out there now and will be trhough the day. maybe thats why they shifted it west, purely based on observations from recon on intensity and the steering thats going to pull henri west.

Guess im only one here ray where are u, we need ur input on whats go on with the models versus NHC, and recon just found 80.5 mph winds.

jmanley32 wrote:Guess im only one here ray where are u, we need ur input on whats go on with the models versus NHC, and recon just found 80.5 mph winds.

I’m up for a bit longer, Jman. It’s important for people to remember that the National Hurricane Center doesn’t hug models—they are a team of forecasters incredibly seasoned in interpreting data from every direction (literally) and rely on far more than individual model to model runs to produce their forecasts.

[quote="SoulSingMG"]

jmanley32 wrote:Guess im only one here ray where are u, we need ur input on whats go on with the models versus NHC, and recon just found 80.5 mph winds.

Jman I am with ya............... Going to get wet and wild around here for sure.

This is their reasoning and it's pretty in line with rays thoughts since day 1.

Tropical Storm Henri Discussion Number 21
NWS National Hurricane Center Miami FL AL082021
1100 PM EDT Fri Aug 20 2021

Satellite imagery shows that Henri is becoming better organized
this evening, with the low-level center becoming more embedded in
the convective overcast and an increase in convective banding.
There has also been an increase in the anticyclonic outflow.
However, reports from Air Force Reserve and NOAA Hurricane Hunter
aircraft show that this has not yet resulted in strengthening, as
the maximum winds remain about 60 kt to the southeast of the
elongated center and the central pressure is in the 994-996 mb
range.

Henri has turned northward, and the initial motion is now 010/8.
A deep-layer mid-latitude trough over the Appalachians and the Ohio
Valley will cut off into a closed low during the next 12-24 h,
while a ridge builds northward to the east and northeast of Henri.
This evolution should cause the storm to move north-northeastward
for 12-24 h, followed by a turn toward the north-northwest from
24-48 h. This motion should bring the center of Henri over the
mid-Atlantic states or southern New England between 36-48 h. After
48 h, the cyclone should get caught up in the southern edge of the
westerlies and turn generally eastward across southern New England
and the Gulf of Maine. There has been little change in the
direction of the forecast guidance since the last advisory, but the
guidance is faster on this cycle through 48 h. Thus, the new track
forecast, which lies close to the consensus models, is faster than
the previous forecast through the 48 h point.

A combination of decreasing shear, improved organization, and
upper-level divergence associated with the trough to the west
should allow Henri to strengthen for the next 24 h or so, and the
new intensity forecast calls for a peak intensity of 75 kt. After
24 h, the center should move over cooler water, and weakening
should start before landfall in the northeastern United States.
However, the cyclone is still expected to be at or near hurricane
intensity at landfall. After landfall, Henri should weaken quickly
and become post-tropical by the 72 h time. Dissipation is forecast
between 96-120 h. The new intensity forecast follows the overall
trend of the intensity guidance.

Lol omg I can't make this up I knew the 06z nam would go back to 06z yesterday basically a far western LI NYC landfall. Last night did not have the data that he was intensifying. 5am I think he is a cane. And that post about a period of almost due west happens on the 06z run. Thinking hurricane warnings to up for Fairfield CT to NYC today IMO. That is if this western track now holds. The models have been a rollercoaster. Kudos to nhc for not buying into the east shift in models. I still think the models were not considering much if any intensification on last night's runs. 06z is clearly now showing what most guidance has shown yesterday morning and 00z night b4.

Recon is showing a area to the se of center with hurricane force winds. Still displaced but convection appears to be working to wrap into center. Again thinking cane at 5am and hurricane warnings added to west to southern NY May be including nyc. nhc already upped the wind forecast for my area to 45mph gusts and just to the east like 50 miles to 65 to 80 mph.

Nope still not a cane cone stayed nearly same maybe slightly west.

jmanley32 wrote:Nope still not a cane cone stayed nearly same maybe slightly west.

Despite Henri not being upgraded at 5am the NHC stated that shear has finally abated and that strengthening will commence today. I just looked at the latest IR satellite and Henri looks to me that it’s becoming more vertically stacked. I would expect an upgrade to hurricane status later this morning.

nutleyblizzard wrote:

jmanley32 wrote:Nope still not a cane cone stayed nearly same maybe slightly west.

Despite Henri not being upgraded at 5am the NHC stated that shear has finally abated and that strengthening will commence today. I just looked at the latest IR satellite and Henri looks to me that it’s becoming more vertically stacked. I would expect an upgrade to hurricane status later this morning.

convection went down but it is refiring. yeah ur prolly right.

gfs is sig east...

Sorry, but I absolutely passed out last night aha as expected modeling is jumping around more now between west/east than it has the last two days, when the changes were all in one direction. At this point, I’d start looking at observations. So, let’s do that:

1. Henri looks like trash, and is certainly less organized than I was expecting by this point. That trailing convection on its south side is absolutely messing with the overall structure and efficiency in my opinion, and sroc’s shear was no benefit either. That said, I’m very surprised that no upgrade to category 1 has been granted yet, as there have now been a couple reconnaissance flights that have recorded the proper wind speeds. I guess their argument is that they aren’t translating to the surface too we’ll basis the dropsonde data? I’m not sure.

2. Henri’s window for intensification will remain open for the next 12-18 hours, though we might start to see some of that occurring shortly for reasons in the next point.

3. Based on recent satellite and water vapor imagery, it looks to me that the interaction between the trough and Henri’s circulation is well underway, and that we might already be seeing the phasing of some of the energy from the trough with Henri’s circulation. Earlier this winter I was having a discussion with billg (which, by the way, where has he been?) about particular signs or hints that the  atmosphere gives you during particular events. There’s no rhyme or reason as to why that I’ve been able to figure out yet, and sometimes their presence defies all logic and physical reasoning (at least basis my understanding of atmospheric dynamics/physics). As of now, it looks like this may be one such case. Check out the annotated image below:



First, take a look at the yellow arc that I have drawn along the western periphery of the cloud line. This is actually the back edge of what’s called deformation banding, which we see all the time in our winter storms on the back side of the low’s circulation. Essentially, it’s an area of frontogenesis in the mid-levels that helps force upward motion/precipitation. When you jackpot in a snow storm, it’s almost always because you were lucky enough be located near the pivot point of this zone. There’s always a spot where throughout the storm’s evolution, the whole area of deformation sets up and rotates around a central point, like a fulcrum.

That takes me to the red circle and arrows. If you play the satellite loop below, focus on where I have the red circle. You’ll notice that the cloud line there makes almost no eastward progress, but appears to just be streaming over roughly the same spot. Meanwhile, the clouds to that position’s north are making westward (northwestward) progress at the same time the clouds to the south are making eastward (southeastward) progress. This, to me, is indicating that we may already be seeing the establishment of an approximate pivot point.

https://www.tropicaltidbits.com/sat/satlooper.php?region=us&product=ir

Lastly, take a look at the blue outline denoting the expanse of the outermost clouds/showers propagating from Henri’s circulation. Notice how it’s almost like an arrow pointing at southern NJ, and if you watch the loop above, all of the convection is moving in that same direction, which, if you notice, is also PARALLEL to the yellow arc. This indicates to me that we are already seeing a capture of Henri’s circulation by the ULL/trough that sroc and I have been debating, and a simultaneously increasing negative tilt/amplification of the overall system. The movement as outlined by the blue, to me, also indicates that we are seeing more of an overall southeast-northwest flow becoming established within a larger northward progression. This is not dissimilar to what happened with Sandy, but it is not on that scale, as sroc correctly mentioned.

So what does this all mean? Well, to ME, it looks like an overall western track should be the result, and here’s why:

1. If the above analysis is correct, then we should start to see more convection/clouds fire in the zone east of the yellow arc and within the blue outline.

2. If we see the expected result in (1), then that means there is an atmospheric tendency for the best vertical motion in that zone.

3. Since the trough’s/ULL’s energy appears to be phasing with Henri’s circulation, that means that Henri will become less and less of its own entity, and more and more a part of the evolution of the larger system - meaning Henri’s circulation should start to follow the trends/movement of the convection/clouds to its north (aka - start turning more northwestward or north-northwestward).

4. Since Henri will be feeling the effects of phasing/general large scale ascent being forced by the interaction with the ULL/trough, strengthening over the short term should not be ruled out even though the satellite imagery is less than attractive. Remember, it will be drawing on two totally different types of forcing mechanisms now, so its appearance doesn’t necessarily have to look good to see an increase in strength.

It’s important to realize that the directional changes of Henri’s movement will not be immediate, so I am not calling for a landfall in southern NJ lol these things are a steady evolution. So Henri will continue to move north, but we should start to see the convection shifting toward the northwestern flank of the circulation. If we do, then it would mean that the above analysis is on the right track, and that Henri’s motion should be soon to follow.

We track!!!

In sum, I still like my cone of 70-80% confidence from yesterday haha at least as of now.

Fresh pass of recon is down to 993mb, but they’re only through the first quadrant.

ABC has the storm head right into LI and then brings heavy rain toward the Hudson Valley. GFS runs the storm straight north, NAM and FV3 backs the storm up against NJ bringing a tremendous amount of rain throughout the state of NJ. Wonder what the NHC will say in their 8 am update... Getting pretty concerned, as of now the media is focusing on LI and almost a non-event for NJ. I was going to head home to NNJ tonight to be home for the storm and watch the house, and maybe go to MSG if they don't cancel the concert tomorrow night, so travel is most likely in my future...

rb924119 wrote:Fresh pass of recon is down to 993mb, but they’re only through the first quadrant.

RB excellent write up in your post. That area you outlined in Red is key to where Henri will end up.

I am thinking a strong Cat 1 when Henri shows up in these parts.

Going to be tracking all day while I get my house in Kings Park ready.

Dunnzoo wrote:ABC has the storm head right into LI and then brings heavy rain toward the Hudson Valley. GFS runs the storm straight north, NAM and FV3 backs the storm up against NJ bringing a tremendous amount of rain throughout the state of NJ. Wonder what the NHC will say in their 8 am update... Getting pretty concerned, as of now the media is focusing on LI and almost a non-event for NJ. I was going to head home to NNJ tonight to be home for the storm and watch the house, and maybe go to MSG if they don't cancel the concert tomorrow night, so travel is most likely in my future...

The HRRR brings the storm in on LI but also likes the idea of dumping tons of rain across parts of NJ...

Nice write up Ray and I agree and noticed that area that looks like a pivot last night. I was like hey is that ehat ray was talk bout? So now I wonder if sroc will agree or he thinks st else is go on. If you didn't tell me I wouldn't know there was a TS he looks beyond ugly and ya that elongated southern part has to be effecting the storm. Probably negatively. Well let's see if nhc shifts the cone west at 11. Recon is finding hurricane forces but the western side is nearly devoid of wind. Very lopsided .

Hurricane Hunter’s words as of this morning…