ATL: ELSA - Post-Tropical - Discussion

[Dean4Storms]

Appears to me that Recon went around the eastern side into the southern side of the storm going around the center and also missed the strongest winds, might have been due to mountains of Barbados in its pass.

[NDG]

Why is the recon at 10K trying to find the COC? Is mind boggling.

[SunnyThoughts]

https://twitter.com/webberweather/statu ... 1974733827

[InfernoFlameCat]

Wow this is a lot weaker than expected. The central pressure isn’t even below 1000 mbar and no hurricane force winds have been found yet. Maybe this actually isn’t a hurricane yet.

I mean, it produced sustained hurricane force winds over Barbados so it is by definition a hurricane. Even if it shouldn’t be. Also the sustained hurricane force winds were part of the eyewall which rules out mesocyclone based outside the center,( could still have been a Mesocyclone located in the center but still would classify it as a hurricane)

[NotoSans]

Recon may have missed the strongest wind but the center fix is still at the edge of the convective canopy, which seems to be more in line with low-res microwave imagery than high-res radar imagery.

[HurricaneEnzo]

What is the elevation of barbados? Could have an impact on windspeeds they were seeing versus actual surface winds.

[SconnieCane]

00Z HWRF run was scary...held serve with a monster MH now shooting the gap between Jamaica and Cuba...it then gets gutted by crossing Cuba but in the process turns into a gigantic, sprawling Ike-like sloshmaker...would be disastrous for a large part of the Gulf side of Florida.

06Z doesn't get quite as strong (although still very impressive, especially for early July) and takes an even bigger hit from Cuba (all the way back up to 1000 mb after emerging near the Keys), but still manages to re-consolidate some before landfall on the Florida Gulf coast.

[Mialco]

Appears to me that Recon went around the eastern side into the southern side of the storm going around the center and also missed the strongest winds, might have been due to mountains of Barbados in its pass.

Barbados doesn't geographically have mountains... Some big-ish hills, but nothing that compares to the actual mountains of other islands which are all volcanic (Barbados is essentially a coral island).

[InfernoFlameCat]

What is the elevation of barbados? Could have an impact on windspeeds they were seeing versus actual surface winds.

The reported sustained hurricane force winds at sea level.

[SFLcane]

The winds are misleadingly strong because of the trades.

[Blown Away]

So we have Hurricane Elsa out there before reaching the LA, with her getting stronger faster than expected, will this result more poleward movement or further West before turning North.

I’ve seen the Caribbean storm with the center of the cone over western FL/eastern Gulf many times. Guess it’ll depend on steering currents in the higher levels but a stronger storm would usually pull up the East Coast as opposed to the Gulf.

Actually, the opposite should be expected here, since winds are less southerly in the upper levels. This is consistent with shear displacing the LLC north of convection yesterday. For steering implications, see:
https://twitter.com/JackSillin/status/1410931036733657092?s=20

Elsa is just SW of Barbados now which puts her on the extreme N edge of the ECMWF ensembles cluster as a hurricane and not a TD as shown by the majority of the ensembles.

[NDG]

Appears to me that Recon went around the eastern side into the southern side of the storm going around the center and also missed the strongest winds, might have been due to mountains of Barbados in its pass.

Barbados has no Mountains, it has hills, the highest I see in the northern middle of the Island not even 1k feet at the highest.

[jasons2k]

Update from Jeff Lindner:

USAF mission into Elsa along with radar data and surface observations from Barbados indicate that Elsa is now a hurricane.

Hurricane conditions are quickly spreading into the Windward Islands….various watches and warnings are in effect for portions of the Caribbean Islands (See graphic below).

Discussion:
Elsa has been able to take advantage of favorable conditions over the last 24 hours and based on data from the first USAF mission this morning and Barbados which reported sustained winds of 74g86mph this morning, Elsa has been upgraded to a hurricane. Radar data indicates good banding features with the hurricane and a small central core convective area near the center. Elsa continues to race WNW near 30mph which is extremely fast for a hurricane, but the system has thus far been able to keep its low level and upper level centers aligned.

Track:
Elsa is racing W to WNW and this motion is expected to continue with the strong sub-tropical ridge of high pressure to the north of the hurricane. As mentioned this is really fast for a tropical system. This motion should continue through day 2 (48 hours) and then Elsa will approach a weakness in the strong sub-tropical ridge over the western Atlantic as a mid latitude trough moves across the US east coast. The ECWMF continues to be very fast and weak with Elsa…and why it may have the fast forward speed correct, Elsa is already stronger than the ECWMF suggests. It continues to be an eastern outlier and nearly dissipates Elsa over the Dominican Republic by Sunday. However the GFS and UKMET indicate more of a WNW motion longer and more gradual turn of Elsa into the weakness. This appears to be the increasingly more likely outcome, but guidance ensemble spread is very large from east of the Bahamas to near the northern Yucatan at days 4-5 so confidence remains lower than average on the track.

Intensity:
Conditions are seemingly favorable for development as clearly noted this morning. The fast forward motion of Elsa could at some point become a negative factor to intensification, but thus far this does not seem to be effecting the development of the system. Based on the track reasoning above, land interaction with the high mountains of Hispaniola appear less likely. There remains a large spread in the intensity guidance with most keeping Elsa near the intensity it is now…a strong tropical storm or weak hurricane, while some guidance is much stronger. NHC continues to lean toward the lower end of the guidance spectrum, and the current forecast keeps the system as a weak hurricane or strong tropical storm through the period. It continues to be indicated that Elsa could be stronger than forecasted especially over the NW Caribbean Sea early next week.

[Mialco]

What is the elevation of barbados? Could have an impact on windspeeds they were seeing versus actual surface winds.

Highest point is just over 330m/1100ft... But that's not on the south... The south is virtually flat, and that's where the winds were recorded.

[aspen]

Seeing how Elsa isn’t nearly as deep as anticipated by this point, today’s 06z HWRF run is probably on to something. It also got the 12z intensity correct: 1004 mbar.

[HurricaneEnzo]

Looking at IR there were some small hot towers popping on the Southern end of Barbados as Elsa passed. Could have been increased winds under those. Would have been very localized.

[jlauderdal]

What is the elevation of barbados? Could have an impact on windspeeds they were seeing versus actual surface winds.

Highest peak is 1100 ft..the bottom line is this system looks cool on IR and had a nice blowup of pretty colors but structurally it's really not that impressive, give it some more time to get into a better setup downstream...85mph winds are what they are but there are different ways produce those speeds...some critical info in the next couple of days including sampling the atmosphere to the north(land and recon), 6 hour balloon launches in the united states...all of this will tighten up the gfs-euro battle as they are seeing things very different

[Hypercane_Kyle]

Something isn't quite right here. There's definitely an eye/eyewall on radar, with a closed LLC that produced hurricane force winds in Barbados only an hour ago.

Recon barely shows a tropical cyclone, with 55 knot winds.

[Steve]

If I was down on the peninsula, I'd probably get some basics knocked out today - ice, water, top off those gas tanks, etc. It's already going to be a holiday weekend with lots of travel. Fair chance the majority of the peninsula could be in line for tropical storm effects. NHC doesn't yet have a strong storm paralleling and then landfalling along the coast. But if it's stronger than what they've put out so far, it could be worse. Don't forget the system that came up a few years ago, and people around greater Miami were surprised how strong those E-W feeders were on the Atlantic Coast. I'm not at all being alarmist here. It's just that whatever you can get done ahead of a surge of other people, you don't have to do later. And I hate lines.

Nice spiraling in as the visibles start coming in.
https://www.star.nesdis.noaa.gov/GOES/f ... 52021#tab2

[AutoPenalti]

Something isn't quite right here. There's definitely an eye/eyewall on radar, with a closed LLC that produced hurricane force winds in Barbados only an hour ago.

Recon barely shows a tropical cyclone, with 55 knot winds.

It's possible that Barbados may have been caught in a mesovort.