SIO: Ambali - Very Intense Tropical Cyclone

[Nancy Smar]

92S INVEST 191202 1800 5.0S 65.0E SHEM 15 0

[Grifforzer]

Over the last 36 hours, an area of disturbed weather developed east of the system 02R. Its quick development has probably been favored by the passage of an active equatorial rossby wave. The system currently benefits from an excellent upper level divergence, both equatorward and poleward. Over the last hours, convective bursts triggered near the estimated location of the circulation center. The 1745z ASCAT-B swath showed max winds of 20 knots concentrated in the southeastern semi-circle, where the convection is mainly triggering.

In terms of track, a low to mid-level ridge centered over the eastern half of the basin steers the system generally south-southwestard. The dispersion of the euro ensemble remains moderate. This weekend, as the system is forecast to weaken significantly, the steering flow should come back down to the low levels. Thus, after having bumped into the high pressures in the south, the residual low should driflt generally westward while filling-up.

At first, the system 03R benefits from conducive environmental conditions. The low-level convergence is good over the eastern semi-circle and concentrates convection near the center of circulation. In the upper levels, divergence remains high and vertical windshear weak. Ohc is particularly high over this area of the basin. Thursday, an upper trough arrives from the southwest and takes part in a strengthening of the poleward divergence. A gradual intensification of this system is forecast over this period. Some models suggest a more rapid development, likely due to a smaller size of the system. However, from friday as the upper trough comes closer, a westerly shear constraint appears in the mid-levels, then in the upper levels quickly after. A rather rapid weakening is suggested by the available intensity guidance.

Area of Disturbed Weather 03

[aspen]

Now named Tropical Storm Ambali. It is already up to 50 kt and is within an OHC hot spot that can theoretically support a pressure of 880 mbar or lower. Based on its tiny core and good outflow, I would not rule out RI within the next 24-48 hours.

[WAcyclone]

Ambali appears to be rapidly intensifying. SMAP already suggested a maximum 1-minute wind of 54 kt at 01:45Z and the storm looks much better now than it did back then.

[aspen]

Ambali appears to be rapidly intensifying. SMAP already suggested a maximum 1-minute wind of 54 kt at 01:45Z and the storm looks much better now than it did back then.

https://i.imgur.com/OTcnoZ3.gif

https://i.imgur.com/fRrKpm9.gif

That might be worthy of 65-70 kt now. I have a feeling we could see a phase of ERI, not just because of the already very favorable environment (5-10 kt shear, good outflow, and very high SSTs/OHC), but because of how small Ambali’s core is.

[wxman57]

Ambali appears to be rapidly intensifying. SMAP already suggested a maximum 1-minute wind of 54 kt at 01:45Z and the storm looks much better now than it did back then.

https://i.imgur.com/OTcnoZ3.gif

https://i.imgur.com/fRrKpm9.gif

That might be worthy of 65-70 kt now. I have a feeling we could see a phase of ERI, not just because of the already very favorable environment (5-10 kt shear, good outflow, and very high SSTs/OHC), but because of how small Ambali’s core is.

I agree, yet La Reunion (official RSMC) is saying it's a TS and won't have more than 50kt winds. What's up with these RSMCs? Don't they look at the data? Can't they see the eye starting to open up?

[wxman57]

The eye is now clearing up on this "tropical storm". I know it's the middle of the night in La Reunion, but they must be able to determine that this is not a 50kt TS.

[WAcyclone]

The eye is now clearing up on this "tropical storm". I know it's the middle of the night in La Reunion, but they must be able to determine that this is not a 50kt TS.

http://wxman57.com/images/Ambali.JPG

I might be wrong but I think Meteo France only issues advisories every six hours.They will certainly upgrade Ambali's intensity with their 18Z advisory.

[aspen]

Up to 70 kt 1-min sustained winds, and expected to reach 100 kt in 12 hours. RI has started and ERI is a distinct possibility.

[aspen]

That’s a very tiny eyewall: http://rammb.cira.colostate.edu/product ... 051222.GIF

[aspen]

The tiny eyewall is compete as of 13:30z
http://rammb.cira.colostate.edu/product ... 051331.GIF

[WAcyclone]

New SMAP pass from 14Z estimates a max. 1-minute windspeed of 75 kt.

[aspen]

CMG ring around a full LG eye with a few pixels of MG, maybe close to T#5.0 by now.

[aspen]

ADT is recording single digit positive eye temps. I think this is already a 120 (+/-5) kt Category 4 system. Incredible.

Does anyone know where else besides Tropical Tidbits I can find updated best track intensities and positions? TT is no longer showing any storm data for some reason.

[aspen]

Eye temps are up to +16.7 C!

http://tropic.ssec.wisc.edu/real-time/adt/odt03S.html

ADT estimates seem to be heavily constrained, as it’s only 80 kt despite how Ambali is an easy Cat 4, possibly up to 130 kt.

[aspen]

Eye temp is now +20.4 C, raws up to T#6.8. This is easily 130-140 kt.

[Highteeld]

Eye temp hovering around 20*C. Jtwc has T 6.5 rn

[Grifforzer]

0.A NUMERO DU BULLETIN : 9/3/20192020
1.A CYCLONE TROPICAL INTENSE 3 (AMBALI)
2.A POSITION A 1800 UTC LE 05/12/2019 ANS UN RAYON DE 20 MN AUTOUR DU POINT 10.0 S / 62.5 E(DIX DEGRES ZERO SUD ET SOIXANTE DEUX DEGRES CINQ EST)DEPLACEMENT: SUD-SUD-OUEST 11 KT
3.A ANALYSE DE DVORAK: 5.5/5.5/D 2.0/6 H
4.A PRESSION AU CENTRE: 962 HPA
5.A VENT MAX (MOYEN/10 MN): 90 KT

Intense Tropical Cyclone 90 knots with estimated 125 knots gusts now

[aspen]

0.A NUMERO DU BULLETIN : 9/3/20192020
1.A CYCLONE TROPICAL INTENSE 3 (AMBALI)
2.A POSITION A 1800 UTC LE 05/12/2019 ANS UN RAYON DE 20 MN AUTOUR DU POINT 10.0 S / 62.5 E(DIX DEGRES ZERO SUD ET SOIXANTE DEUX DEGRES CINQ EST)DEPLACEMENT: SUD-SUD-OUEST 11 KT
3.A ANALYSE DE DVORAK: 5.5/5.5/D 2.0/6 H
4.A PRESSION AU CENTRE: 962 HPA
5.A VENT MAX (MOYEN/10 MN): 90 KT

Intense Tropical Cyclone 90 knots with estimated 125 knots gusts now

Is that seriously a T#5.5 at 18z? How did they get that when everything else points to at least a T#6.5?

[aspen]

The 21z intensity for Ambali is out: a mere 100 kt.

I have two questions: are they mad, and who put all the constraints on the Dvorak analyses?

At least they’re calling for a peak of 130 kt later today, but I wouldn’t be surprised if Ambali’s maximum intensity is short-lived, and it starts to weaken before the next advisory.