NATL: MELISSA - Hurricane - Discussion

[Travorum]

If the AF plane's pressure extrap is accurate (medium if) Melissa might have deepened a bit since NOAA left, the last HDOB line reported 953.6mb still with 97kts FL wind and 105kt SFMR. Wait for the dropsonde to be sure. This was also in the weaker SE quad so winds might be up a bit.

Edit: 946.9mb in the eye, so maybe a few mb depending on how the extrap is calibrated relative to NOAA. There was a 114kt SFMR reading heading out of the eye, but only 111kt flight level winds. That's certainly not going to justify anything over 110kts.

[WaveBreaking]

Recon found 122 kt FL winds in the SE eyewall.

[cycloneye]

Minimum Extrap. Pressure: 946.9mb at 16:45z

[BobHarlem]

Long duration radar loop

[cycloneye]

Dropsonde is at 949 mbs.

[Teban54]

Note that there's no double wind maxima on this eye pass, even though it doesn't strictly preclude the onset of an EWRC.

Edit: I may have spoken too soon, as the next set of data showed a small wind maximum albeit far removed from the eyewall.

[sasha_B]

Much like Rafael last year, if it weren't for recon observations, this could be treated as a much stronger storm. Subjective and objective satellite estimates (final T-numbers, not instantaneous!) have reached 7.0, and raw numbers have for the most part been hovering between 7.1 and 7.5 for upwards of 12 hours. Probably a number of factors inducing this upward bias in Dvorak intensity estimates.

[cycloneye]

Eye is closed and is smaller.

VORTEX DATA MESSAGE AL132025
A. 26/16:45:00Z
B. 16.38 deg N 076.82 deg W
C. 700 mb 2680 m
D. 949 mb
E. 360 deg 26 kt
F. CLOSED
G. C8
H. 105 kt
I. 107 deg 8 nm 16:42:30Z
J. 211 deg 122 kt
K. 110 deg 9 nm 16:42:00Z
L. 114 kt
M. 276 deg 5 nm 16:47:00Z
N. 005 deg 111 kt
O. 282 deg 6 nm 16:47:30Z
P. 9 C / 3063 m
Q. 20 C / 3044 m
R. 7 C / NA
S. 12345 / 7
T. 0.02 / 3 nm
U. AF307 1613A MELISSA OB 05
MAX FL WIND 122 KT 110 / 9 NM 16:42:00Z
;

[Iceresistance]

Melissa's eye is now a pinhole type at 8 Nautical Miles, uh oh

https://s12.gifyu.com/images/b3ujb.png

[kevin]

Eye contraction can also happen prior to an EWRC. The next pass should provide clarification. If the pressure has dropped significantly then it's most likely a stable pinhole, otherwise it could instead be eye size contractions as a precursor to an EWRC.

[cheezyWXguy]

Eye dropsonde had 949mb with 26kt. Good for 947mb.

[CrazyC83]

Without Recon, this would probably be analyzed at 130-135 kt right now. The best guess on that data is 115 kt for the actual intensity.

It's almost an inverse of Delta 2020, which in the Caribbean never went above T5.0 but aircraft supported 120 kt.

[Teban54]

Without Recon, this would probably be analyzed at 130-135 kt right now. The best guess on that data is 115 kt for the actual intensity.

It's almost an inverse of Delta 2020, which in the Caribbean never went above T5.0 but aircraft supported 120 kt.

It's also a miniature and less extreme version of Eta, with raw T8.0+ when recon measured 130 kt in reality.

[storm_in_a_teacup]

Just want to shout out a quick "THANKS" to fellow members for imparting some really insightful details and analysis regarding a few micro characteristics at hand that play into a major hurricane's subtle fluctuations, RI, and the often occuring "secondary" or appendage blob affect that seems to occur in an number of Atlantic basin storms. The combination of a great satellite and radar presentation along with well explained & concise explanation makes for a great sit-back with popcorn visual learning event

I just wish I wasn’t super tired then I could actually figure out what my questions about the explanations are

[sasha_B]

Without Recon, this would probably be analyzed at 130-135 kt right now. The best guess on that data is 115 kt for the actual intensity.

It's almost an inverse of Delta 2020, which in the Caribbean never went above T5.0 but aircraft supported 120 kt.

Given the fact that deepening seems to have resumed, albeit at a slower pace, and there's been no appreciable reduction in satellite estimates, it's possible that they maintain intensity at 18z for continuity's sake until there's clearer evidence that an EWRC is in progress.

[USTropics]

It's difficult to ascertain exactly what is going on without some tail doppler radar. While fully closed, the western side of the eyewall hasn't exhibited the same level of depth as the eastern eyewall for much of past 6 hours (with even brief periods of being open). Here is the latest radar image:


TROPICS-5 pass from about 2 hours ago:

[aspen]

It's difficult to ascertain exactly what is going on without some tail doppler radar. While fully closed, the western side of the eyewall hasn't exhibited the same level of depth as the eastern eyewall for much of past 6 hours (with even brief periods of being open). Here is the latest radar image:
https://i.imgur.com/PmrlUJW.png

TROPICS-5 pass from about 2 hours ago:
https://i.imgur.com/h355b8v.jpeg

https://i.imgur.com/ojlfvPv.png

That thick band/partial outer eyewall on the NW side is probably responsible for the double wind maxima on recon, I reckon. Perhaps that also has something to do with the inner eyewall’s weak spot?

[eastcoastFL]

Is Jamaica's met website broken for anyone else too? I was trying to see radar but barely anything's loaded.

This mirror works well and doesnt have any gaps

https://flhurricane.com/imageanimator.php?960

Those outer rain bands are starting hang over Kingston. This is the start of a very long couple of days for the people there.

[kevin]

It feels like only a matter of time until the intensity matches Melissa's appearance, because the storm keeps getting more impressive. We're now already at 15 hours of raw T# above 7.0.

[sasha_B]

Seeing mixed opinions on whether or not radar data indicate that an EWRC is in progress. There's no mention of it on the 18z intermediate advisory, but there have been some signs of dual wind maxima, and the eye contraction we saw earlier could back that up. Either way, the next VDM might help to clarify the situation - extrapolated pressure is still dropping, FWIW. Down to 944 hPa, about 2 hPa deeper than it was on the last pass about an hour and a half ago.