EPAC: BONNIE - Post-Tropical - Discussion

[aspen]

Assuming no more hiccups during the next 12-18 hours, Bonnie could be a major by sunset at this rate. It’ll be the first time the name Bonnie has been used for a major since 1998.

[Yellow Evan]

 https://twitter.com/pppapin/status/1543952888384442368

[cycloneye]

[tolakram]

Still in range for the east floater

https://weather.cod.edu/satrad/?parms=meso-meso1-02-96-1-50-1&checked=map&colorbar=undefined

[tolakram]

saved loop

[cheezyWXguy]

Starting to see some hints at the shear Yellow Evan posted about yesterday, looks like out of the NE. Doesn’t look like enough to prevent strengthening, but may see some tilting (again, as he said). Good call.

[Yellow Evan]

Starting to see some hints at the shear Yellow Evan posted about yesterday, looks like out of the NE. Doesn’t look like enough to prevent strengthening, but may see some tilting (again, as he said). Good call.

Yea it’s definitely there but not really disrupting the storm yet.

[ScottNAtlanta]

At first glance I thought the eye was tightening up, but looking at the high resolution images, it seems like shear is tilting it somewhat making it just look smaller from above.

[cheezyWXguy]

At first glance I thought the eye was tightening up, but looking at the high resolution images, it seems like shear is tilting it somewhat making it just look smaller from above.

Appears to be intermittent issues in that regard, but the shear looks to be waning for the moment. Albeit cloud filled, the eye and cdo are becoming more circular

[cycloneye]

[InfernoFlameCat]

Looks like a high end cat 2 right now. Good job Bonnie.

[Yellow Evan]

TXPZ25 KNES 041804
TCSENP

A. 02L (BONNIE)

B. 04/1730Z

C. 13.6N

D. 99.5W

E. ONE/GOES-E

F. T4.5/4.5

G. IR/EIR/VIS

H. REMARKS...LG EYE SURROUNDED BY B AND EMBEDDED IN LG RESULTS IN DT
OF 4.5 AFTER -0.5 EYE ADJ. MET AND PT AGREE. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...BROWN

[Meteophile]

Even If the ohc is very Low, the MPI (Emmanuel) is very high in the forecast path of the Storm. Is this a non-negligible indicator ? I don't know the reliability of this calculation. And i also don't know If the picture link Works.

[cycloneye]

Cat 2.

EP, 04, 2022070418, , BEST, 0, 137N, 996W, 85, 978, HU

[Kingarabian]

Even If the ohc is very Low, the MPI (Emmanuel) is very high in the forecast path of the Storm. Is this a non-negligible indicator ? I don't know the reliability of this calculation. And i also don't know If the picture link Works.

https://istreetview.com/preview/?id=hOVDkDcy&url=3cRltBdhUaYc2lJ275Ez4NhqjMmC+vaqAQ4m3zXbsrDDGm94YNcv67oTZnzk9ZoqZ9HfoXoky5+WIji8wuIwi+nPi3z46mhC1HIMew==

OHC is almost irrelevant in the EPAC. Always go with MPI. You will almost always see an EPAC system thriving in what would be unfavorable OHC.

[Sciencerocks]

[aspen]

It's always interesting to see how different many of these Cat 2-3 hurricanes look on IR and visible. Looks fantastic on the latter, but really ragged on the former. You can barely tell there's an eye on IR.


If it wasn't for the fluctuating low-moderate shear and the displaced anticyclone, then I would've expected a storm with this structure to easily make it to Cat 4 intensity. Instead, Bonnie might level off soon.

[cheezyWXguy]

Even If the ohc is very Low, the MPI (Emmanuel) is very high in the forecast path of the Storm. Is this a non-negligible indicator ? I don't know the reliability of this calculation. And i also don't know If the picture link Works.

https://istreetview.com/preview/?id=hOVDkDcy&url=3cRltBdhUaYc2lJ275Ez4NhqjMmC+vaqAQ4m3zXbsrDDGm94YNcv67oTZnzk9ZoqZ9HfoXoky5+WIji8wuIwi+nPi3z46mhC1HIMew==

OHC is almost irrelevant in the EPAC. Always go with MPI. You will almost always see an EPAC system thriving in what would be unfavorable OHC.

Interesting. Is this because of a lower tendency for storms to stall in areas of low OHC, or because of a higher tendency for strong storms to become annular? (Not sure if either of those tendencies are true or not, just something your post would incline me to think about)

[Yellow Evan]

Even If the ohc is very Low, the MPI (Emmanuel) is very high in the forecast path of the Storm. Is this a non-negligible indicator ? I don't know the reliability of this calculation. And i also don't know If the picture link Works.

https://istreetview.com/preview/?id=hOVDkDcy&url=3cRltBdhUaYc2lJ275Ez4NhqjMmC+vaqAQ4m3zXbsrDDGm94YNcv67oTZnzk9ZoqZ9HfoXoky5+WIji8wuIwi+nPi3z46mhC1HIMew==

OHC is almost irrelevant in the EPAC. Always go with MPI. You will almost always see an EPAC system thriving in what would be unfavorable OHC.

Interesting. Is this because of a lower tendency for storms to stall in areas of low OHC, or because of a higher tendency for strong storms to become annular? (Not sure if either of those tendencies are true or not, just something your post would incline me to think about)

OHC is only particularly important if a TC is moving slowly or in the GOM where waters can pretty shallow. Yes, there are portions of the tropics where SSTs are 26-27C and as you’d expect the resultant OHC is fairly low but it in itself isn’t a huge problem if the wind shear is low. I wouldn’t say OHC is irrelevant but low OHC and marginal SSTs aren’t a huge hinderance if shear is favorable.

[Yellow Evan]