BoB: Very Severe Cyclonic Storm SIDR

[Derek Ortt]

another EWRC in all liklihood

This should be the final EWRC based upon how the rainbands are starting to evolve

[Squarethecircle]

But JTWC still kills it (like, really KILLS it) before landfall... What's their rationale? Can anyone take a guess?

[wxman57]

But JTWC still kills it (like, really KILLS it) before landfall... What's their rationale? Can anyone take a guess?

Strong SSW upper-level winds as it nears the coast (wind shear). But it may also be accelerating as it approaches land, which could partially compensate for the increased flow aloft.

[Derek Ortt]

I'm not ready to buy that JTWC forecast either. The storm is accelerating far more than the models are suggesting and could even be inland within the next 48 hours

Even so, this is a water storm, not a wind storm, even if this were to cross the coast as a cat 5. Could easily see a 15-20 foot tidal surge into Calcutta and Bangladesh out of this

[Coredesat]

This 15Z (yes, I know it's nearly 21Z right now) image shows concentric eyewalls, so Sidr is (well, was at the time) likely in the middle of an ERC:

[wxman57]

Here's the current satellite with 250mb 18Z winds (GFS) layered on top. Note the 50-60 kt SW winds to the north of Sidr today. GFS does forecast these winds to drop to about 30 kts by Thursday afternoon, however. It's possible that Sidr could be moving at around 15kts at landfall, maybe faster. That could reduce the relative shear and keep it a bit stronger than forecast. But the key, as Derek (and I have) said, is the structure of its wind field more so than the peak wind in any one part of the storm. It's a little larger than an average sized storm, and the area it's headed for is about as flat as southwest Louisiana.

[Coredesat]

Can someone update the thread title to Sidr's actual name?

Sidr's actual name is too long to fit in the thread title without being cut off (Very Severe Cyclonic Storm SIDR), although it would fit if "NIO:" and the number were removed.

In fact, could a mod rename this thread to "Bay of Bengal: Very Severe Cyclonic Storm SIDR" if possible? If it's not possible, try using "NIO:" instead.

[Squarethecircle]

I'm not going to even bother figuring out what the hell this storm is doing; it's getting rather confusing. All I know is that the anticyclone should help penetrate the shear and that the JTWC is taking shear into account too much; a fast-moving storm in the face of shear can persist fairly well.

[HURAKAN]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 13 NOV 2007 Time : 200000 UTC
Lat : 13:56:44 N Lon : 89:30:30 E

CI# /Pressure/ Vmax
6.6 / 910.8mb/129.6kt

6hr-Avg T# 3hr-Avg T# Adj T# Raw T#
6.6 6.6 6.6 6.6

Latitude bias adjustment to MSLP : +0.0mb

Estimated radius of max. wind based on IR :<10 km

Center Temp : -34.6C Cloud Region Temp : -78.2C

Scene Type : PINHOLE EYE

Positioning Method : SPIRAL ANALYSIS

Ocean Basin : INDIAN
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

****************************************************

In numerology all that many 6s are a very bad omen.

[cycloneye]

SSD is below UW-CMISS.

13/2030 UTC 13.9N 89.4E T5.5/6.0 SIDR -- Bay of Bengal

[Squarethecircle]

That's why the eye's not visible... It's contracting.

[CrazyC83]

Could this be stronger than everyone thinks because of the pinhole eye?

[Coredesat]

It's not a pinhole eye. The eye is contracting because the inner eyewall is collapsing; the system is finishing an eyewall replacement cycle.

[Squarethecircle]

That seems accurate enough. The convective signature looks much healthier now.

[Derek Ortt]

seems like an equatorward outflow channel is trying to establish itself

[Squarethecircle]

Now it all comes back down to how much it can re-intensify before it begins its weakening trend.

[Derek Ortt]

18Z model NCEP has a total about face


Now it takes the storm just east of Calcutta and into Bangladesh

[Cyclone1]

Unfortunately, it has plenty of room...

[hcane27]

[HURAKAN]