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WxWatcher007

Hurricane Sally

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Just now, Yeoman said:

The CoC seems to be turning into a hot tower

'I'm guessing that's the SW eyewall. I see a meso there on radar

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Anyone that looks at TT and sees wacky low pressure drop sonde for Sally from NOAA2, note the date on it: September 27, 2020. It's from 13 days in the future. All I can say is: wtf? I'm guessing someone forgot to turn off reporting for a test. Just noting this before someone goes posting it and thinks it's real.

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I think "RI" is becoming more and more an irrelevant term lately, or at least maybe an updated definition may be needed, especially with strong TS's blowing up in the GOM.  Even just 20 years ago it was a big deal as it occurred much more rarely.  "RI", especially with storms along the Gulf coast seem to be more and more common over the last decade.  There have been storms go from 40KT's to 80-100KT's in less than 24 hours on approach to the coast lately.  Shallow coastal waters running at consistent 30-31C temps year after year, I think, are the main drivers.  A 20KT sheared storm can under go impressive RI (i.e. Hermine) with a tilted vortex on approach to the coast in the GOM. 

Technically with the time this one may have left over water any substantial strengthening could be considered RI.  Current RIPA tables are as high as they've been with this storm potentially adding another 30 to 35KT's.  Not saying it will happen, RI forecast models always should be taken with a grain.

2020al19_ripaprob_000000000000.gif

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53 minutes ago, StormChaser4Life said:

Curious if the slow movement will create enough upwelling to keep Sally from really taking off. Looking at IR it has leveled off somewhat temporarily but the convective max is approaching 

I think that the NHC is taking the upwelling effect into account for Sally's intensity. 

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4 minutes ago, brianc33710 said:

Laura had a high pressure for a 150 mph hurricane. Sally has high pressure for a 100 mph hurricane. 

Because right now it is more like an 80mph hurricane :).

 

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I'm interested in seeing how Sally's track compares with Ivan. Having lived in Gulf Shores for many years, Ivans track went basically up AL Hwy 59, which roughly breaks Baldwin Co in half. West of Hwy 59, Eastern Shore towns & Ft Morgan, faired fairly well, as the eye went over that part of the county. East of 59, Orange Beach & Perdido Key, were slammed by the right front quadrant, and got hammered pretty badly. 

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4 minutes ago, Calderon said:

Why are you so fixated on it?

I don't like smug condescension and summary dismissal of valid points.

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I've been tracking hurricanes for twenty years. One thing everyone seems to forget it takes time for a hurricane to wind up, generally 36-48+ hours minimum for a non-sheared storm after it hits "curved band" status (usually reached as a strong Tropical Storm) before a storm becomes what I consider "well formed" - that is, have a definite eye visible on IR (typically appears as a stronger cat 2 storm). Storms this year have been having wind speeds jump up before the core finishes forming, and I'm not sure why that's happening; usually you need a fully wrapped eye (radar based; may not be visible on IR yet) before the winds start moving above Category 1 strength. This is my rule of thumb, some storms are faster, but it's rare. Many storms are slower, especially if sheared or over cooler water.

Sally has one big limiting factor: it's proximity to land. This is going to be a big negative impediment to intensification. If the storm was a couple hundred more miles offshore, we could easily see a cat 4 by landfall with the high gulf heat content, but land impacts will probably limit it's strength to cat 2, maybe weak cat 3 if it can finish wrapping its core before landfall (it sure is trying).

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If it stays this slow  or  completely stalls and eventually comes  in around al/fla  line at whatever strength the  possibilty  increases  of a 2nd chance even further south in the atlantic.

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4 minutes ago, ldub23 said:

If it stays this slow  or  completely stalls and eventually comes  in around al/fla  line at whatever strength the  possibilty  increases  of a 2nd chance even further south in the atlantic.

You make my head hurt. 

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4 minutes ago, ldub23 said:

If it stays this slow  or  completely stalls and eventually comes  in around al/fla  line at whatever strength the  possibilty  increases  of a 2nd chance even further south in the atlantic.

This was voice to text wasn’t it

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11 minutes ago, ldub23 said:

If it stays this slow  or  completely stalls and eventually comes  in around al/fla  line at whatever strength the  possibilty  increases  of a 2nd chance even further south in the atlantic.

Wtf u talkin bout?

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00z GFS looks like it's at the AL MS border in 30 hrs. Around 981mb

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1 hour ago, Doc Jon said:

I don't like smug condescension and summary dismissal of valid points.

I get it, but we've also had multiple new folks lately say "eye this" and "eye that" without much in the way of discussion of substantiating evidence, so it's not exactly unexpected.

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1 hour ago, Doc Jon said:

Sooo, uh, for all you who were giving me a bunch of crap earlier, is this NOT an eye?

http://tropic.ssec.wisc.edu/real-time/mimtc/2020_19L/web/displayGifsBy12hr_05.html

 

MIMIC is not a good reference source for hurricane form. It's based on the 85GHz microwave passes from satellite that occur every 6-15 hours on average, with often large gaps between them, then a computer "morphs" those images together to create a pseudo-continuous look at what the storm probably is. Use the raw microwave passes available at the NRL Tropical Cyclone site rather than the MIMIC if you want to reference the 85GHz-observed internal structure.

That said, microwave data is most useful well away from shore where you have no radar coverage to tell internal structure. It is less detailed than radar and shows similar information about the storm's structure. Sally has luckily been in range of radar extensively during her development, meaning we have very good information on the central structure of the storm.

I agree that an eye did try to pop out earlier on IR, and has been well visible on radar for quite a while. That said, it is still not a well wrapped storm with the eye not yet fully closed. Give it another 6-12 hours and we'll probably have a closed eye, so long as land interference and shear don't cause issues. Once it pops out on radar in a good, well wrapped state you'll know very clearly that we have an eye, and no one will dispute it. Right now the updraft just isn't yet strong enough to clear away the hot towers convective structures from overshooting the eye, even though radar shows the eye about 60% to 70% wrapped. Once it gets fully wrapped the outflow will only be via the central core: the eye will clear and the pressure will drop. It will be clear to everyone that we have a well formed eye.

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25 minutes ago, Random Chaos said:

I've been tracking hurricanes for twenty years. One thing everyone seems to forget it takes time for a hurricane to wind up, generally 36-48+ hours minimum for a non-sheared storm after it hits "curved band" status (usually reached as a strong Tropical Storm) before a storm becomes what I consider "well formed" - that is, have a definite eye visible on IR (typically appears as a stronger cat 2 storm). Storms this year have been having wind speeds jump up before the core finishes forming, and I'm not sure why that's happening; usually you need a fully wrapped eye (radar based; may not be visible on IR yet) before the winds start moving above Category 1 strength. This is my rule of thumb, some storms are faster, but it's rare. Many storms are slower, especially if sheared or over cooler water.

Sally has one big limiting factor: it's proximity to land. This is going to be a big negative impediment to intensification. If the storm was a couple hundred more miles offshore, we could easily see a cat 4 by landfall with the high gulf heat content, but land impacts will probably limit it's strength to cat 2, maybe weak cat 3 if it can finish wrapping its core before landfall (it sure is trying).

I truly believe it’s because the storms we’ve had this occur with have been extremely close to land thus we have had constant recon/radar/observations to go off of. The NHC as rule of thumb is pretty strict in upgrading storms unless they have the hard data to do so. Out in the heart of the Atlantic it may be a well-timed ASCAT pass but otherwise they are going off of satellite estimates and general presentation. When we have radar and hard data in a storm constantly, it is much easier to make quick adjustments. Fact is, a lot of the storms you mentioned have only strengthened within a couple hundred miles of the coastline, affording the NHC the ability to have the hard data to make large intensity upgrades,

As for the storm at present- I do not believe this is a cat 2. There is no data to support it at the moment. I believe this to be a 70-75 kt system based on SFMR, radar velocities, and flight level winds, and this may be generous. The NHC is reluctant to pull down the winds knowing it could enter a period of intensification shortly and the general public reacts wildly different to the perception of a weakening storm vs one that is still trying to organize. You can bet your butt if things haven’t changed by 5am they will decrease the intensity 

 

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11 minutes ago, Random Chaos said:

MIMIC is not a good reference source for hurricane form. It's based on the 85GHz microwave passes from satellite that occur every 6-15 hours on average, with often large gaps between them, then a computer "morphs" those images together to create a pseudo-continuous look at what the storm probably is. Use the raw microwave passes available at the NRL Tropical Cyclone site rather than the MIMIC if you want to reference the 85GHz-observed internal structure.

That said, microwave data is most useful well away from shore where you have no radar coverage to tell internal structure. It is less detailed than radar and shows similar information about the storm's structure. Sally has luckily been in range of radar extensively during her development, meaning we have very good information on the central structure of the storm.

I agree that an eye did try to pop out earlier on IR, and has been well visible on radar for quite a while. That said, it is still not a well wrapped storm with the eye not yet fully closed. Give it another 6-12 hours and we'll probably have a closed eye, so long as land interference and shear don't cause issues. Once it pops out on radar in a good, well wrapped state you'll know very clearly that we have an eye, and no one will dispute it. Right now the updraft just isn't yet strong enough to clear away the hot towers convective structures from overshooting the eye, even though radar shows the eye about 60% to 70% wrapped. Once it gets fully wrapped the outflow will only be via the central core: the eye will clear and the pressure will drop. It will be clear to everyone that we have a well formed eye.

will do.  Thx.

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