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Major Hurricane Milton


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1 minute ago, SnowGoose69 said:

Isabel i believe never came close to its initial peak strength.  I was working that week and recall it made it back to maybe a a weak 3 but that was all 

Early on September 10, the eyewall became less defined, the convection near the eye became eroded, and northeasterly outflow became slightly restricted.[10] As a result, Isabel weakened slightly to a Category 3 hurricane. The hurricane turned more to the west due to the influence of the Bermuda-Azores High.[1] Later on September 10, Isabel restrengthened to a Category 4 hurricane after convection deepened near the increasingly organizing eyewall.[11] The hurricane continued to intensify, and Isabel reached its peak intensity of 165 mph (266 km/h) and a minimum central pressure of 915 mbar (hPa; 27.02 inHg) on September 11, a Category 5 hurricane on the Saffir–Simpson Hurricane Scale.[1] Due to an eyewall replacement cycle, Isabel weakened slightly, though it retained Category 5 status for 24 hours.[12] As Isabel underwent another eyewall replacement cycle, outflow degraded in appearance and convection around the eye weakened,[13] and early on September 13, Isabel weakened to a strong Category 4 hurricane. A weakness in the ridge to its north allowed the hurricane to turn to the west-northwest.[1] After completing the replacement cycle, the hurricane's large 40 miles (64 km) wide eye became better defined,[14] and late on September 13, Isabel re-attained Category 5 status.[1] During this time, Isabel attained annular characteristics, becoming highly symmetrical in shape and sporting a wide eye.[1] Hurricane Isabel also displayed a "pinwheel" eye, a rare feature that is found in some annular tropical cyclones.[15] A NOAA Hurricane Hunter Reconnaissance Aircraft flying into the hurricane launched a dropsonde which measured an instantaneous wind speed of 233 mph (375 km/h), the strongest instantaneous wind speed recorded in an Atlantic hurricane.[16] Cloud tops warmed again shortly thereafter,[17] and Isabel weakened to a strong Category 4 hurricane early on September 14. Later that day, it re-organized, and for the third time, Isabel attained Category 5 status while located 400 miles (640 km) north of San Juan, Puerto Rico.[1]

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30 minutes ago, WxWatcher007 said:

Given how high end it is structurally and the contracting inner eye, I wonder if we see a smoother merger of the concentric eyes rather than a major disruption. I’d place a bet on that right now which could make tomorrow even more likely to be the peak than tonight. 

We actually saw this with Hurricane Matthew. Made me ponder if ERC are actually a sign of a healthy and optimally functioning storm. The storm would go through the ERC, expand in size and increase in strength in a rather quick fashion. 

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3 minutes ago, DDweatherman said:

Early on September 10, the eyewall became less defined, the convection near the eye became eroded, and northeasterly outflow became slightly restricted.[10] As a result, Isabel weakened slightly to a Category 3 hurricane. The hurricane turned more to the west due to the influence of the Bermuda-Azores High.[1] Later on September 10, Isabel restrengthened to a Category 4 hurricane after convection deepened near the increasingly organizing eyewall.[11] The hurricane continued to intensify, and Isabel reached its peak intensity of 165 mph (266 km/h) and a minimum central pressure of 915 mbar (hPa; 27.02 inHg) on September 11, a Category 5 hurricane on the Saffir–Simpson Hurricane Scale.[1] Due to an eyewall replacement cycle, Isabel weakened slightly, though it retained Category 5 status for 24 hours.[12] As Isabel underwent another eyewall replacement cycle, outflow degraded in appearance and convection around the eye weakened,[13] and early on September 13, Isabel weakened to a strong Category 4 hurricane. A weakness in the ridge to its north allowed the hurricane to turn to the west-northwest.[1] After completing the replacement cycle, the hurricane's large 40 miles (64 km) wide eye became better defined,[14] and late on September 13, Isabel re-attained Category 5 status.[1] During this time, Isabel attained annular characteristics, becoming highly symmetrical in shape and sporting a wide eye.[1] Hurricane Isabel also displayed a "pinwheel" eye, a rare feature that is found in some annular tropical cyclones.[15] A NOAA Hurricane Hunter Reconnaissance Aircraft flying into the hurricane launched a dropsonde which measured an instantaneous wind speed of 233 mph (375 km/h), the strongest instantaneous wind speed recorded in an Atlantic hurricane.[16] Cloud tops warmed again shortly thereafter,[17] and Isabel weakened to a strong Category 4 hurricane early on September 14. Later that day, it re-organized, and for the third time, Isabel attained Category 5 status while located 400 miles (640 km) north of San Juan, Puerto Rico.[1]

My memory has gotten really bad.  I probably want to forget that week since for a good day all the models had it hitting New York City then in one shot they all moved south  

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13 minutes ago, USCG RS said:

We actually saw this with Hurricane Matthew. Made me ponder if ERC are actually a sign of a healthy and optimally functioning storm. The storm would go through the ERC, expand in size and increase in strength in a rather quick fashion. 

Yes. You can see on the goes 16 meso 2 minute floater imagery right now the ring of concentric cloud tops colder than -80 C. That correlates to a broad zone of long and deep positive cape soundings (talking theory here). ERCs can be triggered by a couple different things - so they aren't a universal sign of health. But they do typically signify that a storm has reached maximum potential intensity for the given environment. If you have more heat energy available than the eyewall can convert into kinetic energy, you get a second eyewall. That can happen both in a great environment like this one, and a worsening environment where the storm can no longer support the intensity of the eyewall it has, from what I've observed. 

Physically, when an EWRC occurs, the pressure wind relationship shifts. The kinematic and thermodynamic energy of the inner eyewall is trapped by the outer eyewall. As subsidence increases in the inner eyewall, wind speed is transferred to the outer eyewall as it contracts, with pressure rising. Thus, temporarily, we get a stronger wind speed than pressure would portend. As convection in the old eyewall ceases and the column disintegrates, the outer eyewall becomes dominant and then can mix freely and the relationship flattens again. So, in the context of a record-nearing storm, it isn't a sign of "bad health". It's simply physics. Storm can't get stronger with the eye it has, so it's going out to get a new ring.

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46 minutes ago, SnowGoose69 said:

I’ve never seen a cat 4 or 5 have a second peak after an ERC higher than the first from what I remember.  It’s probably happened at some point but it’s rare 

In 2017 I think Irma was going to but crashed into Cuba.

In 2019, IIRC Lorenzo's first peak looked better on satellite at the dreaded 135kt but it was the second that was actually assessed as Cat. 5.

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523 

URNT12 KNHC 080119

VORTEX DATA MESSAGE AL142024

A. 08/01:00:30Z

B. 21.81 deg N 090.28 deg W

C. 700 mb 2319 m

D. 912 mb

E. 050 deg 13 kt

F. CLOSED

G. CO4-24

H. 135 kt

I. 345 deg 2 nm 00:59:30Z

J. 093 deg 128 kt

K. 028 deg 6 nm 00:58:30Z

L. 166 kt

M. 264 deg 3 nm 01:02:00Z

N. 356 deg 158 kt

O. 264 deg 3 nm 01:02:00Z

P. 13 C / 3062 m

Q. 22 C / 2996 m

R. 15 C / NA

S. 12345 / 7

T. 0.02 / 1 nm

U. AF302 1114A MILTON OB 12

MAX FL WIND 158 KT 264 / 3 NM 01:02:00Z

OUTER EYEWALL OPEN SW

;

 

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Just now, kpantz said:

The microwave imagery tells quite a story, including the recent transformation at ERC start. Mean little Cheerio there for a while, yikes.

last24hrs.gif

I was literally about to post this. Last two hours especially 

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This may be banter, but I saw this AccuWeather graphic which shows Milton as a Cat 2 hurricane before exiting the east coast of FL.  As far as I know, the NHC has not said whether Milton will be Cat 2 or Cat 1 as it exits the east coast of FL. They simply show it being a Cat 3 just after landfall and it being a Cat 1 (85 mph) when it's about 85 miles off the coast. One can guesstimate that it could be Cat 2 (>95 mph) as it reaches the east coast, but that's not the official NHC forecast. I've wished for years that the NHC would explicitly provide the windspeed and pressure data for landfall and exit point from a landmass, but they don't (or if they do I've never seen it).  Anyone?  

MiltonTrack7Oct8p.jpg?w=632

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9 minutes ago, dseagull said:

Its not banter per se, but an important observation that highlights sensationalism.   The end result may be more extensive public preparation.  But, its a gamble (boy who cried wolf.)

 

Scientifically, its dishonest and based in exaggeration with no backbone.  It is an equally important observation though.  

The question is how much of the winds mix to the surface. Winds aloft on some of the Hurricane models definitely support Cat 2, but they aren't mixing the winds to the surface. It's probably good to highlight the risk on the east coast of FL for winds even if they don't materialize, though surge will be substantially less with an exiting system as opposed to a land-falling system. Coastal locations along the east coast need to opportunity to board up and secure flying objects. Accuweather is doing a responsible job of warning of the potential, even if that potential fails to materialize or only materializes over a very small area. The models effectively start transitioning Milton to a asymmetric system as shear rips into it as it crosses Florida, causing it's windfield to substantially expand. Some models bring hurricane force coastal winds to a large swath of eastern FL and up into GA in some cases. This expansion (speed and amount) may play a critical component in how strong the winds are at the coast. FL is known for not disrupting hurricanes much, so the shear becomes the bigger question: how strong and how quickly does it tear Milton apart.

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Just now, WxSynopsisDavid said:

Ever since Milton began this ERC, the overall symmetry of Milton is drastically improving. Though it’s not annular, it’s definitely starting to gain similar characteristics. 

BC06B1D6-A7E9-42CE-B183-1EF5AE993F14.jpeg

Will be interesting to see how much this spreads out the wind field as well. Not good for surge.

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Looking at the latest recon pass, big drop in the strength of the inner eyewall winds and the outer eyewall seems to be starting to take over. At this rate the ERC might finish fairly quickly and we see re-strengthening by early tomorrow.

Max surface winds SFMR down to 123kts, max flight level winds down to 185kts, pressure up to 915mb in latest pass. Outer eyewall still 24 and now open NE.HDOB data shows that the outer eyewall windfield is approaching that of the inner eyewall speeds now (more that the inner eyewall is being starved and weakening).

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Lightning kicking up in what will be the new core.  Wish there was more data on how much of an indicator this was for ERC completion and reintensification in these intense storms.  Usually this means intensification, but when they're this intense it seems to be more of business as usual.

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18 minutes ago, gallopinggertie said:

NHC new track is ever so slightly shifted south, with a landfall between Sarasota and St. Petersburg.

Those little wobbles are gonna make a huge difference for the Tampa bay area

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