vortex95

Do yo have an elevation of the anemometer height?

One SVR LSR report pet peeve of mind is "wires down." A LTG strike can do that! Just over time, it seems issuing warnings have become looser and looser as to criteria. I recall last summer, they issued a flash flood warning for the DC metro even before the line of tstms got to the metro! Given a line can quickly weaken as to rainfall rates, that is putting the wagon in front of the horse..

You and @CoastalWx have so much in common it sounds! Want to know how much a snow weenie he is? Last winter, when he *finally* got 6" of snow in a storm after an excruciating 4 years w/o one at his house, he goes "it looks VIOLENTLY BEAUTIFUL out there!" I never thought I'd see those two words used together!

Look at the disparity from sustained to gusts. In a minimal HU, NHC will say "max winds sustained 65 kt with gusts to 80 kt" Standard gust factor over water. However, over land, that difference becomes much larger!

Sounds like @CoastalWx response! It's not snow, so MEH!

It has been in ET transition for at least the last 6 hr. Once the srn part of the eyewall was gone, that was the first signal.

If so, they are violating their own directive. Why have thresholds for warnings if they are just deliberately ignored? Why not lower the criteria for a svr tstm warming for winds less then 58 mph in gusts b/c they can still do damage? How about pea size hail? A lot of pea size hail can devastate crops. Issue a warning for that? It is slippery slope. There comes a point of diminishing returns. Excessive alerts eventually become counterproductive.

Whoa! So it did happen at the very last min. Just delayed from what the HAFS showed earlier. This is non-trivial rise in what, less than 90 min? From the winds where the pressure was taken, the actual pressure is about 970 mb That barely supports 85 kt winds in a purely tropical system, which Isaias is not and has not been for some time. Operationally, I can see it higher when it makes landfall, post-analysis though? Katrina its rapid weakening phase originally was 120 kt at landfall, but they reduced it to 110 kt. Lili was 90 kt, but reduced it to 80 kt later. Also, when a TC is rapidly weakening near landfall, NHC often keeps it higher for winds that reality b/c they do not want to have ppl et their guard down too much, They clearly did this w/ Milton. So obvious when you saw FL and SFMR winds, and the assigned intensity. I find that disingenuous. We all look at the same data and see things for what they are. Don't insult our intelligence! So models had the right idea, just timing was off, but you really can't expect them to nail down something as mesoscale as an inner core of HU as to when it starts to degrade quickly.

For the EWW issued in FL now. EWW is defined to expect winds *sustained* 115 mph (not gusts). Look at the plot attached. What are the chances of sustained winds this strong *anywhere* but the immediate coast, say within 5 mi? Due to friction, sustained winds drop off very, very quickly once inland. And for a hurricane that is right at the threshold of 115 mph for winds over *water*, you are going to be hard pressed to even see such sustained winds anywhere on land. It goes to show how warnings often are overdone and do not account for obvious factors, like how strong a hurricane is, how large or fasting-moving it is. or how far inland locations are. Objectively, getting winds 115 mph sustained more than a few miles inland at near ground level is practically unheard of more than a few miles inland. Exceptions would be Andrew, Michael and Camille, but Isaias is no where near any of them. You can't treat hurricane landfalls as one-size-fits-all. We have the skill, knowledge, and tech to fine-tune things better and narrow down warning areas these days. And it is not like people this area of the FL PH are not already warned the wazoo a hurricane is making landfall. That very fact has already resulted in major action and lock downs, so people are more than prepared. The word "hurricane" in itself prompts immense action.

The big tor threat is often the day after landfall, when it becomes a baroclinic system w/ low-level tropical dew points and all you need is just breaks in the clouds for a little CAPE, and look out! 44 tors in FL from Milton on 10/9/24 This is the largest calendar day tor outbreak on record In October and among the top 5 biggest tor outbreaks in Oct in the U.S. Milton also produced the costliest TC tor on record -- $514M from an EF3 that tracked in St Lucie and Indian River Counties.

Stalled fronts in the Gulf sometimes lead to sig HU development. One of most notable ones was Alicia in Aug 1983 that struck HOU as a Cat 3.

You can have major HUs in very strong El Nino years. Debby in the western Atlantic was Cat 4 in Sep 1982. Bob in Aug 1991 just off Hatteras was a Cat 3 that went on to hit New England. Erika in the western Atlantic in Sep 1997 was almost a Cat 4. Joaquin near the Bahamas in Oct 2015 was almost a Cat 5. So Isaias occurring here is not atypical overall given the strength of El Nino. The key is that frequency of major HUs in very strong El Nino years is down relative to avg and there is lack of long-tracked Cabo Verde classics.

The thing is the models shows the thing getting ripped apart clearly, the primary HU models as well (HAFS) Why wouldn't you think that w/ the shear increasing to 40 kt and that much dry air present? There have been other cases like Isaias,, but also cases where unexpected rapid weakening occurs as well (Katrina and LIli are prime examples). So you can't fault ppl for driving the point home. We have a strong baroclinic situation here, so one wouldn't just ignore than. I would not say rapid intensification not long before landfall used to be definite rarity. That is recency bias largely. Since 1995, we have been in an active phase of the AMO for favorable Atlantic TC activity. Also, we are much better in determining absolute intensity now, esp. for the stronger HUs b/c of things like the GPS dropsonde, which did not come into use until 1998, and the SFMR, which did not exist on recons until 2004. This advancement in tech has allowed us to diagnose *much* better extreme winds that we could not directly measure before. Prior, it was largely just FL winds at 700 mb, but that serves only as a proxy and does not work all the time. So in recent decades we are seeing things we never could detect before, but were always there. Also, and this is a biggie, through the 1960s, if a hurricane was thought be 100 kt or stronger, many recons wouyld not penetrate the eyewall and get into the eye for direct measurements. They would fly only as close enough to get a solid radar scan of the eye, and then turn away. So many HUs were underestimated by 1 or even 2 categories at times in the first decades of the recon era!

For a few hours now, the core has been "halved" on radar in terms of an eyewall. I realize there is some attenuation, but if the eyewall ring was complete and intense, we'd easily be seeing a closed ring starting a few hours ago. Ever seem intense TC at extreme range of radars? The eye and a solid eyewall show up very well even 200 nm away! So dry air and shear are have impacted the inner core, however, this has not impacted the central pressure or winds much at all! This shows that the relationship between sig shear and dry air and a HU is complex and it is definitely not one-size-fits-all! As discussed earlier, why did Lili, Opal, and Dennis weaken so much after a solid RI period in and environment not as strongly baroclinic overall than Isaias? Actually, think about Katrina! It went from 150 kt to 110 kt from peak onshore to landfall in ~24 hr with a ton of dry air ingested into the core and quite ragged convective structure compared to Isaias right now. And Katrina was way larger than Isaias, so you would think it could resist dry air intrusions better. Also, Katrina was in Aug. The mean atmosphere as to being conducive for a strong TC that time of year is significantly better than Oct! You don't have troughs of this magnitude cutting across the nrn Gulf in Aug! That being said, the upper level outflow plume for Isaias is outstanding. That unquestionably is a factor here as to keeping it from weakening.