vortex95

Another item, MQE ended up w/ 5.76" of rain for the Perfect Storm in 1991, far more than any model showed. Of course, no hires models then, but what the ECMWF is showing does makes sense when you have extended duration big ENE fetch moist flow.

But give it some "TYME!!!" It has lots of it to meander "down there."

What about 99 bottles of BEER on the wall?

Sct embedded tstms likely. CAPE not bad in SNE for a Nor'easter today and Sunday. So bring down those winds as @ineedsnow would say!

This is not your typical "cold" ET storm evolution. The initial surface low development was S of the 576 dm 1000-500 thickness line and by 25/18z, a small 582 closed thickness pool had formed over the low center (see ECMWF 12z 06 hr and 18z 03 hr forecast attached). This is a much higher thickness than what you would find in a typical strong ET storm development near 37N in late September in this region off the U.S. East Coast. A 582 thickness pool is what you commonly see on the global models over a mature hurricane, so I would be cautious here as this is an outlier case and conventional rules of thumb may not apply. This is why I mentioned in an earlier post that one needs to think outside the box here. Yes, I know that this mid-level warm pool alone does not make it even close to a ST system currently, but you have to admit this is unusually warm for initial strong baroclinic development and a high launching pad, relativity speaking. Nothing quite like this (at least in the last 50 yr) has occurred in September in this particular region when a strong ET low develops during the near peak climo of SSTs that are 2-4 C above average and the low meanders for days in the same region close to the coast. I attached the SSTs analysis and the approximate position of the surface low at 25/18z. It is over SSTs more than enough to support ST transition and is going nowhere fast the next 72 hr off the Mid-Atlantic coast, so I would not let one's guard down here. The closest analog is the Perfect Storm Oct-Nov 1991 and the hurricane that formed from it eventually, so such a scenario here is not unprecedented. If I recall correctly, a recon was flown into that system when the transition had occured and they found a 981 pressure and 88 kt FL winds.

Good! So much rain in Weymouth, it will "drown out" @CoastalWx's constant boring whining nonsense! LOL

Concerning the East Coast storm, I wanted to point out something I can not recall seeing in this region in Sep. This is not your typical "cold" ET storm evolution. The initial surface low development was S of the 576 dm 1000-500 thickness line and by 25/18z, a small 582 closed thickness pool had formed over the low center (see ECMWF 12z 06 hr and 18z 03 hr forecast attached). This is a much higher thickness than what you would find in a typical strong ET storm development near 37N in late Se in this region off the U.S. East Coast. A 582 thickness pool is what you commonly see on the global models over a mature hurricane, so I would be cautious here as this is an outlier case and conventional rules of thumb may not apply. This is why I mentioned in an earlier post that one needs to think outside the box here. Yes, I know that this mid-level warm pool alone does not make it even close to a ST system currently, but you have to admit this is unusually warm for initial strong baroclinic development and a high launching pad, relativity speaking. Nothing quite like this (at least in the last 50 yr) has occurred in Sep in this particular region when a strong ET low develops during the near peak climo of SSTs that are 2-4 C above average and the low meanders for days in the same region close to the coast. I attached the SSTs analysis and the approximate position of the surface low at 25/18z. It is over SSTs more than enough to support ST transition and is going nowhere fast the next 72 hr off the Mid-Atlantic coast, so I would not let one's guard down here. The closest analog is the Perfect Storm ET low Oct-Nov 1991 and the hurricane that formed from it eventually, so such a scenario here is not unprecedented. A recon was flown into that system when the transition had occured and they found a 981 pressure and 88 kt FL winds.

If anyone is wondering, has a HU ever been at Cat 5 strength 3 different times? Yes, Allen in Aug 1980 in the Atlantic. Classic Cabo Verde HU! Each time it peaked at Cat 5 (155, 165, 155 kt), it weakened in-between to a Cat 3. At the time, it was only the second Atlantic HU sub-900 mb (899). https://www.aoml.noaa.gov/hurricane_blog/35th-anniversary-of-hurricane-allen/ One of the most epic TC sat image ever -- see attachments (I recall being awed by this in college back in the day). Look at the size of it and perfect symmetry! Also, Ivan in 2004 in the Atlantic cycled up an down to Cat 5 3x. There may be 1 or 2 others in the Atlantic. I'm sure there are plenty of cases in the NWPAC given how that TC is for activity.

That's an excellent question! Each tropical basin has it own list of names, and the names are a mix of types of names from all countries in that particular region, so you are not going to get traditional names you'd see in the U.S. all the time. The CPAC has its own list of names and almost all of them are derived from Hawaiian culture. It is pure coincidence that Polo in the EPAC, which has its own set of names, and Nolo, in the CPAC are occurring at the same time. That just how things have worked out as to what has gone on for TCs. Inconvenient, yes, but they are not going to change the lists for something like this. You can't account for every variance in the atmosphere! These name lists are set years in advance, and cycle through the same single large list for each tropical basin. For NWPAC names, you see the variety there, and it is not always a person name, some names are of animals, plants, and inanimate objects. The only time you get change is when a name gets retired b/c that TC was of serious impact and a new name is inserted. What constitutes "serious impact?" For a U.S. landfall, typically a hurricane of Cat 3 or greater, it gets retired b/c of impact. However, strength of a TC is irrelevant really, it is all about impact. TSs can get retired. Allison in 2001 and Imelda in 2019 b/c even though they were only TSs, you got record rains and flooding. One oddity is Emily from 2005. It was the first Cat 5 on record in July in the Atlantic, and made two Cat 3 landfalls in Mexico, but it was not retired. Since impacts were all in Mexico, they held the reins as to requesting it to be retired or not, and they did not do so. No idea why. Bret in 1999 made landfall as Cat 3 in TX, but that location was the very sparsely populated area between CRP and BRO, so impact was minimized and thus Bret was not retired.

40-48 hr the 00z HRRR shows it taking on more ST characteristics w/ a more focused core wind field. RRFS does this but it take more than 24 hr after this time, and the low just meanders around to the S of us for the entire 84 hr period! Lots of time to do odds stuff! @WxWatcher007 I know will be closely tracking the exact sfc low position relative to the SSTs!

Get them here! https://www.ncei.noaa.gov/gibbs/

00z HRRR shows the E Coast low taking on more ST characterists 40-48 hr as a inner core contracted wind field develops. RRFS it take over 24 hr longer to do this.

On Wed, five sites in ME/Quebec set all-time record high pressures for Sep. @CoastalWx take note. It's an exceptional pattern! Frenchville Montreal Quebec City Val D’Or Chibougamau-Chapais.

Just a nit from the 25/03z discussion for Nolo: Nolo is expected to pass near or just south of the Big Island of Hawaii on Saturday as a major hurricane. It's closet approach is about 125 mi S of the srn tip of the Big Island. Is that really "near or just S" for such a distance, esp. for an avg size TC? The wording makes it sounds closer than it really will be. That's a big deal when it comes to winds in a TC, esp. a strong one.

Don't even get me started w/ Sandy! I'll spare you all a rant write-up on that! One thing I will say, at a SNE conference I think 12 years ago, one of the BOX mets who is the resident WFO TC expert was talking about the reanalysis of big HUs that hit New England. And Sandy came up. He was asked if he thought it was still a TC at landfall, and he said, w/ his boss (MIC) on stage w/ him, "offline after a few beers, I say yes it was!"