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Tropical Major Hurricane Maria

Folks, keep in mind that a TC left behind in weak steering often will tend to move poleward/northward. Webb, correct me if I'm wrong, but don't TCs have a tendency of sorts to move slowly north in the absence of much steering?

One more thing: just because there's a strong ridge one day doesn't mean that that ridge can't start weakening pretty quickly. Ridges and troughs strengthen and weaken constantly and often their axes move around as nothing is even close to remaining stable for long periods. An eroding ridge is nothing extraordinary. This is based on nearly 20 years of staring at current model runs as well as looking back at decades of historical wx maps.
 
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Cloud tops around the center are extremely cold at the moment and more are cooling. Organization is just insane it seems. I bet we may have a surprise in the morning with her.
 
GaWx said:
Folks, keep in mind that a TC left behind in weak steering often will tend to move poleward/northward. Webb, correct me if I'm wrong, but don't TCs have a tendency of sorts to move slowly north in the absence of much steering?

One more thing: just because there's a strong ridge one day doesn't mean that that ridge can't start weakening pretty quickly. Ridges and troughs strengthen and weaken constantly and often their axes move around as nothing is even close to remaining stable for long periods. An eroding ridge is nothing extraordinary. This is based on nearly 20 years of staring at current model runs as well as looking back at decades of historical wx maps.
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Yes, in the absence of steering flow, TCs have a tendency to move northwestward due to the beta effect as opposing beta gyres (high to the northwest of the TCs circulation & low to the southeast) steer it a net direction to the northwest due to planetary vorticity advection. The beta effect becomes larger for stronger TCs with larger wind fields... The motion directly attributable to the beta effect usually accounts for about 10% of a TCs motion and can have a magnitude of up to 5 m/s, but even in very weak steering flow the beta effect's contribution onto TC motion is still smaller than the large-scale flow but has a non-negligible influence nonetheless. Not too small to where we can completely ignore it, but while in most cases it's so small that it's almost never the primary steering agent
 
Maria's central dense overcast is containing to expand and persist over its center, this storm is about to knock on the door of becoming a cat 2. Arguably about 80 knots atm... Looks very similar to Ida (2009) when it became a category 2 hurricane in the western Caribbean...
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2009AL11_4KMIRIMG_200911090015.gif
 
I think if she does go over the Shredder everything changes anyway... a weaker system would probably go west...

I don't think anything is set in stone about the US threat yet... sure if she clears Hispanola and is a major going north, yeah she'll probably recurve, but that is a big if at this point.

I've seen too many storms before where the models are too far NE and not saying it'll happen here, but even a slight west shift could be a wildly different solution for a week from now
 
I think Maria may be undergoing rapid intensification... The most recent example of an asymmetrical, sheared TC like this with a very intense CDO accompanying an (initially) small inner core and LLC near the east-central Caribbean and Lesser Antilles is Matthew (2016) & this is what he looked like right as he began his infamous RI phase into a category 5 hurricane over the Central Caribbean Graveyard.

2016AL14_4KMIRIMG_201609300245.gif


Several lightning strikes were also recently detected underneath Maria's very deep/persistent CDO, relatively close to the eyewall, which is often a sign of rapid intensification in TCs. We may have a category 3 or 4 hurricane by later tomorrow morning at the rate we're going...

Maria satellite image 945pm Sep 17 2017.gif

Eyewall lightning Maria.png

Link to real-time lightning data:
http://en.blitzortung.org/historical_maps.php
 
Webberweather53 said:
I think Maria may be undergoing rapid intensification... The most recent example of an asymmetrical, sheared TC like this with a very intense CDO accompanying an (initially) small inner core and LLC near the east-central Caribbean and Lesser Antilles is Matthew (2016) & this is what he looked like right as he began his infamous RI phase into a category 5 hurricane over the Central Caribbean Graveyard.

View attachment 1284


Several lightning strikes were also recently detected underneath Maria's very deep/persistent CDO, relatively close to the eyewall, which is often a sign of rapid intensification in TCs. We may have a category 3 or 4 hurricane by later tomorrow morning at the rate we're going...

View attachment 1282

View attachment 1283

Link to real-time lightning data:
http://en.blitzortung.org/historical_maps.php
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Yeah, I mentioned we could see a surprise tomorrow morning, so the idea of RI would probably confirm the bad part of RI. How strong she gets is a question of timing between the first eyewall formation and the ERCs, to the time she gets to Puerto Rico, since strong hurricanes undergo the process. She is definitely looking far better than earlier.
 
ForsythSnow said:
Yeah, I mentioned we could see a surprise tomorrow morning, so the idea of RI would probably confirm the bad part of RI. How strong she gets is a question of timing between the first eyewall formation and the ERCs, to the time she gets to Puerto Rico, since strong hurricanes undergo the process. She is definitely looking far better than earlier.
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Yeah agreed. Lightning in/around the inner core of a TC is often a red flag of RI because it tends to occur during eyewall contractions which means Maria is probably intensifying a lot. This lightning actually looks like its not just under the CDO but in the southern & western semi circles of the eyewall...
Screen Shot 2017-09-17 at 10.36.54 PM.png
 
NHC has it as a major hurricane Friday, and doesn't look like much in its way then to shred it.

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The easterlies the storm is embedded in are a bit concerning. From some of the HDOB's from the last flight they could be a bit deeper than the models have them. There's also some mid-level NE flow occurring evident in shortwave IR. The storm is also trying to center itself under it's accompanying upper ridge as the center of that ridge seems displaced a little to the west,. The leading ULL is also imparting a western drag on the storm. All of these may be minute influences but combined they may be having a noticeable influence. In know way am I wishcasting this thing west, but imo there's a stronger western component in the flow in the short term. I'm also extremely leery of OTS tracks atm with the trends in the forecast over the conus for the next week. A track into southern or even western Hispaniola is not out of the question atm. Once again just my opinion :weenie:
 
The Rapid Intensification Index of the SHIPS model
forecast better than a 50 percent chance of 25-30 kt of
strengthening during the next 24 h, and about a 35 percent chance
of 55 kt of strengthening during the next 48 h.

getting close to a 5 if that 35 percent happens
 
Storm5 said:
Nope just hopefully OTS

Sent from my SM-J320VPP using Tapatalk
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Hopefully, but looks like its going to have to take a turn right before the Carolinas, and I don't feel good about that.
 
Brent said:
The Rapid Intensification Index of the SHIPS model
forecast better than a 50 percent chance of 25-30 kt of
strengthening during the next 24 h, and about a 35 percent chance
of 55 kt of strengthening during the next 48 h.

getting close to a 5 if that 35 percent happens
Click to expand...
Wasn't it somewhere around 60 for Irma? This is just insane. We may very well see another cat 5.
 
Hot towers firing in NW eyewall. I bet we start seeing the eye clearing in the next few hours as that rotates around it.
 
Yeah the SHIPS RI index has about a 35% for either intensification into a 130 knot upper end category 4 hurricane in 2 days, or 140 knot category 5 hurricane in 3 days when Maria is expected to pass nearly over Puerto Rico...

Screen Shot 2017-09-17 at 11.png


Only the 1928 Lake Okeechobee (which is one the deadliest hurricanes in US history & basin wide) has made a direct hit on Puerto Rico as a category 5 hurricane....
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SHIPS Prob RI for 20kt/ 12hr RI threshold= 34% is 6.2 times sample mean ( 5.4%)
SHIPS Prob RI for 25kt/ 24hr RI threshold= 57% is 5.0 times sample mean (11.5%)
SHIPS Prob RI for 30kt/ 24hr RI threshold= 51% is 6.9 times sample mean ( 7.4%)
SHIPS Prob RI for 35kt/ 24hr RI threshold= 40% is 9.3 times sample mean ( 4.3%)
SHIPS Prob RI for 40kt/ 24hr RI threshold= 36% is 13.0 times sample mean ( 2.8%)
SHIPS Prob RI for 45kt/ 36hr RI threshold= 38% is 7.5 times sample mean ( 5.1%)
SHIPS Prob RI for 55kt/ 48hr RI threshold= 36% is 6.8 times sample mean ( 5.3%)
SHIPS Prob RI for 65kt/ 72hr RI threshold= 34% is 5.7 times sample mean ( 6.0%)

34% chance of a Cat 5 according to this
 
just to add to this, Irma's forecast peak before she bombed was also 140 mph

and now here we have Maria with the same peak
 
Conditions in this part of the Atlantic are absolutely unreal to support this kind of intensification. I'm sure on higher resolution, there are warmer pockets.

cdas-sflux_sst_watl_1.png
 
GFS also has Maria missing Puerto Rico to the NE... doesn't seem very realistic, a LOT of northward motion would be needed
 
As I mentioned earlier today, even if Jose sticks around, if he's too weak to create enough of a dimple in the ridge extending from the SW Atlantic to SE Canada to snatch Maria, the chances for a close call or impact to the US obviously increase. Still a long ways to go however
Screen Shot 2017-09-18 at 12.12.26 AM.png
 
Incredible anticylone over top at 168hrs. Also aided by the ULL to the west, Maria will have a ton of ventilation.
 
the CMC goes to SC with Jose a hurricane east of Bermuda...

I think I have seen everything now
 
The ridging on the Canadian must be overdone. Jose slips through to the North and the ridging builds in, very very strongly right after. while rotating Jose SE (again). GFS starts to break the ridging down too quickly, as a known bias. Euro will be good tonight.
 
GFS is desperately trying to slip Maria through an imaginary crack in this upper level ridge over southeastern Canada just off the east coast. There would be a crack there if Jose is still somewhat formidable...
gfs_z500a_us_33.png
 
I don't even know what the GFS is doing at this point lol, now all the sudden there's a path north?

In any case it's west of the 18z for sure
 
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