Hurricane Maria

[Random Chaos]

Winds coming back up even though IR looks degraded.

128kt just above the surface in the NE eyewall (surface was 970mb, wind was measured at 968mb) - although that looks like a gust signature (note the 117kt at 965mb). Even more impressive is the 951kt winds at 923mb.

[ncforecaster89]

48 minutes ago, Paragon said:

Plus the surge generated (especially with Katrina) was a Cat 5-type surge since it had spent so much time as a Cat 5 when it strengthened over the Gulf Loop.

I find the measured wind gust-maximum sustained wind relationship fascinating.  Do you have any data on Harvey's maximum wind gusts?  I had heard they exceeded 140 at Rockport.   

Anyway with regards to Irma and Maria- I remember that we had a 112 sustained 142 gust with Irma, which is why that little rule of thumb I applied earlier projected an estimated 140 sustained Cat 4 at landfall.  With Maria we had a 137 gust on PR and a 140 gust on a small island just east of PR, so you'd get a similar value for landfall strength.

 

Hi Paragon, I am only aware of the empirical wind data contained in the NWS post-storm report that actually features a wind gust measurement of 122 kt (140 mph).  Given that it's highly unlikely that the maximum wind gusts will be measured at a single station, I'd suspect it's probable that peak gusts were as high as 150 mph.  As far as Rockport, it appears an estimate of 140 mph gusts seems most reasonable, maybe slightly higher, but not the locality of the highest winds experienced on land.   

In many cases, your rule of thumb would be applicable, but in the aforementioned cases of Katrina and Irma, it would significantly overestimate the MSW.  Although Irma generated extreme wind gusts =/> 142 mph in the Naples area, the cumulative data clearly suggests it was not a 140 mph category-four at that time.    

Edit: The NWS report also lists a 1-sec gust of 126 kt (145 mph) at virtually the same location  (between Fulton and Lamar) as the 122 kt measurement mentioned above.   Important to emphasize that these are both 1-second gusts, rather than the 3-sec standard, which makes it a slightly inflated value.       

[apm]

1 hour ago, WxReese said:

The forecasts from the GFS, CMC, and EURO have been fairly consistent thus far. The real test comes the next day or two when the CMC has Maria flirting with the Turks and Caicos while the GFS and EURO keep it well east of them. We'd have to see a rather significant shift west tonight for the CMC's forecasts to verify. 

GFS: 

EURO

CMC: 

Great post.  Normally one wouldn't give a second thought to the CMC here, but...the last few recon fixes, as they have been all day long, are well to the west of the forecast path.

 

[Paragon]

40 minutes ago, ncforecaster89 said:

Hi Paragon, I am only aware of the empirical wind data contained in the NWS post-storm report that actually features a wind gust measurement of 122 kt (140 mph).  Given that it's highly unlikely that the maximum wind gusts will be measured at a single station, I'd suspect it's probable that peak gusts were as high as 150 mph.  As far as Rockport, it appears an estimate of 140 mph gusts seems most reasonable, maybe slightly higher, but not the locality of the highest winds experienced on land.   

In many cases, your rule of thumb would be applicable, but in the aforementioned cases of Katrina and Irma, it would significantly overestimate the MSW.  Although Irma generated extreme wind gusts =/> 142 mph in the Naples area, the cumulative data clearly suggests it was not a 140 mph category-four at that time.    

Edit: The NWS report also lists a 1-sec gust of 126 kt (145 mph) at virtually the same location  (between Fulton and Lamar) as the 122 kt measurement mentioned above.   Important to emphasize that these are both 1-second gusts, rather than the 3-sec standard, which makes it a slightly inflated value.       

Thanks for your input, I believe you're right, since Katrina was a strong Cat 3 at landfall (with a Cat 5 surge.)  Irma had interacted with land by the point that measurement at Naples had been recorded and wound down a bit from its Cat 4 impact in the Keys.  Perhaps it was close to 140 during its original Keys landfall.

 

[Sophisticated Skeptic]

emotional interview from prime minister of Dominica...he started crying on couple occasions -

like around 13:00 minute mark

 

[allgame830]

As of 5am... Maria's center was only 35 miles ENE from the Turks and Caicos which was closer then both the 12z GFS and EURO and irconically closer to where the CMC had it... any signficance here?? 

[Regan]

16 minutes ago, allgame830 said:

As of 5am... Maria's center was only 35 miles ENE from the Turks and Caicos which was closer then both the 12z GFS and EURO and irconically closer to where the CMC had it... any signficance here?? 

And she's creeping NW still at 7 mph. Slow. 

[winterymix]

Updated GFS indicates the OTS solution holding.

[Regan]

I just don't, like many mets are saying now, think Jose will be strong enough to steer Maria. Not saying she slams the coast hard like the CMC was saying by any means. Just saying maybe these mets are right that she may meander off the coast somewhere a day or 2 before maybe coming in a bit west (not sure how far) and finally a system coming from the NW pushes her out.  Heard this last night several times and Bernie did a scope last night as well. Just a thought. Who knows until the day. She's down to moving NW at 7mph now. Creeping along. They are saying it gives Jose more time to weaken and move out.  Tough. 

[Treckasec]

5 minutes ago, Regan said:

I just don't, like many mets are saying now, think Jose will be strong enough to steer Maria. Not saying she slams the coast hard like the CMC was saying by any means. Just saying maybe these mets are right that she may meander off the coast somewhere a day or 2 before maybe coming in a bit west (not sure how far) and finally a system coming from the NW pushes her out.  Heard this lat night several times and Bernie did a scope last night as well. Just a thought. Who knows until the day. She's down to moving NW at 7mph now. Creeping along. They are saying it gives Jose more time to weaken and move out.  Tough. 

Hmm ... we’ll just have to see! I think that it makes sense to me ... it’s not just about how strong Jose is, I think Maria will be influenced to go towards the weakness in ridging by Jose whether it’s breathing its last breathe or is still an actual storm. If the ridge doesn’t build back in, or is unable to, Maria will go towards the weakness and not the coast. That’s how I see it at least!

[Regan]

I see 3 scenarios. One of which you are saying. And no. It's not just about Jose's strength of course. We will have to wait. It's not as simple a set up and people want to believe.  How many more days of hurricane season? Lol 

[mappy]

With two Hs in place, and a weak ULL that won't amount to much, a direct east coast hit from Maria just isn't in the cards. 

[OSUmetstud]

Those mike ventrice corrected ensemble probabilities for hurricane force winds in nyc look to be working out really well.  

[Jfreebird]

I have a question/questions.... just because I love crunching data lol and I see a few outlying members with Maria...   The ECMWF model Ensemble has 50 members.. Each of those members have a name IE EN01,EN02 etc....

1. Are there Ensemble members that are more accurate than others?

2. If so then what are they and where can you find a graph with the latest run that shows the ensemble members with their names?

 

Thanks for everyone's knowledge and help

[dtk]

9 minutes ago, Jfreebird said:

I have a question/questions.... just because I love crunching data lol and I see a few outlying members with Maria...   The ECMWF model Ensemble has 50 members.. Each of those members have a name IE EN01,EN02 etc....

1. Are there Ensemble members that are more accurate than others?

2. If so then what are they and where can you find a graph with the latest run that shows the ensemble members with their names?

 

Thanks for everyone's knowledge and help

A well calibrated ensemble prediction system will generate forecasts consistent with the probability density function associated with the forecast uncertainty/error.  While true that there will be members that perform well for any individual event, there are not members that are inherently more skillful on the average.  That is by design.  In fact, most ensemble systems use stochastic components to help represent the random errors in the initial conditions and subsequent forecasts.  This is true for single model ensembles like ecmfw eps and ncep gefs.  Multi model ensembles like the sref and Canadian eps are more complicated since they will have members that are more skillful based on the components within each member.

[MJO812]

47 minutes ago, mappy said:

With two Hs in place, and a weak ULL that won't amount to much, a direct east coast hit from Maria just isn't in the cards. 

It will come down to the trough . Maria will come west if the trough is slower than modeled. Still some time but as of right now Maria looks ots.

[TomAtkins]

6 minutes ago, Snow88 said:

It will come down to the trough . Maria will come west if the trough is slower than modeled. Still some time but as of right now Maria looks ots.

But again - is there anything pushing her anywhere close to landfall? Not really. The ULL is weak. The ridge isnt in the right place (its more under the ridge as it builds back than on the periphery). 

Like I said yesterday - there will be just enough model uncertainty to keep weenies hoping for a landfall, but no realistic shot at one. I mean just to put a fine point on it - the NHC track right now has Maria about as close to Bermuda as the Outer Banks. We are now at the point where landfall is 4-5 days away if its going to happen, and it would take a huge shift by both the Euro and GFS which are showing basically the same solution, to get a landfall. 5% maybe at best.

[MJO812]

5 minutes ago, TomAtkins said:

But again - is there anything pushing her anywhere close to landfall? Not really. The ULL is weak. The ridge isnt in the right place (its more under the ridge as it builds back than on the periphery). 

Like I said yesterday - there will be just enough model uncertainty to keep weenies hoping for a landfall, but no realistic shot at one. I mean just to put a fine point on it - the NHC track right now has Maria about as close to Bermuda as the Outer Banks. We are now at the point where landfall is 4-5 days away if its going to happen, and it would take a huge shift by both the Euro and GFS which are showing basically the same solution, to get a landfall. 5% maybe at best.

The percentage of hitting the U.S is very low but not impossible.

[WinterWolf]

This is a kind of situation where you check back here and there over the weekend, just to see if anything has shifted significantly, instead of looking at each run of the major models.  I wouldn't be investing much time in this, it's almost definitely an Ocean Storm.

[Lady Di]

Stayed closer but still at or just a bit warmer than the mean
of the ensemble guidance for Tuesday and Wednesday given some
uncertainty with Maria. NHC/WPC forecast guidance currently
shows Maria remaining to our southeast and staying offshore
through the middle of next week. A cold front is likely to help
Steer Maria out to sea by the later part of next week. However,
trends should be watched because a slower approach of this front
could allow Maria to track closer to the coast.

From my local AFD.  I agree it's a situation to check back over the weekend, but it's not likely there is a scenario that would have Maria come up the east coast heading NNW instead of N and NNE.

Fine with me stay out to sea.  We've been enjoying a real nice stretch of weather here in SE PA.

 

[OSUmetstud]

pretty much steady-state on the latest pass.  107 kt peak unflagged sfmr and flight level winds to 121 kts in the ne quad. 

[Hazey]

Those mike ventrice corrected ensemble probabilities for hurricane force winds in nyc look to be working out really well.  

How's Atlantic Canada looking? Still in play or a whiff? Seems latest guidance is leaning toward the latter.

[OSUmetstud]

Just now, Hazey said:

How's Atlantic Canada looking? Still in play or a whiff? Seems latest guidance is leaning toward the latter.

Ensembles are between St. John's and the Grand Banks..moved east over the last 3 days, out of your hood for almost certain.  

 

[MJO812]

Jose will be a big part of where Maria will go. It looks like Maria will follow Jose so if Jose goes further south and west, I wonder if Jose will follow.

[CheeselandSkies]

11 hours ago, ncforecaster89 said:

...I would add that each hurricane is unique and there's not necessarily a one to one correlation between Recon estimated MSW at the surface and the actual winds that occur on land.

Slightly OT (mods, move to a new thread if you feel necessary but please don't delete) but is this how Andrew was so badly underestimated? This blog suggests that the extreme winds being mixed down over land in small pockets of Andrew's eyewall may have been caused by unusual (for TCs) convective processes within the hurricane.

Obviously it couldn't be in 1992, but is there any way this sort of thing could be predicted (other factors such as oceanic TCHP, shear, max potential intensity, etc in the path toward landfall being favorable to maintain a high-end hurricane) with enough lead time to add extra urgency to forecasts and thus evacuation orders?

[eaglesin2011]

[Regan]

Interesting about the NHC track. 

[NortheastPAWx]

7 minutes ago, Regan said:

Interesting about the NHC track. 

I think that bend is forecast by most models before she's kicked out.

[donsutherland1]

1 hour ago, Hazey said:

How's Atlantic Canada looking? Still in play or a whiff? Seems latest guidance is leaning toward the latter.

Historical climatology based on hurricanes within 100 nautical miles of Maria's 11 am position are consistent with the modeling showing only a very low probability of landfall in Atlantic Canada (around 10%). Nova Scotia was favored, but landfall appears to be very unlikely at this point.

[Regan]

29 minutes ago, NortheastPAWx said:

I think that bend is forecast by most models before she's kicked out.

They just said the curve was made more extreme and closer to the coast. That's what I was pointing out. Interesting seeing the cone evolve.