Hurricane Maria

[WhiteoutWX]

11 minutes ago, NJwx85 said:

Recon is en route, they must be expecting the center to be back over water very soon.

Looks like the northern eye wall has already emerged offshore per satellite.

[donsutherland1]

Based on Maria's 11 am position (18.4°N, 66.5°W) over northern Puerto Rico almost between Arecibo and San Juan, there is little change in the probability of landfall based on the historic data set and the data set adjusted for the current synoptic pattern. It appears that Maria will likely find a weakness in the ridging to its north-northeast somewhere in the vicinity of 72.5°W-73.5°W.

This scenario is consistent with the 9/28 0z run of the ECMWF. The ECMWF has displayed consistently superior performance throughout the duration of Maria's lifetime so far. By 72 hours, no model has come close to its performance. For purposes of comparison, the GFS has an error that is twice as large as the ECMWF. The lower-verifying GFS, not the ECMWF, has periodically flirted with landfall scenarios on a number of runs over the past two days.

By the time Maria reaches the weakness, it will likely turn northward and then come under the increasing influence of Jose's still expansive circulation. Most of the overnight guidance resulted in Jose's circulation shrinking especially beyond 72 hours, but not enough to allow Maria to escape its influence. Therefore, if the guidance is right, Maria should then turn northeastward and away from the U.S. Coast.

Based on the overall spread in the EPS and GEFS combined with the adjusted data set (1-in-3 probability of landfall), there still remains some possibility of landfall on the mainland U.S. My thinking of a 30% probability may be a bit generous, but there haven't been sufficiently large changes in the guidance for me to change that idea.

Possible factors that could increase Maria's landfall prospects include:

1. More expansive ridging to Maria's north that results in its tracking farther west than currently modeled
2. More persistent ridging  to Maria's that results in a delayed turn to the north toward the influence of Jose's circulation
3. More rapid weakening and/or departure of Jose than currently modeled
4. Slower forward motion for Maria than anticipated over the next 72 hours

[eyewall]

Wow just wow at this river gage. 42ft and rising (flood begins at 10ft). The old record as 25ft.
http://water.weather.gov/ahps2/hydrograph.php?wfo=sju&gage=ciap4

[jviper]

6 minutes ago, WhiteoutWX said:

Looks like the northern eye wall has already emerged offshore per satellite.

http://cimss.ssec.wisc.edu/goes/blog/wp-content/uploads/2017/09/GOES16_RedVis-20170920_1017_1117anim.gif

 

[mappy]

2 minutes ago, eyewall said:

Wow just wow at this river gage. 42ft and rising (flood begins at 10ft). The old record as 25ft.
http://water.weather.gov/ahps2/hydrograph.php?wfo=sju&gage=ciap4

contamination, maybe? I saw another that was showing some 80 feet at peak... 

[Ginx snewx]

Of course we will never know but at LF at 300 feet

[das]

11 minutes ago, mappy said:

contamination, maybe? I saw another that was showing some 80 feet at peak... 

Lots of them look like this.  Likely not contamination system wide.

http://water.weather.gov/ahps2/hydrograph.php?wfo=sju&gage=comp4

Map of all sites.  Hover over site for quick view:

http://water.weather.gov/ahps2/index.php?wfo=sju

[f2tornado]

15 minutes ago, eyewall said:

Wow just wow at this river gage. 42ft and rising (flood begins at 10ft). The old record as 25ft.
http://water.weather.gov/ahps2/hydrograph.php?wfo=sju&gage=ciap4

Insane if even remotely accurate. Almost 100x record flow rate. 

[Isotherm]

16 minutes ago, donsutherland1 said:

Based on Maria's 11 am position (18.4°N, 66.5°W) over northern Puerto Rico almost between Arecibo and San Juan, there is little change in the probability of landfall based on the historic data set and the data set adjusted for the current synoptic pattern. It appears that Maria will likely find a weakness in the ridging to its north-northeast somewhere in the vicinity of 72.5°W-73.5°W.

This scenario is consistent with the 9/28 0z run of the ECMWF. The ECMWF has displayed consistently superior performance throughout the duration of Maria's lifetime so far. By 72 hours, no model has come close to its performance. For purposes of comparison, the GFS has an error that is twice as large as the ECMWF. The lower-verifying GFS, not the ECMWF, has periodically flirted with landfall scenarios on a number of runs over the past two days.

By the time Maria reaches the weakness, it will likely turn northward and then come under the increasing influence of Jose's still expansive circulation. Most of the overnight guidance resulted in Jose's circulation shrinking especially beyond 72 hours, but not enough to allow Maria to escape its influence. Therefore, if the guidance is right, Maria should then turn northeastward and away from the U.S. Coast.

Based on the overall spread in the EPS and GEFS combined with the adjusted data set (1-in-3 probability of landfall), there still remains some possibility of landfall on the mainland U.S. My thinking of a 30% probability may be a bit generous, but there haven't been sufficiently large changes in the guidance for me to change that idea.

Possible factors that could increase Maria's landfall prospects include:

1. More expansive ridging to Maria's north that results in its tracking farther west than currently modeled
2. More persistent ridging  to Maria's that results in a delayed turn to the north toward the influence of Jose's circulation
3. More rapid weakening and/or departure of Jose than currently modeled
4. Slower forward motion for Maria than anticipated over the next 72 hours

 

There is also the possibility, albeit low probability, that Jose propagates sufficiently southwest such that it acts as a capture instrument, drawing Maria toward the coast. This will only occur if the mid level ridge forces Jose at or west of the east coast's longitude. Prior runs of the EC and other models had suggested that possibility. Both Jose's eventual demise and movement will be critical.

[Papa Joe]

4 minutes ago, f2tornado said:

Insane if even remotely accurate. Almost 100x record flow rate. 

I tend to believe it. If you look at the gauges on the east of the island, you'll see the peak flood already starting to recede. That's what you'd expect with steep terrain. 

 

Note that the streams on the west are still on the way up. 

[Hurricane Agnes]

USGS deployed some sensors along the southern coast to collect data (haven't seen any data uploaded yet) and they have a nice page where you can zoom in and hover over markers to see flow data/conditions at various spots around the island - https://www2.usgs.gov/water/caribbeanflorida/hurricane_maria.html

[mappy]

16 minutes ago, das said:

Lots of them look like this.  Likely not contamination system wide.

http://water.weather.gov/ahps2/hydrograph.php?wfo=sju&gage=comp4

Map of all sites.  Hover over site for quick view:

http://water.weather.gov/ahps2/index.php?wfo=sju

Thanks, Das!  

[NJwx85]

20 minutes ago, Ginx snewx said:

Of course we will never know but at LF at 300 feet

And that wasn't even in the RFQ.

[NJwx85]

The 12z GFS is OTS. If that trough coming through the lakes days 6-8 is true, then it's game over.

[das]

4 minutes ago, mappy said:

Thanks, Das!  

No prob.  Thanks for your deputized Mod work in here.  Super glad they ask you to do so during significant weather events.

[yoda]

1 minute ago, NJwx85 said:

The 12z GFS is OTS. If that trough coming through the lakes days 6-8 is true, then it's game over.

lol

The 12z GGEM brings Maria into the Norfolk/Hampton Roads area at 144

[Paragon]

2 hours ago, Roger Smith said:

On subject of "weakening" at landfall, in these cases where a strong hurricane approaches a hilly or mountainous region, we have to understand that the forward half of the circulation is being squeezed up so there would be some tendency for the surface elements of the eyewall region to be lifted up near the coast, net effect being a pressure rise and wind decrease at sea level but no doubt the cat-5 winds continued on to make an elevated landfall.

When Patricia came inland there was evidence that pressures had risen 30-40 mbs in the six hours to landfall but winds at some elevation inland (northwest portion of eyewall) were still representative of lower eye central pressures, so really this discussion is somewhat moot, it depends on where you want to measure the winds -- but officially it is the conditions at the sea level landfall point. Those may not be known for a while but from the radar I suspect there may be patchy cat-5 damage evidence in the right front quarter of the eyewall. There will probably be widespread cat-5 type blowdown on ridges (and unfortunately the radar was located in such a spot). 

In Patricia's case wasn't that one weakening a few hours before landfall?  Patricia was a world record 215 mph (not sure what her lowest pressure was) and then weakened significantly a few hours before landfall.

 

[Paragon]

1 hour ago, Roger Smith said:

Arecibo reports now updated to (edit) 1418z, peak gust  98 knots at 1354z (wind still NE to 1418z and still gusting to 96 knots).

Degraded eye must be very close now, next hour of reports will probably capture it if the sensors survive the surge.

Interesting to note that sustained winds increase from 72 knots at 10m to 78 knots at 20m. If that rate of increase was sustained to 100m (top of high rise buildings in San Juan) it would imply 126 knots at that level -- probably not quite that linear but over 100 knots likely. 

Hopefully no major damage to the big radio telescope or any other part of the island (wishful thinking)

 

[WinterWolf]

3 minutes ago, NJwx85 said:

The 12z GFS is OTS. If that trough coming through the lakes days 6-8 is true, then it's game over.

6-8 days out is an eternity away....but I'm sure something saves the area from any direct impacts...so who knows at this early juncture..lots of factors at play for sure.  One thing is for sure, the models will change a lot going forward.

[Jfreebird]

I noticed a few things on the 12z GFS run

1. it has the storm traveling much slower compared to the past few runs.

2. The 12z GFS at hour 156 is almost exactly where the ECMWF 00z hr 168 has it..  

 

[NJwx85]

The eye appears to now be completely back over water and the presentation on IR already looks better.

[qg_omega]

49 minutes ago, donsutherland1 said:

Based on Maria's 11 am position (18.4°N, 66.5°W) over northern Puerto Rico almost between Arecibo and San Juan, there is little change in the probability of landfall based on the historic data set and the data set adjusted for the current synoptic pattern. It appears that Maria will likely find a weakness in the ridging to its north-northeast somewhere in the vicinity of 72.5°W-73.5°W.

This scenario is consistent with the 9/28 0z run of the ECMWF. The ECMWF has displayed consistently superior performance throughout the duration of Maria's lifetime so far. By 72 hours, no model has come close to its performance. For purposes of comparison, the GFS has an error that is twice as large as the ECMWF. The lower-verifying GFS, not the ECMWF, has periodically flirted with landfall scenarios on a number of runs over the past two days.

By the time Maria reaches the weakness, it will likely turn northward and then come under the increasing influence of Jose's still expansive circulation. Most of the overnight guidance resulted in Jose's circulation shrinking especially beyond 72 hours, but not enough to allow Maria to escape its influence. Therefore, if the guidance is right, Maria should then turn northeastward and away from the U.S. Coast.

Based on the overall spread in the EPS and GEFS combined with the adjusted data set (1-in-3 probability of landfall), there still remains some possibility of landfall on the mainland U.S. My thinking of a 30% probability may be a bit generous, but there haven't been sufficiently large changes in the guidance for me to change that idea.

Possible factors that could increase Maria's landfall prospects include:

1. More expansive ridging to Maria's north that results in its tracking farther west than currently modeled
2. More persistent ridging  to Maria's that results in a delayed turn to the north toward the influence of Jose's circulation
3. More rapid weakening and/or departure of Jose than currently modeled
4. Slower forward motion for Maria than anticipated over the next 72 hours

Disagree, we want Maria to speed up to increase chances of a US landfall.  Jose is not a big issue, ideally we want Jose to move as far SW as possible to grab Maria and sling it NW.  The faster Maria moves the better chance it has at impacting the US ahead of a massive trough foretasted over the area by next weekend. 

[so_whats_happening]

2 hours ago, donsutherland1 said:

Since 1851, 15 hurricanes made landfall in Puerto Rico. 60% went on to make U.S. landfall. However, 2/3 of then were at or west of 70°W longitude when they reached 20°N latitude and 78% were at or west of 74°W longitude when they reached 25°N latitude. Almost all of the guidance has Maria passing east of those benchmarks. Therefore, based on those benchmarks and the guidance, there is a much lower likelihood of U.S. landfall than what might be implied solely from climatology.

You kill it everytime with the stats I love it. Gotta figure out what you use to come up with those because that is really interesting.

[NaoPos]

Has anyone heard from Josh at all?

[Hurricane Agnes]

2 minutes ago, eaglesin2011 said:

it is but interesting to see how much bigger the overall storm profile is now!

This is what she looked like a couple minutes ago -

 

[donsutherland1]

15 minutes ago, qg_omega said:

Disagree, we want Maria to speed up to increase chances of a US landfall.  Jose is not a big issue, ideally we want Jose to move as far SW as possible to grab Maria and sling it NW.  The faster Maria moves the better chance it has at impacting the US ahead of a massive trough foretasted over the area by next weekend. 

I was thinking of a scenario kind of like Helene in 1958 with a sharp turn to the east with the slower forward motion. The window of opportunity ahead of the trough's arrival is limited. I don't see Jose getting in position to push Maria northwestward onto shore.

[NJwx85]

17 minutes ago, irishbri74 said:

Has anyone heard from Josh at all?

His twitter account has been inactive for the last 8 hours. He had been giving updates at least once an hour prior to that. Here is his last post.

Josh Morgerman‏Verified account @iCyclone  8h8 hours ago

More

4:30 am. Building groaning. Airplane sounds. Pressure falling like a rock. 967 mb #MARIA @WeatherNation

[Paragon]

7 minutes ago, donsutherland1 said:

I was thinking of a scenario kind of like Helene in 1958 with a sharp turn to the east with the slower forward motion. The window of opportunity ahead of the trough's arrival is limited. I don't see Jose getting in position to push Maria northwestward onto shore.

It's often the case on the east coast that it's a race between a trough to the west and the TC coming in from the east- and the trough usually wins.  In this case we have Jose as a third factor.  So Maria has two negative factors to deal with; even if all three factors were equal (which they are not), the highest probability of landfall would be around 33%.

 

What I was wondering, Don, is if Jose can influence Maria's path, can Maria also influence Jose's path (especially since it is stronger than Jose?)

 

[wxmx]

Eye is still partially inland, but looking at data from recon, pressure is probably up in the 950s

[donsutherland1]

11 minutes ago, Paragon said:

It's often the case on the east coast that it's a race between a trough to the west and the TC coming in from the east- and the trough usually wins.  In this case we have Jose as a third factor.  So Maria has two negative factors to deal with; even if all three factors were equal (which they are not), the highest probability of landfall would be around 33%.

 

What I was wondering, Don, is if Jose can influence Maria's path, can Maria also influence Jose's path (especially since it is stronger than Jose?)

 

Maria might have a little influence, but Jose currently has the larger circulation. Jose's IKE is also quite a bit higher than Maria's despite Maria's intensity. That also suggests that Jose is more likely to have a greater impact on Maria's track than Maria would have on Jose's track. Jose is also leaving a weakness in the ridging that might otherwise be more expansive, thus allowing Maria greater opportunity to find that larger weakness.