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Hurricane Maria

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18 minutes ago, Ginx snewx said:

It actually made things worse, it wasn't the extreme winds in the tight core that was going to cause Island wide extensive  infrastructure damage,  it was the spreading out of those winds, the rapid cooling of tops at landfall exacerbated the rainfall, what was a tight core with cane winds confined to a 30 mile radius spread those out 100's of miles. There is nothing good save for the areas that would have gotten wind speeds 25 mph higher

Maximum sustained winds weakened.

Only fact I stated.

I believe that is what the Saffir/Simpson Scale is based on.

Obviously there are other factors at play when speaking of structural changes. 

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2 minutes ago, medville said:
BULLETIN
Tropical Storm Jose Advisory Number  61
NWS National Hurricane Center Miami FL       AL122017
1100 AM EDT Wed Sep 20 2017

...AIR FORCE HURRICANE HUNTERS INDICATE THAT JOSE IS A STRONG
TROPICAL STORM...
...DANGEROUS SURF AND RIP CURRENTS EXPECTED TO CONTINUE FOR SEVERAL
MORE DAYS ALONG MUCH OF THE EAST COAST OF THE UNITED STATES...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...39.0N 70.0W
ABOUT 150 MI...245 KM S OF NANTUCKET MASSACHUSETTS
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...NE OR 35 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...976 MB...28.82 INCHES

Hi, we have a Jose thread. This thread is for Maria. Thanks!

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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. 

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The SailFlow private sensor on Culebrita survived the passage recording gusts of ~140mph...

the sensor is on the light house which is the highest point on the (tiny) island - i've attached a photo i took from the light house a few years ago

culebrita.PNG

IMG_1846 (1).JPG

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Hurricane Maria Discussion Number  18
NWS National Hurricane Center Miami FL       AL152017
1100 AM AST Wed Sep 20 2017

The last radar image from the San Juan WSR-88D was received at 0950
UTC when Maria's eye was located only about 5 n mi off the
southeastern coast of Puerto Rico.  Subsequent 1-minute imagery from
the GOES-16 satellite, as well as surface observations, indicate
that the eye made landfall a little south of Yabucoa Harbor, Puerto
Rico, around 1015 UTC.  Now that the center is moving over the
mountainous terrain of the island, the eye has become cloud filled,
and the infrared satellite presentation has degraded. Without radar
velocity data, the initial intensity is incredibly uncertain, but my
best guess is 120 kt based on a typical inland decay rate.  Maria's
center is expected to move off the northern coast of Puerto Rico
soon, and an Air Force Reserve reconnaissance aircraft is scheduled
to intercept the center early this afternoon and provide a better
estimate of how much Maria has weakened.

The initial motion is northwestward, or 305/10 kt.  This
northwestward motion is forecast to continue for the next 48 hours,
followed by a turn toward the north by days 4 and 5, while Maria
moves between a mid-level high centered southeast of Bermuda and a
broad trough extending from Tropical Storm Jose southwestward into
the Gulf of Mexico.  The track guidance is tightly clustered this
cycle, and there were no significant changes made to the NHC
forecast track.

Once Maria moves off the coast of Puerto Rico, it will take some
time for the structure to reorganize over the warm waters of the
Atlantic Ocean.  However, the shear is expected to be less than 10
kt for the next 24-36 hours, and Maria has an opportunity to
restrengthen a bit over that time period.  After 36 hours, a gradual
increase in shear is likely to lead to a commensurate gradual
decrease in the hurricane's intensity through the end of the
forecast period.  Since the SHIPS model, in particular, responds to
the favorable conditions for intensification, the NHC intensity
forecast lies just above the intensity consensus through much of the
forecast period.

Since we don't have radar imagery from San Juan, and the eye has
become cloud filled in satellite imagery, the hourly position
updates are being discontinued.


KEY MESSAGES:

1. Maria's core is moving over Puerto Rico, with life-threatening
wind, storm surge, and rainfall impacts continuing over the
island. Everyone in Puerto Rico should follow advice from local
officials to avoid life-threatening flooding from storm surge and
rainfall. A Hurricane Warning remains in effect for the Virgin
Islands, but conditions should gradually improve there later today.

2. Wind speeds atop and on the windward sides of hills and mountains
and on high-rise buildings could be much stronger than the
near-surface winds indicated in this advisory.

3. A Hurricane Warning is also in effect for the northern coast of
the Dominican Republic, the Turks and Caicos Islands and the
southeastern Bahamas, where Maria is expected to bring dangerous
wind, storm surge, and heavy rainfall.


FORECAST POSITIONS AND MAX WINDS

INIT  20/1500Z 18.4N  66.5W  120 KT 140 MPH...OVER PUERTO RICO
 12H  21/0000Z 19.2N  67.6W  120 KT 140 MPH
 24H  21/1200Z 20.2N  69.0W  125 KT 145 MPH
 36H  22/0000Z 21.2N  70.1W  125 KT 145 MPH
 48H  22/1200Z 22.4N  71.0W  120 KT 140 MPH
 72H  23/1200Z 25.3N  72.4W  110 KT 125 MPH
 96H  24/1200Z 28.5N  73.0W  100 KT 115 MPH
120H  25/1200Z 31.5N  73.0W   90 KT 105 MPH

$$
Forecaster Berg

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Looks like Maria took a gulp of dry air just to the South of the eye thanks to the down sloping off the higher terrain to the South of San Juan. You can see that dry air where the crescent shade of light green appears near the center of the island on the WV loop. The actual center of Maria is probably located just to the North of there and should be completely back over water within the next 2-3 hrs.

 

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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.

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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

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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

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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.

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4 minutes ago, f2tornado said:

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

PR.JPG

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. 

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20 minutes ago, Ginx snewx said:

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

DKLbkkZUIAALHM7.jpg

And that wasn't even in the RFQ.

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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

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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.

 

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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)

 

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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.

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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..  

 

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