Hurricane Agnes

Remnants of former Tropical Storm/Tropical Depression Karen

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Levi is confirming the 2 centers ("eyes") of this storm - one at the lower level and one at the mid-level.  And since the 2 are not stacked over each other, then you won't get the traditional "eye" where you can see down to the surface. And this system is dragging these 2 pieces along as it moves north.  I believe Jerry ran into the same issue with displaced/unaligned layers.

 

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27 minutes ago, Hurricane Agnes said:

Levi is confirming the 2 centers ("eyes") of this storm - one at the lower level and one at the mid-level.  And since the 2 are not stacked over each other, then you won't get the traditional "eye" where you can see down to the surface. And this system is dragging these 2 pieces along as it moves north.  I believe Jerry ran into the same issue with displaced/unaligned layers.

 

I was about to call BS

But after looking.  The mid level center is clearly  over PR. But looking at Radar maybe some truth that statement. 

LLC definitely NE of PR. But how so quickly? 

Edit. 

LLC is definitely NE of PR.

Developing convection NE of PR shows banding on radar.

 

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3 minutes ago, FLweather said:

I was about to call BS

But after looking.  The mid level center is clearly  over PR. But looking at Radar maybe some truth that statement. 

LLC definitely NE of PR. But how so quickly? 

 

 

AF300 has been in there tonight and has focused on the low-level center (where it appears the previous run was looking at the mid-level center) -

recon_AF300-0612A-KAREN-1000pm-09242019.png

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11 pm update (pressure continues to drop and storm motion has significantly increased)  -

Quote
000
WTNT32 KNHC 250237
TCPAT2

BULLETIN
Tropical Storm Karen Advisory Number  12
NWS National Hurricane Center Miami FL       AL122019
1100 PM AST Tue Sep 24 2019

...HEAVY RAIN AND FLASH FLOODING WILL CONTINUE OVER PUERTO RICO AND
THE VIRGIN ISLANDS...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...19.1N 65.0W
ABOUT 85 MI...140 KM NE OF SAN JUAN PUERTO RICO
ABOUT 50 MI...80 KM N OF ST. THOMAS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...NNE OR 15 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* U.S. Virgin Islands
* Puerto Rico, including Vieques and Culebra
* British Virgin Islands

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.

Interests elsewhere in the Lesser Antilles should monitor the
progress of Karen.

For storm information specific to your area in the United States,
including possible inland watches and warnings, please monitor
products issued by your local National Weather Service forecast
office. For storm information specific to your area outside of the
United States, please monitor products issued by your national
meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 1100 PM AST (0300 UTC), the center of Tropical Storm Karen was
estimated near latitude 19.1 North, longitude 65.0 West. Karen is
moving toward the north-northeast near 14 mph (22 km/h). Karen
should continue to move toward the north-northeast through Wednesday
night.  On the forecast track, the center of Karen will move away
from Puerto Rico and the Virgin Islands during the next few hours,
but the strong squalls which are to the south of the center will
continue to affect that area through tonight. Karen should move over
the western Atlantic later tonight and Wednesday.

Maximum sustained winds are near 45 mph (75 km/h) with higher gusts.
Some strengthening is forecast during the next 48 hours.

Tropical-storm-force winds extend outward up to 80 miles (130 km)
to the southeast of the center.

The estimated minimum central pressure was 1002 mb (29.59 inches).


HAZARDS AFFECTING LAND
----------------------
Rainfall: Karen is expected to produce the following rainfall
accumulations through Wednesday:

Puerto Rico, Vieques and the Virgin Islands...3 to 6 inches,
isolated 10 inches.

Leeward Islands...1 to 2 inches, isolated 4 inches.

These rains may cause flash flooding and mudslides, especially in
mountainous areas.

WIND:  Tropical-storm-force winds, especially in gusts, are
currently spreading across the warning area.  Winds could be higher
on the windward sides of hills and mountains, and also in elevated
terrain. This winds should gradually decrease on Wednesday.


NEXT ADVISORY
-------------
Next intermediate advisory at 200 AM AST.
Next complete advisory at 500 AM AST.

$$
Forecaster Avila
Quote
000
WTNT42 KNHC 250237
TCDAT2

Tropical Storm Karen Discussion Number  12
NWS National Hurricane Center Miami FL       AL122019
1100 PM AST Tue Sep 24 2019

During the afternoon and early evening hours, satellite images
indicated that the cloud pattern associated with Karen was
becoming a little better organized. Then, surface observations from
the area just east of Puerto Rico indicated that the pressures
were falling, and a center was apparently becoming better defined.
The presence of this center was confirmed by a reconnaissance
plane which was able to fix a tight small circulation of about 1002
or 1003 mb.  This, by no means, indicates that the overall
circulation of the cyclone is well organized. Winds are still swirly
on the western portion of the circulation and are responding to an
elongated trough of low pressure north of Puerto Rico. In fact, I
would not be surprised if another center reforms father to west
within the trough or the large cyclonic envelope, and the center we
are tracking dissipates. In any case, preliminary analysis indicates
that the center of Karen that we were tracking moved very near or
over Vieques around 2100 UTC and then over Culebra a little bit
later. This small center could also have been a meso-vortex within
the larger circulation.

Data from the reconnaissance plane and satellite intensity estimates
yield an initial intensity of 40 kt. These winds are occurring
primarily to the southeast of the center. Karen is heading toward a
shear environment that is not ideal at all for significant
intensification. As previously indicated, the NHC forecast calls for
a very modest increase in intensity during the next 3 to 5 days as
indicated by the HCCA model.  However, some of the statistical
guidance brings Karen to hurricane status by the end of the
forecast period.

Satellite and reconnaissance fixes indicate that Karen is moving
toward the north-northeast or 015 degrees at 12 kt. This motion
however, is highly uncertain because it includes the reformation of
the center.  The circulation of Karen is trapped between a
subtropical high over the Atlantic and a mid-level trough over the
Bahamas. This flow pattern will continue to steer Karen in this same
generaldirection for the next 3 days. After that time, the steering
flow is forecast to collapse, and Karen, if it is still a cyclone,
will begin to meander. This would allow another ridge to develop
north of the cyclone and force it to move westward. This is the
solution provided by most of the global models.


Key Messages:

1.  Karen will continue to bring heavy rainfall, flash floods and
mudslides to Puerto Rico, Vieques and the U.S. and British Virgin
Islands into Wednesday even as the center moves away from the
region.

FORECAST POSITIONS AND MAX WINDS

INIT  25/0300Z 19.1N  65.0W   40 KT  45 MPH
 12H  25/1200Z 20.8N  64.6W   45 KT  50 MPH
 24H  26/0000Z 23.2N  64.0W   45 KT  50 MPH
 36H  26/1200Z 25.5N  63.4W   50 KT  60 MPH
 48H  27/0000Z 27.0N  62.5W   55 KT  65 MPH
 72H  28/0000Z 26.8N  61.5W   55 KT  65 MPH
 96H  29/0000Z 26.5N  61.5W   55 KT  65 MPH
120H  30/0000Z 26.0N  65.5W   55 KT  65 MPH

$$
Forecaster Avila

 

024252_5day_cone_no_line_and_wind.png

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I'm looking at these models in the 5-7 range, and I'm literally saying outloud: Why isn't Karen moving? That ridge is dominant as hell, this thing should be sailing into Key Largo and Corpus, yet it spins like an idiot in the Sargasso Sea for a week. 

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2 am update (no change) -

Quote
682 
WTNT32 KNHC 250559
TCPAT2

BULLETIN
Tropical Storm Karen Intermediate Advisory Number 12A
NWS National Hurricane Center Miami FL       AL122019
200 AM AST Wed Sep 25 2019

...HEAVY RAIN AND FLASH FLOODING WILL CONTINUE OVER PUERTO RICO AND
THE VIRGIN ISLANDS TODAY...


SUMMARY OF 200 AM AST...0600 UTC...INFORMATION
----------------------------------------------
LOCATION...19.8N 65.1W
ABOUT 100 MI...160 KM N OF ST. THOMAS
ABOUT 110 MI...180 KM NNE OF SAN JUAN PUERTO RICO
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...N OR 10 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* U.S. Virgin Islands
* Puerto Rico, including Vieques and Culebra
* British Virgin Islands

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area.

For storm information specific to your area in the United States,
including possible inland watches and warnings, please monitor
products issued by your local National Weather Service forecast
office. For storm information specific to your area outside of the
United States, please monitor products issued by your national
meteorological service.


DISCUSSION AND OUTLOOK
----------------------
At 200 AM AST (0600 UTC), the center of Tropical Storm Karen was
located by the NOAA San Juan Doppler radar and an Air Force Reserve
reconnaissance aircraft near latitude 19.8 North, longitude 65.1
West. Karen is moving toward the north near 14 mph (22 km/h). Karen
is expected to move toward the north today, followed by a motion
toward the north-northeast tonight through Thursday.  On the
forecast track, the center of Karen will continue to move farther
away from Puerto Rico and the Virgin Islands today. However, strong
squalls located to the south and southeast of the center will
continue to affect those areas early this morning before subsiding
by late morning.

Data from the reconnaissance aircraft indicate that maximum
sustained winds remain near 45 mph (75 km/h) with higher gusts.
Some strengthening is forecast during the next 48 hours.

Tropical-storm-force winds extend outward up to 80 miles (130 km)
to the southeast of the center.  A wind gust to 43 mph (67 km/h)
was recently reported at a couple of locations on St. Thomas.

The estimated minimum central pressure is 1002 mb (29.59 inches)
based on information from the reconnaissance aircraft.


HAZARDS AFFECTING LAND
----------------------
Rainfall: Karen is expected to produce the following rainfall
accumulations through today:

Puerto Rico, Vieques and the Virgin Islands...3 to 6 inches,
isolated 10 inches.

Leeward Islands...1 to 2 inches, isolated 4 inches.

These rains may cause flash flooding and mudslides, especially in
mountainous areas.

WIND:  Tropical-storm-force winds, especially in gusts, will
continue across the warning area this morning.  Winds could be
higher on the windward sides of hills and mountains, and also in
elevated terrain. This winds should gradually decrease later today.


NEXT ADVISORY
-------------
Next complete advisory at 500 AM AST.

$$
Forecaster Stewart

 

060053_5day_cone_no_line_and_wind.png

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5 am update (little change) -

Quote
000
WTNT32 KNHC 250852
TCPAT2

BULLETIN
Tropical Storm Karen Advisory Number  13
NWS National Hurricane Center Miami FL       AL122019
500 AM AST Wed Sep 25 2019

...TROPICAL STORM WARNING DISCONTINUED FOR PUERTO RICO AND THE ALL
OF THE VIRGIN ISLANDS...
...RAINS AND FLASH FLOODING WILL CONTINUE OVER PUERTO RICO AND THE
VIRGIN ISLANDS TODAY...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...20.5N 65.2W
ABOUT 155 MI...250 KM NNE OF SAN JUAN PUERTO RICO
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The Tropical Storm Warning for Puerto Rico, Vieques, Culebra, and
the U.S. Virgin Islands has been discontinued. The government of
Antigua and Barbuda has discontinued the Tropical Storm Warning for
the British Virgin Islands.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

There are no coastal watches or warnings in effect.


DISCUSSION AND OUTLOOK
----------------------
At 500 AM AST (0900 UTC), the center of Tropical Storm Karen was
located near latitude 20.5 North, longitude 65.2 West. Karen is
moving toward the north near 14 mph (22 km/h), and this general
motion is expected to continue this morning.  A motion toward the
north-northeast is forecast to occur by this afternoon and continue
through Thursday. On the forecast track, the center of Karen will
continue to move farther away from Puerto Rico and the Virgin
Islands today through Thursday.

Maximum sustained winds are near 45 mph (75 km/h) with higher gusts.
Some strengthening is forecast during the next 48 hours.

Tropical-storm-force winds extend outward up to 70 miles (110 km)
from the center.

The estimated minimum central pressure is 1003 mb (29.62 inches).


HAZARDS AFFECTING LAND
----------------------
Rainfall:  Karen is expected to produce additional rainfall
accumulations of 1 to 2 inches across Puerto Rico and the Virgin
Islands, with isolated storm totals of 8 inches.

These rains may cause flash flooding and mudslides, especially in
mountainous areas. Some areas in southeastern Puerto Rico have
already received up to 5 inches of rainfall, which has caused some
flooding.


NEXT ADVISORY
-------------
Next complete advisory at 1100 AM AST.

$$
Forecaster Stewart
Quote
000
WTNT42 KNHC 250852
TCDAT2

Tropical Storm Karen Discussion Number  13
NWS National Hurricane Center Miami FL       AL122019
500 AM AST Wed Sep 25 2019

Karen's convection has increased significantly and become better
organized since the previous advisory. The well-defined low-level
circulation center that previously had been fully exposed now has
intense convection with cloud tops of -85C to -90C almost completely
encircling the center at times. During the last leg of an earlier
Air Force Reserve reconnaissance mission, an 850-mb flight-level
wind of 46 kt and SFMR surface winds of 37 kt were observed in the
southeastern quadrant, suggesting that Karen may have weakened
slightly during an earlier convective hiatus. However, the recent
increase in deep convection over the center, along with a pronounced
increase in the Doppler velocities and the development of a smaller
radius of maximum winds of less than 10 nmi above 20,000 ft, suggest
that Karen has likely strengthened. For now, however, the intensity
is being maintained at 40 kt. The secondary mid-level circulation
that had developed north of Puerto Rico several hours ago has since
weakened based on San Juan Doppler radar data and satellite images.

Now that deep convection has redeveloped, resulting in a stronger
and deeper the vortex column, the motion has steadied off in a
northerly direction of 360/12 kt over the past 6 hours. A northward
motion is forecast to continue this morning, followed by a turn
toward the north-northeast by this afternoon. A north-northeastward
to northeastward motion accompanied by a gradual decrease in forward
speed is expected in the 12-48 hour period. By 72 hours, steering
currents are forecast to collapse and Karen is expected to stall or
make a clockwise loop. By 96 and beyond, the global models forecast
that a ridge will build eastward from the southeastern United States
to Bermuda, forcing Karen in a slow westward to west-southwestward
direction. The new NHC track forecast is very close to the previous
advisory track, and lies close to the simple consensus track model
TVCN, which is about midway between the corrected-consensus models
FSSE located to the north and NOAA-HCCA to the south.

The intensity forecast remains somewhat perplexing with the
dynamical global and regional models showing no strengthening for
the next 4 days, followed by weakening and even dissipation by day
5, whereas the GFS- and ECMWF-based statistical-dynamical models
show slow but steady strengthening during the forecast period with
Karen becoming a hurricane by 120 hours. The main reasons for global
models weakening the cyclone is due to the low- and upper-level
circulations decoupling in about 3 days, followed by very dry
mid-level overspreading of the low-level circulation, shutting
off convective development. The problem with that scenario is that
Karen will be moving into very low vertical shear conditions and
underneath an upper-level anticyclone by 36 hours, which favors
strengthening since the cyclone will also be sitting over 29 deg C
water of considerable depth. For now, the new official intensity
forecast remains a compromise between the weak dynamical model
solutions and the stronger SHIPS intensity forecasts, which is a
little above the intensity consensus models IVCN, HCCA, and FSSE.

Key Messages:

1.  Karen will continue to produce rainfall causing flash floods and
mudslides across Puerto Rico, Vieques and the U.S. and British
Virgin Islands today even as the center moves away from the region.


FORECAST POSITIONS AND MAX WINDS

INIT  25/0900Z 20.5N  65.2W   40 KT  45 MPH
 12H  25/1800Z 22.3N  64.5W   45 KT  50 MPH
 24H  26/0600Z 24.5N  63.9W   45 KT  50 MPH
 36H  26/1800Z 26.4N  63.2W   50 KT  60 MPH
 48H  27/0600Z 27.3N  62.5W   55 KT  65 MPH
 72H  28/0600Z 27.1N  61.9W   55 KT  65 MPH
 96H  29/0600Z 26.3N  64.4W   55 KT  65 MPH
120H  30/0600Z 25.9N  67.8W   55 KT  65 MPH

$$
Forecaster Stewart

 

085751_5day_cone_no_line_and_wind.png

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Maybe I'm just wishcasting but I don't see how Karen doesn't get its act together today.  It's sitting over hot water, low shear, and moist air.  It also looks like it's trying to get banding together on satellite rather than being just a blob of convection. 

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3 hours ago, cptcatz said:

Maybe I'm just wishcasting but I don't see how Karen doesn't get its act together today.  It's sitting over hot water, low shear, and moist air.  It also looks like it's trying to get banding together on satellite rather than being just a blob of convection. 

Looks like a disorganized mess this morning imo 

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7 minutes ago, Orangeburgwx said:

Get a load of this interesting feature to the west of Karen over the Bahamas, ULL?726c64403012391eb481ba5f4c7c35a3.jpg

Sent from my SM-S327VL using Tapatalk
 

I saw that last night on one of the sat floaters (and it was spinning too) and thought it might have been a naked Karen but then saw other images of Karen that were to the east and showed the convection we have seen around Karen previously. I wasn't sure WTF that was!  Maybe some MCS or water spout or something. :lol:

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I saw that last night on one of the sat floaters (and it was spinning too) and thought it might have been a naked Karen but then saw other images of Karen that were to the east and showed the convection we have seen around Karen previously. I wasn't sure WTF that was!  Maybe some MCS or water spout or something.
That would be the mother of all water spouts because even that recon path shows a spinning low... Those 60-64kt wind barbs really are a "what are they doing there?!" feature

Sent from my SM-S327VL using Tapatalk

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19 minutes ago, Orangeburgwx said:

That would be the mother of all water spouts because even that recon path shows a spinning low... Those 60-64kt wind barbs really are a "what are they doing there?!" feature

Sent from my SM-S327VL using Tapatalk
 

Here's a screenshot I annotated (a bit silly I know :lol:) - pretty fascinating stuff going on there!

20192681410_GOES16-ABI-FL-GEOCOLOR-AL122019-1000x1000-1036am-09252019-annotated-text.jpg

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I wouldn't be surprised if Karen is dropped later today or tomorrow. 

That is indeed a ULL. Karen is on the eastern side. So more than likely she will get shredded apart by the trough. 

Note that swirl above the ULL is Jerry... well what's left.https://cdn.star.nesdis.noaa.gov/GOES16/ABI/SECTOR/car/08/1000x1000.jpg

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That feature being discussed above is a mid-to-upper level low. It's not represented much below the 400 mb level though. This feature could actually help enhance Karen as it retrogrades WSW if Karen would ever get its act together and consolidate a stacked vortex. But alas, Karen is finicky and hasn't shaken off its interaction with PR and NErly mid-level displacement.

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Tropical Storm Karen Discussion Number  14
NWS National Hurricane Center Miami FL       AL122019
1100 AM AST Wed Sep 25 2019

Karen is still having a tough time establishing and maintaining a
well-organized structure.  The deep convection which developed over
the center earlier this morning has since collapsed, leaving a
ragged and disorganized cloud pattern.  In addition, a sizable
outflow boundary moving away from the eastern part of the
circulation suggests that there is dry air within the vortex.  The
initial intensity is being held at 40 kt, pending possible
scatterometer data later this morning and a reconnaissance flight
this afternoon.

The initial position is a little difficult to locate, but the best
estimate of the current motion is 360/13 kt.  Karen is moving
northward between a mid-level high centered over the central
Atlantic and a mid- to upper-level low located just east of the
Bahamas.  This low is expected to slowly retrograde westward, with
ridging developing over the western Atlantic by day 3.  This change
in steering will cause Karen to turn northeastward during the next
48 hours but then make a clockwise loop once it is blocked by the
ridge.  After day 3, the ridge should force Karen to move
west-southwestward.  Most of the track models agree on this general
scenario.  There is some latitudinal spread on days 4 and 5 after
the loop occurs, with the HWRF being the most notable outlier by
not showing much of a westward motion.  The consensus aids,
however, have remained fairly steady, and therefore there was no
compelling reason to make any significant changes compared to the
previous track forecast.

Except for the possibility of dry air in the circulation, it's not
quite evident why Karen has not been able to sustain organization.
Still, the cyclone is expected to move beneath an upper-level
anticyclone during the next 24-48 hours, and if the shear does
indeed decrease, then some strengthening would be expected.  There
continues to be a dichotomy among the intensity models, with the
dynamical models (including the GFS and ECMWF) keeping the cyclone
weak while the statistical-dynamical models still show
intensification through days 4 and 5.  It's difficult to ignore
what's being shown by the global models, since there must be
something in the environment that they're deeming to be negative
for continued strengthening.  The best course of action at this
point is to maintain a steady intensity after 48 hours, but it
should be noted that what is shown in the official forecast still
lies above the ICON intensity consensus and the HCCA corrected
consensus aid.

Key Messages:

1.  Karen will continue to produce heavy rainfall, potentially
causing additional flash floods and mudslides, across Puerto Rico
and the Virgin Islands today even as the center moves away from the
region.


FORECAST POSITIONS AND MAX WINDS

INIT  25/1500Z 21.7N  64.9W   40 KT  45 MPH
 12H  26/0000Z 23.4N  64.4W   45 KT  50 MPH
 24H  26/1200Z 25.4N  63.7W   45 KT  50 MPH
 36H  27/0000Z 26.9N  62.9W   50 KT  60 MPH
 48H  27/1200Z 27.5N  62.0W   55 KT  65 MPH
 72H  28/1200Z 26.8N  62.0W   55 KT  65 MPH
 96H  29/1200Z 26.0N  65.0W   55 KT  65 MPH
120H  30/1200Z 25.5N  68.5W   55 KT  65 MPH

$$
Forecaster Berg

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1 minute ago, FLweather said:

I wouldn't be surprised if Karen is dropped later today or tomorrow. 

That is indeed a ULL. Karen is on the eastern side. So more than likely she will get shredded apart.

Note that swirl above the ULL is Jerry... well what's left.https://cdn.star.nesdis.noaa.gov/GOES16/ABI/SECTOR/car/08/1000x1000.jpg

Well now that I found the source of this handy dandy site - there is a small area where Karen could move without shredding.

windshear-karen-wg8shr-1107am-09252019.GIF

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3 minutes ago, yoda said:
Tropical Storm Karen Discussion Number  14
NWS National Hurricane Center Miami FL       AL122019
1100 AM AST Wed Sep 25 2019

Karen is still having a tough time establishing and maintaining a
well-organized structure.  The deep convection which developed over
the center earlier this morning has since collapsed, leaving a
ragged and disorganized cloud pattern.  In addition, a sizable
outflow boundary moving away from the eastern part of the
circulation suggests that there is dry air within the vortex.  The
initial intensity is being held at 40 kt, pending possible
scatterometer data later this morning and a reconnaissance flight
this afternoon.

The initial position is a little difficult to locate, but the best
estimate of the current motion is 360/13 kt.  Karen is moving
northward between a mid-level high centered over the central
Atlantic and a mid- to upper-level low located just east of the
Bahamas.  This low is expected to slowly retrograde westward, with
ridging developing over the western Atlantic by day 3.  This change
in steering will cause Karen to turn northeastward during the next
48 hours but then make a clockwise loop once it is blocked by the
ridge.  After day 3, the ridge should force Karen to move
west-southwestward.  Most of the track models agree on this general
scenario.  There is some latitudinal spread on days 4 and 5 after
the loop occurs, with the HWRF being the most notable outlier by
not showing much of a westward motion.  The consensus aids,
however, have remained fairly steady, and therefore there was no
compelling reason to make any significant changes compared to the
previous track forecast.

Except for the possibility of dry air in the circulation, it's not
quite evident why Karen has not been able to sustain organization.
Still, the cyclone is expected to move beneath an upper-level
anticyclone during the next 24-48 hours, and if the shear does
indeed decrease, then some strengthening would be expected.  There
continues to be a dichotomy among the intensity models, with the
dynamical models (including the GFS and ECMWF) keeping the cyclone
weak while the statistical-dynamical models still show
intensification through days 4 and 5.  It's difficult to ignore
what's being shown by the global models, since there must be
something in the environment that they're deeming to be negative
for continued strengthening.  The best course of action at this
point is to maintain a steady intensity after 48 hours, but it
should be noted that what is shown in the official forecast still
lies above the ICON intensity consensus and the HCCA corrected
consensus aid.

Key Messages:

1.  Karen will continue to produce heavy rainfall, potentially
causing additional flash floods and mudslides, across Puerto Rico
and the Virgin Islands today even as the center moves away from the
region.


FORECAST POSITIONS AND MAX WINDS

INIT  25/1500Z 21.7N  64.9W   40 KT  45 MPH
 12H  26/0000Z 23.4N  64.4W   45 KT  50 MPH
 24H  26/1200Z 25.4N  63.7W   45 KT  50 MPH
 36H  27/0000Z 26.9N  62.9W   50 KT  60 MPH
 48H  27/1200Z 27.5N  62.0W   55 KT  65 MPH
 72H  28/1200Z 26.8N  62.0W   55 KT  65 MPH
 96H  29/1200Z 26.0N  65.0W   55 KT  65 MPH
120H  30/1200Z 25.5N  68.5W   55 KT  65 MPH

$$
Forecaster Berg

145203_5day_cone_with_line_and_wind.png.4d1ec07184627d7e109dbeb6707b7072.png

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NHC 11am advisory:

"Except for the possibility of dry air in the circulation, it's not quite evident why Karen has not been able to sustain organization.... It's difficult to ignore what's being shown by the global models, since there must be something in the environment that they're deeming to be negative for continued strengthening."

In other words:

 

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25 minutes ago, Windspeed said:

That feature being discussed above is a mid-to-upper level low. It's not represented much below the 400 mb level though. This feature could actually help enhance Karen as it retrogrades WSW if Karen would ever get its act together and consolidate a stacked vortex. But alas, Karen is finicky and hasn't shaken off its interaction with PR and NErly mid-level displacement.

Levi tweeted a 6z GFS run of what was assumed to be Karen, rolling across the Bahamas.  But am wondering if the GFS may have been keying on that ULL.

 

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