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WxWatcher007

Major Hurricane Florence

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Here is the 0Z SHIP output. It is showing 110+ kts. 12Z COAMPS brings it up to 140 kts. And with HMON and HWRF also firmly in the major camp we have pretty good consensus from cyclone model guidance that Florence will become a major hurricane as it approaches the east coast. 

 

                    * ATLANTIC     2018 SHIPS INTENSITY FORECAST     *
                    * IR SAT DATA AVAILABLE,       OHC AVAILABLE     *
                    *  FLORENCE    AL062018  09/08/18  00 UTC        *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    50    50    50    51    54    59    65    73    82    92    97   105   106
V (KT) LAND       50    50    50    51    54    59    65    73    82    92    97   105   106
V (KT) LGEM       50    49    49    49    51    55    62    74    88   100   109   114   113
Storm Type      TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP

SHEAR (KT)        22    19    13     6     6     7     5     1     4     4     5    11    13
SHEAR ADJ (KT)     3     0     5     7     3     2    -1    -3    -2     0    -2    -6    -2
SHEAR DIR        241   253   256   241   211   243   178   164    53    56   200   194   197
SST (C)         28.4  28.5  28.5  28.6  28.6  28.7  28.8  28.9  29.0  28.9  29.1  29.0  29.1
POT. INT. (KT)   141   142   142   143   143   145   147   151   153   152   155   153   155
ADJ. POT. INT.   124   124   123   124   124   126   130   135   139   139   142   137   137
200 MB T (C)   -54.5 -54.7 -55.0 -54.8 -54.8 -54.9 -54.4 -54.3 -53.4 -53.0 -52.3 -52.2 -50.9
200 MB VXT (C)   0.9   0.7   0.3   0.4   0.7   0.4   0.6   0.7   1.1   1.1   1.3   1.5   1.7
TH_E DEV (C)      10    10    10    10    10    10    10    10    11    11    12    12    12
700-500 MB RH     46    46    48    49    50    50    51    52    51    51    48    50    47
MODEL VTX (KT)    18    20    19    20    20    20    21    24    26    30    30    34    36
850 MB ENV VOR   -23   -26   -17   -13   -14    -9    -2     5    21    14     6    13    -6
200 MB DIV       -11   -30    -8   -10   -37    -5    -8    -7   -10     4     0    13     5
700-850 TADV      -4    -4    -5     0     0    -3    -2    -2    -5     0    -2     2     1
LAND (KM)       1516  1455  1394  1348  1304  1202  1127  1035   946   947   965   721   415
LAT (DEG N)     24.8  24.8  24.7  24.8  24.8  24.8  25.2  25.7  26.3  27.1  28.3  29.8  31.6
LONG(DEG W)     52.8  53.5  54.1  54.6  55.2  56.4  57.7  59.6  62.3  65.3  68.6  71.6  74.2
STM SPEED (KT)     7     6     5     5     5     6     8    11    13    15    15    15    14
HEAT CONTENT      14    13    13    14    15    21    24    35    26    34    40    30    47

  FORECAST TRACK FROM OFCI      INITIAL HEADING/SPEED (DEG/KT):265/  7      CX,CY:  -6/  0
  T-12 MAX WIND:  55            PRESSURE OF STEERING LEVEL (MB):  705  (MEAN=619)
  GOES IR BRIGHTNESS TEMP. STD DEV.  50-200 KM RAD:  27.1 (MEAN=14.5)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  39.0 (MEAN=65.0)
  PRELIM RI PROB (DV .GE. 55 KT IN 48 HR):            6.1

 

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The upper level environment is going to be nearly perfect beyond 48 hours and SST only increase from here. We’re also near peak heating as well in terms of the extent of the warm pool up the East coast. 

Normally systems taking a similar track are being hindered by at least some shear, however in this case, there’s really nothing to inhibit Florence other than internal processes and possible land interaction. 

If you had to draw up a scenario where you could get a major into the mid Atlantic, this is it.

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57 minutes ago, TriPol said:

Since 1950, we have had more hurricanes ride up the East Coast than go into NC. Do I think that could happen here? Yeah, but you need to convince the EURO of that. That ridge to the north is a monster!

Kind of a specious argument, no?  "Up the east coast" covers a lot more area than a specific state like NC.

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57 minutes ago, TriPol said:

Since 1950, we have had more hurricanes ride up the East Coast than go into NC. Do I think that could happen here? Yeah, but you need to convince the EURO of that. That ridge to the north is a monster!

The ridge is strong but it’s also sliding East and Florence eventually ends up in the Northerly flow on the West side of the high.

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The upper level environment is going to be nearly perfect beyond 48 hours and SST only increase from here. We’re also near peak heating as well in terms of the extent of the warm pool up the East coast. 
Normally systems taking a similar track are being hindered by at least some shear, however in this case, there’s really nothing to inhibit Florence other than internal processes and possible land interaction. 
If you had to draw up a scenario where you could get a major into the mid Atlantic, this is it.
Being honest -speaking as an emergency manager- this is increasingly becoming a nightmare scenario. That being said, all options remain on the table and a nightmare scenario remains just one of these options.

Sent from my SM-N960U using Tapatalk

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Here's an opinion question for everyone. What would you consider to be worse, a hurricane riding along the coast moving up the eastern seaboard (hitting a large area of coast but keeping the worst effects near the shore) or having a hurricane plow westward directly into the coast and moving inland, impacting a smaller area of coastline but putting some inland areas in play for lots of rain and very damaging winds? Models have definitely shown both of these...

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52 minutes ago, Tibet said:

Was about to link that myself... its the HWRF but damnnnnn

Does the HWRF have an intensity bias in general?

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20 minutes ago, AndrewJL said:

Here's an opinion question for everyone. What would you consider to be worse, a hurricane riding along the coast moving up the eastern seaboard (hitting a large area of coast but keeping the worst effects near the shore) or having a hurricane plow westward directly into the coast and moving inland, impacting a smaller area of coastline but putting some inland areas in play for lots of rain and very damaging winds? Models have definitely shown both of these...

There are so many other parameters:  speed, strength, landfall location, and direction, for instance.

In general, though, they're both bad for different reasons.

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5 minutes ago, NJwx85 said:

The upper level environment is going to be nearly perfect beyond 48 hours and SST only increase from here. We’re also near peak heating as well in terms of the extent of the warm pool up the East coast. 

Normally systems taking a similar track are being hindered by at least some shear, however in this case, there’s really nothing to inhibit Florence other than internal processes and possible land interaction. 

If you had to draw up a scenario where you could get a major into the mid Atlantic, this is it.

I'd say the Euros 1004mb 12z isn't happening. There's a good chance it will be closer to 904mb than 1004mb at that time.  Probably somewhere in the 930s or 940s at that time.

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1 hour ago, SnowGoose69 said:

It’s really hard to predict.  We’ve seen in the last 5 years systems that looked like they’d go crazy and then once the core is disrupted they never take off again.  The bad news is this system has a very long time to go before it would reach land 

Yes.....I'm often relatively conservative with intensity forecasts after significant core disruption. Like the one last season that was going to hit Miami, but detoured into Cuba instead...CLASSIC case. Everyone was cat 5 this, cat 5 that....never bought it.

Difference is that, as you point out, this one has an eternity..that one did not...sometimes they just never do take off again, though...the term I use is "skunked". We just end up with this shredded, irregular and imperfect CDO...almost like an aging cyclone.

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Yes.....I'm often relatively conservative with intensity forecasts after significant core disruption. Like the one last season that was going to hit Miami, but detoured into Cuba instead...CLASSIC case. Everyone was cat 5 this, cat 5 that....never bought it.
Difference is that, as you point out, this one has an eternity..that one did not...sometimes they just never do take off again, though...the term I use is "skunked". We just end up with this shredded, irregular and imperfect CDO...almost like an aging cyclone.


I think disruption from mountainous terrain is much harder to recover from than shear and dry air.


.

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58 minutes ago, Seth.P said:

Does the HWRF have an intensity bias in general?

The HWRF is the best intensity guidance in the toolkit. It didn't always used to be that way but because of some wonderful investments it is really good, particularly when there is a well defined center it can initialize with. That said, it flops too, and if there's one area of wx that is consistently and notoriously difficult to get right, it is tropical intensity forecasting.

I'd tell someone who is new to tracking tropical to take intensity forecasts on the models with a grain of salt. It's better to

1) look at the overall environment to analyze potential and what positives and negatives to intensification exist;
2) Look at the trend of the guidance. If you have a lot of guidance bullish (or bearish) on development, it's probably onto something 

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20 minutes ago, yoda said:

State of Emergency declared for NC ahead of Florence

 

This might be a little too early but it's better to be prepared.

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BULLETIN
Tropical Storm Florence Advisory Number  35
NWS National Hurricane Center Miami FL       AL062018
1100 PM AST Fri Sep 07 2018

...FLORENCE FORECAST TO RESTRENGTHEN LATER THIS WEEKEND...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...24.8N 53.2W
ABOUT 780 MI...1260 KM NE OF THE NORTHERN LEEWARD ISLANDS
ABOUT 875 MI...1405 KM ESE OF BERMUDA
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...W OR 265 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES

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Tropical Storm Florence Discussion Number  35
NWS National Hurricane Center Miami FL       AL062018
1100 PM AST Fri Sep 07 2018

Florence remains a sheared tropical cyclone.  Satellite images
indicate that the low-level center is partially exposed on the
southwesterly edge of a large convective mass, with the overall
circulation somewhat elongated from southwest to northeast.
A blend of the latest Dvorak wind speed estimates from TAFB/SAB and
the CIMSS SATCON gives a value of 50 kt for this advisory.

While the winds at 200 mb are already from an easterly direction
near the center of Florence, there is significant shear from
northwesterly winds from 300-500 mb, undercutting the outflow layer.
This shear is forecast to relax by the global models over the next
36 hours as an anticyclone builds to the north of the storm, which
should promote some strengthening by Sunday. After 48 hours, the
deep-layer flow becomes easterly near the cyclone, with very little
shear while the system is over very warm waters.  This pattern
favors significant intensification, and most of the guidance brings
Florence back to a category 4 hurricane in 4 or 5 days.  The
intensity forecast is very similar to the last one, and is raised
slightly at days 3 and 4 to come into better agreement with the
guidance.  It is interesting to note that even with a lower initial
intensity, the guidance is higher than the last cycle, which speaks
to the strength of the signal for intensification in the long range.

The initial motion estimate is 265 degrees at 6 kt.  Florence is
expected to continue moving slowly westward for the next 48 hours
under the influence of a weak mid-level ridge over the western
Atlantic.  By days 4 and 5, an exceptionally strong blocking ridge
is forecast to develop between Bermuda and the Northeast U.S. and
build westward, keeping Florence on a west-northwestward trajectory
with a notable increase in forward speed by the end of the forecast
period.  It feels like a broken record to mention that the overall
guidance envelope keeps shifting southwestward, and the official
forecast is moved in that direction.  Unfortunately with such a
large well-defined steering current from the ridge becoming likely,
the extended-range risk to the United States keeps rising, which is
confirmed by the majority of the latest ensemble guidance.

Key Messages:

1. Regardless of Florence's eventual track, large swells are
affecting Bermuda and will begin to affect portions of the U.S.
East Coast this weekend, resulting in life-threatening surf and rip
currents.

2. The risk of other direct impacts associated with Florence along
the U.S. East Coast next week has increased.  However, there is
still very large uncertainty in model forecasts of Florence's track
beyond day 5, making it too soon to determine the exact location,
magnitude, and timing of these impacts.  Interests near and along
the U.S. East Coast should monitor the progress of Florence through
the weekend and ensure they have their hurricane plans in place.

FORECAST POSITIONS AND MAX WINDS

INIT  08/0300Z 24.8N  53.2W   50 KT  60 MPH
 12H  08/1200Z 24.7N  54.1W   50 KT  60 MPH
 24H  09/0000Z 24.7N  55.2W   55 KT  65 MPH
 36H  09/1200Z 24.7N  56.3W   60 KT  70 MPH
 48H  10/0000Z 25.0N  57.8W   70 KT  80 MPH
 72H  11/0000Z 25.8N  62.3W   95 KT 110 MPH
 96H  12/0000Z 27.5N  68.5W  115 KT 130 MPH
120H  13/0000Z 30.5N  74.5W  115 KT 130 MPH

$$
Forecaster Blake

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Here's an opinion question for everyone. What would you consider to be worse, a hurricane riding along the coast moving up the eastern seaboard (hitting a large area of coast but keeping the worst effects near the shore) or having a hurricane plow westward directly into the coast and moving inland, impacting a smaller area of coastline but putting some inland areas in play for lots of rain and very damaging winds? Models have definitely shown both of these...


As has been stated, each brings their own set of emergency parameters and procedures.

With regards to a hurricane riding up the eastern seaboard, the question becomes does it make landfall. If it does, and stays on the coast, then the question becomes does the front right quadrant ride up the shore. If it does, you then have a large swath of real estate dealing with prolonged storm surge. In turn, this creates certain needs for emergency personnel. The issue with this, however, is the lack of available resources from surrounding areas. There's only so many resources which can be drawn from and considering that the major cities will be the ones receiving the wallop, this means resources will be scarce as most will be not only in harm's way, however, they are also being utilized.

With regards to inland flooding potential, this likely allows for resources more easily donated from large cities, however , issues then become that the terrain becomes much harder to navigate. Also, inland communities, specifically smaller ones, tend to be much less prepared than larger coastal cities. In light of this, while more resources become available; the need for resources can likewise increase for smaller areas, thus presenting more issues.

Likewise, this is a very small overview of the potential issues. I have not covered critical infrastructure, potential evacuations, financial assistance, and much much more.

Sent from my SM-N960U using Tapatalk

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1 minute ago, yoda said:
Tropical Storm Florence Discussion Number  35
NWS National Hurricane Center Miami FL       AL062018
1100 PM AST Fri Sep 07 2018

Florence remains a sheared tropical cyclone.  Satellite images
indicate that the low-level center is partially exposed on the
southwesterly edge of a large convective mass, with the overall
circulation somewhat elongated from southwest to northeast.
A blend of the latest Dvorak wind speed estimates from TAFB/SAB and
the CIMSS SATCON gives a value of 50 kt for this advisory.

While the winds at 200 mb are already from an easterly direction
near the center of Florence, there is significant shear from
northwesterly winds from 300-500 mb, undercutting the outflow layer.
This shear is forecast to relax by the global models over the next
36 hours as an anticyclone builds to the north of the storm, which
should promote some strengthening by Sunday. After 48 hours, the
deep-layer flow becomes easterly near the cyclone, with very little
shear while the system is over very warm waters.  This pattern
favors significant intensification, and most of the guidance brings
Florence back to a category 4 hurricane in 4 or 5 days.  The
intensity forecast is very similar to the last one, and is raised
slightly at days 3 and 4 to come into better agreement with the
guidance.  It is interesting to note that even with a lower initial
intensity, the guidance is higher than the last cycle, which speaks
to the strength of the signal for intensification in the long range.

The initial motion estimate is 265 degrees at 6 kt.  Florence is
expected to continue moving slowly westward for the next 48 hours
under the influence of a weak mid-level ridge over the western
Atlantic.  By days 4 and 5, an exceptionally strong blocking ridge
is forecast to develop between Bermuda and the Northeast U.S. and
build westward, keeping Florence on a west-northwestward trajectory
with a notable increase in forward speed by the end of the forecast
period.  It feels like a broken record to mention that the overall
guidance envelope keeps shifting southwestward, and the official
forecast is moved in that direction.  Unfortunately with such a
large well-defined steering current from the ridge becoming likely,
the extended-range risk to the United States keeps rising, which is
confirmed by the majority of the latest ensemble guidance.

Key Messages:

1. Regardless of Florence's eventual track, large swells are
affecting Bermuda and will begin to affect portions of the U.S.
East Coast this weekend, resulting in life-threatening surf and rip
currents.

2. The risk of other direct impacts associated with Florence along
the U.S. East Coast next week has increased.  However, there is
still very large uncertainty in model forecasts of Florence's track
beyond day 5, making it too soon to determine the exact location,
magnitude, and timing of these impacts.  Interests near and along
the U.S. East Coast should monitor the progress of Florence through
the weekend and ensure they have their hurricane plans in place.

FORECAST POSITIONS AND MAX WINDS

INIT  08/0300Z 24.8N  53.2W   50 KT  60 MPH
 12H  08/1200Z 24.7N  54.1W   50 KT  60 MPH
 24H  09/0000Z 24.7N  55.2W   55 KT  65 MPH
 36H  09/1200Z 24.7N  56.3W   60 KT  70 MPH
 48H  10/0000Z 25.0N  57.8W   70 KT  80 MPH
 72H  11/0000Z 25.8N  62.3W   95 KT 110 MPH
 96H  12/0000Z 27.5N  68.5W  115 KT 130 MPH
120H  13/0000Z 30.5N  74.5W  115 KT 130 MPH

$$
Forecaster Blake

Those are really strong statements...both about track and the intensity signal. 

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1 minute ago, yoda said:
BULLETIN
Tropical Storm Florence Advisory Number  35
NWS National Hurricane Center Miami FL       AL062018
1100 PM AST Fri Sep 07 2018

...FLORENCE FORECAST TO RESTRENGTHEN LATER THIS WEEKEND...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...24.8N 53.2W
ABOUT 780 MI...1260 KM NE OF THE NORTHERN LEEWARD ISLANDS
ABOUT 875 MI...1405 KM ESE OF BERMUDA
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...W OR 265 DEGREES AT 7 MPH...11 KM/H
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES

Maybe it won’t...it’s possible.  Then all of this is for nothing. Not the first time we have tracked a total fail.  I won’t relax until it’s at least a cat 1 again. 

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3 minutes ago, yoda said:
Tropical Storm Florence Discussion Number  35
NWS National Hurricane Center Miami FL       AL062018
1100 PM AST Fri Sep 07 2018

Florence remains a sheared tropical cyclone.  Satellite images
indicate that the low-level center is partially exposed on the
southwesterly edge of a large convective mass, with the overall
circulation somewhat elongated from southwest to northeast.
A blend of the latest Dvorak wind speed estimates from TAFB/SAB and
the CIMSS SATCON gives a value of 50 kt for this advisory.

While the winds at 200 mb are already from an easterly direction
near the center of Florence, there is significant shear from
northwesterly winds from 300-500 mb, undercutting the outflow layer.
This shear is forecast to relax by the global models over the next
36 hours as an anticyclone builds to the north of the storm, which
should promote some strengthening by Sunday. After 48 hours, the
deep-layer flow becomes easterly near the cyclone, with very little
shear while the system is over very warm waters.  This pattern
favors significant intensification, and most of the guidance brings
Florence back to a category 4 hurricane in 4 or 5 days.  The
intensity forecast is very similar to the last one, and is raised
slightly at days 3 and 4 to come into better agreement with the
guidance.  It is interesting to note that even with a lower initial
intensity, the guidance is higher than the last cycle, which speaks
to the strength of the signal for intensification in the long range.

The initial motion estimate is 265 degrees at 6 kt.  Florence is
expected to continue moving slowly westward for the next 48 hours
under the influence of a weak mid-level ridge over the western
Atlantic.  By days 4 and 5, an exceptionally strong blocking ridge
is forecast to develop between Bermuda and the Northeast U.S. and
build westward, keeping Florence on a west-northwestward trajectory
with a notable increase in forward speed by the end of the forecast
period.  It feels like a broken record to mention that the overall
guidance envelope keeps shifting southwestward, and the official
forecast is moved in that direction.  Unfortunately with such a
large well-defined steering current from the ridge becoming likely,
the extended-range risk to the United States keeps rising, which is
confirmed by the majority of the latest ensemble guidance.

Key Messages:

1. Regardless of Florence's eventual track, large swells are
affecting Bermuda and will begin to affect portions of the U.S.
East Coast this weekend, resulting in life-threatening surf and rip
currents.

2. The risk of other direct impacts associated with Florence along
the U.S. East Coast next week has increased.  However, there is
still very large uncertainty in model forecasts of Florence's track
beyond day 5, making it too soon to determine the exact location,
magnitude, and timing of these impacts.  Interests near and along
the U.S. East Coast should monitor the progress of Florence through
the weekend and ensure they have their hurricane plans in place.

FORECAST POSITIONS AND MAX WINDS

INIT  08/0300Z 24.8N  53.2W   50 KT  60 MPH
 12H  08/1200Z 24.7N  54.1W   50 KT  60 MPH
 24H  09/0000Z 24.7N  55.2W   55 KT  65 MPH
 36H  09/1200Z 24.7N  56.3W   60 KT  70 MPH
 48H  10/0000Z 25.0N  57.8W   70 KT  80 MPH
 72H  11/0000Z 25.8N  62.3W   95 KT 110 MPH
 96H  12/0000Z 27.5N  68.5W  115 KT 130 MPH
120H  13/0000Z 30.5N  74.5W  115 KT 130 MPH

$$
Forecaster Blake

NHC seems to be going all in on this one. At least we have better chances here than a slot machine! 

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15 minutes ago, WxWatcher007 said:

Those are really strong statements...both about track and the intensity signal. 

 

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