ATL: TEN - Post-Tropical - Discussion

[NDG]

I see a slow westward drift during the day, several eddies rotating around a larger circulation. GFS shows it turning NE eventually as it gets closer to the Coast of the GA & or Carolinas.

[HurricaneRyan]

This might finally become a tropical cyclone after 84 years

[cycloneye]

BULLETIN
Potential Tropical Cyclone Ten Advisory Number 1
NWS National Hurricane Center Miami FL AL102017
500 PM EDT Sun Aug 27 2017

...TROPICAL STORM WATCH ISSUED FOR A PORTION OF THE COAST OF THE
CAROLINAS...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...31.2N 80.0W
ABOUT 110 MI...180 KM S OF CHARLESTON SOUTH CAROLINA
ABOUT 245 MI...390 KM SSW OF WILMINGTON NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...STATIONARY
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


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

A Tropical Storm Watch is in effect from South Santee River, South
Carolina, to Duck, North Carolina.
---------------------------------------------

DDHHMM

Potential Tropical Cyclone Ten Discussion Number 1
NWS National Hurricane Center Miami FL AL102017
500 PM EDT Sun Aug 27 2017

Convection associated with the broad area of low pressure located
east of the Georgia coast has increased markedly today. Visibile
satellite imagery shows multiple low-level swirls rotating around a
mean center, but ASCAT data earlier today showed that the
circulation was not yet well-defined. The ASCAT data and buoy
observations indicate that the initial intensity is 30 kt, and buoy
data suggest the central pressure is around 1007 mb. While the
system is expected to remain sheared, it has a high chance of
becoming a tropical depression or tropical storm before it becomes
baroclinic in about 48 hours. Given that, and the potential for
this system to bring tropical storm conditions to the coast from
northern South Carolina through North Carolina, advisories are
being initiated on this system as a Potential Tropical Cyclone.

The system is currently moving little in a region of weak steering,
but should begin to move slowly northward and then quickly
accelerate northeastward ahead of a mid-latitude trough moving into
the mid-Atlantic states. The NHC forecast follows the trend of the
global models keeping the low center near the coast, but as usual
there is more uncertainty than usual in the track forecast for a
weak/developing system. After the system moves into the western
Atlantic, it should continue accelerating east-northeastward ahead
of the upper trough through the end of the period.

Despite the sheared envirionment, the system should be able to
intensify a little via diabatic processes before it intensifies
further as it undergoes a more substantial baroclinic
intensification at 48 hours and beyond. The NHC intensity forecast
follows the intensity consensus through 36 hours and then follows
the trend of the global model guidance and guidance from the NOAA
Ocean Prediction Center.

Although the potential impacts are within 36 hours, given the
uncertainty in whether tropical storm force winds will occur on land
in northeastern South Caroilna and southeastern North Carolina,
south, a tropical storm watch has been issued for these areas.
Note that north of Duck, North Carolina, hazards from this system
will be handled with non-tropical products issued by local National
Weather Service offices.


FORECAST POSITIONS AND MAX WINDS

INIT 27/2100Z 31.2N 80.0W 30 KT 35 MPH...POTENTIAL TROP CYCLONE
12H 28/0600Z 31.6N 80.1W 35 KT 40 MPH...TROPICAL CYCLONE
24H 28/1800Z 32.4N 80.0W 35 KT 40 MPH
36H 29/0600Z 34.1N 78.0W 35 KT 40 MPH...INLAND
48H 29/1800Z 36.6N 75.0W 45 KT 50 MPH...POST-TROPICAL
72H 30/1800Z 40.0N 66.0W 55 KT 65 MPH...POST-TROP/EXTRATROP
96H 31/1800Z 43.0N 55.0W 60 KT 70 MPH...POST-TROP/EXTRATROP
120H 01/1800Z 47.0N 43.0W 50 KT 60 MPH...POST-TROP/EXTRATROP

$$
Forecaster Brennan

[LarryWx]

Buoy 4008 just off the GA coast has had the lowest SLP as well as largest SLP drop over the last 3 hours (2.3 mb drop down to 1009.5 mb or 29.81"). Also winds there have picked up quite a bit with sustained of 29 knots and gusts to 35 knots. They were only 23/27 4 hours ago. Waves are now up to 8.9 feet vs only 4.9 feet 6 hours ago.

http://www.ndbc.noaa.gov/station_page.php?station=41008

Buoy map: http://www.ndbc.noaa.gov/maps/Florida.shtml

It has been a windy day today here (SAV) with winds recently picking up more. It has the look of a nearby TD of nor'easter. Here it is tropical with low 70s TDs. However, along the SC coast NE of CHS as well as in all of NC, TDs are drier (mainly 55-60). The question I'm wondering about is whether or not that drier air can get into the circulation as it develops. If so, I'd favor ST over TC. But if it moves NE far enough offshore, I'd give a TC a better chance. Will be interesting to follow. Regardless, I'm not currently all that worried about anything all that bad here and in lower SC as of now as we'd be on the weaker left side if it were to get strong as it moves NE but I'm definitely watching this closely just in case it does something unexpected.

[northjaxpro]

I am still getting strong northeast wind gusts up to 30 mph at times currently. I just checked the Brunswick ob and they are getting gusts to 38 mph already. Tropical storm force gusts are already occurring from the coastal region north to the SC coast now. The gradient tightening and. 92L is getting its act together.

[TheStormExpert]

Looks like it'll make landfall in NC as a TS.

[xironman]

Looks like it'll make landfall in NC as a TS.

Not great for the sound side OBX

[northjaxpro]

Just to say again, as Harvey and 92L have now both shown us all remarkably, and what I have always in my years of analyzing the tropics, use this rule of thumb::

NEVER. EVER, write off any trackable vorticity traversing the basin. PERIOD!

[psyclone]

Just to say again, as Harvey and 92L have now both shown us all remarkably, and what I have always in my years of analyzing the tropics, use this rule of thumb::

NEVER. EVER, write off any trackable vorticity traversing the basin. PERIOD!

this is especially true at peak season. when you have vorticity traversing the basin from late august into October...many times development is when and not if. look back to hermine last year which huffed and puffed for what seemed an eternity before finally blossoming.

[ForeverFlorida90s]

It's weird on this side of Atlantic if I remember correctly Hurricane Gert intensified quickly something to watch and does anyone feel like it's going to be a busy season?

[seahawkjd]

Tropical Storm Watch

Ten Local Watch/Warning Statement/Advisory Number 1
National Weather Service Newport/Morehead City NC AL102017
530 PM EDT Sun Aug 27 2017

NCZ095-280530-
/O.NEW.KMHX.TR.A.1010.170827T2130Z-000000T0000Z/
Carteret-
530 PM EDT Sun Aug 27 2017

...TROPICAL STORM WATCH IN EFFECT...

A Tropical Storm Watch means Tropical storm wind conditions are
possible somewhere within this area and within the next 48 hours

* LOCATIONS AFFECTED
- Morehead City
- Beaufort
- Emerald Isle

* WIND
- LATEST LOCAL FORECAST: Equivalent Tropical Storm force wind
- Peak Wind Forecast: 30-40 mph with gusts to 60 mph
- Window for Tropical Storm force winds: early Tuesday
morning until Tuesday afternoon

- CURRENT THREAT TO LIFE AND PROPERTY: Elevated
- Emergency plans should include a reasonable threat for
tropical storm force wind of 39 to 57 mph.
- To be safe, prepare for the potential of limited wind
impacts. Remaining efforts to secure properties should now
be brought to completion.
- Hazardous wind is possible. Failure to adequately shelter
may result in serious injury. Move to safe shelter before
the wind becomes hazardous.

- POTENTIAL IMPACTS: Limited
- Damage to porches, awnings, carports, sheds, and unanchored
mobile homes. Unsecured lightweight objects blown about.
- Many large tree limbs broken off. A few trees snapped or
uprooted, but with greater numbers in places where trees
are shallow rooted. Some fences and roadway signs blown
over.
- A few roads impassable from debris, particularly within
urban or heavily wooded places. Hazardous driving
conditions on bridges and other elevated roadways.
- Scattered power and communications outages.

* STORM SURGE
- LATEST LOCAL FORECAST: Localized storm surge possible
- Peak Storm Surge Inundation: The potential for up to 2 feet
above ground somewhere within surge prone areas
- Window of concern: Begins early Tuesday morning

- CURRENT THREAT TO LIFE AND PROPERTY: Elevated
- Emergency plans should include a reasonable threat for peak
storm surge flooding of greater than 1 foot above ground.
- To be safe, prepare for the potential of limited storm
surge flooding impacts. Efforts should now be brought to
completion before conditions deteriorate.
- Localized inundation is possible. Follow the instructions
of local officials. Consider voluntary evacuation if
recommended. Leave immediately if evacuation orders are
issued.

- POTENTIAL IMPACTS: Limited
- Localized inundation with storm surge flooding mainly along
immediate shorelines and in low-lying spots, or in areas
farther inland near where higher surge waters move ashore.
- Sections of near-shore roads and parking lots become
overspread with surge water. Driving conditions dangerous
in places where surge water covers the road.
- Moderate beach erosion. Heavy surf also breaching dunes,
mainly in usually vulnerable locations. Strong rip currents.
- Minor to locally moderate damage to marinas, docks,
boardwalks, and piers. A few small craft broken away from
moorings.

* FLOODING RAIN
- LATEST LOCAL FORECAST:
- Peak Rainfall Amounts: 3-5 inches, with locally
higher amounts

- CURRENT THREAT TO LIFE AND PROPERTY: Elevated
- Emergency plans should include a reasonable threat for
minor flooding where peak rainfall totals are near amounts
conducive for localized flash flooding and rapid inundation.
- To be safe, prepare for the potential of limited flooding
rain impacts.
- Localized flooding is possible. If flood related watches
and warnings are issued, heed recommended actions.

- POTENTIAL IMPACTS: Limited
- Localized rainfall flooding may prompt a few evacuations.
- Rivers and tributaries may quickly rise with swifter
currents. Small streams, creeks, canals, and ditches may
become swollen and overflow in spots.
- Flood waters can enter a few structures, especially in
usually vulnerable spots. A few places where rapid ponding
of water occurs at underpasses, low-lying spots, and poor
drainage areas. Several storm drains and retention ponds
become near-full and begin to overflow. Some brief road and
bridge closures.

* TORNADO
- LATEST LOCAL FORECAST:
- Situation is somewhat favorable for tornadoes

- CURRENT THREAT TO LIFE AND PROPERTY: Elevated
- When implementing emergency plans, include a reasonable
threat for isolated tornadoes.
- To be safe, prepare for the potential of limited tornado
impacts.
- Listen for tornado watches and warnings. Be ready to
shelter quickly if a tornado approaches.

- POTENTIAL IMPACTS: Limited
- The occurrence of isolated tornadoes can hinder the
execution of emergency plans during tropical events.
- A few places may experience tornado damage, along with
power and communications disruptions.
- Locations could realize roofs peeled off buildings,
chimneys toppled, mobile homes pushed off foundations or
overturned, large tree tops and branches snapped off,
shallow-rooted trees knocked over, moving vehicles blown
off roads, and small boats pulled from moorings.

* FOR MORE INFORMATION:
- http://ready.gov/hurricanes

$$

[NDG]

IMO the NHC is wrong in the position of the low pressure, clearly seen on radar and vis satellite is a bit further west closer to the coast of GA/FL border.
I estimate it to be near 30.9N & 80.7W

[seahawkjd]

Tropical Cyclone Ten Local Statement Advisory Number 1
NCZ105>110-SCZ053>056-280530-

Tropical Cyclone Ten Local Statement Advisory Number 1
National Weather Service Wilmington NC AL102017
526 PM EDT Sun Aug 27 2017

This product covers Southeastern North Carolina and Northeastern
South Carolina.

**Potential Tropical Cyclone Number 10 is developing off the Georgia
coast and may strengthen as it moves north.**

NEW INFORMATION
---------------

* CHANGES TO WATCHES AND WARNINGS:
- A Tropical Storm Watch has been issued for Coastal Brunswick,
Coastal Georgetown, Coastal Horry, Coastal New Hanover, Coastal
Pender, Inland Brunswick, Inland Georgetown, Inland Horry,
Inland New Hanover, and Inland Pender

* CURRENT WATCHES AND WARNINGS:
- A Tropical Storm Watch is in effect for Coastal Brunswick,
Coastal Georgetown, Coastal Horry, Coastal New Hanover, Coastal
Pender, Inland Brunswick, Inland Georgetown, Inland Horry,
Inland New Hanover, and Inland Pender

* STORM INFORMATION:
- About 250 miles south-southwest of Wilmington NC or about 180
miles south-southwest of Myrtle Beach SC
- 31.2N 80.0W
- Storm Intensity 35 mph
- Movement Stationary

SITUATION OVERVIEW
------------------

Potential Tropical Cyclone Number 10 is located off the Georgia
coast and is expected to move north along the coast of South and North
Carolina Monday afternoon through Tuesday morning. Winds may
increase to tropical storm force as the storm`s center moves by, with
rainfall amounts up to six inches possible. The low pressure area is
not yet well defined, and considerable uncertainty remains with exactly
how organized this system could become in the time remaining before
it reaches our area.

POTENTIAL IMPACTS
-----------------

* WIND:
Prepare for hazardous wind having possible limited impacts across
Northeast South Carolina and Southeast North Carolina.
Potential impacts in this area include:
- Damage to porches, awnings, carports, sheds, and unanchored
mobile homes is possible. Unsecured lightweight objects may be
blown about.
- Some large limbs may break from trees. A few shallow rooted or
weak trees may snap or be knocked down. Some fences and roadway
signs damaged.
- A few roads may become impassable due to debris, particularly
within urban or heavily wooded locations. Hazardous driving
conditions are possible, especially for high profile vehicles
on bridges and other elevated roadways.
- Scattered power and communications outages are possible.

Elsewhere across Southeastern North Carolina and Northeastern
South Carolina, little to no impact is anticipated.

* FLOODING RAIN:
Prepare for locally hazardous rainfall flooding having possible
limited impacts across Southeastern North Carolina and Northeastern
South Carolina. Potential impacts include:
- Localized flooding from rainfall may occur, especially in
low-lying and poor drainage areas. Some rivers and creeks may
rise as a result of the rain. Small streams, creeks, and
ditches may overflow in some locations.
- Several storm drains and retention ponds may become full and
begin to overflow. Some brief road closures are possible.

* TORNADOES:
Prepare for a tornado event having possible limited impacts across
Northeast South Carolina and Southeast North Carolina. Potential
impacts include:
- The occurrence of isolated tornadoes can hinder the execution
of emergency plans during tropical events.
- A few places may experience tornado damage, along with power
and communications disruptions.
- Tornadoes can cause damage to trees, vehicles, boats, and
buildings. Unsecured mobile homes and poorly constructed
structures are particularly vulnerable.

Elsewhere across Southeastern North Carolina and Northeastern
South Carolina, little to no impact is anticipated.

PRECAUTIONARY/PREPAREDNESS ACTIONS
----------------------------------

* EVACUATIONS:
None at this time.

* OTHER PREPAREDNESS INFORMATION:
When securing your property, outside preparations should be conducted
as soon as possible before conditions deteriorate. The onset of
strong gusty winds and heavy rain can cause certain preparedness
activities to become unsafe.

Be a Good Samaritan and check on those who may not be fully aware of
the situation or who are unable to make personal preparations.

Closely monitor NOAA Weather Radio or other local news outlets for
official storm information. Listen for possible changes to the
forecast.

* ADDITIONAL SOURCES OF INFORMATION:
- For information on appropriate preparations see ready.gov
- For information on creating an emergency plan see getagameplan.org
- For additional disaster preparedness information see redcross.org

NEXT UPDATE
-----------

The next local statement will be issued by the National Weather
Service in Wilmington NC around Midnight EDT, or sooner if conditions
warrant.

$$

TRA

[NDG]

It's weird on this side of Atlantic if I remember correctly Hurricane Gert intensified quickly something to watch and does anyone feel like it's going to be a busy season?

Totally different set up, Gert was much further away from the trough of low pressure over the NE US so it did not encountered any shear after it developed.
This system is still under moderate to strong shear forecasted only to come down by a little bit but by then it will be inland and merging with the frontal system.

[northjaxpro]

Well, NDG, based on wind gusts I continue to get and looking at in a along the coast, you may be right about the current position of the Low center. Pressure at Brunswick Regional Airport on their latest ob is reported at 1010.5 mb . NE wind gusting to 38 mph there.

[northjaxpro]

Also., observing closely that visible imagery, the sheared Low Pressure center area is actually drifting a bit south of due west at the moment in those last couple of frames.

The Low Pressure center should hopefully lift northeast later tonight and through the short term.

[Emmett_Brown]

Perhaps the strong northerly shear is preventing it from moving NE immediately?

[xironman]

Maybe straight to STS
Wind Speed (WSPD): 31.1 kts

http://www.ndbc.noaa.gov/station_page.php?station=41008

[xironman]

Perhaps the strong northerly shear is preventing it from moving NE immediately?

The shear is giving the extra-tropical system its life. Now according to the models the shear will dissipate giving the low a chance to transition to a tropical low.

[NDG]

:uarrow:

Well, NDG, based on wind gusts I continue to get and looking at in a along the coast, you may be right about the current position of the Low center. Pressure at Brunswick Regional Airport on their latest ob is reported at 1010.5 mb . NE wind gusting to 38 mph there.

One of those eddies is rotating your way.