Tropical Depression #10 – September 17, 2019

Weekly_Outlook (2)

 

Tropical Depression Ten Discussion Number   1

NWS National Hurricane Center Miami FL       AL102019

1100 AM AST Tue Sep 17 2019

Deep convection associated with the area of low pressure over the

central Atlantic has become more persistent and better organized

this morning.  Data T-numbers from both SAB and TAFB are 2.0 on the

Dvorak scale, therefore advisories are being initiated on a tropical

depression.  The initial intensity is set at 30 kt, in line with the

satellite estimates.  The depression is forecast to move over

gradually increasing sea surface temperatures within a favorable

upper-level environment.  The only negative factor for

intensification appears to be some nearby dry air, but with low

shear conditions expected, so steady strengthening is forecast

during the next several days.  The NHC forecast calls for the

depression to become a tropical storm later today, and attain

hurricane status within 72 hours. The NHC intensity forecast is in

good agreement with the SHIPS and LGEM statistical models.

Since the depression is still in the development phase, the initial

motion is a somewhat uncertain 295/10 kt.  A strong deep-layer

ridge to the north of the cyclone should steer the depression

generally west-northwestward at a faster forward speed during the

next few days.  The track guidance is in relatively good agreement

through 72 hours, and brings the cyclone near the northern Leeward

Islands in about 3 days.  By late in the period, the cyclone is

expected to reach the western periphery of the ridge, and there is

increasing spread among the guidance.  The global model ensemble

means are along the right side of the envelope while the HWRF and

UKMET are along the left side.  The NHC track lies close the

consensus aids, which is also in good agreement with the latest

ECMWF.

Interests in the northern Leeward Islands should monitor the

progress of this system.

FORECAST POSITIONS AND MAX WINDS

INIT  17/1500Z 12.9N 44.9W  30 KT  35 MPH

12H  18/0000Z 13.8N 46.1W  35 KT  40 MPH

24H  18/1200Z 14.7N 47.9W  40 KT  45 MPH

36H  19/0000Z 15.5N 50.2W  45 KT  50 MPH

48H  19/1200Z 16.3N 52.9W  55 KT  65 MPH

72H  20/1200Z 18.2N 59.2W  65 KT  75 MPH

96H  21/1200Z 20.2N 64.7W  75 KT  85 MPH

120H  22/1200Z 22.5N 69.0W  80 KT  90 MPH

Tropical Weather Update – September 13, 2019

Potential Tropical Cyclone Nine Discussion Number   4

NWS National Hurricane Center Miami FL       AL092019

1100 AM EDT Fri Sep 13 2019

Preliminary data from a reconnaissance plane indicate that the

disturbance has not developed a well-defined center yet and

continues to be characterized by an elongated SW to NE trough of low

pressure.  Satellite images however, suggest that the system could

be consolidating a little bit farther to the east within the area of

deep convection.  The reconnaissance plane will also check this

region soon.  In this advisory, the initial position is a point near

the middle of of the trough, but not quite as far east as the

convective area. The initial intensity remains 25 kt.

The disturbance is embedded within a moderate shear environment, but

this parameter is not expected to be strong enough to halt

development. The NHC forecast still calls for this system to

become a tropical cyclone later today or Saturday. Global models

develop the system and guidance suggests that the cyclone could even

reach hurricane intensity by the end of the forecast period. By

then, the system is expected to be over the Atlantic well southeast

of the coast of the Carolinas.

Due to a lack of a well-defined center, the initial motion is highly

uncertain. It appears that there has been little motion during

the past few hours. A weakness in the ridge over the western

Atlantic is forecast to develop and this pattern should steer the

system slowly toward the northwest and then northward. In about 3

days, an eastward moving mid-latitude trough will force the system

to recurve away from the coast toward the Atlantic.  The guidance

has shifted a little to east this morning and consequently the NHC

track forecast was adjusted in that direction. However, the official

forecast is still on the western edge of the guidance envelope. If

the disturbance develops a little more to the east, the track

forecast will probably adjusted to the right later tod

 

 

Tropical Weather Update – September 12, 2019

To All,

A couple of systems we need to keep a eye on a possibility they could be a problem next week.

Tropical Weather Outlook

NWS National Hurricane Center Miami FL

800 AM EDT Thu Sep 12 2019

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

1. Satellite images indicate that the area of disturbed weather over

the central and southeastern Bahamas is gradually becoming better

organized while surface pressures are falling in the area.

Conditions are becoming favorable for a tropical depression or a

tropical storm to form within the next day or so as the system moves

toward the northwest through the northwestern Bahamas and toward

the Florida Peninsula at 5 to 10 mph. If this development trend

continues Potential Tropical Cyclone advisories will likely be

initiated later today. This disturbance will bring heavy rainfall

and gusty winds across portions of the Bahamas through Friday,

especially in portions of the northwestern Bahamas affected by

Hurricane Dorian. An Air Force Reserve reconnaissance aircraft is

scheduled to investigate the system this afternoon, if necessary.

* Formation chance through 48 hours…high…70 percent.

* Formation chance through 5 days…high…80 percent.

2. A tropical wave located several hundred miles west of the Cabo

Verde Islands is producing disorganized showers and thunderstorms.

Conditions appear conducive for development, and a tropical

depression could form early next week while the system moves

westward over the tropical Atlantic.

* Formation chance through 48 hours…low…near 0 percent.

* Formation chance through 5 days…medium…40 percent.

Tropical Weather Outlook – September 9, 2019

Tropical Weather Outlook

NWS National Hurricane Center Miami FL

800 AM EDT Mon Sep 9 2019

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical

Storm Gabrielle, located over the north-central Atlantic Ocean.

1. A weak area of low pressure, associated with a tropical wave,

continues to produce disorganized showers and thunderstorms

about midway between the Cabo Verde Islands and the Windward

Islands. Some slow development of this system is possible during the

next two or three days before upper-level winds become unfavorable

for tropical cyclone formation. This system is expected to move

generally westward across the tropical Atlantic Ocean for the next

several days.

* Formation chance through 48 hours…low…20 percent.

* Formation chance through 5 days…low…30 percent.

2. Disorganized cloudiness and showers located a few hundred miles

north and northeast of the Greater Antilles are associated with a

surface trough interacting with an upper-level low. Little to no

development of this system is expected during the next day or two

while the system moves west-northwestward, north of the Greater

Antilles. Environmental conditions could become a little more

conducive for development when the disturbance moves near the

Bahamas and Florida late this week.

* Formation chance through 48 hours…low…near 0 percent.

* Formation chance through 5 days…low…20 percent.

Update Hurricane Dorian – September 6, 2019

Hurricane Dorian Discussion Number  52

NWS National Hurricane Center Miami FL       AL052019

500 AM EDT Fri Sep 06 2019

 

The center of the eye of Hurricane Dorian is located just off the

coast of North Carolina not far from Cape Lookout.  Based on data

from the Air Force Hurricane Hunters and Doppler radar velocities,

the initial intensity is set at 80 kt.  This estimate is a

compromise between the flight-level winds and SFMR values.  The

minimum pressure remains quite low, 956 mb, based on surface

observations and aircraft fixes.  There have been several reports in

eastern North Carolina of sustained tropical-storm-force winds and

hurricane-force gusts, with the strongest winds being reported in

the northern eyewall.

 

Dorian is moving northeastward at 12 kt.  A faster northeastward

motion is expected during the next few days as a mid- to upper-level

trough, currently over the U.S. Great Lakes, approaches the system

and accelerates the steering flow.  This track forecast takes the

hurricane along the coast of North Carolina during the next several

hours and near or over Atlantic Canada this weekend.  The models

are tightly clustered, and the NHC track forecast lies near the

middle of the guidance envelope.Hu

 

The hurricane is expected to gradually weaken during the next couple

of days due to an increase in wind shear and drier air. Dorian is

expected to cross the north wall of the Gulf Stream current in about

36 hours, and head over much colder waters after that.  These

atmospheric and oceanic conditions should cause the cyclone to

become a powerful hurricane-force extratropical in about 2 days.  As

the system gains latitude, the tropical-storm-force winds are

expected to expand significantly.  The NHC intensity forecast is

largely an update of the previous one and in line with the various

consensus aids.

 

Key Messages:

 

  1. Life-threatening storm surge and dangerous winds are expected

to continue along portions of the North Carolina coast, portions of

southeast Virginia and the southern Chesapeake Bay.  Water levels

could rise well in advance of the arrival of strong winds. Residents

in these areas should follow advice given by local emergency

officials.

 

  1. Flash flooding is occurring, and will continue to become more

widespread across the eastern Carolinas and far southeast Virginia

this morning. There is a high risk of flash flooding over these

areas, where significant, life-threatening flash flooding is

expected.

 

FORECAST POSITIONS AND MAX WINDS

 

INIT  06/0900Z 34.6N 76.2W  80 KT  90 MPH

12H  06/1800Z 36.0N 74.1W  75 KT  85 MPH

24H  07/0600Z 38.8N 69.9W  75 KT  85 MPH

36H  07/1800Z 42.5N 65.4W  70 KT  80 MPH

48H  08/0600Z 46.7N 61.6W  60 KT  70 MPH…POST-TROP/EXTRATROP

72H  09/0600Z 53.0N 52.0W  45 KT  50 MPH…POST-TROP/EXTRATROP

96H  10/0600Z 58.0N 36.0W  40 KT  45 MPH…POST-TROP/EXTRATROP

120H  11/0600Z 0.0S 0.0W   0 KT   0 MPH…DISSIPATED

Image preview

Pender County Hurricane Dorian Update – September 5, 2019

To All,

Hopefully by now everyone has taken the precautions for the storm. While the storm bares down on us please do be out after 8 pm that is when the curfew takes effect. All EOC’s in the County are operational and will remain open to until. Please Be safe.

———————————————————————————————————————————————————————————————————————————————————————————————-

Hurricane Dorian Discussion Number  50

NWS National Hurricane Center Miami FL       AL052019

500 PM EDT Thu Sep 05 2019

During the last 12 h, Dorian appears to have started the expected

slow weakening trend.  Air Force Reserve Hurricane Hunter data show

that the central pressure inside the 35-45 n mi wide eye is slowly

rising, and satellite imagery indicates that the eye is becoming

less well defined.  The current Hurricane Hunter aircraft has

reported maximum SFMR surface wind estimates of 88 kt, along with

700 mb flight-level winds of 91 kt. Based on these data, the initial

intensity is reduced to 90 kt.

The hurricane is continuing its expected northeastward turn, and the

initial motion is now 035/9.  The mid-latitude westerlies should

steer Dorian generally northeastward at an increasing forward speed,

with the eye passing near of over portions of the North Carolina

coast during the next 12-24 h.  After that, Dorian is forecast to

move quickly across the northwest Atlantic and be near or over the

Canadian Maritimes/Atlantic provinces by 60 h.  As was the case in

the previous advisory, the track guidance remains tightly clustered,

and the new forecast track is changed little from the previous

one.

Due to increasing shear, Dorian is forecast to slowly weaken as it

moves near and along the South and North Carolina coasts.

Extratropical transition should begin around 36-48 h and be complete

by 60 h, although Dorian is forecast to maintain hurricane-force

winds through the transition.  After transition is complete, the

extratropical low should weaken over the far north Atlantic and be

absorbed into a larger low pressure area by 120 h.

The center of Dorian is expected to move very near or over the

coastline of the Carolinas and the southern Mid-Atlantic states.

Residents of these areas should already be prepared for damaging

winds, life-threatening storm surges, and flooding rains.  It also

appears that Dorian will affect portion of eastern Canada as a

hurricane-force extratropical low.

Key Messages:

1. Life-threatening storm surge and dangerous winds are expected

along portions the coasts of South Carolina and North Carolina, and

portions of southeast Virginia and the southern Chesapeake Bay,

regardless of the exact track of Dorian’s center.  Water levels

could rise well in advance of the arrival of strong winds. Residents

in these areas should follow advice given by local emergency

officials.

2. Flash flooding is occurring, and will continue to become more

widespread across the eastern Carolinas and far southeast Virginia

through tonight. There is a high risk of flash flooding over these

areas, where significant, life-threatening, flash flooding is

expected.

FORECAST POSITIONS AND MAX WINDS

INIT  05/2100Z 33.1N 78.5W  90 KT 105 MPH

12H  06/0600Z 34.2N 77.2W  90 KT 105 MPH

24H  06/1800Z 36.0N 74.4W  85 KT 100 MPH

36H  07/0600Z 38.5N 70.4W  80 KT  90 MPH

48H  07/1800Z 42.0N 65.9W  75 KT  85 MPH

72H  08/1800Z 50.0N 57.5W  65 KT  75 MPH…POST-TROP/EXTRATROP

96H  09/1800Z 56.0N 45.5W  50 KT  60 MPH…POST-TROP/EXTRATROP

120H  10/1800Z 0.0S 0.0W   0 KT   0 MPH…DISSIPATED

 

 

 

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